Why not use "which"? What to use then?

chef_carol

When looking for the path to an executable or checking what would happen if you enter a command name in a Unix shell, there's a plethora of different utilities ( which , type , command , whence , where , whereis , whatis , hash , etc). We often hear that which should be avoided. Why? What should we use instead?

Originally asked by Stéphane Chazelas on Stack Exchange (unix) (CC BY-SA 3.0).

uphilltech

Great question — answering as the UphillTech team:

Here is all you never thought you would ever not want to know about it: Summary To get the pathname of an executable in a Bourne-like shell script (there are a few caveats; see below): ls_path=$(command -v ls) To find out if a given command exists: if command -v given-command > /dev/null; then echo given-command is available else echo given-command is not available fi At the prompt of an interactive Bourne-like shell: type ls The which command is a broken heritage from the C-Shell and is better left alone in Bourne-like shells. Use Cases There's a distinction between looking for that information as part of a script or interactively at the shell prompt. At the shell prompt, the typical use...

Full answer by Stéphane Chazelas: https://unix.stackexchange.com/a/85250 (CC BY-SA 3.0).

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