linux 在线帮助

1.whatis  简单介绍命令的作用

  1.1 使用方法

[root@test6 ~]# whatis whatis
whatis               (1)  - search the whatis database for complete words
[root@test6 ~]# whatis ls
ls                   (1)  //man手册中页数  - list directory contents
ls                   (1p)                 - list directory contents

  1.2 如果没安装可以使用 makewhatis 安装

2. --help  简单介绍最常用的参数

  2.1 使用方法

[root@test6 ~]# ls --help
用法:ls [选项]... [文件]...
List information about the FILEs (the current directory by default).
Sort entries alphabetically if none of -cftuvSUX nor --sort.

长选项必须用的参数在使用短选项时也是必须的。
  -a, --all                  不隐藏任何以 . 字符开始的项目
  -A, --almost-all           列出除了 . 及 .. 以外的任何项目
      --author               和 -l 同时使用时列出每个文件的作者
  -b, --escape               以八进制溢出序列表示不可打印的字符
      --block-size=大小      块以指定<大小>的字节为单位
  -B, --ignore-backups       不列出任何以 ~ 字符结束的项目
  -c                         配合 -lt:根据 ctime 排序及显示 ctime (文件
                               状态最后更改的时间)
                               配合 -l:显示 ctime 但根据名称排序
                               否则:根据 ctime 排序
  -C                         list entries by columns
      --color[=WHEN]         control whether color is used to distinguish file
                               types.  WHEN may be `never', `always', or `auto'
  -d, --directory            list directory entries instead of contents,
                               and do not dereference symbolic links
  -D, --dired                generate output designed for Emacs' dired mode
  -f                         do not sort, enable -aU, disable -lst
  -F, --classify             append indicator (one of */=>@|) to entries
      --file-type            likewise, except do not append `*'
      --format=WORD          across -x, commas -m, horizontal -x, long -l,
                               single-column -1, verbose -l, vertical -C
      --full-time            like -l --time-style=full-iso
  -g                         like -l, but do not list owner
  -G, --no-group             like -l, but do not list group
  -h, --human-readable       with -l, print sizes in human readable format
                               (e.g., 1K 234M 2G)
      --si                   likewise, but use powers of 1000 not 1024
  -H, --dereference-command-line
                             follow symbolic links listed on the command line
      --dereference-command-line-symlink-to-dir
                             follow each command line symbolic link
                             that points to a directory
      --hide=PATTERN         do not list implied entries matching shell PATTERN
                               (overridden by -a or -A)
      --indicator-style=WORD append indicator with style WORD to entry names:
                               none (default), slash (-p),
                               file-type (--file-type), classify (-F)
  -i, --inode                with -l, print the index number of each file
  -I, --ignore=PATTERN       do not list implied entries matching shell PATTERN
  -k                         like --block-size=1K
  -l                         使用较长格式列出信息
  -L, --dereference          当显示符号链接的文件信息时,显示符号链接所指示
                               的对象而并非符号链接本身的信息
  -m                         所有项目以逗号分隔,并填满整行行宽
  -n, --numeric-uid-gid      like -l, but list numeric user and group IDs
  -N, --literal              print raw entry names (don't treat e.g. control
                               characters specially)
  -o                         like -l, but do not list group information
  -p, --indicator-style=slash
                             append / indicator to directories
  -q, --hide-control-chars   以 ? 字符代替无法打印的字符
      --show-control-chars   直接显示无法打印的字符 (这是默认方式,除非调用
                               的程序名称是“ls”而且是在终端机画面输出结果)
  -Q, --quote-name           将项目名称括上双引号
      --quoting-style=方式   使用指定的 quoting <方式>显示项目的名称:
                               literal、locale、shell、shell-always、c、escape
  -r, --reverse              逆序排序
  -R, --recursive            递归列出所有子目录
  -s, --size                 和 -l 同时使用时以块为单位列出每个文件的大小
  -S                         根据文件大小排序
      --sort=WORD            以下是可选用的 WORD 和它们代表的相应选项:
                               extension -X       status   -c
                               none      -U       time     -t
                               size      -S       atime    -u
                               time      -t       access   -u
                               version   -v       use      -u
      --time=WORD            和 -l 同时使用时显示 WORD 所代表的时间而非修改时
                             间:atime、access、use、ctime 或 status;加上
                             --sort=time 选项时会以指定时间作为排序关键字
      --time-style=STYLE     和 -l 同时使用时根据 STYLE 代表的格式显示时间:
                               full-iso、iso、locale、posix-iso、+FORMAT。
                             FORMAT 即是“date”所用的时间格式;如果 FORMAT
                             是 FORMAT1<新行>FORMAT2,FORMAT1 适用于较旧
                             的文件而 FORMAT2 适用于较新的文件;如果 STYLE
                             以“posix-”开头,则 STYLE 仅在 POSIX 语系之外
                             生效。
  -t                         根据修改时间排序
  -T, --tabsize=宽度         自行指定 tab 的<宽度>,而非 8 个字符
  -u                         with -lt: sort by, and show, access time
                               with -l: show access time and sort by name
                               otherwise: sort by access time
  -U                         do not sort; list entries in directory order.
                             In combination with one_per_line format `-1',
                             it will show files immediately and it has no
                             memory limitations.
  -v                         sort by version
  -w, --width=COLS           自行指定萤幕宽度而不使用目前的数值
  -x                         逐行列出项目而不是逐栏列出
  -X                         根据扩展名排序
  -1                         每行只列出一个文件

