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paste

The paste command does the opposite of cut. Rather than extracting a column of text from a file, it adds one or more columns of text to a file. It does this by reading multiple files and combining the fields found in each file into a single stream on standard output. Like cut, paste accepts multiple file arguments and/or standard input. To demonstrate how paste operates, we will perform some surgery on our distros.txt file to pro- duce a chronological list of releases.

From our earlier work with sort, we will first produce a list of distros sorted by date and store the result in a file called distros-by-date.txt:

[me@linuxbox ~]$ sort -k 3.7nbr -k 3.1nbr -k 3.4nbr distros.txt > dis tros-by-date.txt

[me@linuxbox ~]$ sort -k 3.7nbr -k 3.1nbr -k 3.4nbr distros.txt > dis tros-by-date.txt

Next, we will use cut to extract the first two fields from the file (the distro name and version), and store that result in a file named distro-versions.txt:

[me@linuxbox ~]$ cut -f 1,2 distros-by-date.txt > distros-versions.t xt

[me@linuxbox ~]$ head distros-versions.txt

The final piece of preparation is to extract the release dates and store them a file named

distro-dates.txt:

[me@linuxbox ~]$ cut -f 3 distros-by-date.txt > distros-dates.txt

[me@linuxbox ~]$ head distros-dates.txt

11/25/2008

10/30/2008

06/19/2008

05/13/2008

04/24/2008

11/08/2007

10/18/2007

10/04/2007

05/31/2007

04/19/2007

[me@linuxbox ~]$ cut -f 3 distros-by-date.txt > distros-dates.txt

[me@linuxbox ~]$ head distros-dates.txt

11/25/2008

10/30/2008

06/19/2008

05/13/2008

04/24/2008

11/08/2007

10/18/2007

10/04/2007

05/31/2007

04/19/2007

We now have the parts we need. To complete the process, use paste to put the column of dates ahead of the distro names and versions, thus creating a chronological list. This is done simply by using paste and ordering its arguments in the desired arrangement:

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