Check If a Command Exists from Shell ScriptWed Nov 23, 2016
I often need to check if a particular executable is present in the
PATH before I can proceed with what I am doing in a shell script. Also I need to work with both
bash scripts. Below presents the different solutions that have worked for these shell scripts for me.
Bash Shell #
The below solution using
hash was with the help of this SO solution.
if ! hash some_exec 2>/dev/null then echo "'some_exec' was not found in PATH" fi
Here is the TL;DR from the above SO solution:
Where bash is your shell/hashbang, consistently use
hash(for commands) or
type(to consider built-ins & keywords). When writing a POSIX script, use
Tcsh Shell #
Looks like the
tcsh shell does not have the same
hash command as the
bash shell. But the below solution using
where which I found with the help of this SO solution works fine.
if ( `where some_exec` == "" ) then echo "'some_exec' was not found in PATH" endif