dw       刪除詞，剪切詞。 ( 3dw刪除 3 單詞)
    cw       替換一個單詞。 (cw 和 dw 的區別 cw 刪除某一個單詞后直接進入編輯模式，而dw刪除詞后仍處于命令模式)
    cc       替換一行
    C        替換從光標到行尾
    yy       復制行 (用法同下的 Y ，見下行)
    Y        將光標移動到要復制行位置，按yy。當你想粘貼的時候，請將光標移動到你想復制的位置的前一個位置，然后按 p
    yw       復制詞
    p        當前行下粘貼
    1,2co3   復制行1，2在行3之后
    4,5m6    移動行4，5在行6之后
    u        當你的前一個命令操作是一個誤操作的時候，那么可以按一下 u鍵，即可復原。只能撤銷一次
    r file2  在光標所在處插入另一個文件

    ~        將字母變成大寫
    J        可以將當前行與下一行連接起來
    /字符串   從上往下找匹配的字符串
    ?字符串   從下往上找匹配的字符串
    n        繼續查找
    1,$s/舊串/新串/g   替換全文(或者  %s/舊串/新串/g)
                      (1表示從第一行開始)    沒有g則只替換一次，加g替換所有

3、存盤和退出 
     w            存盤
     w newfile    存成新文件
     wq           存盤再退出VI(或者ZZ或 X)
     q!           強行退出不存盤

查看用戶 
users      顯示在線用戶(僅顯示用戶名)。
who        顯示在線用戶，但比users更詳細，包括用戶名、終端號、登錄時間、IP地址。
 who am i  僅顯示自己，(但包括用戶名、端口、登錄時間、IP地址；信息量＝who)。
 whoami    也僅顯示自己，但只有用戶名(僅顯示自己的有效的用戶名)。
w          顯示比who更多內容，還包括閑置時間、占CPU、平均占用CPU、執行命令。
           用法 w [ -hlsuw ] [ 用戶 ]

su         改變用戶，需再輸入密碼。
           用法  su [-] [ username [ arg ... ] ]
 su －      相當于退出再重新登錄。

查找 
find   查找文件
    用法 find  [-H | -L] 路徑列表 謂詞列表
    find / -name perl 從根目錄開始查找名為perl的文件。
    find . -mtime 10 -print 從當前目錄查找距離現在10天時修改的文件，顯示在屏幕上。
           (注 “10”表示第10天的時候；如果是“+10”表示10天以外的范圍；“-10”表示10天以內的范圍。)

grep 文件中查找字符；有過濾功能，只列出想要的內容
    用法  grep -hblcnsviw 模式 文件 . . .
    如 grep abc /etc/passwd  在passwd文件下找abc字符
wc 統計
    -l 統計行數；  -w統計單詞數；   -c 統計字符數
    如  grep wang /etc/passwd|wc -l    統計passwd文件含“wang”的行數
du 查看目錄情況
    如   du -sk *    不加-s會顯示子目錄，-k按千字節排序
    用法 du [-a] [-d] [-h|-k] [-r] [-o|-s] [-H|-L] [文件...]

進程管理 
ps 顯示進程。
    用法 ps [ -aAdeflcjLPyZ ] [ -o 格式 ] [ -t 項列表 ]
    [ -u 用戶列表 ] [ -U 用戶列表 ] [ -G 組列表 ]
    [ -p 進程列表 ] [ -g 程序組列表 ] [ -s 標識符列表 ] [ -z 區域列表 ]
    ps 顯示自己的進程。
    ps －e 顯示每個進程，包括空閑進程。
    ps －f 顯示詳情。
    ps －ef 組合－e和－f，所有進程的詳情。
    ps －U uidlist(用戶列表) 具體查看某人的進程。

kill 
pkill 
sleep 

jobs 
    用法  jobs [-l ]
fg ％n 
bg ％n 
stop ％n 掛起(僅csh能用)
Ctrl+C 
Ctrl+Z 

網絡鏈接 
ping 
    usage  ping host [timeout]
    usage  ping -s [-l | U] [adLnRrv] [-A addr_family] [-c traffic_class] [-g gateway [-g gateway ...]] [-F flow_label] [-I interval] [-i interface] [-P tos] [-p port] [-t ttl] host [data_size] [npackets]

