Ubuntu man page ambiguity

Question

There are certain C functions whose names are ambiguous with the Ubuntu commands eg: getopt. How do I view the man page of these functions? No doubt it is easily available on the internet but I am keen to not leave the terminal as far as possible.

Answer 1

Use the format man [section] name (e.g. man 3 getopt) where section can be one of the followings:

   1      User Commands
   2      System Calls
   3      C Library Functions
   4      Devices and Special Files
   5      File Formats and Conventions
   6      Games et. Al.
   7      Miscellanea
   8      System Administration tools and Deamons

Consult man man for more information.

Answer 2

man 3 getopt shows the manpages for C getopt.

see man man

Answer 3

man 3 getopt gives c function information.
where as man 1 getopt or man getopt gives command information.

Pages are traditionally referred to using the notation "name(section)": for example, ftp(1). The same page name may appear in more than one section of the manual, as when the names of system calls, user commands, or macro packages coincide.

Answer 4

man -wa getopt gives you the list of manual pages for getopt: in my system, it is:

/usr/share/man/man1/getopt.1.bz2
/usr/share/man/man3/getopt.3.bz2
/usr/share/man/man3p/getopt.3p.bz2

Or, alternatively, man -f getopt:

getopt               (1)  - parse command options (enhanced)
getopt               (3)  - Parse command-line options
getopt []            (1)  - parse command options (enhanced)
getopt []            (3)  - Parse command-line options
getopt []            (3p)  - command option parsing

You can then select the right manual page by using the number that is in the filename (in the first output) or in between parenthesis (in the second output): for example, man 1 getopt or man 3 getopt.

Answer 5

$ man 3 getopt where 3 is section.

$ man man

As Sections. states:

The manual is generally split into eight numbered sections, organized as follows (on BSD, Unix and Linux):

Section     Description
 1.         General commands
 2.         System calls
 3.         Library functions, covering in particular the C standard library
 4.         Special files (usually devices, those found in /dev) and drivers
 5.         File formats and conventions
 6.         Games and screensavers
 7.         Miscellanea
 8.         System administration commands and daemons

Unix System V uses a similar numbering scheme, except in a different order:

Section     Description
 1.         General commands
 1M.        System administration commands and daemons
 2.         System calls
 3.         C library functions
 4.         File formats and conventions
 5.         Miscellanea
 6.         Games and screensavers
 7.         Special files (usually devices, those found in /dev) and drivers