一天一条Linux指令-man

用途说明

man命令是个常用的命令，如果你稍微熟悉Unix/Linux系统的话，它用来显示在线手册页，是获取命令、函数、配置文件等的帮助信息的重要手段，另外一个手段是info命令。manpage就是手册页，它有一定的编写格式，Linux系统在文档方面是做得相当不错的，这给我们使用Linux提供了方便。shell内置命令的手册页，显示的是bash全部内置命令的手册页，可以采用help命令来获取内置命令的帮助信息。

 

常用参数

格式：man <cmd>

显示<cmd>命令的手册页。默认情况下，man命令使用less作为显示文档的命令。

 

手册页的操作指令：

按q退出，这个最重要，因为Ctrl+C都没法退出来

按下箭头可以往后一行

按回车或者上箭头可以往前一行

按End键可以翻到最后一页

按Home键可以翻到第一页

按空白键或者PgDn键可以往后翻一页

按PgUp键可以往前翻一页

输入/keyword回车可以搜索keyword

输入?keyword回车可以往前搜索keyword

按n可以往前或往后搜索下一个

 

格式：man -k <cmd>

格式：apropos <cmd>

显示与<cmd>有关的手册页列表。

 

格式：man 1 <cmd>

显示<cmd>命令的手册页。

 

格式：man 2 <syscall>

显示系统调用<syscall>的手册页。

 

格式：man <section> <name>

显示<name>指定章节<section>的手册页，其中<section>包括

1、Standard commands （标准命令）

2、System calls （系统调用）

3、Library functions （库函数）

4、Special devices （设备说明）

5、File formats （文件格式）

6、Games and toys （游戏和娱乐）

7、Miscellaneous （杂项）

8、Administrative Commands （管理员命令）

 

使用示例

示例一 显示man的手册页

[root@jfht ~]# man man 

man(1)                                                                  man(1)

NAME

       man - format and display the on-line manual pages

SYNOPSIS

       man  [-acdfFhkKtwW] [--path] [-m system] [-p string] [-C config_file] [-M pathlist] [-P pager] [-B browser] [-H

       htmlpager] [-S section_list] [section] name ...

DESCRIPTION

       man formats and displays the on-line manual pages.  If you specify section, man only looks in that  section  of

       the  manual.  name is normally the name of the manual page, which is typically the name of a command, function,

       or fil
4000
e.  However, if name contains a slash (/) then man interprets it as a file specification, so that you can

       do man ./foo.5 or even man /cd/foo/bar.1.gz.

       See below for a description of where man looks for the manual page files.

OPTIONS

       -C  config_file

              Specify the configuration file to use; the default is /etc/man.config.  (See man.config(5).)

       -M  path

              Specify  the  list  of  directories  to search for man pages.  Separate the directories with colons.  An

              empty list is the same as not specifying -M at all.  See SEARCH PATH FOR MANUAL PAGES.

       -P  pager

              Specify which pager to use.  This option overrides the MANPAGER  environment  variable,  which  in  turn

              overrides the PAGER variable.  By default, man uses /usr/bin/less -is.

       -B     Specify  which browser to use on HTML files.  This option overrides the BROWSER environment variable. By

              default, man uses /usr/bin/less-is,

       -H     Specify a command that renders HTML files as text.  This  option  overrides  the  HTMLPAGER  environment

              variable. By default, man uses /bin/cat,

       -S  section_list

              List is a colon separated list of manual sections to search.  This option overrides the MANSECT environ-

              ment variable.

       -a     By default, man will exit after displaying the first manual page it finds.  Using this option forces man

:q 

[root@jfht ~]#

 

示例二 显示C函数printf的手册页

[root@jfht ~]# man printf 

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.

       --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

       \NNN   character with octal value NNN (1 to 3 digits)

       \\     backslash

       \a     alert (BEL)

       \b     backspace

       \c     produce no further output

       \f     form feed

       \n     new line

       \r     carriage return

       \t     horizontal tab

       \v     vertical tab

:q

注：上面显示的是命令printf的手册页，但不是C函数printf的手册页。 

[root@jfht ~]# man 3 printf 

PRINTF(3)                  Linux Programmer’s Manual                 PRINTF(3)

NAME

       printf, fprintf, sprintf, snprintf, vprintf, vfprintf, vsprintf, vsnprintf - formatted output conversion

SYNOPSIS

       #include <stdio.h>

       int printf(const char *format, ...);

       int fprintf(FILE *stream, const char *format, ...);

       int sprintf(char *str, const char *format, ...);

       int snprintf(char *str, size_t size, const char *format, ...);

       #include <stdarg.h>

       int vprintf(const char *format, va_list ap);

       int vfprintf(FILE *stream, const char *format, va_list ap);

       int vsprintf(char *str, const char *format, va_list ap);

       int vsnprintf(char *str, size_t size, const char *format, va_list ap);

DESCRIPTION

       The  functions  in  the  printf() family produce output according to a format as described below. The functions

       printf() and vprintf() write output to stdout, the standard output stream; fprintf() and vfprintf() write  out-

       put to the given output stream; sprintf(), snprintf(), vsprintf() and vsnprintf() write to the character string

       str.

       The functions vprintf(),  vfprintf(),  vsprintf(),  vsnprintf()  are  equivalent  to  the  functions  printf(),

       fprintf(),  sprintf(),  snprintf(), respectively, except that they are called with a va_list instead of a vari-

       able number of arguments. These functions do not call the va_end macro. Consequently, the value of ap is  unde-

       fined after the call. The application should call va_end(ap) itself afterwards.

       These eight functions write the output under the control of a format string that specifies how subsequent argu-

       ments (or arguments accessed via the variable-length argument facilities of stdarg(3)) are converted  for  out-

       put.

   Return value

       Upon  successful  return,  these  functions return the number of characters printed (not including the trailing

       ’\0’ used to end output to strings).  The functions snprintf() and vsnprintf() do  not  write  more  than  size

       bytes  (including  the  trailing ’\0’).  If the output was truncated due to this limit then the return value is

       the number of characters (not including the trailing ’\0’) which would have been written to the final string if

[root@jfht ~]#

 

示例三 查找与kill有关的手册页

[root@jfht ~]# man -k kill

kill                 (1)  - terminate a process

kill                 (1p)  - terminate or signal processes

kill                 (2)  - send signal to a process

kill                 (3p)  - send a signal to a process or a group of processes

kill [builtins]      (1)  - bash built-in commands, see bash(1)

killall              (1)  - kill processes by name

killchar [curs_termattrs] (3x)  - curses environment query routines

killpg               (2)  - send signal to a process group

killpg               (3)  - send signal to all members of a process group

killpg               (3p)  - send a signal to a process group

killwchar [curs_termattrs] (3x)  - curses environment query routines

mysql_waitpid        (1)  - kill process and wait for its termination

mysql_zap            (1)  - kill processes that match a pattern

pkill [pgrep]        (1)  - look up or signal processes based on name and other attributes

pthread_kill         (3p)  - send a signal to a thread

skill                (1)  - send a signal or report process status

snice [skill]        (1)  - send a signal or report process status

tgkill               (2)  - Send signal sig to one specific thread, tgid

tkill                (2)  - send a signal to a single process

xkill                (1x)  - kill a client by its X resource

yes                  (1)  - output a string repeatedly until killed

[root@jfht ~]#