sqsh - Online in the Cloud

PROGRAM:

NAME

sqsh - Interactive database shell (version 2.1.7)

SYNOPSIS

sqsh [[options]] [[args......]]
[ -a count ]
[ -A packet_size ]
[ -b ]
[ -B ]
[ -c [cmdend] ]
[ -C sql ]
[ -d severity ]
[ -D database ]
[ -e ]
[ -E editor ]
[ -f severity ]
[ -G tds_version ]
[ -h ]
[ -H hostname ]
[ -i filename ]
[ -I interfaces ]
[ -J charset ]
[ -k keywords ]
[ -K keytab]
[ -l debug_flags ]
[ -L var=value ]
[ -m style ]
[ -n on|off ]
[ -N appname ]
[ -o filename ]
[ -p ]
[ -P [password] ]
[ -Q query_timeout ]
[ -r [sqshrc] ]
[ -R server principal ]
[ -s colsep ]
[ -S server ]
[ -t [filter] ]
[ -T login_timeout ]
[ -U username ]
[ -v ]
[ -V [bcdimoqru]]
[ -w width ]
[ -X ]
[ -y directory ]
[ -z language ]
[ -Z [secmech|default|none] ]

DESCRIPTION

Sqsh (pronounced skwish) is short for SQshelL (pronounced s-q-shell), and is intended as a
replacement for the venerable 'isql' program supplied by Sybase. It came about due to
years of frustration of trying to do real work with a program that was never meant to
perform real work.

Sqsh is much more than a nice prompt, it is intended to provide much of the functionality
provided by a good shell, such as variables, aliasing, redirection, pipes, back-grounding,
job control, history, command substitution, and dynamic configuration. Also, as a by-
product of the design, it is remarkably easy to extend and add functionality.

OPTIONS

The following options may be used to adjust some of the behavior of sqsh, however a large
portion of the configuration options are available only through environment variables
which may be set at runtime or via a .sqshrc file.

Options may also be supplied in the SQSH environment variable. This variable is parsed
prior to parsing the command line, so in most cases the command line will override the
contents of the variable. Be aware that for options which are allowed to be supplied
multiple times, such as -c, supplying them both in a variable and on the command line will
be the same as supplying them multiple times on the command line.

-a count
Sets the maximum count of failures (as determined by the $thresh_fail variable) that
may occur before sqsh will abort. Setting this to 0 indicates that sqsh should not
exit on errors. This value defaults to 0 and may also be set using the $thresh_exit
variable. See section EXIT STATUS for details.

-A packetsize
Specifies the size of the network TDS packets used to communicate with the SQL server.
This value must be between 512 and 8192, and be a multiple of 512. Check your SQL
Server configuration to determine supported packet sizes. This value may also be
specified at run-time using the $packet_size variable.

-b Suppress the banner message upon startup. This is unnecessary in cases where stdout
has been redirected to a file. This option may also be set via the $banner variable.

-B Turns off all buffering of stdin, stdout, and stderr. This feature allows sqsh to be
run from an interactive control script such as chat and expect.

-c [cmdend]
Internally sqsh provides the command \go to send a batch of SQL to the database and
provides a single alias, go for this command. Each time cmdend is supplied a new alias
for \go is established.

-C sql
Causes the sql command to be executed by sqsh, similar to the same behavior exhibited
by the -i flag. This sql statement may not contain double quotes (this limitation may
be lifted in a future release of sqsh).

-d severity
Sets the minimum SQL Server error severity that will be displayed to the user. The
default is 0, and valid ranges are from 0 to 22. This may also be set using the
$thresh_display variable. See section EXIT STATUS.

-D database
Causes sqsh to attempt to start with your database context set to database rather than
your default database (usually master). This may also be set using the $database
variable.

-e Includes each command issued to sqsh to be included in the output. This option may
also be set via the $echo variable (which is unrelated to the \echo command).

-E editor
Set the default editor to editor. This may also be set using the UNIX environment
variable $EDITOR to the name of the editor desired.

-f severity
Sets the minimum severity level considered a failure by sqsh. This is the same as
setting the $thresh_fail variable. See section EXIT STATUS for details.

-G tds_version
Set the TDS version to use. Valid versions are 4.0, 4.2, 4.6, 4.9.5, 5.0 and freetds
additionally supports versions 7.0 and 8.0. The specified value is assigned to the
variable $tds_version. Input validation is not performed by sqsh. However, when an
invalid TDS version is specified, the default version of 5.0 will be used. After a
session is setup, the variable $tds_version will be set to the TDS version in effect.
The variable will not be available if option -G is not used. Meant for test and
debugging purposes only.

TDS stands for Tabular Data Stream and is the communication protocol Sybase and
Microsoft uses for Client-Server communication.

-h Turns off column headers and trailing "(# rows affected)" from batch output.

-H hostname
Sets the client hostname as reported in sysprocesses. This may also be set via the
$hostname variable.

-i filename
Read all input from filename rather than from stdin.

-I interfaces
When a connection is established to the database, the interfaces file is used to turn
the value of $DSQUERY into the hostname and port to which the connection will be made,
by default this is located in $SYBASE/interfaces. This flag allows this default to be
overridden.

-J charset
Specifies the character set to be used on the client side to communicate with SQL
Server. This may also be set using the $charset environment variable.

-k keywords
Specifies a file containing a list of keywords to be used for keyword tab completion,
if readline support has been compiled into sqsh. This file may also be set via the
$keyword_file variable, which defaults to $HOME/.sqsh_words.

-K keytab
Kerberos support. Specify the keytab file name for DCE.

See the Kerberos Support section below for details.

-l debug_flags
If sqsh has been compiled with -DDEBUG, this option may be used to turn on and off
debugging options. See the $debug variable, below.

-L var=value
Sets the value of $var to value. This may be used to set the value of any sqsh
variable even if an explicit command line variable is supplied for setting the
variable. The -L flag may be used to set the value of non-configuration variables as
well.

-m style
Changes the current display style to style. Currently supported styles are horiz,
vert, bcp, csv, html, meta, pretty and none. The current display style may also be set
using the $style variable or via the -m flag to the \go command.

-n on|off
Enables chained transaction mode on connect (if set to on). Chained transaction mode
is also known as "AutoCommit off" mode.

-N appname
Set the application name sqsh uses to identify itself to the SQL server. The
application name can be retrieved from the server using the column program_name of the
master.dbo.sysprocesses table. Defaults to sqsh-2.1.7.

-o filename
Redirects all output to filename rather than stdout.

-p Display performance statistics upon completion of every SQL batch. This option may
also be turned on via the $statistics variable, or by supplying the -p flag to the \go
command.

-P [password]
The Sybase password for username required to connect to server (default, NULL). The
password may also be set via $password. Supplying a password of '-' causes the
password to be read from the first line of stdin.

sqsh takes pains to hide the password from any user trying to view the command line
used to launch sqsh, so using -P should not constitute a security hole.
Alternatively, you can store your default password in .sqshrc file which is not
readable by anyone other than yourself. (chmod 600 .sqshrc)

-Q value
Query timeout value (equivalent to isql's -t option). If set, will timeout a long
running query. Maps to the $query_timeout variable.

For example:

sqsh -SASE1502 -Usa -P -Q30
ASE1502.sa.master.1> cd tix
ASE1502.sa.tix.1> select count(*) from E_TIX;
Open Client Message
Layer 1, Origin 2, Severity 2, Number 63
ct_results(): user api layer: internal Client Library error:
Read from the server has timed out.
ASE1502: Query or command timeout detected, command/batch cancelled
ASE1502: The client connection has detected this 1 time(s).

See also the $max_timeout variable, which controls the number of times a timeout may
occur on the current connection before the session is aborted.

-r [sqshrc]
Specifies an alternate .sqshrc file to be processed, rather than the default. If no
sqshrc is supplied following -r, then no initialization files are processed. This flag
must be the first argument supplied on the command line, all other instances will be
ignored.

-R server_principal
Kerberos support: Specifies a server principal to use for network (Kerberos)
authentication, if the server name in the interfaces file differs from the real server
name.

See the Kerberos Support section below for details.

-s colsep
Causes the string colsep to be used to delimit SQL column output columns, this
defaults to " ".

-S server
The name of the Sybase server to connect, the default of this is the external
environment variable $DSQUERY. If neither -S nor $DSQUERY is set then defaults to
"SYBASE". This value may also be set via the internal variable $DSQUERY.

-t [filter]
Enables filtering of command batches through an external program, filter, and prior to
being sent to the SQL Server. If filter is not supplied, then $filter_prog is used
(default is 'm4 -'). This value may also be set via the $filter and $filter_prog
variables.

-T value
Specifies the login timeout (similar to isql's -l flag). If set specifies the number
of seconds sqsh will wait before timing out a login request. Maps to the
$login_timeout variable.

-U username
The Sybase username to connect to the database as, this defaults to the username of
the user running sqsh. The username may also be set via the $username variable.

-v Displays the version number, $version, and exits.

-V [bcdimoqru]
Kerberos support: Specify the security options to use.

See the Kerberos Support section below for details.

-w width
The maximum output width of a displayed result set, this defaults to your screen width
in interactive mode.

-X Initiates the login connection to the server with client-side password encryption (if
supported). If either SQL Server does not recognize this option, or if the version of
CT-Lib used to compile sqsh does not support this option, then it will be ignored.
This option may also be set using the $encryption environment variable.

-y directory
Specifies a SYBASE directory to use other than the value of $SYBASE in order to find
the interfaces file.

-z language
Specifies an alternate language to display sqsh prompts and messages. Without the -z
flag, the server's default language will be used. This may also be set using the
$language variable.

-Z [secmech|default|none]
Kerberos support: Specify the security mechanism to use.

See the Kerberos Support section below for details.

args...
If sqsh is run with the -i flag specifying an input file to be processed (rather than
initiating an interactive session), arguments may be supplied on the command line to
be passed to the input file. These arguments may be accessed using the variables ${0},
${1}, ... (see the Variables section, below, for more information).

Initialization
Upon startup, sqsh initializes all internal environment variables, commands, and aliases
to their default values, it then looks in the system-wide configuration file, /etc/sqshrc,
followed by a local configuration file $HOME/.sqshrc (this may be overridden via the
SQSHRC external environment variable). If this file is found it is executed just like a
script would be using the -i flag.

The .sqshrc file may contain anything that could normally be typed at the prompt, however
it should be noted that at the time this file is read sqsh has yet to establish a
connection to the database, however most commands that perform database activity, such as
\go will attempt to establish a database connection when executed (it may also prompt you
for a password if necessary). Also, if database activity is required within this startup
file, the \connect command (see COMMANDS, below) may be executed.

After the .sqshrc file has been executed, sqsh then parses any command line options (thus
any variables set in your .sqshrc file may be overridden by command line options).
Following that, if sqsh is run in interactive mode (i.e. without -i and if stdin is
attached to a tty), it then looks for .sqsh_history and loads the contents of that file
into this history buffer (see BUFFERS, below).

Immediately prior to establishing a connection to the database (either during startup, or
by an explicit \connect or \reconnect command), the file $HOME/.sqsh_session is executed.
The name of this file may be overridden using the $session variable.