SELinux options:

      --lcontext             Display security context.   Enable -l. Lines
                               will probably be too wide for most displays.
      -Z, --context          Display security context so it fits on most
                               displays.  Displays only mode, user, group,
                               security context and file name.
      --scontext             Display only security context and file name.


      --help     显示此帮助信息并退出
      --version  输出版本信息并退出

[大小]可以是以下的单位(单位前可加上整数):
kB 1000,K 1024,MB 1000000,M 1048576,还有 G、T、P、E、Z、Y。

By default, color is not used to distinguish types of files.  That is
equivalent to using --color=none.  Using the --color option without the
optional WHEN argument is equivalent to using --color=always.  With
--color=auto, color codes are output only if standard output is connected
to a terminal (tty).  The environment variable LS_COLORS can influence the
colors, and can be set easily by the dircolors command.

Exit status is 0 if OK, 1 if minor problems, 2 if serious trouble.

请向 <bug-coreutils@gnu.org> 报告错误。

3. man  手册 manual pages

  3.1常用使用方法

    3.1.1 man 命令  也可在man 后边加数字,代表查看具体的哪一页 如:man 5 passwd 查看passwd man 手册的第五页

[root@test6 ~]# man ls
Cannot open the message catalog "man" for locale "zh_CN.UTF-8"
(NLSPATH="<none>")

Formatting page, please wait...
LS(1)                            User Commands                           LS(1)

NAME
       ls - list directory contents

SYNOPSIS
       ls [OPTION]... [FILE]...

DESCRIPTION
       List  information  about  the FILEs (the current directory by default).
       Sort entries alphabetically if none of -cftuvSUX nor --sort.

       Mandatory arguments to long options are  mandatory  for  short  options
       too.

       -a, --all
              do not ignore entries starting with .

       -A, --almost-all
              do not list implied . and ..

       --author
              with -l, print the author of each file

       -b, --escape
              print octal escapes for nongraphic characters

       --block-size=SIZE
              use SIZE-byte blocks

       -B, --ignore-backups
              do not list implied entries ending with ~

       -c     with -lt: sort by, and show, ctime (time of last modification of
              file status information) with -l: show ctime and  sort  by  name
              otherwise: sort by ctime

       -C     list entries by columns

       --color[=WHEN]
              control  whether  color is used to distinguish file types.  WHEN
              may be ‘never’, ‘always’, or ‘auto’

       -d, --directory
              list directory entries instead of contents, and do not  derefer-
              ence symbolic links

       -D, --dired
              generate output designed for Emacs’ dired mode

       -f     do not sort, enable -aU, disable -lst

       -F, --classify
              append indicator (one of */=>@|) to entries

       --file-type
              likewise, except do not append ‘*--format=WORD
              across  -x, commas -m, horizontal -x, long -l, single-column -1,
              verbose -l, vertical -C

       --full-time
              like -l --time-style=full-iso

       -g     like -l, but do not list owner

       -G, --no-group
              like -l, but do not list group

       -h, --human-readable
              with -l, print sizes in human readable format (e.g., 1K 234M 2G)

       --si   likewise, but use powers of 1000 not 1024

       -H, --dereference-command-line
              follow symbolic links listed on the command line

       --dereference-command-line-symlink-to-dir
              follow  each  command line symbolic link that points to a direc-
              tory

       --hide=PATTERN
              do not list implied entries matching shell  PATTERN  (overridden
              by -a or -A)

       --indicator-style=WORD append indicator with style WORD to entry names:
              none  (default),  slash  (-p), file-type (--file-type), classify
              (-F)

       -i, --inode
              with -l, print the index number of each file

       -I, --ignore=PATTERN
              do not list implied entries matching shell PATTERN

       -k     like --block-size=1K

       -l     use a long listing format

       -L, --dereference
              when showing file information for a symbolic link, show informa-
              tion  for  the file the link references rather than for the link
              itself

       -m     fill width with a comma separated list of entries

       -n, --numeric-uid-gid
              like -l, but list numeric user and group IDs

       -N, --literal
              print raw entry names (don’t treat e.g. control characters  spe-
              cially)

       -o     like -l, but do not list group information

       -p, --indicator-style=slash
              append / indicator to directories

       -q, --hide-control-chars
              print ? instead of non graphic characters

       --show-control-chars
              show  non  graphic  characters  as-is (default unless program is
              ‘ls’ and output is a terminal)

