WYNTK: UNIX System Admininistrator

If a program isn’t working properly, you could be running a different version of it.

When programs don’t work the way they’re supposed to, one thing to investigate is that you’re running the correct version of the program.

For example, when I run ls to list files, I’m used to seeing the files ordered in multiple columns. So I was surprised one day when I saw that all my files were being listed in a single column, but none of the filenames were long enough to require a single-column listing:

% ls
Mail
discards
discards.backup
finger.mail
mysteries
notes.lmui
schedule

What was happening was that I recently changed my search path so /usr/5bin appeared before /usr/bin. Using the which command , I learned that the version of ls I was running was /usr/5bin/ls.

% which ls
/usr/5bin/ls

What I’m used to is /usr/bin/ls.

% /usr/bin/ls
Mail        discards.backup  mysteries       schedule
discards    finger.mail      notes

MANPATH variable

The MANPATH environment variable should be set to the location of manpages on your system.

The man and apropos commands usually just look in /usr/man for manpages. If you have some manpages installed elsewhere on your system, you should use the MANPATH environment variable to set a more elaborate search path for man and apropos. For example, if you also have manpages in /usr/local/man and /proj/local/man, you might set MANPATH in your startup script as follows. If you use csh or tcsh:

setenv MANPATH /usr/man:/
usr/local/man:/proj/local/man

If you use sh, ksh or bash:

MANPATH=/usr/man:/usr/ ...