Table of Contents
在Linux中我們要查命令的用法就可以用到幫助
1.<command> --help
用此命令可以查看命令的基本用法,例如:
[dw@localhost Desktop]$ passwd --help
Usage: passwd [OPTION...] <accountName>
-k, --keep-tokens keep non-expired authentication tokens
-d, --delete delete the password for the named account (root
only); also removes password lock if any
-l, --lock lock the password for the named account (root only)
-u, --unlock unlock the password for the named account (root only)
-e, --expire expire the password for the named account (root only)
-f, --force force operation
-x, --maximum=DAYS maximum password lifetime (root only)
-n, --minimum=DAYS minimum password lifetime (root only)
-w, --warning=DAYS number of days warning users receives before password
expiration (root only)
-i, --inactive=DAYS number of days after password expiration when an
account becomes disabled (root only)
-S, --status report password status on the named account (root
only)
--stdin read new tokens from stdin (root only)
Help options:
-?, --help Show this help message
--usage Display brief usage message
可以看到給出了三列,第一列爲參數,第二列爲具體表示的意思,第三列爲詳細的解釋。
其中首行中[]中的內容爲選填,<>中的內容爲必填,內容後面 ... 表示可以填多項。
2.whatis <command>
用此命令可以查看命令的用途,例如:
[dw@localhost Desktop]$ whatis passwd
passwd (5) - password file
openssl-passwd (1ssl) - compute password hashes
passwd (1) - update user's authentication tokens
3.man 等級數 <command>
我們可以先用whatis 命令查看對應命令有哪幾個級別的幫助信息,然後進入man命令查看幫助。
man手冊的使用方法:
上下健瀏覽
space健向後翻一頁
b 向前翻一頁
Enter 向後翻一行
k 向前翻一行
查看時要查找時:
/關鍵詞 或者 ?關鍵詞
n 向後查找
N 向前查找