The command is not available on the system.
The command directory is not in the search path.
To fix a search path problem, you need to know the pathname of the directory where the command is stored.
If the wrong version of the command is found, a directory that has a command of the same name is in the search path. In this case, the proper directory may be later in the search path or may not be present at all.
You can display your current search path by using the echo $PATH command. For example:
$ echo $PATH /home/kryten/bin:/sbin:/usr/sbin:/usr/bin:/usr/dt:/usr/dist/exe
Use the which command to determine whether you are running the wrong version of the command. For example:
$ which acroread /usr/doctools/bin/acroread
Note - The which command looks in the .cshrc file for path information. The which command might give misleading results if you execute it from the Bourne or Korn shell and you have a .cshrc file than contains aliases for the which command. To ensure accurate results, use the which command in a C shell, or, in the Korn shell, use the whence command.
$ echo $PATH
Is the search path correct?
Is the command in one of the search paths?
If the path needs correction, go to step 3. Otherwise, go to step 4.
$ which command
Example 19-1 Diagnosing and Correcting Search Path Problems
This example shows that the mytool executable is not in any of the directories in the search path using the which command.
venus% mytool mytool: Command not found venus% which mytool no mytool in /sbin /usr/sbin /usr/bin /etc /home/ignatz/bin . venus% echo $PATH /sbin /usr/sbin /usr/bin /etc /home/ignatz/bin venus% vi ~/.cshrc (Add appropriate command directory to the search path) venus% source .cshrc venus% mytool
If you cannot find a command, look at the man page for its directory path. For example, if you cannot find the lpsched command (the lp printer daemon), the lpsched(1M) man page tells you the path is /usr/lib/lp/lpsched.