       -Q, --quote-name
              enclose entry names in double quotes

       --quoting-style=WORD
              use quoting style WORD for entry names: literal, locale,  shell,
              shell-always, c, escape

       -r, --reverse
              reverse order while sorting

       -R, --recursive
              list subdirectories recursively

       -s, --size
              with -l, print size of each file, in blocks

       -S     sort by file size

       --sort=WORD
              extension  -X, none -U, size -S, time -t, version -v, status -c,
              time -t, atime -u, access -u, use -u

       --time=WORD
              with -l, show time as WORD instead of modification time:  atime,
              access,  use, ctime or status; use specified time as sort key if
              --sort=time

       --time-style=STYLE
              with -l, show times using style STYLE: full-iso, long-iso,  iso,
              locale,  +FORMAT.   FORMAT is interpreted like ‘date’; if FORMAT
              is FORMAT1<newline>FORMAT2, FORMAT1 applies to non-recent  files
              and FORMAT2 to recent files; if STYLE is prefixed with ‘posix-’,
              STYLE takes effect only outside the POSIX locale

       -t     sort by modification time

       -T, --tabsize=COLS
              assume tab stops at each COLS instead of 8

       -u     with -lt: sort by, and show, access time with  -l:  show  access
              time and sort by name otherwise: sort by access time

       -U     do  not  sort;  list entries in directory order.  In combination
              with one_per_line format ‘-1’, it will  show  files  immediately
              and it has no memory limitations.

       -v     sort by version

       -w, --width=COLS
              assume screen width instead of current value

       -x     list entries by lines instead of by columns

       -X     sort alphabetically by entry extension

       -1     list one file per line

       SELinux options:

       --lcontext
              Display  security  context.    Enable -l. Lines will probably be
              too wide for most displays.

       -Z, --context
              Display security context so it fits on most displays.   Displays
              only mode, user, group, security context and file name.

       --scontext
              Display only security context and file name.

       --help display this help and exit

       --version
              output version information and exit

       SIZE  may  be (or may be an integer optionally followed by) one of fol-
       lowing: kB 1000, K 1024, MB 1000*1000, M 1024*1024, and so on for G, T,
       P, E, Z, Y.

       By  default,  color is not used to distinguish types of files.  That is
       equivalent to using --color=none.  Using the --color option without the
       optional  WHEN  argument  is  equivalent to using --color=always.  With
       --color=auto, color codes are output only if standard  output  is  con-
       nected  to  a  terminal  (tty).  The environment variable LS_COLORS can
       influence the colors, and can be set easily by the dircolors command.

       Exit status is 0 if OK, 1 if minor problems, 2 if serious trouble.

AUTHOR
       Written by Richard Stallman and David MacKenzie.

REPORTING BUGS
       Report bugs to <bug-coreutils@gnu.org>.

COPYRIGHT
       Copyright © 2006 Free Software Foundation, Inc.
       This is free software.  You may redistribute copies  of  it  under  the
       terms       of       the      GNU      General      Public      License
       <http://www.gnu.org/licenses/gpl.html>.  There is NO WARRANTY,  to  the
       extent permitted by law.

SEE ALSO
       The  full  documentation  for ls is maintained as a Texinfo manual.  If
       the info and ls programs are properly installed at your site, the  com-
       mand

              info ls

       should give you access to the complete manual.

ls 5.97                          February 2010                           LS(1)
(END) 
       optional  WHEN  argument  is  equivalent to using --color=always.  With
       --color=auto, color codes are output only if standard  output  is  con-
       nected  to  a  terminal  (tty).  The environment variable LS_COLORS can
       influence the colors, and can be set easily by the dircolors command.

       Exit status is 0 if OK, 1 if minor problems, 2 if serious trouble.

AUTHOR
       Written by Richard Stallman and David MacKenzie.

REPORTING BUGS
       Report bugs to <bug-coreutils@gnu.org>.

COPYRIGHT
       Copyright © 2006 Free Software Foundation, Inc.
       This is free software.  You may redistribute copies  of  it  under  the
       terms       of       the      GNU      General      Public      License
       <http://www.gnu.org/licenses/gpl.html>.  There is NO WARRANTY,  to  the
       extent permitted by law.

SEE ALSO
       The  full  documentation  for ls is maintained as a Texinfo manual.  If
       the info and ls programs are properly installed at your site, the  com-
       mand

              info ls

       should give you access to the complete manual.

ls 5.97                          February 2010                           LS(1)
~
~

    3.1.2 man 配置文件  这些配置文件模板,大多在 /usr/share/doc 目录下,里面每一个目录都是一个软件帮助文档。

[root@test6 ~]# man /etc/httpd/conf/httpd.conf 
原文地址:https://www.cnblogs.com/sangmu/p/6658181.html