Linux commands: sort

Oct 3, 2020

Learn how the Linux sort command orders the lines of a file or piped input, with -r to reverse, -n for numeric order, and -u to drop duplicate lines.

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Suppose you have a text file which contains the names of dogs:

Terminal showing dogs.txt file with unsorted list of dog names: Roger, Syd, Vanille, Luna, Ivica, Tina

This list is unordered.

The sort command helps us sorting them by name:

Terminal showing sort dogs.txt command with output alphabetically sorted: Ivica, Luna, Roger, Syd, Tina, Vanille

Use the r option to reverse the order:

Terminal showing sort -r dogs.txt command with output in reverse alphabetical order: Vanille, Tina, Syd, Roger, Luna, Ivica

Sorting by default is case sensitive, and alphabetic. Use the --ignore-case option to sort case insensitive, and the -n option to sort using a numeric order.

If the file contains duplicate lines:

Nano text editor showing dogs.txt file with duplicate entries: Roger, Syd, Vanille, Luna, Ivica, Tina, Roger, Syd

You can use the -u option to remove them:

Terminal showing sort -u dogs.txt command with duplicates removed: Ivica, Luna, Roger, Syd, Tina, Vanille

sort does not just works on files, as many UNIX commands it also works with pipes, so you can use on the output of another command, for example you can order the files returned by ls with:

ls | sort

sort is very powerful and has lots more options, which you can explore calling man sort.

Terminal showing man sort manual page with command description, synopsis, and various options like -c, -m, -o, -S, -T, -u

The sort command works on Linux, macOS, WSL, and anywhere you have a UNIX environment

Tagged: CLI · All topics

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