Command line
When a line is first read by sqsh, the first word is separated from the line. This word
is then expanded of all variables (see Variable Substitution, below), followed by command
expansion (see Command Substitution, below). The first word of the resulting string is
then analyzed to see if it is either a valid sqsh command or alias.

The sqsh command line follows many of the same rules as Bourne shell, allowing file
redirection, pipelining, command substitution, and back-grounding via the same syntax.

Comments
Any line beginning with a # followed by a non-alphanumeric character (any character other
than 0-9, a-z, A-Z, and _) causes the entire line to be ignored. Because of the possible
collision with T-SQL session specific temp-table names, the line will not be ignored if
the first character following the #, is alphanumeric.

Quoting
Quoting is used to prevent the interpretation of special keywords or characters to sqsh,
such as white-space, variable expansion, or command substitution. There are three types of
quoting, escape, single-quotes, and double-quotes.

Enclosing characters in single quotes preserves the literal interpretation of each
character contained within the quotes. A single quote may not appear within single quotes,
even when preceded by an escape. For example:

1> \echo I can not expand '$username'

outputs

I can not expand $username

The characters \\ are used to escape the meaning (and thus prevent the interpretation) of
the character immediately following them. The \ character itself may be escaped. For
example:

1> \echo I can\\'t expand '$username'

outputs

I can't expand $username

The escape character may also be used to escape a new-line in order to perform a line
continuation, in this case the new-line is discarded and the continued line is
automatically appended to the previous line, for example:

1> \echo Hello \\
--> World!
Hello World!

Enclosing characters in double quotes preserves the literal meaning of all characters
within them with the exception of $, ', and \\. A double quote may be contained within
double quotes by escaping it.

1> \echo "\\"I can't deny it, I like $username\\", she said"

prints out

"I can't deny it, I like gray", she said

Expansion
After a line of input has been read, sqsh attempts to expand the line of any aliases (see
Aliasing, below), following that it attempts to determine if the line begins with a
command keyword. Once a line has been determined to contain a command name it has two
types of expansion performed up it: variable substitution, followed by command
substitution respectively. Following this expansion the command line is separated into
words and the command is executed.

Variable Substitution
The character $ is used to indicate variable substitution or expansion within a word.
These variables may be assigned values by the \set command like so:

1> \set name=value

name may be a character or underscore followed by any combination of characters, digits,
or underscore, and may not contain any special characters, such as (') and ("). The
restriction on the first character being a digit is introduced because SQL allows the
representation of money data types as $nn.nn where n is a digit.

value may contain anything, however if it is to include white-space, then it must be
quoted (see Words & Quoting, above). Note that in order to prevent the expansion of a
variable use either single quotes, or two \'s, like thus:

1> \echo \\$name
$name

Variables may be referenced in one of two ways:

$variable In this manner all characters, digits, and underscores are treated as the name
of the variable until another type of character is reached (either a special character, or
a white-space). ${variable} The braces are required only when variable is followed by a
letter, digit, or underscore that is not to be interpreted as part of its name. Note that
the same effect may be achieved using double quotes.

It should be noted that because the variables are expanded prior to breaking the command
line into words, if the contents of the variable contain white spaces, they are treated as
significant by the parser. In the following example:

1> \set x="1 2 3"
1> \echo $x

the \echo command receives three arguments, "1", "2", and "3", although it looks as if
only one argument was passed to it. This behavior is consistent with most shells (such as
csh, bourne shell, etc.).

Command Substitution
Sqsh supports a second form of expansion called command substitution. This form of
expansion substitutes a command on the command line with the output of the external UNIX
command. This expansion may be achieved by placing the command line to be executed in
back-quotes (`). For example:

1> \set password=`/sybase/bin/getpwd $DSQUERY`
1> \echo $password
ilikepickles

This example, the external program /sybase/bin/getpwd is executed with the current
contents of the $DSQUERY environment variable, the entire expression is then replaced with
the output of getpwd (ilikepickles) prior to executing the \set command. By default, the
output of the substituted command is first broken into words according to the contents of
the $ifs variable prior to assembling together back into the command line. So, by
overriding the contents of $ifs you may affect the behavior of the substitution process.

For example:

1> \set ifs=":"
1> \echo `echo hello:how:are:you`
hello how are you

This mechanism is frequently useful for parsing input files, such as /etc/passwd into
fields.

Input/Output Redirection
As with standard Bourne shell (and most other shells, for that matter), a command's input
and output may be redirected using a special notation interpreted by the shell. The
following may appear anywhere on the command line, but only redirection that is specified
prior to a pipe (|) actually has any effect on the behavior of internal sqsh commands
(refer to Pipes, below).

<word
Use the file word as the standard input for the command. Typically very few sqsh
commands actually read anything from stdin, so this will usually have no effect (see
the \loop command).

[n]>word
Associate the output of file descriptor n (stdout, by default) with file word. If this
file does not exist it is created; otherwise it is truncated to zero length.

[n]>>word
Append the output of file descriptor n (stdout, by default) to file word, creating it
if it does not exist.

[m]>&n
Redirect the output of file descriptor m (stdout by default), to same output as file
descriptor n. The order in which redirections are specified on the command line is
significant, as the redirections are evaluated left-to-right. For example:

1> select * from select /* syntax error */
2> \go >/tmp/output 2>&1

This statement first redirects the standard output of the \go command to the file
/tmp/output, then redirects the stderr to the same file. So, when the commands fails,
the error output will be found in the file /tmp/output.

However, by changing the order of redirection, you can completely change the meaning:

1> select * from select
2> \go 2>&1 >/tmp/output
Msg 156, Level 15, State 1
Server 'SQSH_TEST', Line 1
Incorrect syntax near the keyword 'select'.

In this case, error output will be sent to stdout, while what would have gone to
stdout is redirected to /tmp/output (in this case /tmp/output will be empty).

Please read the section on Background Jobs, below, for detailed info on the interaction
between file redirection and background jobs.

Pipes
A pipeline is a sequence of one or more commands separated by a '|', each command using
the stdout of the preceding program for its own stdin. However the first command in the
pipeline must be a sqsh command, and all other commands must be external (or UNIX)
programs. Any sqsh command may be run through a pipeline, although for many of them (such
as the \set command) it doesn't really make any sense to do this. The following is an
example of a pipeline:

1> select * from syslogins
2> \go | more

This command causes the result set generated by the \go command to be sent to the more(1)
program, which then sends it to your screen, pausing at each screen full of data (this is
the primary reason that I wrote sqsh).

There are several peculiarities in the way in which sqsh deals with pipelines as opposed
to the way in which standard Bourne shell treats them.

Everything following the first occurrence of a pipe (|) character is broken into white-
space delimited words, including such special shell commands as '2>&1' and other
occurrences of pipes. If there are any variables contained in these words they are
expanded following the same quoting rules as described in Words & Quoting, above, with the
one exception that all quotes are left in place. These words are then reassembled into a
single string and shipped off to /bin/sh for processing.

In short, sqsh makes no attempt to interpret what follows the first pipe, instead it is
shipped off to a "real" shell to do the work. The rationale behind this is that I was lazy
and didn't feel like writing all of the same bizarre variable handling, &&'ing, ||'ing,
grouping, and variable expansion rules that Bourne shell supports, and instead I let
Bourne do the dirty work.

The advantage of this method is that you can do some very complex stuff after the
pipeline, such as:

1> select * from syscolumns
2> \go | (cd /tmp; compress -c > sysolumns.Z)

Not that I can think of any real reason to do this...but you can if you want to.

Background Jobs
Backgrounding provides a mechanism whereby you may run any sqsh command as a background
process and continue working while it runs. Sqsh offers two types of backgrounding:

Deferred
In this mode sqsh redirects all output of the background job to a temporary file
(located in the directory $tmp_dir) while the job is running, so that the output is
not intermixed with what you are currently working on. When the job completes you are
notified of the process completion and the output may be viewed using the \show
command.

Non-Deferred
This corresponds to the common idea of a background process under UNIX. In this mode
the output of the job is not implicitly redirected for you, and thus may become
intermingled with what you are currently working. The mode selection you choose is
selectable via the $defer_bg variable (which defaults to '1', or 'On'). Typically the
only reason to not use deferred mode is to prevent large result sets from filling up
your file system.

To specify that a job be run in the background, simply append a & to the end of the
command line, as:

1> sp_long_arduous_proc 1, 30
2> \go &
Job #1 running [xxxx]
1>

When sqsh encounters the & on the end of the command line it spawns a child process (with
a Unix process id of xxxx) then the child process calls the \go. \go command then
establishes a new connection to the database (using the current values of the $DSQUERY,
$username, $password variables) and executes the shown query. While the job is executing
the commands \jobs \wait and \kill may be used to monitor or alter a currently running job
(see section COMMANDS, below). When any job completes sqsh will display a notification,
such as:

1> select count(*) from <return>
Job #1 complete (output pending)
2>

When a job completes, if it had no output, it is immediately considered terminated and
will not show up in the current list of running jobs. However if the complete job has
pending output, it will continue to be displayed as a running job (with the \jobs command)
until a \show is used to display the output of the job.

There is a known bug with job backgrounding when used in conjunction with pipes, please
refer to the BUGS section at the end of the manual.

Buffers
In normal isql only two buffers are maintained; the buffer into which you are currently
typing, and a buffer that contains the last batch executed (this is kept around for when
you run 'vi', or 'edit').

Sqsh maintains several distinct sets of buffers:

Work Buffer: This buffer corresponds directly to the isql work buffer. It is the buffer
into which you enter the current batch prior to sending it to the database.

History Buffer: This is actually a chain of 0 or more buffers (configurable by the
$histsize variable) of the last $histsize batches that have been run. This buffer is only
maintained when sqsh is run in interactive mode; that is, batches executed using the -i
flag, or executed via redirection from the UNIX prompt will not be maintained in history
(after all, they are already in a file somewhere).

If the variable $histsave is True (see section SPECIAL VARIABLES), and sqsh is in
interactive mode, then the current history buffer is written to $HOME/.sqsh_history when
you exit. This file is then read back into sqsh the next time it is started in interactive
mode.

Named Buffers: At any time during a session the Work Buffer, or any of the History Buffers
may be copied into a named buffer using the \buf-copy command (see section COMMANDS,
below). These buffers are lost when you exit (however you may use the \buf-save command to
save named buffers to a file).

Buffer Short-Hand

Many commands allow all of these buffers to be referenced in a short-hand fashion, very
similar to the way that csh(1) references its commands history. Any of these shorthands
may be used for any buffer parameter described in the COMMANDS section:

!. The current work buffer.

!! The last command executed (note, this is not available in non-interactive mode as it
does not maintain a history).

!+ The next available history entry. This is a write-only buffer, so typically only
applies to such commands as \buf-copy.

!n Refers to history #n. Each time an entry is written to history it is assigned an
increasing number from the last entry, with this short-hand you may reference any
given history.

!buf_name
Just for consistency this is supplied as a reference to named buffer buf_name, however
buf_name without the leading '!' is also considered correct.

buf_name
Refers to the named buffer buf_name.

Variables

Variables may also be contained within work buffers. Under these circumstances the
variables remain unexpanded until the buffer is sent to the database (via the \go
command), during which time they are expanded and replaced within the buffer. This
behavior may be altered via the $expand variable. (see Special Variables, below).

