[SOLVED] man and the paths where man looks for manuals.

stf92 · 06-09-2010, 04:09 PM

Before the whole thing began, echo $MANPATH output four elements (paths): path1,...,path4. I edited /etc/profile and removed the MANPATH statement, which contains path1 and path2. I rebooted, and I see echo $MANPATH outputs only path3 and path4. OK. But running man mplayer, I get the manual! This seems to contradict man's manual, which says that /usr/lib/man.conf won't be read if MANPATH is not empty (or unset). (Only in man.conf does the path of the mplayer manual appears.) Anybody explains me (maybe I'd say teach me)?

bathory · 06-09-2010, 05:35 PM

Doh, you're right. According to the man manpage:

Quote:

If MANPATH is set, man uses it as the path to search for manual page files. It overrides the configuration file and the automatic search path, but is overridden by the -M invocation option.

it shouldn't happen.
I guess this is because the new MANPATH starts with a ":" in case you comment it out from /etc/profile, e.g in my box (running Slack64), it's

Code:

:/usr/lib64/java/man:/usr/lib64/java/man:/usr/share/texmf/man

Running

Code:

man -w

it gives:

Quote:

/usr/local/share/man:/usr/share/man:/usr/man:/usr/lib64/java/man:/usr/share/texmf/man:/usr/local/man:/usr/X11R6/man

so apparently it uses man.conf.
You should also read the "SEARCH PATH FOR MANUAL PAGES" part of the man manpage.

BTW you don't need to reboot after editing /etc/profile. You can logout/login again, or run

Code:

source /etc/profile

to use the new settings.

Regards

stf92 · 06-09-2010, 08:31 PM

Identical thing happens in my box:
# echo $MANPATH
:/usr/lib/java/man:/usr/share/texmf/man
# man -w
/usr/local/share/man:/usr/man:/usr/lib/java/man:/usr/share/texmf/man:/usr/local/man:/usr/X11R6/man

It seems to be true that "man uses a SOPHISTICATED method of finding manual page files" (man manpage, SEARCH PATH FOR MANUAL PAGES). Well, I think that removal of the MANPATH statement from /etc/profile, will not modify the system behavior except in allowing me quick access to the mplayer manpage. All the more so that the two elements contained in the MANPATH statement in /etc/profile are already contained in /usr/lib/man.conf.

Thanks, bathory, and I expect soon to be able to close this thread before it grows longer than it is worth.

stf92 · 07-02-2010, 06:52 AM

SLACKWARE 12.0 distro:

Then, this is the current state of the system:

Code:

root@darkstar:~# locate mplayer.1
/usr/local/share/man/man1/mplayer.1

From /etc/profile (the line was commented by me):
#export MANPATH=/usr/local/man:/usr/man

From /usr/lib/man.conf
MANPATH /usr/man
MANPATH /usr/share/man
MANPATH /usr/local/man
MANPATH /usr/local/share/man
MANPATH /usr/X11R6/man
#
MANPATH_MAP     /bin                    /usr/share/man
MANPATH_MAP     /sbin                   /usr/share/man
MANPATH_MAP     /usr/bin                /usr/share/man
MANPATH_MAP     /usr/sbin               /usr/share/man
MANPATH_MAP     /usr/local/bin          /usr/local/share/man
MANPATH_MAP     /usr/local/sbin         /usr/local/share/man
MANPATH_MAP     /usr/X11R6/bin          /usr/X11R6/man
MANPATH_MAP     /usr/bin/X11            /usr/X11R6/man
MANPATH_MAP     /usr/bin/mh             /usr/share/man
#
Current path used by man:
root@darkstar:/etc# man -w
/usr/local/share/man:/usr/share/man:/usr/man:/usr/lib/java/man:/usr/share/texmf/man:/usr/local/man:/usr/X11R6/man
Current MANPATH enviroment variable contents:
root@darkstar:/etc# echo $MANPATH
:/usr/lib/java/man:/usr/share/texmf/man
Notice the ':' starting the line, as pointed out by bathory.

The mplayer installer did this:
Allocated its man file in /usr/local/share/man/man1/mplayer.1. Then it modified /etc/profile, adding the line
MANPATH /usr/local/share/man/man1

I think, if 'man mplayer' did not output the manual it was due to strange behaviour on the part of man and its path searching mechanism, and the mplayer installer is not to be blamed. These are notes to myself rather than any other thing. Anyways,

The solution:
I commented out the line 'export MANPATH=/usr/local/man:/usr/man'

Now 'man mplayer' outputs the manual. Of course, this is only one of several possible fixes and could not be done without the generous help of LQers. Regards.