How to Diagnose and Correct Search Path Problems

1. Display the current search path to verify that the directory for the command is not in your path or that it isn't misspelled.

   $ echo $PATH

2. Check the following:

   • Is the search path correct?

   • Is the search path listed before other search paths where another version of the command is found?

   • Is the command in one of the search paths?

   If the path needs correction, go to step 3. Otherwise, go to step 4.

3. Add the path to the appropriate file, as shown in this table.

   Shell	File	Syntax	Notes
   Bourne and Korn	$HOME/.profile	$ PATH=$HOME/bin:/sbin:/usr/local /bin ... $ export PATH	A colon separates path names.
   C	$HOME/.cshrc or  $HOME/.login	hostname% set path=(~bin /sbin /usr/local/bin ...)	A blank space separates path names.

4. Activate the new path as follows:

   Shell	File Where Path Is Located	Use this Command to Activate The Path
   Bourne and Korn	.profile	$ . ./.profile
   C	.cshrc	hostname% source .cshrc
   	.login	hostname% source .login

5. Verify the new path.

   $ 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.