Process Substitution in the Shell


Imad Dabbura


January 19, 2023

<(CMD) is called process substitution, which will execute CMD and place the output in a temporary file and substitute the <() with that file’s name. This comes in handy because some commands such as diff expect values to be passed as files instead of standard input. For example, diff <(ls dir1) <(ls dir2) will show differences between files in a & b directories.