The following is an example of using variables within a buffer:

1> \set table_name=syscolumns
1> select count(*) from $table_name
2> \go

This is the equivalent of performing the query:

1> select count(*) from syscolumns
2> \go

directly. Typically this feature is useful for reusing large complex where clauses, or
long column names.

Quoting rules apply the same in SQL buffers as they do in command lines. That is, any
variables contained within double quotes (") are expanded and variables contained within
single quotes (') are left untouched. Thus:

1> select "$username", '$username'
2> \go

yields the results

---- ---------
gray $username

Command Substitution

As with the command line, the output of UNIX commands may also be substituted within a SQL
buffer upon execution (once again, only if the $expand variable is set to 1, or true). In
this circumstance the command contained within back quotes (`) is replaced with its output
prior to forwarding the buffer to SQL server. For example:

1> select count(*) from `echo syscolumns`
2> \go

Causes the strings 'echo syscolumns' to be replaced by the word syscolumns prior to
executing the command. It should be noted that the contents of the substituted command are
only executed at the time of the \go command, not when the line of SQL is input.

Flow-of-Control
New with version 2.0 of sqsh, is the ability to perform basic flow-of-control and
functions using the \if, \while, \do, and \func commands.

Blocks & SQL Buffers

All sqsh flow-of-control commands are block-based. That is, if the test expression of the
command is met, then a block of sqsh-script will be executed. For example, the definition
of the \if command is:

\if expression
block
\fi

This block may be any number of lines of sqsh commands, SQL, or flow-of-control statements
to be executed if the expression evaluates to a success condition (0).

Each block has its own SQL buffer for the duration that the block is executed. That is,
the following statements:

1> /*
2> ** IMPROPER USAGE OF IF BLOCK
3> */
4> select count(*) from
5> \if [ $x -gt 10 ]
6> sysobjects
7> \else
8> sysindexes
9> \fi
5> go

will yield:

Msg 102, Level 15, State 1
Server 'bps_pro', Line 1
Incorrect syntax near 'from'

because the string 'sysobjects' or 'sysindexes' were inserted into their own SQL buffers.
These buffers are discarded as soon as the end of the block was reached, and since a \go
command was not contained within the block, no additional errors were generated.

Thus, the correct way to write the above expression would be:

1> /*
2> ** PROPER USAGE OF IF BLOCK
3> */
4> \if [ $x -gt 10 ]
5> select count(*) from sysobjects
6> go
7> \else
8> select count(*) from sysindexes
9> go
10> \fi

or, even:

1> /*
2> ** PROPER USAGE OF IF BLOCK
3> */
4> \if [ $x -gt 10 ]
5> \set table_name=sysobjects
6> \else
7> \set table_name=sysindexes
8> \fi
4> select * from $table_name
5> go

Also, note that the line number displayed in the sqsh prompt resets to the current
position in the outer SQL buffer after reaching the \fi terminator.

Expressions

All flow-of-control statements in sqsh take an expression to determine which block of code
to execute. Just like UNIX's Bourne Shell, this expression is simply an operating system
program that is executed by sqsh. If the command returns a success status (calls exit(0)),
then it is considered successful.

For example, with following statement:

\while test $x -lt 10
block
\done

will execute the contents of block while the current value of $x is less than 10. Note
that 'test' is a standard UNIX program to perform basic string or numeric comparisons
(among other things). Also, unlike many shells, sqsh has no built-in version of 'test'.

Sqsh does, however, support the standard short form of 'test':

\while [ $x -lt 10 ]
block
\done

With this expression the open brace ('[') is replaced by the sqsh parser with 'test', and
the close brace (']') is discarded.

Unsupported Expressions

Currently sqsh does not support the standard shell predicate operators '&&' and '||'.
These can be performed like so:

\if sh -c "cmd1 && cmd2"
block
\done

\if statement

The \if command performs conditional execution of a sqsh block based upon the outcome of a
supplied expression:

\if expr1
block1
\elif expr2
block2
\else
block3
\fi

In this example, if expression expr1 evaluates to true, then the block block1 is
evaluated. Otherwise, if the expression expr2 evaluates to true, then block block2 is
evaluated. Finally, if all other tests fail block3 is evaluated.

Note that, unlike Bourne Shell, every \if command must be accompanies by a trailing \fi
statement. Also the sqsh parser is not terribly intelligent: The \else and \fi statements
must be the only contents on the line in which they appear, and they may not be aliased to
another name.

\while statement

The \while command executes a block of sqsh code for the while a supplied expression
remains true.

\while expr
block
\done

In this example, while the expression expr evaluates to true, then the block block is
evaluated.

The \break statement may be used to break out of the inner-most \while or \for loop (more
on \for below).

\for statement

The \for command executes a block of sqsh code for each word supplied:

\for var in word ...
block
\done

For each word supplied, the value of the variable $var is set to the word and the block of
code is executed. Execution ends when there are no more words in the list.

As with \while the \break statement may be used to break out of the inner-most execution
loop.

\do command

The \do command is kind of a cross between a statement and a command.

It is a form of \go (see below for details on the \go command) in which a block of sqsh
code may be executed for each row of data returned from the query. When the block is
executed, special sqsh variables #[0-9]+ (a hash followed by a number) may be used to
reference the values in the returned query. For example the following command:

select id, name from master..sysdatabases
\do
\echo "Checkpointing database #2, dbid #1"
use #2
go
checkpoint
go
\done

would cause a CHECKPOINT command to be issued in each database on the server.

Command line options

The \do command establishes a new connection to be used by the block of code when
executed. By default, this connection is established to the current server (the current
setting of $DSQUERY), using the current username ($username) and the current password
($password). This behavior may, however, be overridden using command line options:

-D database
Establishes the connection to the database as the supplied database.

-U username
Establishes the connection to the server as the supplied username.

-P password
Establishes the connection to the server using the supplied password (which is
hopefully a valid password for the supplied username).

-S server
Establishes the connection to the supplied server.

-n Do not create a connection for use by the \do loop. This flag is mutually exclusive
with the above flags. With this flag enabled, attempts to perform database commands
within the block will generate a flurry of CT-Library errors.

Column variables

As mentioned above, the values of the columns in the current result set may be determined
using the special #[0-9]+ variables. Thus, the variable #1 would contain the value of
column number one of the current result set, and #122 could contain the value of the
122'nd column (column numbers begin at 1).

In the case of nested \do loops, values in previous nesting levels may be referred to by
simply appending an addition '#' for each previous nesting level, like so:

select id, name from sysobjects
\do
select name, indid from sysindexes where id = #1
\do
\echo "Table ##2 (objid ##1) has index #1"
\done
\done

obviously, this isn't the way you would do this query in real life, but you get the idea.

When expanding columns with NULL values, the column variable will expand to an empty
string (''). Also, references to non-existent columns, such as #0, will result in an empty
string ('').

As with regular sqsh variables (those referenced with a '$'), column variables will not be
expanded when contained within single quotes.

Aborting

If the \break or \return commands are issued during the processing of a \do loop, the
current query will be canceled, the connection used by the loop will be closed (unless the
-n flag was supplied) and the \do loop will abort.

\func command

The \func command is used to define a reusable block of sqsh code as a function. Functions
are defined like so:

\func stats
\if [ $# -ne 1 ]
\echo "use: stats [on | off]"
\return 1
\fi
set statistics io ${1}
set statistics time ${1}
go
\done

In this example a new function is established called stats that expects a single argument,
either "on" or "off". Using this argument, stats will enable or disable time-based and
I/O-based statistics.

Once established, the function may be called like so:

\call stats on

Causing all instances of ${1} to be replaced with the first command line argument to
stats.

Command line options

Currently only one command line argument is available to the \func command.

-x Causes the function to be exported as a sqsh command. That is, the function may be
invoked directly without requiring the \call command. This behavior is optional
because command names can potentially conflict with T-SQL keywords. When using this
flag it is recommended that you prepend a backslash (\) to your function name.

Function variables

As shown in the example above, several special variables are available for use within the
body of the function. These are:

$# Expands to the number of arguments supplied to the function or script when invoked.

$* Expands to the complete list of arguments supplied to the function or script when
invoked.

${0}..${N}
Expands to positional arguments to the function. ${0} is the name of the function
being invoked, ${1} is the first argument, ${2} the second and so-on, up to argument
N. Note that, unlike most shells, sqsh requires that function arguments be referred to
using the special curly brace syntax (${1}, rather than $1). The reason for this is
that $1 is a valid MONEY value and using the curly braces gets rid of this ambiguity.

$? After the invocation of a function, this will contain its return value (see below).

Return value

A value may be returned from a function via the \return command.

Like so:

\return N

Where N is a positive value. This return value is available to the caller of the function
via the $? variable. As convention, a return value of 0 is used to indicate a success.

If \return is not explicitly called, the default return value is the current value of the
$? variable (which is set to 0 upon entry of the function). Thus, if any SQL statements
are invoked within the function, the default return value of $? will be the last error
code returned during the processing of the SQL statement.

Kerberos Support
Starting with version 2.1.6, sqsh provides the same command line options as isql to handle
Kerberos network authentication.

In version 2.1.5 experimental Kerberos support was added using the -K and -R options. -K
was merely a switch to set Kerberos on. In sqsh 2.1.6 a more advanced implementation of
network authentication is introduced, although still experimental.

By using the parameters -K, -R, -V, -Z you can make use of your defined network security
settings (libtcl.cfg). The named options are identical to the ones defined for isql.

-K keytab_file
Keytab_file name for DCE.

-R server_principal
Server principal name when servername specified in interfaces differs from the real
server name.

-V [bcdimoqru]
Specify security options to use with the security mechanism. Each character stands for
a specific security service.

-Z [secmech|default|none]
Request a security mechanism defined for Kerberos, DCE or PAM in your libtcl.cfg file.
Use secmech to specify the name of a SECURITY entry or default for the first available
entry in libtcl.cfg. None must be specified to disable network authentication or reset
possible existing values in variables $secmech or $secure_options.

For example, connecting to a server using Kerberos (which happens to be the default, i.e.
first entry in libtcl.cfg [SECURITY] tab in this example):

~> sqsh -SSYB1502 -Uuser1 -RFC6A1502 -Z
\connect: Network authenticated session expires at:
16 Feb 2010 15:28:39 (11764 secs)
SYB1502.user1.master.1> select @@servername,@@authmech,
show_sec_services();
---------------- ----------- ----------------------------------
FC6A1502 kerberos unifiedlogin delegation mutualauth
integrity confidentiality
detectreplay detectseq

Note that the real name of the server (@@servername) differs from the server name in the
interfaces file, so we have to specify the principal name through the -R parameter. When
you do not specify the -V parameter together with -Z, all available security options will
be enabled. When -V is specified without any security service options, only option u for
Network Authentication will be implicitly set and the default security mechanism will be
used if -Z is not specified.

