The man page(manual page) is a documentation manual of different commands available in unix or unix like operating systems.
To check manual entry for any command use,
man command_name
In this article, I'm using command
printf for my demonstrations.
man printf
Output:
PRINTF(1) User Commands PRINTF(1)
NAME
printf - format and print data
SYNOPSIS
printf FORMAT [ARGUMENT]...
printf OPTION
DESCRIPTION
Print ARGUMENT(s) according to FORMAT, or execute according to OPTION:
--help display this help and exit
--version
output version information and exit
FORMAT controls the output as in C printf. Interpreted sequences are:
\" double quote
\\ backslash
\a alert (BEL)
...
If you observe carefully the above output, the top line contains
PRINTF(1), the 1 in braces is type of man entry. The number basically corresponds to section of the manual page.
The manual is split into 8 sections, which are(on Research Unix, BSD, macOS 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 |
Let's continue with the example of
PRINTF, for all entries, try below command:
man -a printf
Output:
PRINTF(1) User Commands PRINTF(1)
NAME
printf - format and print data
SYNOPSIS
printf FORMAT [ARGUMENT]...
printf OPTION
DESCRIPTION
Print ARGUMENT(s) according to FORMAT, or execute according to OPTION:
--help display this help and exit
--version
output version information and exit
FORMAT controls the output as in C printf. Interpreted sequences are:
\" double quote
...
When you type q to exit, the below text appears on terminal, press enter to continue to see another entry of printf
--Man-- next: printf(3) [ view (return) | skip (Ctrl-D) | quit (Ctrl-C) ]
Output continued:
PRINTF(3) Linux Programmer's Manual PRINTF(3)
NAME
printf, fprintf, dprintf, sprintf, snprintf, vprintf, vfprintf, vdprintf, vsprintf, vsnprintf - formatted output conversion
SYNOPSIS
#include
int printf(const char *format, ...);
int fprintf(FILE *stream, const char *format, ...);
int dprintf(int fd, const char *format, ...);
int sprintf(char *str, const char *format, ...);
int snprintf(char *str, size_t size, const char *format, ...);
#include
int vprintf(const char *format, va_list ap);
int vfprintf(FILE *stream, const char *format, va_list ap);
...
To check specific entry to printf or any other command, you can directly provide section number, for example:
man 3 printf
Output: It will show man entry corresponding to section 3 of printf.
Some useful man command options:
1)
-f option
man -f printf
Output:
It will display the short description of printf, if available similar to
printf - format and print data
2)
-k option
man -k printf
Output:
It will search the short manual page descriptions for keywords and display any matches.
printf (1) - format and print data
printf (1p) - write formatted output
printf (3) - formatted output conversion
printf (3p) - print formatted output
printf [builtins] (1) - bash built-in commands, see bash(1)
3)
-w option
It prints the location of cat files that will be displayed rather than the content of files.
man -w printf
Output:
/usr/share/man/man1/printf.1.gz
4)
-K option
It will search for text in all manual pages.
man -K printf
Output:
It will display all man entries containing printf keyword, and after each entry is display you can press enter for viewing second entry.
For example:
The below is prompted to view second entry for printf, you can either skip it or quit to terminate the command.
--Man-- next: git-show(1) [ view (return) | skip (Ctrl-D) | quit (Ctrl-C) ]
References :
1)
wiki/Man_page
2) Man entry of man
