reptyr - Online in the Cloud

PROGRAM:

NAME

reptyr - Reparent a running program to a new terminal

SYNOPSIS

reptyr PID

reptyr -l|-L [COMMAND [ARGS]]

DESCRIPTION

reptyr is a utility for taking an existing running program and attaching it to a new
terminal. Started a long-running process over ssh, but have to leave and don't want to
interrupt it? Just start a screen, use reptyr to grab it, and then kill the ssh session
and head on home.

reptyr works by attaching to the target program using ptrace(2), redirecting relevant file
descriptors, and changing the program's controlling terminal (See tty(4)) It is this last
detail that makes reptyr work much better than alternatives such as retty(1).

After attaching a program, the program will appear to be either backgrounded or suspended
to the shell it was launched from (depending on the shell). For maximal safety you can run

bg; disown

in the old shell to remove the association with the program, but reptyr will attempt to
ensure that the target program remains running even if you close the shell without doing
so.

OPTIONS

-T

Use an alternate mode of attaching, "TTY-stealing". In this mode, reptyr will not
ptrace(2) the target process, but will attempt to discover the terminal emulator
for that process' pty, and steal the master end of the pty. This mode is more
reliable and flexible in many circumstances (for instance, it can attach all
processes on a tty, rather than just a single process). However, as a downside,
children of sshd(8) cannot be attached via -T unless reptyr is run as root. See
⟨https://blog.nelhage.com/2014/08/new-reptyr-feature-tty-stealing/⟩ for more
information about tty-stealing.

-l, -L [COMMAND [ARGS]]

Instead of attaching to a new process, create a new pty pair, proxy the master end
to the current terminal, and then print the name of the slave pty. This can be
passed to e.g. gdb´s set inferior-tty option.

If an optional COMMAND and ARGS are passed in conjunction with -l, that command
will be executed as a child of reptyr with the REPTYR_PTY environment variable set
to the name of the slave pty. If -L is used instead of -l, then fds 0-2 of the
child will also be redirected to point to the slave, and the child will be run in a
fresh session with the slave as its controlling terminal.

-s

By default, reptyr will move any file descriptors in the target that were connected
to the target's controlling terminal to point to the new terminal. The -s option
will cause reptyr to unconditionally attach file descriptors 0, 1, and 2 in the
target, even if the target has no controlling terminal or they are not connected to
a terminal.

-v

Print the version of reptyr and exit.

-h

Print a usage message and exit.

-V

Print verbose debug output while running.

NOTES

reptyr depends on the ptrace(2) system call to attach to the remote program. On Ubuntu
Maverick and higher, this ability is disabled by default for security reasons. You can
enable it temporarily by doing

# echo 0 > /proc/sys/kernel/yama/ptrace_scope

as root, or permanently by editing the file /etc/sysctl.d/10-ptrace.conf, which also
contains more information about this setting.

Use reptyr online using onworks.net services