[user1@linux-fc6a ~]$ sqsh -SFC6A1502 -Uuser1 -V
Open Client Message
Layer 7, Origin 9, Severity 5, Number 1
ct_connect(): security service layer: internal security control
layer error:
Security service provider internal error -1765328352
occurred.
[user1@linux-fc6a ~]$ kinit
Password for user1@LOCALDOMAIN:
[user1@linux-fc6a ~]$ sqsh -SFC6A1502 -Uuser1 -V
\connect: Network authenticated session expires at:
16 Feb 2010 15:28:39 (10964 secs)
FC6A1502.user1.master.1>

When the connection succeeds, sqsh will store the real name of the security mechanism in
the variable $secmech. For example: "\echo $secmech" may show csfkrb5. The parameter -V
takes a list of characters from the possible values of bcdimoqru. The option u enables
Network Authentication, is the default and will allways be set when using -V or -Z,
specified or not.

b - chanbinding : Channel binding
c - confidentiality : Data confidentiality service
d - delegation : Allow delegated credentials
i - integrity : Data integrity service
m - mutualauth : Mutual authentication for connection
establishment
o - dataorigin : Data origin stamping service
q - detectseq : Out-of-sequence detection
r - detectreplay : Data replay detection
u - unifiedlogin : Network Authentication

Please check master.dbo.syssecmechs for available services. Non-existing or not supported
services supplied with -V are silently ignored. If you specify -V and/or -Z, sqsh assumes
network authentication is tried and no password is required.

If you have a network authenticated connection and want to \reconnect using normal ASE
authentication with username and password, you have to reset the network authentication
variables by specifying -Znone

For example:

[user1@linux-fc6a ~]$ sqsh -SFC6A1502 -Uuser1 -V
\connect: Network authenticated session expires at:
16 Feb 2010 15:28:39 (10764 secs)
FC6A1502.user1.master.1> \echo $secmech csfkrb5
FC6A1502.user1.master.1> \reconnect -SASE1502 -Usa -Psybase
Open Client Message
Layer 7, Origin 9, Severity 5, Number 8
ct_connect(): security service layer: internal security control
layer error:
Consistency checks performed on the credential failed
(minor status 0).
FC6A1502.user1.master.1> \reconnect -SASE1502 -Usa -Psybase -Znone
ASE1502.sa.master.1>

The first \reconnect fails because sqsh still wants to try network authentication.
However, no user principal for 'sa' exists and no ticket is set and thus the connection
fails. The second \reconnect succeeds as the -Znone option reset appropriate variables.
If the Kerberos ticket is renewed with kinit or any other client tool, the sqsh session
must perform a \reconnect to refresh the credentials and to prevent a premature session
abort. With the command \snace you can request for the session expiration interval.
Depending on the security services that are set, the database connection may be closed
without warning as soon as the ticket expires.

See chapter 16 "External Authentication" from the Sybase System Administration Guide
volume 1 for more information on Kerberos network authenticationi, e.a.

COMMANDS

Read-Eval-Print
The read-eval-print loop is the heart of the sqsh system and is responsible for prompting
a user for input and determining what should be done with it. Typically this loop is for
internal use only, however they are open to the user because there are some creative
things that can be done with them.

\loop [-i] [-n] [-e sql] [file]
The \loop command reads input either from a file, a supplied SQL statement, or from a
user (see the options below), determining whether the current line is a portion of a
TSQL statement or a sqsh command, and performing the appropriate action. When run in
an interactive mode \loop is also responsible for displaying the current prompt (see
$prompt below).

\loop completes when all input has been depleted (end-of-file is encountered) or when
a command, such as \exit requests that \loop exit.

-i Normally, if file is supplied and does not exist, \loop will return with an error
condition, usually causing sqsh to exit. By supplying the -i flag, control will be
returned to the calling loop as if end-of-file had been reached (that is, with no
error condition).

-n By default, \loop will automatically attempt to connect to the database if a
connection has not already been established via the \connect command. The -n flag
disables this behavior allowing \loop to process commands that do not require
database support.

-e sql
Causes \loop to process the contents of sql as if the user had typed it at the
prompt and an implicit call to \go is automatically appended to the statement. If
multiple instances of -e are supplied, they are all sent as a single batch to the
SQL Server for processing. This option may not be used in combination with a file
name as well.

file
Specifies the name of a file to be used as input rather than reading input from
the user or from the -e flag.

Database Access

Given the size and complexity of sqsh (just look at the length of this man page), it is
amazing how few database manipulation commands that there actually are. The following are
commands that affect or use the current database connection:

\connect [-c] [-D db] [-S srv] [-U user] [-P pass] [-I ifile] [-K keytab] [-R
server_principal] [-n] [-N appname] [-Q query_timeout] [-T login_timeout] [-V [bcdimoqru]]
[-Z [secmech|default|none]]
This command is used primarily for internal use to establish a connection to a
database. If a connection is already established it has no effect, however if a
connection has not been established and $password has not been supplied, then the
password is requested and a connection is established. \connect accepts the following
parameters:

-c By default, the \connect command uses the contents of $database to determine the
database context that should be used upon establishing the connection (this is
used by \reconnect to preserve the current database context upon reconnection).
The -c flag suppresses this behavior and the default database context of login is
used instead.

-D db
Causes \connect to attempt to automatically switch the database context to db
after establishing the connection.

Using this flag is identical to setting the $database variable prior to
establishing the connection.

-S srv
The name of the Sybase server to connect, this defaults to $DSQUERY if not
supplied.

-U user
The Sybase user to connect to the database as, this defaults to $username variable
if not supplied.

-P pass
The password for user required to connect to server. This defaults to $password if
not supplied.

-I ifile
The full path of an alternate Sybase interfaces file to use.

-K keytab_file
Used for DCE user authentication.

-R principal_name
Use for Kerberos user authentication to specify the name of the server principal
when the name differs from the $DSQUERY value.

See also the discussion on Kerberos support.

-n Specifies that the connection must use ANSI compliant chained mode.

-N appname
Specify the application name the server will use for program_name in the
sysprocesses table.

-Q query_timeout
Set a query timeout period in seconds.

-T login_timeout
Specifies a maximum wait time for session setup.

-V [bcdimoqru]
Security services used for Kerberos support and other security mechanisms.

-Z [secmech|default|none]
Specifies the security mechanism to use for user authentication. For example
csfkrb5 for Kerberos support.

\reconnect [-c] [-D db] [-S srv] [-U user] [-P pass] [-I ifile] [-K keytab] [-R
server_principal] [-n] [-N appname] [-Q query_timeout] [-T login_timeout] [-V [bcdimoqru]]
[-Z [secmech|default|noe]]
The \reconnect command may be used to force a reconnection to the database using a new
username, server name, or password (if desired). If this command fails, the current
connection remains (if there is any), however if it succeeds then the current
connection is closed and the new connection becomes the only active one.

All arguments that are accepted by \connect are also accepted by \reconnect (in fact
\reconnect uses \connect to establish the new connection).

\snace
Will show the session expiration interval for a network authenticated session, using
Kerberos tickets, for example.

\go [options] [xacts]
Sends the contents of the Work Buffer to the database, establishing a new connection
to the database if one does not already exist (by calling the \connect above). It them
displays the results of the query back to stdout and returns, causing the Work Buffer
to be cleared and moved to the end of the History Buffer.

If the Work Buffer is empty and the $repeat_batch variable is set to "On", \go will
attempt to re-run the last command executed (this will only work in interactive mode
if history support is enabled).

\go accepts the following arguments:

-d display
If X11 support is compiled into sqsh, and X display mode is being used (see -x,
below), then display will be used as the X display area for the result set. By
default the environment variable $DISPLAY is assumed.

-f Turns off the display of the footer message "(%d rows affected)". Footer messages
may also be turned off via the $footers variable.

-h Turns off all column headers. These may also be turned off via the $headers
variable.

-m style
Temporarily changes the display style to style for the duration of the command.
Currently supported styles are horiz (or hor or horizontal), vert (or vertical),
bcp, csv, html, meta, pretty and none. The display style may be permanently set
via the $style variable or the -m command line flag.

-n Turns off variable expansion in the Work Buffer prior to sending it to the server,
this may also be turned off via the $expand variable.

-p Turns on output of performance statistics when the result set has been
successfully returned from the server. This may also be turned on via the -p
command line argument to sqsh, or the $statistics variable.

-s sec
If the value of xacts is greater than 1, this causes sqsh to sleep for sec seconds
before executing the next transaction. Note that the time spent sleeping is
excluded from the statistical information displayed with the -p flag.

-t [filter]
Filters the command batch through an external program, filter, and prior to being
sent to the SQL Server. If filter is not supplied, then $filter_prog is used
(default is 'm4 -'). This value may also be set via the $filter and $filter_prog
variables.

-w width
Overrides the value of $width for the life of the query (see $width below).

-x [xgeom]
Turns on the X11 display filter (only if X11 support is compiled into sqsh), which
causes the result set to be sent to a separate window. If xgeom is supplied, then
this value will be used as $xgeom for the life of the query (see $xgeom below).

-T xwin_title
Specify the title name of the X result window to create. This will temporarily
override the value of $xwin_title. Only useful to specify -T in conjunction with
-x.

xacts
Specifies number of times the contents of the Work Buffer should be executed.
Note that, similar to isql, a result set will only be displayed during the final
execution of the batch. Also, the contents of the Work Buffer are only expanded
once, prior to the first execution, so the contents of the buffer will not change
between subsequent executions.

\bcp [bcp_options] table
The \bcp commands acts as a sort of enhanced \go command that redirects the result
set(s) of the batch to another server via the bcp protocol. While it is possible to
\bcp the result set back to the current server (the $DSQUERY variable), this is
achieved more easily via a SELECT INTO.

The nitty-gritty details of \bcp go like this: First the current SQL batch is expanded
(unless the $expand variable is set to 0) and shipped off to the database for
processing. If all goes well, a new connection is established to the destination
database (as specified via $DSQUERY or the -S flag) to transfer the result set using
bcp. Then, the output of the source database connection is bound to the new bcp
connection and data transfer is performed. \bcp can handle multiple result sets
without any problem (including result sets returned from stored procedures, etc.)
provided that all of the result sets are valid for the destination table.

The equivalent of a "bcp out" may be performed using the bcp display style setting and
file redirection (see the $style variable).

-A packet
Specifies the TDS packet size used to communicate with the destination server. If
not supplied this defaults to the value the $packet_size variable, or (if that is
not set), the default server packet size (usually 512 bytes).

-b batch_size
The number of records transferred in a single transaction between servers. Note
that reaching the end of a result causes the batch to be transferred, regardless
of the value of batch_size. The default is the entire result set.

-I ifile
The full path of an alternate Sybase interfaces file to use.

-J charset
Specifies the default charset used to communicate with the SQL Server. This
defaults to the current character set (the value of the $charset variable).

-m maxerr
The maximum number of batches that may fail before \bcp gives up the ghost
(default is 10). Note that this only refers to failures within a given batch.
When performing a bcp of multiple result sets to a server, if a given result set
has, say, too many columns or bad data types, then the entire bcp process is
aborted regardless of the value of maxerr.

-N Indicates that the value for an identity column in the destination table is being
supplied within the result set.

-P password
The password for user required to connect to server. This defaults to $password if
not supplied.

-S server
The name of the Sybase server to connect, this defaults to $DSQUERY if not
supplied.

-U user
The Sybase user to connect to the database as, this defaults to $username variable
if not supplied.

-X Causes password negotiation with the destination server to be performed using
client-side encryption.

-z language
Specifies the language setting to use.

table
As with regular bcp, table may be either a fully or partially specified table name
in the destination server. Note that since a new database connection is
established during the bcp processes that the database context of the connection
may not be the same as the current context, so it is usually safest to fully
specify the table name in the form database.owner.table.

