--help: 是一个工具选项,可以用来显示一些工具的信息 man : 可以显示系统手册页中的内容，这些内容大多数都是对命令的解释信息 PS: (1) Space 键可以显示下一屏的文本信息 (2) q 键是退出 info: 是一个基于菜单的超文本系统，是由GNU项目开发并由Linux发布。 info 工具包括一些关于Linux Shell,工具，GNU项目开发程序说明文档 PS: (1) ? 键可以列出info窗口中的相关命令 (2) Space 键可以进行滚动浏览
info
File: dir Node: Top This is the top of the INFO tree This (the Directory node) gives a menu of major topics. Typing "q" exits, "?" lists all Info commands, "d" returns here, "h" gives a primer for first-timers, "mEmacs<Return>" visits the Emacs topic, etc. In Emacs, you can click mouse button 2 on a menu item or cross reference to select it. * Menu: Archiving * Cpio: (cpio). Copy-in-copy-out archiver to tape or disk. * Tar: (tar). Making tape (or disk) archives. Basics * Common options: (coreutils)Common options. Common options. * Coreutils: (coreutils). Core GNU (file, text, shell) utilities. * Date input formats: (coreutils)Date input formats. * File permissions: (coreutils)File permissions. Access modes. * Finding files: (find). Operating on files matching certain criteria. * ed: (ed). The GNU Line Editor. Editors * nano: (nano). Small and friendly text editor. Emacs * IDN Library: (libidn)Emacs API. -----Info: (dir)Top, 2021 lines --Top----------------------------------------------------------------- Welcome to Info version 4.13. Type h for help, m for menu item.
help
[root@dep5 ~]# help GNU bash, version 4.1.2(1)-release (x86_64-redhat-linux-gnu) These shell commands are defined internally. Type `help' to see this list. Type `help name' to find out more about the function `name'. Use `info bash' to find out more about the shell in general. Use `man -k' or `info' to find out more about commands not in this list. A star (*) next to a name means that the command is disabled. job_spec [&] history [-c] [-d offset] [n] or history -anrw [> (( expression )) if COMMANDS; then COMMANDS; [ elif COMMANDS; th> . filename [arguments] jobs [-lnprs] [jobspec ...] or jobs -x command > : kill [-s sigspec | -n signum | -sigspec] pid | > [ arg... ] let arg [arg ...] [[ expression ]] local [option] name[=value] ... alias [-p] [name[=value] ... ] logout [n] bg [job_spec ...] mapfile [-n count] [-O origin] [-s count] [-t] > bind [-lpvsPVS] [-m keymap] [-f filename] [-q na> popd [-n] [+N | -N] break [n] printf [-v var] format [arguments] builtin [shell-builtin [arg ...]] pushd [-n] [+N | -N | dir] caller [expr] pwd [-LP] case WORD in [PATTERN [| PATTERN]...) COMMANDS ;> read [-ers] [-a array] [-d delim] [-i text] [-n> cd [-L|-P] [dir] readarray [-n count] [-O origin] [-s count] [-t> command [-pVv] command [arg ...] readonly [-af] [name[=value] ...] or readonly -> compgen [-abcdefgjksuv] [-o option] [-A action]> return [n] complete [-abcdefgjksuv] [-pr] [-DE] [-o option]> select NAME [in WORDS ... ;] do COMMANDS; done compopt [-o|+o option] [-DE] [name ...] set [--abefhkmnptuvxBCHP] [-o option-name] [arg> continue [n] shift [n] coproc [NAME] command [redirections] shopt [-pqsu] [-o] [optname ...] declare [-aAfFilrtux] [-p] [name[=value] ...] source filename [arguments] dirs [-clpv] [+N] [-N] suspend [-f] disown [-h] [-ar] [jobspec ...] test [expr] echo [-neE] [arg ...] time [-p] pipeline
man太多了= =