Emacs provides a nice manual viewer which could be used for obtaining documentation for C syscalls (at point with Man-default-man-entry. However, it always starts searching manuals from section 0. How can I configure man viewer so that it will start from section 2, then 3, and then 0?
man 1 perror doesn't make much sense
Emacs defers to the external man command's section choice in the absence of a specific section value.
You can edit the SECTION definition in /etc/manpath.config to modify the default priority order.
You can override that value with the MANSECT environment variable.
Finally, you can override all of that by passing a --sections=list option to the command itself.
(See man man for details.)
For the final approach, you can set the Man-switches variable in Emacs. e.g.:
(setq Man-switches "--sections=2,3,1,n,l,8,3posix,3pm,3perl,5,4,9,6,7")
Note that Emacs re-uses man page buffers where possible, so kill the existing buffers before testing this.