\rpc [rpc_opt] rpc_name [[parm_opt] [@var=]value ...]
The \rpc command is used to directly invoke a stored procedure call in the connected
server. This command is particularly useful for communicating with an Open Server that
does not directly support language calls.

\rpc invokes the remote procedure rpc_name with one or more parameters that may be
named (using @var) or anonymous (by not supplying a name). Unfortunately, due to the
fact that Sybase's implementation of RPC's, does not directly support most implicit
data type conversions (mainly between VARCHAR (the string you supply on the command
line) and the most other data types (that the remote procedure is expecting), the
syntax for the \rpc command is somewhat complex. However, in short here is how things
work:

As the \rpc command line is being parsed, sqsh attempts to guess the data type of the
parameter value based on the format (for example if it contains only digits, it is
assumed to be an integer), sqsh then performs an explicit data type conversion prior
to calling the remote procedure call. If sqsh guesses wrong, several flags are
supplied to force it to perform the correct data type conversion (see parm_opt).

Display Options

The following options may be supplied anywhere on the command line and are used to affect
the manner in which the result set(s) returning from the remote procedure call are
displayed:

-d display
If X support is compiled into sqsh, the value of display is used as the X windows
DISPLAY variable. Note, this is usually supplied with the -x flag, below.

-f Turns off the display of the footer message "(%d rows affected)". Footer messages may
also be turned off via the $footers variable.

-h Turns off all column headers. These may also be turned off via the $headers variable.

-m style
Temporarily changes the display style to style for the duration of the command.
Currently supported styles are horiz (or hor or horizontal), vert (or vertical), bcp,
csv, html, meta, pretty and none. The display style may be permanently set via the
$style variable or the -m command line flag.

-r Request to recompile the procedure prior to execution.

-w width
Temporarily sets the output width to width. The output width may be permanently set
via the $width variable.

-x [xgeom]
Sends output to a separate X window. If xgeom is supplied, then the X window uses this
geometry (see $xgeom for details).

-T xwin_title
Specify the title name of the X result window to create. This will temporarily
override the value of $xwin_title. Only useful to specify -T in conjunction with -x.

Parameter Options

The following options may be supplied immediately prior to specifying a parameter value
and are used to affect the way in which sqsh interprets the contents of the value prior to
calling the remote procedure. Although sqsh will allow any combination of these parameters
to be combined, it only really makes sense to combine the -x flag with any other flag.

-b Indicates that the value that is specified should be converted to VARBINARY before
calling rpc_name. This flag is implicit (i.e. you need not supply it) if value starts
with "0x" and contains only digits.

-c Indicates that the value that is specified should be converted to VARCHAR prior to
calling rpc_name. This flag is implicit if value does not match any of the implicit
conversions for the other data types.

-d Indicates that the value that is specified should be converted to double (float)
before calling rpc_name. This flag is implicit if value is in valid floating point
notation (e.g. 0.1, .1, 1.4e10, or 4e10).

-i Indicates that the value that is specified should be converted to integer (int) before
calling rpc_name. This flag is implicit if value contains only digits (and,
optionally, a leading sign).

-y Indicates that the value that is specified should be converted to money before calling
rpc_name. This flag is implicit if value begins with a "$", and contains only digits
and, optionally, a decimal.

-n Indicates that the value that is specified should be converted to numeric before
calling rpc_name. This flag is never implicit, as value would always match either int
(-i) or float (-d); however, both of these types will implicitly be converted to a
numeric as necessary by the procedure call.

-u Indicates that value should be ignored and treated as a NULL value, This flag is
implicit if value is "".

Buffers
The following commands may be used to create, destroy, or manipulate the various buffers
described in the BUFFERS section, above.

\clear
The \clear command will discard the current buffer and in contradiction with the
\reset command, will not save the current buffer to the history. When sqsh is compiled
with readline support, this command will also clear the screen. (as ^l does.) The
alias clear is automatically established upon startup.

\history [-i] [-x count]
Displays the last $histsize batches that have either been sent to the database via the
\go command or cleared from the Work Buffer via the \reset command. With option -i
also display the number of times the buffer is used and the last time the buffer was
used. This information may be of special interest when using the $histunique feature.
The -x option may specify the number of most recent history entries to display instead
of the total list of history entries.

\hist-load [filename]
Load a history file and append items to the current history list. Use $history if no
filename is specified as a parameter.

\hist-save [filename]
Will save the current history buffers to the $history file or to the filename
specified as a parameter.

\redraw
Returns a request back to the current read-eval-print loop for it to redisplay the
current Work Buffer. If run from non-interactive mode, this command has no effect.

\reset
The \reset command corresponds directly to the isql 'reset' command, returning a
request to the read-eval-print loop to clear the contents of the current Work Buffer
and, if you are running in interactive mode, place a copy of the buffer into the
History Buffer. The alias reset is automatically established upon startup of sqsh for
backward compatibility with isql.

\buf-append dst-buffer [src-buffer]
Appends the contents of src-buffer (defaults to !.) to the contents of dst-buffer, if
it exists. If dst-buffer doesn't exist it is created.

\buf-copy dst-buffer [src-buffer]
Copies the contents of src-buffer (defaults to !., the Work Buffer, if not supplied),
to dst-buffer. Refer to BUFFERS for information on buffer naming conventions.

\buf-del [buffer|range]
Remove a history buffer from the history list. You can also specify a range list
consisting of the first and last buffer numbers separated by a '-'. For example:
"\buf-del 1-10" will delete the first 10 history entries. Another example, "\buf-del
21" will only delete buffer number 21. Note that the history buffers will be
renumbered consecutively.

\buf-edit [-r read-buf] [-w write-buf]
The \buf-edit command is used to edit the contents of a buffer and place the changes
into another buffer. This command may only be run while in interactive mode. If read-
buf is not supplied then the buffer to be edited defaults to !., if it is not empty,
otherwise it defaults to !!. If write-buf is not supplied then the edited buffer is
written back to !..

By default, \buf-edit uses the environment variable $EDITOR first, followed by $VISUAL
to determine which editor to use, defaulting to 'vi' if the variable is not set.

It is important to note that as of release 1.2, \buf-edit is no longer able to use the
name of an alias to it as the name of the editor to launch. This is primarily due to
the change in the behavior of alias (see section Aliasing, below, for details).

The commands edit vi and emacs are automatically established upon startup of sqsh for
backward compatibility with isql.

\buf-get buffer
The \buf-get command is supplied as a shorthand method of running \buf-copy It is the
equivalent of running:

\buf_append !. buffer

\buf-load [-a] filename [dst-buffer]
Copies the contents of filename in dst-buffer (defaults to !.). If the -a flag is
supplied, the contents of filename are appended to dst-buffer. Note that it is illegal
to attempt to write to the contents of the history buffer.

\buf-save [-a] filename [src-buffer]
Saves the contents of src-buffer (defaults to !.) to filename. If the -a flag is
supplied the contents are appended to filename rather than overwriting the current
contents.

\buf-show [buffer]
Displays the contents of the named buffer. If buffer is not supplied, then the
contents of all named buffers are displayed. This command is slightly different from
the commands above in that it is only legal to supply a Named Buffer buffer, History
Buffers, and the Work Buffer will have no results.

Variables
The following command(s) are used to manipulate the contents of internal variables and
environment variables.

\set [-x] [name=value ...]
If no arguments are supplied to \set then the current values of all variables are
displayed. Otherwise the variable name is set to value. Note that some internal
variables (see SPECIAL VARIABLES) may only be set with certain values, so this action
may fail, leaving the previous contents on name intact. The -x flag causes the
variable to be exported to the environment of any programs launched from sqsh.

Job Control
The following commands are used to view the status of, or manipulate background jobs that
are currently running, these correspond roughly to the commands supplied by such shells as
csh(1).

\jobs [-i]
Displays the status of any currently running jobs, including whether or not these jobs
have pending output, how long they have been running, and when they were started. The
-i option will show some additional job information. Note that the total run time of
the job is determined from the moment the job is marked complete by the read-eval-
print loop when polled, not when it actually ended and is flagged as terminated by the
signal handler.

\wait [job_id]
Will pause until job designated by job_id completes. If job_id is a negative number
then \wait will pause until any pending jobs completes. If there are no jobs pending,
or job_id does not belong to a running job, then an error message is displayed. Note
that if multiple jobs are running, and a \wait is issued for one of them, the other
jobs may not automatically get signaled when completed within the wait period of the
specific job. The other jobs may need to get signaled with a \wait -1 as well to be
noticed complete by sqsh.

\kill job_id
Terminates the job specified by job_id, throwing away any output that may be deferred
for the job. If job_id is not a running job then an error message is displayed.

\show job_id
Displays the deferred output of completed background job job_id and removes the job
from the list of pending jobs (removing the defer file in the process). If job_id is
still running, or is not a valid complete job, then an error message is displayed. You
may need to issue a \wait job_id first, to get notified of actual job completion.

Aliasing
As of release 1.2, sqsh supports full csh-style command aliasing. With this feature, sqsh
checks the first word of each line, prior to any form of expansion, to see if it matches
the name of an existing alias. If it does, the command is reprocessed with the alias
definition replacing its name. Unlike csh, however, only one form of history substitution
is available within an alias: the '!*' entry, indicating the current line being expanded.
If no history expansion is called for, the arguments on the command line remain unchanged.

Like csh, aliases are not recursively expanded, so it is perfectly legal to create an
alias that expands to a command by the same name.

The following command is used to create an alias:

\alias [alias_name=alias_body]
If no arguments are supplied to the \alias command, then the list of aliases currently
in effect is displayed. Otherwise, it creates a new alias with a name of alias_name
and a body of alias_body; if alias_name already exists, the body of the existing
alias_name is replaced with the new definition.

After defining the new alias, whenever sqsh encounters a line beginning with
alias_name, the remainder of the line is replaced with alias_body before any further
processing is performed.

If the string '!*' exists anywhere within alias_body, the arguments supplied to the
alias are inserted at that point, otherwise the argument are appended to the end of
the alias definition. For example:

1> \alias hi='\echo !* said hello'
1> hi Scott
Scott said hello

where as if the alias does not include the !* keyword, then it behaves like so:

1> \alias hi='\echo said hello'
1> hi Scott
said hello Scott

It is perfectly legal to include a !* more than once within a given alias_body.
Currently there is no way to escape the string !*, if you really need this feature
send me mail.

\unalias alias_name
Removes alias_name.

Miscellaneous
The left over commands.

\exit [x]
The \exit command requests that current read-eval-print loop cease processing. When
the last loop returns, sqsh exit(1)s. You may specify a exit code as parameter which
will be stored in $exit_value and will be used as return value to the shell upon exit
of sqsh. (0 <= x <= 255).

\abort
Causes all nested read-eval-print loops to abort processing, causing sqsh to exit with
an exit value of 254 (see section EXIT STATUS).

\read [-a] [-n] [-h] var_name
Reads a line of input from the user, placing the text of the line in the variable
var_name. If the -n is used, then the trailing new-line is left on the line of text,
and if -a is supplied, then the text of the line is appended to the existing value of
var_name. The -h flag turns off echoing of typed characters back to the user.

