which (1) - Linux Manuals
which: locate a command
which - locate a command
SYNOPSISwhich [-a] filename ...
DESCRIPTIONwhich returns the pathnames of the files (or links) which would be executed in the current environment, had its arguments been given as commands in a strictly POSIX-conformant shell. It does this by searching the PATH for executable files matching the names of the arguments. It does not canonicalize path names.
- print all matching pathnames of each argument
- if all specified commands are found and executable
- if one or more specified commands is nonexistent or not executable
if an invalid option is specified