How to run cut command in vim and change the current file

Question

How do I run cut command inside vim and change the contents of the file being edited. I tried following but did not work.

:r ! cut -d ":" -f 1 % > %

and some other variants of it. I want to edit the currently open file using cut and want to know how to accomplish this using only cut inside vim itself.

Answer 1

The reason it doesn't work is because the redirection operator > makes the shell truncate the file before the command is executed, so cut sees an empty input file.

You could instead use :w to pipe the contents of the current buffer to cut via stdin, then redirect to the file:

:w ! cut -d ":" -f 1 > %

This has a side effect of Vim prompting you to reload the file. You can use alternatives that don't exhibit this behaviour, such as a substitution:

:%s/:.*//

or a filter command:

:% ! cut -d ":" -f 1