\sleep seconds
Causes sqsh too pause for seconds. This is useful within scripts of batches which need
to pause briefly between batches (it was primarily useful to me for testing background
jobs).

\echo [-n] [args ...]
Just like the UNIX echo(1), this prints its arguments to stdout, followed by a new-
line. If the -n flag is supplied, the newline is omitted.

\warranty
Displays the standard GNU warranty.

\help [command]
Without any arguments \help displays a brief list of all available commands,
otherwise, it provides specific help for command, if available. When help is requested
on a specific command, \help looks for the file $help_dir/command.hlp and displays it
to stdout.

\shell [shell command]
If shell command is not supplied then sqsh executes $SHELL. If the $SHELL variable has
not been set, then, by default, /bin/sh is executed. Otherwise, if shell command is
supplied then it is executed. The exit status of the command executed is stored in the
special $? read-only environment variable.

\lock
Locks the current session until the correct password is typed. By default \lock
attempts to use the UNIX password (from /etc/passwd) associated with the user running
sqsh, however if the $lock variable is set then the contents of that is used for
validation instead.

Note, on systems using Shadow Passwords (in which even the encrypted password is
unavailable), \lock will only work using the $lock variable.

Aliases
The following aliases are established upon startup of sqsh, and are provided primarily for
backward compatibility with isql. These may be removed at any time using the \unalias
command (either at the prompt, or within your .sqshrc file).

! The ! alias is provided as a csh(1)-like history mechanism, and is an alias of
\buf-append. With release 0.7, this alias is provided only for backwards compatibility
with previous releases of sqsh. See SPECIAL VARIABLES, $history_shorthand for details
on the new shorthand mechanism (the new shorthand more closely resembles that of csh).

clear
An alias for the \clear command, which causes the contents of the current work buffer
to be cleared and discarded. Also the screen will be cleared if readline is compiled
into sqsh.

reset
An alias for the \reset command, which causes the contents of the current work buffer
to be cleared and copied to history (if in interactive mode).

exit [x]
quit [x]
An alias for the \exit [x] command, causes the current read-eval-print loop to
complete.

edit
vi
emacs
These are provided as aliases for the \buf-edit command. See COMMANDS-Buffers for
information on the interactions between \buf-edit and aliases.

go Provided as an alias for the \go command (for obvious reasons).

help
An alias for the \help command.

In-Line \go

If the variable $semicolon_hack is set to 1 (on), then sqsh supports what is called an in-
line \go feature. This allows the current command batch to be terminated and sent to the
database in a single step by appending a ';' onto the end of the current work buffer. This
allows

1> sp_who;

To behave in the same manner as if you had typed:

1> sp_who
2> \go

Likewise, anything following the semicolon is passed to the \go command just as if it was
run as a normal command:

1> sp_who ; 2>/dev/null | more

Unlike most other isql replacements, sqsh attempts to be smart about the semicolons. If a
semicolon is contained within a set of single or double quotes it will not be interpreted.
This includes multiple quotes. For example:

1> select "This is a multiple line
2> quote; it is smart!" ;

In the above example, only the second semicolon (the one at the end of the line) will be
interpreted.

SPECIAL VARIABLES

There are several options that are configurable via the command line options to sqsh,
however these are by no means complete. There are many aspects of sqsh's behavior that may
only be modified by setting special variables. (In fact, the command line options really
only set these variables for you).

Variable Data types
Next to all of the variables that follow is the type of data with which they may be set.
Any attempts to set the variable with a type of data that it does not accept will fail.

string
Any sequence characters.

boolean
A positive boolean value may be represented as either "True", "Yes", "1", or "On"
(case insensitive) and a negative boolean value may be represented as "False", "No",
"0", or "Off" (case insensitive). However, internally the value of the variable will
always be represented as either a "1" or "0".

path
Must be the path name that is readable by the sqsh program.

int Must be one or more digits. Note that some variables also restrict the range of the
integer.

date-spec
This is a string of the format used to specify dates and times for the date(1)
command, or the strftime(3C) and cftime(3C) standard C library functions. For example
'%H:%M:%S' specifies a time of hours in 24 hour format, followed by a colon, followed
by minutes, followed by a colon, followed by seconds.

float-format
A string of the format p.s, where p is the total precision of a floating point value
(the total number of digits to be displayed, including those following the decimal)
and s is the scale of the value (the total number of digits following the decimal to
be displayed).

Variables

The following variables have special meanings within sqsh and the setting of these
variables alter the behavior of the shell.

$? (int)
This read-only variable may contain the following return value:

· The most recent error number returned from the SQL Server (@@errno) of severity >
10 (above informational messages).

· The exit value of a previously executed pipe command.

· The return value of the most recently executed sqsh function.

$$? (int)
This variable may contain the result of the last executed \if statement:

- 0 -
The test evaluated to False.

- 1 -
The test evaluated to True.

- 2 -
There was an error in the test specification.

$# (int)
Contains the number of arguments passed into the sqsh function or script.

$* (string list)
Expands to the complete list of arguments supplied to the function or script when
invoked.

${0}...${N} (int)
Used to reference positional function arguments. Argument ${0} is the name of the
function being called, ${1} is the first argument, etc.

$$ Expands to the process ID of the current running sqsh session.

DISPLAY
May contain the name of the DISPLAY the X-server uses to put the XWindows result
window when using \go -x. Defaults to the $DISPLAY shell environment.

appname
Contains the name sqsh uses to identity itself to the server. Defaults to sqsh-2.1.7.
The application name can be retrieved from the sysprocesses table like:
select program_name from master.dbo.sysprocesses where spid=@@pid;

autouse (string)
Note: the meaning of this variable has been deprecated.

If $autouse is set, and the $database variable has not been set, then this variable
causes \connect to perform a "use $autouse" once a connection has been established.

This variable may also be set using the -D command line option.

banner (boolean)
Turns off the banner message displayed on startup, this variable defaults to 1 and may
also be turned off using the -b command line argument.

batch_failcount (int)
This internal variable is used to keep track of the number of batches that have failed
to execute (essentially, the number of times that the error handler was called).

A batch is considered failed whenever an error of severity $thresh_fail is
encountered. When $batch_failcount reaches $thresh_exit sqsh exits with an exit value
of the total number of batches that have failed. Setting $batch_failcount to the
string "" will cause it to reset to zero, any other value may have unpredictable
results.

See EXIT STATUS for details.

batch_pause (boolean)
Causes a "Paused. Hit enter to continue..." message to be displayed after each batch
is executed. This variable, in conjunction with $echo is good for debugging SQL
scripts specified with the -i option.

bcp_colsep (string)
Used as a separator between columns during BCP style output (see the $style
configuration variable and the -m option to the \go command). The default setting is
"|".

bcp_rowsep (string)
Used as a separator between rows during BCP style output (see the $style configuration
variable and the -m option to the \go command). Note that, a newline ("\n") is
automatically appended this value and should not be supplied. The default setting is
"|".

bcp_trim (boolean)
Controls whether or not BCP style output trims trailing spaces from fixed length
columns. The default is "True".

chained (boolean)
If set then sqsh uses the "chained" transaction mode (aka "AutoCommit off"). Setting
this has NO effect on the current connection. It can be set via the command line
argument -n.

charset (string)
If this variable is set prior to establishing a connection with SQL Server, then
during the connection sqsh will request that the server transform to and from the
requested charset. After establishing a connection, this variable is automatically set
to the current character set in use.

clear_on_fail (boolean)
Normally, whenever the \go command is run, sqsh clears the current work buffer of its
contents, moving them to history. Setting $clear_on_fail to 0, leaves the current work
buffer intact if a failure is encountered while sending the contents to the database.
The default value is 1, or on.

colsep (string)
Causes the string colsep to be used to delimit SQL column output columns, this
defaults to " ", it may also be set via the command line argument -s.

colwidth (int)
Used to control the maximum column width displayed by the pretty display style (see
$style below). If a row of a column exceeds this width, it will be wrapped in a
relatively visually appealing manner at $colwidth characters. Note, however, that if
there is enough screen width to hold all columns $colwidth may be exceeded until the
width of the screen is reached.

database (string)
If this variable is set prior to establishing a connection to the SQL Server, the a
"use $database" is performed immediately after the connection is established. Once a
connection has been established this variable will automatically be set to the current
database context.

date (date-spec)
This variable may be set with a date format (see the man page for date(1)), and the
variable expands to the current date in the supplied format. The default format for
this variable is %d-%b-%y (e.g. 02-Feb-1996).

datetime (date-spec)
This variable may be set with a date format similar to $date and $time and is used to
control the display format of all SQL Server DATETIME and SMALLDATETIME columns.

Note that this features relies upon the operating system specific locale information
for determining such things as the name of the month and day, rather than going
through the CT-Lib locale information. This means that the date format could
potentially miss-match the locale as requested using the -z flag. For example, if sqsh
is run on an operating system configured for US English, but requests French as the
language of choice using -z, the use of $datetime will cause all date information to
be displayed in US English rather than French.

Ordinary characters defined in the variable are left in place without any conversion.
Characters introduced by a '%' character are replaced during display of a column value
as follows:

[] Any contained between a pair of braces ('[' and ']') will be removed when
displaying SMALLDATETIME columns. This feature is particularly useful for removing
the seconds and milliseconds values which are not applicable to SMALLDATETIME
anyway. For DATETIME columns, only the actual braces will be removed.

%a The abbreviated weekday name according to the current operating system locale.

%A The full weekday name according to the current operating system locale.

%b The abbreviated month name according to the current operating system locale.

%B The full month name according to the current operating system locale.

%c The preferred date and time representation for the current operating system's
locale.

%d The day of the month as a decimal number (range 0 to 31).

%D The date in US format (mm/dd/yy).

%H The hour as a decimal number using a 24-hour clock (range 00 to 23)

%I The hour as a decimal number using a 12-hour clock (range 01 to 12)

%j The day of the year as a decimal number (range 001 to 366).

%m The month as a decimal number (range 10 to 12).

%M The minute as a decimal number.

%p Either 'am' or 'pm' according to the given time value, or the corresponding
strings for the current operating system locale.

%r The time in 12-hour format (hh:mm:ss [AM|PM]).

%s Seconds since the epoc (1970-01-01 00:00:00 UTC) (this is not supported on all
systems).

%S The second as a decimal number.

%T The current time in 24-hour format (hh:mm:ss).

%u The millisecond as a decimal number.

%U The week number of the current year as a decimal number, starting with the first
Sunday as the first day of the first week.

%W The week number of the current year as a decimal number, starting with the first
Monday as the first day of the first week.

%w The day of the week as a decimal, Sunday being 0.

%x The preferred date representation for the current locale without the time.

%X The preferred time representation for the current locale without the date.

%y The year as a decimal number without a century (range 00 to 99).

%Y The year as a decimal number including the century.

%Z The time zone (e.g., EDT), or nothing if not time zone is determinable.

