The “which” command will reveal the absolute path of the executable file called when issuing a command.
The linux which command is useful in determining if you may need to add a path to your $PATH variable in your ~/.profile file in order to be able to issue the command.
promt$>which php /usr/bin/php promt$>which wget /usr/bin/wget
The above example echos out the path. It is possible that there are more than one pathh to the executable file in the $PATH variable.
If you want to echo out ALL the paths in the $PATH variable, then use the -a flag (option)