- Find Out About Commands with man
- Search for a Command Based on What It Does
- Quickly Find Out What a Command Does Based on Its Name
- Rebuild man's Database of Commands
- Read a Command's Specific Man Page
- Print Man Pages
- Learn About Commands with info
- Navigate Within info
- Locate the Paths for a Command's Executable, Source Files, and Man Pages
- Read Descriptions of Commands
- Find a Command Based on What It Does
- Find Out Which Version of a Command Will Run
Find Out Which Version of a Command Will Run
Think back to the whereis command and what happened when you ran it against KWord using the -b option, for show binaries only.
$ whereis -b kword kword: /usr/bin/kword /usr/bin/X11/kword
The executable for KWord is in two places. But which one will run first? You can tell that by running the which command.
$ which kword /usr/bin/kword
The which command tells you which version of a command will run if you just type its name. In other words, if you type in kword and then press Enter, your shell executes the one found inside /usr/bin. If you want to run the version found in /usr/bin/X11, you have to change directories using the cd command and then enter ./kword , or use the absolute path for the command and type out /usr/bin/X11/kword .
The which command is also a speedy way to tell if a command is on your system. If the command is on your system and in your PATH, you'll be told where to find it; if the command doesn't exist, you're back on the command line with nothing.
$ which arglebargle $
If you want to find all the locations of a command (just like you would if you used whereis -b), try the -a (for all) option.
$ which -a kword /usr/bin/kword /usr/bin/X11/kword