A interface to the on-line reference manuals, a query interface on the online reference manual, enables us to learn the process of China's longest one help command.
Man [options] Parameter
The number parameter that follows the man command means:
1 executable programs or shell commands# executable or General command 2 system calls (Functions provided by the kernel) #是系统调用, is a call to the functionality provided by the kernel, For example, a function that calls the kernel does not know what header file to add. 3 library calls (functions within program libraries) #是库函数, GLIBC the standard C language library function calls 4 special files (Usually found in /dev) #特殊文件, i.e./ Various device files under Dev 5 file formats and conventions eg /etc/passwd# Some text files or configuration file details help display the 6 games# game (less than basic) 7 miscellaneous (including macro packages and conventions), e.g. man (7), groff (7) #其他一些杂项的使用, such as Linux file system, network protocol , Ascii code description, etc. 8 system administration commands (usually only For root) #是系统管理用的命令, these commands can only be used by root, such as ifconfig9 kernel routines [non Standard] #内核例程
[Email protected] ~]# man-f passwdsslpasswd (1SSL)-Compute password HASHESPASSWD (1)-Update user ' s AUT Hentication TOKENSPASSWD (5)-Password file
[[EMAIL&NBSP;PROTECTED]&NBSP;~]#&NBSP;MAN&NBSP;1&NBSP;PASSWDPASSWD (1) User utilities &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;PASSWD (1) NAME passwd - update user ' S authentication tokenssynopsis &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;PASSWD&NBSP;[-K]&NBSP;[-L]&NBSP;[-U&NBSP;[-F]]&NBSP;[-D]&NBSP;[-E] [-n mindays] [-x maxdays] [-w warndays] [-i inactivedays] [-s] [--stdin] [username] ......
[[EMAIL&NBSP;PROTECTED]&NBSP;~]#&NBSP;MAN&NBSP;5&NBSP;PASSWDPASSWD (5) linux programmer ' s manual &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;PASSWD (5) name passwd - password filedescription the /etc/passwd File is a text file that describes user login accounts for the system. it should have read permission allowed for all users (Many utilities, like ls (1) use it to map user ids to usernames), but write access only for the superuser. ......
[Email protected] ~]# man-f Sysctlsysctl (8)-Configure kernel parameters at Runtimesysctl (2)-RE Ad/write System Parameters
[[Email protected] ~]# man 2 sysctlsysctl (2) linux programmer ' s manual sysctl (2) name sysctl - read/write system parameterssynopsis #include < unistd.h> #include <linux/sysctl.h> int _sysctl (Struct __sysctl_args *args); note: there is no glibc wrapper for this system call; see NOTES. ......
[[Email protected] ~]# man 8 sysctlsysctl (8) System Administration sysctl (8) Name sysctl - configure kernel parameters at runtimeSYNOPSIS sysctl [options] [variable[=value]] [...] sysctl -p [file or regexp] [...] description sysctl is used to modify kernel parameters at runtime. the parameters available are those listed under /proc/sys/. Procfs is required for sysctl support in Linux. You can use sysctl to both read and write sysctl data.
The Whatis command common Tools Command Whatis command is used to query what functions a command performs and print the results of the query to the terminal. The Whatis command finds commands, system calls, library functions, or special file names that are specified by the command parameter in a database created with the Catman command. The Whatis command displays the header line of the manual section. You can then issue the man command to get additional information. The Whatis command is equivalent to using the MAN-F command.
[[email protected] ~]# whatis cdcd (1) - bash built-in commands, see bash (1) cd (1p) - change the working directory[[email protected] ~]# whatis bashbash (1) - GNU Bourne-Again shell[[email protected] ~]# whatis fdiskfdisk (8) - manipulate disk partition table[[email protected] ~]# whatis manman (1) - an interface to the on-line reference manualsman (1p) - display system documentationman (7) - macros to format man pages
External commands commonly used options, the general external command using these two options are more, some external commands may only h or--help, and some are both, specific people in the use of the process can be groped.
The info command is a command that displays command help in info format under Linux.
The info page is better, easier to understand and richer than the man page, but the man page is really much easier to use. A man page has only one page, and the info page almost always organizes its contents into sections (called nodes), and each section may contain sub-extents (called child nodes). The trick to understanding this command is not only to learn how to navigate through a separate Info page, but also to learn how to switch between nodes and child nodes. It may be difficult at first to move between the nodes of the info page and find what you want, it is ironic: originally thought for the novice, something better than the Man command, but the requirements of the English level of everyone has a high demand, my English level is general, so seldom use info this command, If you have a good English, you can learn the command of info. Here are a few of its frequently used shortcut keys.
Knock? Key, it will display the common shortcut keys for info. N: Display (relative to this node) the document contents of the next node P-key: Display (relative to this node) the document content of the previous node U key: Enter the subject of the current command m key: Enter the name of the command after the M key to view the command's Help document G key: Hit the G key after entering the subject name, Go to the topic L Key: Go back to the previous visited page space key: Scroll forward one page backup or del key: Scroll backward one page Q: exit the info command? Display the Help window : in the Help window Ctrl-x 0 Close the Help window Ctrl-x Ctrl-c Close Entire Info q exit infon Open with Ben node associated Next Nodep open previous Nodeu associated with this Node Open the previous Nodel associated with this Node Go back to the last visited nodem or g Select a menu item (node name) Enter the name of the specified menu and press ENTER. Opens the specified menu item associated with the node space bar Next page (pagedown can also, next page from the last two of the current pageLine start) next Node (if the current page is at the end of the Node document) del key Previous page (pageup can also, the previous page starts at the beginning of the current page) previous Node (if the current page Node start of the document) b or t or Home the beginning of the document (b is begining meaning) e or End the end of the document (b is ending ) ctrl-l Refresh the current page and ctrl-g the command you typed if there is a problem with the current document display
5. Help command
Shell built-in command to display Help for the shell's internal commands. The help command can only display command assistance information inside the shell. The Help information for external commands can only be viewed using the man or Info command.
Help (options) (parameters)
-S: Briefly displays a summary of the usage of each shell's built-in command format.
-D: A simple description of the output command.
-M: Details how the command is used, and the output format of the information is similar to the Man command, so it is also called a pseudo-help command.
Internal command: Specifies the shell internal command that needs to display help information.
#每个命令的简单描述, which means simply introducing what this command is for.
[Email protected] ~]# help-d helphelp-display information about BUILTIN commands.
[Email protected] ~]# help-s helphelp:help [-DMS] [pattern ...]
#显示shell命令的详细帮助文档, the output format is similar to the Man command.
[[email protected] ~]# help -m helpname help - Display information about builtin commands. SYNOPSIS&NBSP;&NBSP;&NBSP;&NBSP;HELP&NBSP;[-DMS]&NBSP;[PATTERN&NBSP, ...] description display information about builtin commands. displays brief summaries of builtin commands. If PATTERN is specified, gives detailed help On all commands matching pattern, otherwise the list of help topics is printed. options: -doutput short description for each topic -mdisplay usage in pseudo-manpage format & nbsp; -soutput only a short usage synopsis for each topic matching pattern arguments: PATTERNPattern specifiying a help topic exit status: returns success unless pattern is not found or an invalid option is given. See also bash (1) implementation gnu bash, version 4.2.46 (1)-release (X86_64-REDHAT-LINUX-GNU) Copyright (C) 2011 Free Software Foundation, Inc. License GPLv3+: GNU Gpl version 3 or later
This article is from the "Cowboy" blog, make sure to keep this source http://fangniuwa.blog.51cto.com/10209030/1751098
Summary of common help man,whatis,info,help under Linux systems