%% A literal '%' character.

debug (string)
If sqsh has been compiled with debugging enabled (-DDEBUG), this variable may be used
to control the amount of debugging output displayed. $debug may be set to a pipe (|)
delimited (logical OR) set of the following words to turn on various pieces of
debugging: ALIAS, AVL, BCP, DISPLAY, ENV, ERROR, EXPAND, FD, JOB, READLINE (abbr. RL),
RPC, SCREEN, SIG, SIGCHLD (or SIGCLD) or ALL.

defer_bg (boolean)
Normally, when a job is run in the background (via a '&' on the command line), the
output of the job is deferred to a temporary file (located in $tmp_dir) until the user
requests the output to be displayed using \show jobid. This way the results of the job
will not interfere with what the user is doing. Setting this variable to false will
result in no deferred output files being created and output sent to the screen
immediately

echo (boolean)
Setting $echo to on (1) causes each command submitted to the database via the \go
command to be displayed prior to the output. This variable defaults to 0 (or off), and
may also be set using the -e command line option.

encryption (boolean)
Setting the $encryption variable prior to establishing a connection to the server will
cause the login connection to be initiated using client-side password encryption. This
variable may also be set using the -X command line option.

exit_failcount (boolean)
Settings this value to 1 causes sqsh to return an exit status of $batch_failcount
rather than 0, upon a non-error termination. See EXIT STATUS for details. The default
value is 0.

exit_value (int)
When you exit sqsh by specifying an exit code, like \exit 3 or using one of the
aliases exit or quit commands, then this value is assigned to the $exit_value
variable. You can also assign a value using the \set command. When sqsh determines
this variable has a non-zero value during termination, this value will be used as exit
code. See EXIT STATUS for details.

expand (boolean)
By default when the \go command is executed, the contents of the current work buffer
is expanded of all environment variables prior to being sent to the database for
execution. By setting this variable to "0", the buffer will no longer be expanded
before being sent to the database. This is useful when you either (1) have strings in
the buffer that contain a '$' and you don't want them to be expanded, or (2) for
performance reasons; it takes time (and an extra copy of the buffer) to perform the
variable expansion.

filter (boolean)
Toggles filtering of the SQL batch through an external program (defined by the
$filter_prog variable, below) prior to being sent to the SQL Server. Default is '0',
or 'off'.

filter_prog (string)
Defines the external program through which the SQL batch will be filtered prior to
being sent to the SQL Server. This variable is ignored if $filter is set to '0' or
'off'. The default is 'm4 -'.

float (float-format)
Defines the display format (the precision and scale) for all floating point values
displayed by sqsh. The default is '18.6'. Note that values exceeding the defined
precision are not truncated, so setting this value too low may cause columns in a
result set to be miss-aligned.

footers (boolean)
Toggles the "(%d rows affected)" following a result set. The default for this variable
is '1'.

headers (boolean)
Toggles the column headers preceding a result set. The default for this variable is
'1'.

help_dir (path)
This is the location of the help files used by the \help command, typically it
defaults to something like /usr/local/lib/sqsh/help.

hist_auto_save (int)
When variable $histsave is on and the $hist_auto_save variable has a value greater
than 0, then the history will be automatically saved to $history after $hist_auto_save
modifications of the history buffers. When the value is 0 (default), then no automatic
history save will be performed.

histnum (int)
Contains the history number that will be assigned to the current command batch as soon
as the \go command is executed. This variable should be considered read-only. See also
the discussion on the $histunique variable.

history (path)
This is the location of the history file used to store and retrieve a user's history
during start-up and shutdown. This defaults to $HOME/.sqsh_history. This variable is
expanded each time it is referenced by sqsh, much in the same way that $prompt is
referenced each time the prompt is displayed.

history_shorthand (boolean)
This variable is only meaningful within an interactive session. If set, it turns on
the ability to append any named buffer or history buffer onto the current work buffer
in a 'sh' history style, such as '!40'. Be careful with this feature, sqsh is not
terribly intelligent with looking for history shorthand, so it is possible that it may
get confused (although, it is smart enough to ignore !'s in quoted strings).

histsave (boolean)
The value of this variable is used by sqsh to indicate whether the history should be
saved to $history prior to termination of sqsh.

histsize (int)
The value of this variable is used to alter the maximum number of history entries are
maintained by sqsh (the default is 10). Note that decreasing the value of this
variable causes some history entries to be lost.

histunique (boolean)
If set, sqsh maintains a MRU-LRU order of executed buffers and does not store
duplicate command buffers. For example, observe the following situation:

LINUX1502.user1.master.1> \history
(1) sp_who
(2) grant role mon_role to sa_role
(3) select * from monProcessActivity
(4) select @@authmech,show_sec_services()
(5) select @@servername,@@authmech,show_sec_services()
LINUX1502.user1.master.1> sp_who
LINUX1502.user1.master.2> go
... output omitted
LINUX1502.user1.master.1> \history
(1) grant role mon_role to sa_role
(2) select * from monProcessActivity
(3) select @@authmech,show_sec_services()
(4) select @@servername,@@authmech,show_sec_services()
(5) sp_who

sp_who is the last executed command and the buffer - originally the last in the list -
is now on top of the list. When an already existing buffer is reused, the value of the
$histnum variable is not changed.

hostname (string)
Used during the connection process to indicate to SQL Server the name of the host from
which sqsh is connecting. This variable may also be set using the -H flag.

ifs (string)
The list of Internal Field Separators.

ignoreeof (boolean)
By default, sqsh terminates if the user presses ^d (control-D) on an empty line and
readline support is compiled in. If $ignoreeof is set in the sqshrc file you get a
warning message instead:

CTRL-D: Use "exit" or "quit" to leave the sqsh shell.

This is equivalent to using "set -o ignoreeof" in the bash shell.

interactive (boolean)
This is a variable used internally and should probably not be altered by the user. If
$interactive is '0', then the prompt is not displayed, the history is neither read nor
written and some user messages are suppressed.

interfaces (path)
This is the full path name of the interfaces file, it defaults to $SYBASE/interfaces.

keytab_file (string)
Used in Kerberos and DCE user authentication security mechanisms. Corresponds with the
-K startup option.

See also the discussion on Kerberos Support.

keyword_completion (int/string)
This variable only applies if GNU Readline support has been compiled into sqsh.
$keyword_completion is used to control the TSQL keyword completion feature in
readline, and may be set using either an integer between 0 and 4, or one of the
strings none, lower, upper, smart, or exact. If it is set to either 0 or none, then no
keyword completion is performed (this is the default). lower or 1, causes sqsh to
complete the keyword in lowercase, regardless of the case that the partially completed
keyword was typed. upper or 2 forces completion to be performed in upper case, smart,
or 3, bases the decision on case upon the first character of the partial keyword, and
exact completes the keyword in exactly the same case as defined in the .sqsh_words
(for the built-in TSQL keywords, this will be lower case).

keyword_file (string)
If readline support has been compiled into sqsh, and sqsh is being run in interactive
mode, the contents of this file are used for keyword tab completion by readline rather
than the default set of TSQL syntactical keywords. The default is $HOME/.sqsh_words.

language (string)
The $language variable is used while establishing a connection to the server to
specify the national language used to display system prompts and messages. The
variable will automatically track the current language setting of the server. This may
also be set via the -z flag.

lineno (int)
This is an internal variable and should not be altered by the user. It is used to
maintain the line number that is being typed into within the current work buffer.

linesep (string)
Used to configure the line separator for the horizontal display style, this defaults
to "\n\t".

lock (string/write-only)
Defines the password to be used by the \lock command. If unset or set to the string
"NULL", then the UNIX password of the user running sqsh is used instead (if possible).
Note that $lock will always expand to the string "*lock*" if referenced.

login_timeout (int)
The number of seconds to wait when attempting to create a new connection to a data
server. Default is 0 (infinite wait). See also the -T command line option.

max_timeout (int)
Controls the number of times a query needs to reach its time-out value before the
session is aborted. See $query_timeout and the -Q command line flag. The following
messages will be displayed and sqsh exits with value 255 when the $max_timeout limit
is reached.

Query or command timeout detected, session aborted
The client connection has detected this x time(s)
Aborting on max_timeout limit

maxlen (int)
Controls the maximum amount of data that will be displayed (in any display mode) in a
single column. This setting will automatically truncate the output of particularly
large data types (such as TEXT) to the value supplied. The default setting is 8192
bytes (8KB).

newline_go (boolean)
This flag is used as a horrible kludge to support an "empty" alias for the \go
command, that is, the equivalent of supplying "-c ''" or just "-c" on the command
line. When on, an empty line is interpreted as a call to the \go command. This feature
is not recommended but is supplied for completeness.

output_parms (boolean)
Flag used to enable or disable the display of output parameter result sets from stored
procedures. The default is to enable the display.

packet_size (int)
Defines the size of the TDS packets used to communicate with SQL. Changing the value
of the variable will not affect the current connection but will take effect upon the
next \reconnect command. Specifying a value of NULL indicates that the default packet
size is desired.

password (string/write-only)
This is the user's current password. A NULL password may be assigned using an explicit
"NULL" string. For security reasons, when referenced the $password variable will
always expand to the string "*password*".

password_retry (boolean)
When the variable is on and sqsh started in interactive mode, sqsh will ask for the
password again if login failed. When set to 'off', sqsh will terminate immediately.
Default is on.

principal (string)
Used in Kerberos user authentication as the Server principal name when it differs from
the $DSQUERY name. Corresponds with the -R startup option.

See also the discussion on Kerberos Support.

prompt (string)
This variable is used by sqsh to build your current prompt. Any variables contained
within $prompt are expanded each time the prompt is displayed. The default value for
this is '${lineno}> '. See also the discussion on color support below.

prompt2 (string)
This contents of this prompt are expanded and displayed during interactive use when
sqsh requires additional input, such as during a line continuation. The default value
is '--> '.

query_timeout (int)
Number of seconds to wait for a query to return data. If the timeout is reached the
query is aborted (canceled). See also $max_timeout and the -Q command line option.

rcfile (path)
Contains a colon (:) delimited list of sqsh resource (sqshrc) files. The default
setting is /etc/sqshrc followed by $HOME/.sqshrc).

readline_history (string)
If readline support has been compiled into sqsh, the contents of the readline line-by-
line history will be written to the file specified by the $readline_history variable.
The default is $HOME/.sqsh_readline.

readline_histsize (int)
If readline support has been compiled into sqsh, the value of $readline_histsize
specifies the number of lines that are saved in the readline line-by-line history.
Setting this to a value of 0 causes every line to be saved. The default value is 100.

real (float-format)
Defines the display format (the precision and scale) for all real values displayed by
sqsh. The default is '18.6'. Note that values exceeding the defined precision are not
truncated, so setting this value too low may cause columns in a result set to be miss-
aligned.

repeat_batch (boolean)
When set to On or True, a \go executed with an empty SQL Buffer will cause the
previous batch to be re-executed.

secmech (string)
The name of the security mechanism used for user authentication. For instance csfkrb5.
When using the -Z option, the name of the security mechanism can be specified, or when
no secmech is supplied, the OpenClient will use the default, i.e. the first security
entry from the $SYBASE/$SYBASE_OCS/config/libtcl.cfg file. Note that the name used
must match the name of the corresponding secmech entry in the objectid.dat file. When
the connection to the server is setup, the actual secmech name will be stored in the
$secmech variable.

secure_options (string)
Describe the security options used for user authentication security mechanisms.
Corresponds to the -V startup option.