ifconfig －a 
     /sbin/ifconfig    查看本機的IP地址

netstat －rn 


rlogin 

ftp 
















幫助文件 [sd0807@localhost ~]$       help
GNU bash, version 3.1.17(1)-release (i686-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 [&]                            (( expression ))
 . filename [arguments]                       
 [ arg... ]                              [[ expression ]]
 alias [-p] [name[=value] ... ]         bg [job_spec ...]
 bind [-lpvsPVS] [-m keymap] [-f fi     break [n]
 builtin [shell-builtin [arg ...]]      caller [EXPR]
 case WORD in [PATTERN [| PATTERN].     cd [-L|-P] [dir]
 command [-pVv] command [arg ...]       compgen [-abcdefgjksuv] [-o option
 complete [-abcdefgjksuv] [-pr] [-o     continue [n]
 declare [-afFirtx] [-p] [name[=val     dirs [-clpv] [+N] [-N]
 disown [-h] [-ar] [jobspec ...]        echo [-neE] [arg ...]
 enable [-pnds] [-a] [-f filename]      eval [arg ...]
 exec [-cl] [-a name] file [redirec     exit [n]
 export [-nf] [name[=value] ...] or     false
 fc [-e ename] [-nlr] [first] [last     fg [job_spec]
 for NAME [in WORDS ... ;] do COMMA     for (( exp1; exp2; exp3 )); do COM
 function NAME { COMMANDS ; } or NA     getopts optstring name [arg]
 hash [-lr] [-p pathname] [-dt] [na     help [-s] [pattern ...]
 history [-c] [-d offset] [n] or hi     if COMMANDS; then COMMANDS; [ elif
 jobs [-lnprs] [jobspec ...] or job     kill [-s sigspec | -n signum | -si
 let arg [arg ...]                      local name[=value] ...
 logout                                 popd [+N | -N] [-n]
 printf [-v var] format [arguments]     pushd [dir | +N | -N] [-n]
 pwd [-LP]                              read [-ers] [-u fd] [-t timeout] [
 readonly [-af] [name[=value] ...]      return [n]
 select NAME [in WORDS ... ;] do CO     set [--abefhkmnptuvxBCHP] [-o option] [arg ...]
 shift [n]                              shopt [-pqsu] [-o long-option] opt
 source filename [arguments]            suspend [-f]
 test [expr]                            time [-p] PIPELINE
 times                                  trap [-lp] [arg signal_spec ...]
 true                                   type [-afptP] name [name ...]
 typeset [-afFirtx] [-p] name[=valu     ulimit [-SHacdfilmnpqstuvx] [limit
 umask [-p] [-S] [mode]                 unalias [-a] name [name ...]
 unset [-f] [-v] [name ...]             until COMMANDS; do COMMANDS; done
 variables - Some variable names an wait [n]
 while COMMANDS; do COMMANDS; done  { COMMANDS ; }



輸入    man help

BASH_BUILTINS(1)                       BASH_BUILTINS(1)

NAME
    bash, :, ., [, alias, bg, bind, break, builtin, cd, command, compgen, complete, continue,
    declare, dirs, disown, echo, enable, eval, exec, exit, export, fc, fg, getopts, hash, help,
    history, jobs, kill, let, local, logout, popd, printf, pushd, pwd, read, readonly, return,
    set, shift, shopt, source, suspend, test, times, trap, type, typeset, ulimit, umask, una-
    lias, unset, wait - bash built-in commands, see bash(1)

BASH BUILTIN COMMANDS
    Unless otherwise noted, each builtin command documented in this section as accepting options
    preceded by - accepts -- to signify the end of the options.  For example, the :, true,
    false, and test builtins do not accept options.
    : [arguments]
       No effect; the command does nothing beyond expanding arguments and performing any
       specified redirections. A zero exit code is returned.

    . filename [arguments]
    source filename [arguments]
       Read and execute commands from filename in the current shell environment and return
       the exit status of the last command executed from filename. If filename does not
       contain a slash, file names in PATH are used to find the directory containing file-
       name.  The file searched for in PATH need not be executable. When bash is not in
       posix mode, the current directory is searched if no file is found in PATH.  If the
       sourcepath option to the shopt builtin command is turned off, the PATH is not
       searched. If any arguments are supplied, they become the positional parameters when
       filename is executed. Otherwise the positional parameters are unchanged. The return
       status is the status of the last command exited within the script (0 if no commands
       are executed), and false if filename is not found or cannot be read.

    alias [-p] [name[=value] ...]
       Alias with no arguments or with the -p option prints the list of aliases in the form
       alias name=value on standard output.  When arguments are supplied, an alias is
       defined for each name whose value is given. A trailing space in value causes the
       next word to be checked for alias substitution when the alias is expanded. For each
       name in the argument list for which no value is supplied, the name and value of the
       alias is printed. Alias returns true unless a name is given for which no alias has
       been defined.

    bg [jobspec ...]
       Resume each suspended job jobspec in the background, as if it had been started with
       &. If jobspec is not present, the shell’s notion of the current job is used.  bg
       jobspec returns 0 unless run when job control is disabled or, when run with job con-
       trol enabled, any specified jobspec was not found or was started without job control.

    bind [-m keymap] [-lpsvPSV]
    bind [-m keymap] [-q function] [-u function] [-r keyseq]
    bind [-m keymap] -f filename
    bind [-m keymap] -x keyseq:shell-command
    bind [-m keymap] keyseq:function-name
    bind readline-command
       Display current readline key and function bindings, bind a key sequence to a readline
       function or macro, or set a readline variable. Each non-option argument is a command
       as it would appear in .inputrc, but each binding or command must be passed as a sepa-
       rate argument; e.g., ’"\C-x\C-r": re-read-init-file’. Options, if supplied, have the
       following meanings:
       -m keymap
           Use keymap as the keymap to be affected by the subsequent bindings. Accept-
           able keymap names are emacs, emacs-standard, emacs-meta, emacs-ctlx, vi,
           vi-move, vi-command, and vi-insert. vi is equivalent to vi-command; emacs is
           equivalent to emacs-standard.
       -l   List the names of all readline functions.
       -p   Display readline function names and bindings in such a way that they can be
           re-read.