See also the paragraph on Kerberos Support.

script (string)
If sqsh is run using the -i flag, then this variable contains the name of the script
being executed.

semicolon_cmd (string)
When $semicolon_hack (see below) is enabled, the contents of this variable is executed
when a semicolon is encountered in the SQL Buffer. This variable defaults to the
string '\go'.

semicolon_hack (boolean)
Toggles on the ability to use a ';' as an in-line command terminator. This feature is
not recommended and is only in here because enough users complained. See section
COMMANDS, In-Line Go.

session (string)
The location of the session file that will be processed just before connecting to a
server. The variable will be expanded so it may contain environment variables.

SHELL (string)
The name of the shell to be used to execute pipes and to be used by the \shell command
(default '/bin/sh').

statistics (boolean)
Setting $statistics to 1 causes timing statistics to be displayed upon the successful
execution of every batch of SQL. This variable may also be set via the -t command line
flag, or by supplying -t to the \go command. $statistics defaults to 0.

style (string)
Selects result set display style. Currently eight styles are supported. The horiz
(which may also be defined as hor or horizontal), closely resembles the output of
isql, with the traditional columnar output.

The vert (or vertical) style rotates the output, so that every line is represented by
a column name followed by a column value. This is nice for looking at particularly
wide output.

The bcp style displays results in a format amenable to bcp'ing the result set back
into another table. That is, every column value is separated by $bcp_colsep with the
final column separated by $bcp_rowsep followed by a newline (\n). If $bcp_colsep or
$bcp_rowsep are not defined then '|' is used as the default separator. Note that this
output does not work well with COMPUTE columns, and uses the default conversion
methods for all data types (that is, datetime columns may truncate the millisecond).

The csv display style outputs all result sets in the form of a comma separated
construct. This mode is ideal to import result sets into spreadsheet programs, for
instance.

The html display style outputs all result sets in the form of an HTML <TABLE>
construct. This mode is ideal for the use of sqsh as a CGI application.

The meta display style outputs only the meta-data information associated with the
result and discards the actual row results. This mode is useful for debugging the
result sets generated from a full passthru Open Server gateway, or for those
interested in what is really coming back from the server.

The pretty display style generates a fluffy table-like output using regular ASCII
characters for borders. This mode does not perform any explicit column wrapping, like
the horiz display mode. However, the $colwidth variable can be used to control the
maximum width of a given column on the screen. If the column exceeds $colwidth
characters wide, it is wrapped in a relatively visually appealing manner. Note that
$colwidth may be exceeded if there is enough screen width to hold the columns without
wrapping.

The none display style suppresses all results from being displayed (however it does
actually retrieve result information from the SQL Server). This is particularly useful
when used with the -p flag (or the $statistics variable) for gathering accurate
performance statistics.

term_title (string)
When this variable is set, sqsh will reset the name of the current terminal (xterm)
window it is running in. Works for xterm, rxvt, putty and MS-Windows CMD windows. The
name consists of the sqsh startup name appended with the expanded value of the
$term_title variable.

thresh_display (int)
Sets the minimum SQL Server error severity that will display a message to the user,
the default is 0 and valid ranges are between 0 and 22, inclusive.

thresh_exit (int)
Defines the maximum number of errors of severity level $thresh_fail that may be
encountered before sqsh aborts. This is useful primarily for non-interactive scripts,
but is allowed on an interactive session. Setting $thresh_exit to a value of 0
disables this feature. See section EXIT STATUS for details.

thresh_fail (int)
Sets the minimum SQL Server severity level that is to be considered a failed batch.
The minimum for this value is 0 (meaning any error that is not an information
message), and the maximum is 22. Whenever $thresh_fail is crossed, the variable
$batch_failcount is incremented by 1. See section EXIT STATUS for details.

time (date-spec)
This variable may be set with a time format (see the man page for date(1)), and the
variable expands to the current time in the supplied format. The default format for
this variable is %H:%M:%S (e.g. 14:32:58).

tmp_dir (path)
This contains the directory to which temporary files used internally by sqsh are to be
written. These files are generated either during buffer editing (the \buf-edit
command), or to maintain output defer files for background jobs. The default value
for this variable is /tmp.

username (string)
The name of the user currently connected to the database.

version (none)
This read-only variable contains the current version number. (sqsh-2.1.7)

width (int)
The current width of the SQL output.

xgeom (string/int)
If X11 support is compiled into sqsh, this value is used to configure the default
window size (in characters) of the X display. This variable must be of the format WxH
or just W, where W is the width of the window and H is the height of the window. If
the height of the window is not supplied, then 25 lines is assumed. If $xgeom is not
set, then $width is used as the default width and the height is assumed to be 25. If
neither is set, then 80x25 is assumed.

xwin_title (string)
If X11 support is compiled into sqsh and an X11 result windows is requested by using
the -x parameter of the \go or \rpc commands, then this variable will be used to set
the title name of the window. Can be temporarily overridden with the -T option of the
\go and \rpc commands.

Script Execution
As with most shells, sqsh allows a file containing SQL and script commands to be executed
directly via the magical UNIX #! convention. On most UNIX platforms, when the operating
system encounters the bytes #! as the first two bytes of an executable file it will
automatically pipe the file through the interpreter specified immediately after the #!.
For example, to create an executable sqsh script to run sp_who, you simply need to create
a file like so:

#!/usr/bin/sqsh -i
sp_who
go

Thus, if your sp_who script is executed directly, it will automatically launch
"/usr/bin/sqsh -i sp_who" for you.

And, to make things even more flexible, sqsh supports positional parameters, similar to
most shells, of the form ${n} which will expand to the nth argument to your sqsh script.
For example:

#!/usr/bin/sqsh -i
sp_who ${1}
go

will cause the sp_who stored procedure to be executed with an argument of the first
command line parameter supplied to the sp_who shell script.

Note that positional parameters must be contained between braces to avoid conflicts with
the TSQL money data type (without the braces, the variable will not be expanded).

EXIT STATUS

One of the major complaints of isql is that it provides no facility to detect when an
error condition occurred while it is performing processing. sqsh provides a rather
complex, but flexible mechanism for returning meaningful information concerning its reason
for exit in the form of an exit status (see exit(3)).

When sqsh begins execution two handlers are associated with the current connection to the
database, one is a message handler which is responsible for displaying the text of any SQL
Server messages or errors, and the other is an error handler, which is responsible for
determining what to do with an error condition (bear with me, these are only loose
descriptions). And, associated with each message and error condition is a severity level,
between 0 and 22 (informational message to fatal condition).

Associated with these two message handlers are several variables that are used to either
control their behavior, or are used as indicators by the message handler:

$thresh_display
This variable is used by the message handler to determine the minimum error severity
which will cause a message to be displayed. By default this is 0, which will display
all messages (with a couple of exceptions). Setting this to 1, for example, would
suppress informational messages such as the output of set showplan on.

$thresh_fail
This variable is used by the error handler to determine which error severity is
considered by sqsh to be a failure. Normally, this defaults to 11 which indicates that
any error, other than informational messages, is a failure. The next variable will
explain the importance of this value.

$batch_failcount
This variable should be considered read-only, and contains the total number of times
that batches have caused an error of severity $thresh_fail or more. The only value
that is valid to explicitly set this value to, is "" (the empty string), which will
reset this value to 0, any other value may have unpredictable results.

$thresh_exit
This variable is used to determine the limit at which $batch_failcount will cause sqsh
to exit. If $thresh_exit is 0, then this feature is disabled. In other words, if
$batch_failcount = $thresh_exit and $thresh_exit is greater than 0, then sqsh will
exit, returning $batch_failcount as an exit status.

Note that, unless $exit_failcount is set to 1, sqsh will exit with 0 if the total
number of failures does not reach $thresh_exit.

$exit_failcount
This variable is used only when sqsh would normally exit with a success status (0),
this causes it to instead exit with a value of $batch_failcount (which may, itself, be
0).

$exit_value
When this variable is non-zero, it will override the $exit_failcount and
$batch_failcount values and just exit the value of $exit_value. This variable may be
explicitly set using the \set command, or implicitly using \exit x and its aliased
counterparts.

To recap, here is a list of error codes that may be returned by sqsh upon exit, and the
reason that they could be returned:

- 0 -
No error has been encountered.

- 1...253 -
Between 1 and 253 batches have failed (if you run more than 253 batches, the exit
status of sqsh is undetermined...I may fix this in the future).

- 254 -
An explicit \abort was called, or a SIGINT (^C) was issued during a non-interactive
session.

- 255 -
A general error condition has occurred, such as a bad command line argument to sqsh,
memory allocation failure, file access error, etc.

The following sections provide detailed examples of combinations of variable settings and
the results produced upon exit with certain failure conditions. It is assumed the
$exit_value variable contains 0 in the next examples.

thresh_display=0, thresh_fail=0, thresh_exit=1
With this combination, all error messages will be displayed as they happen, and every
error will be considered an failure condition. Upon reaching the first error, sqsh
will abort with an exit status of 1, or the total number of failures (the
$batch_failcount variable). However, if nothing goes wrong during the whole process, a
zero is returned.

thresh_display=0, thresh_fail=0, thresh_exit=3
This combination will cause all error conditions to be displayed and all of them to be
considered a failure condition. Upon reaching three total failed batches, sqsh will
exit with a status of 3. However if 0, 1, or 2 batches fail, then 0 is returned.

thresh_display=22, thresh_fail=0, thresh_exit=3
This behaves the same as the previous example, with the exception that all error
messages will be suppressed from being displayed. This is particularly useful if you
just care about the exit value more than the actual error.

thresh_display=0, thresh_fail=2, thresh_exit=1
This will cause the first error of severity 2 or higher to be displayed and cause sqsh
to exit with a failure condition of 1.

thresh_display=0, thresh_fail=0, thresh_exit=3, exit_failcount=1
This is identical to the second example, above, however sqsh will return the total
number of batches that failed even if $batch_failcount does not reach 3.

exit_value=nonzero
This will override all conditions explained above and just exit the specific value.

Miscellaneous
Colorizing sqsh prompts, etc.

Color codes are presented as a string like {1;2;3}. If sqsh encounters a { (curly brace)
in the prompt string it will assume a color-code is supplied and will act as such. No
checks will be performed on the validity of the color-code definition itself. The color
definition consists of three values separated by a semicolon.

The first code defines the Color Attribute Code with possible values: 0=none 1=bold

The second value defines the Text Color Code: 30=black 31=red 32=green 33=yellow 34=blue
35=magenta 36=cyan 37=white

The third value defines the Background Color Code: 40=black 41=red 42=green 43=yellow
44=blue 45=magenta 46=cyan 47=white The last color-code for the background may be omitted.

Not all color and attribute combinations will present good results, depending on your
terminal type and color scheme. But the following values work OK on a xterm with a creamy
white background color in Linux as well as rxvt in Cygwin with a black background window:

Prompt: Blue text in white background "{0;34;47}"

Command text: Yellow text "{0;33}"

sqsh will translate the color-codes to an actual color-code string that is presented to
readline: for example "\001\033[0;36;47m\002". Note that if you want to use curly brackets
in your prompt, you have to escape colorization by specifying a double brace, like
{{...}}. For example:

\set prompt_color='{0;34;47}'
\set text_color='{0;33}'
\set prompt='$prompt_color{{$DSQUERY.$username.$database.$lineno}}>$text_color '

Color support is automatically available if sqsh is compiled and linked with readline
support enabled.

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