Linux命令:cd

语法

cd [-L|[-P [-e]]] [dir]
改变shell当前工作目录。仅对执行命令所在的shell有效。

参数

-L 按符号链接进入目录。

-P 按物理链接进入目录

-e 如果指定-P,且路径不存在，则返回-e后指定的退出码。

说明

cd =change directory

进入主目录。不带参数dir，就默认进入当前用户的主目录。等价命令还有 cd ~ 或 cd $HOME。

进入上一次切换前的工作目录。cd - 或 cd $OLDPWD。如果反复执行，则会在最后两次工作目录间来回切换。

cd的默认行为，等于cd <=> cd -L。如果路径中包含符号连接，则跟着符号链接走。

CDPATH环境变量

CDPATH环境变量为cd 提供一组备选的当前目录。也就是说，如果你输入的不是/开头的绝对路径，则进入的目录的绝对路径是CDPATH中的目录+你的目录。举例来说，

架设你当前目录是/usr，myhome在你的/home下。

export CDPATH=/root:/home/:/etc

cd myhome

执行以上命令后，bash会依次将CDPATH中的目录+myhome来进入，最终进入到/home/myhome目录下。【CDPATH中多个路径下都有dir怎么办？】

进入你刚创建的目录

mkdir <dir> && cd $_

不论你创建的目录是否你当前工作目录下的，这个命令都能用。

创建只有一个下划线名字的目录

mkdir ./_

help cd

 1 cd: cd [-L|[-P [-e]]] [dir]
 2     Change the shell working directory.
 3 
 4     Change the current directory to DIR.  The default DIR is the value of the
 5     HOME shell variable.
 6 
 7     The variable CDPATH defines the search path for the directory containing
 8     DIR.  Alternative directory names in CDPATH are separated by a colon (:).
 9     A null directory name is the same as the current directory.  If DIR begins
10     with a slash (/), then CDPATH is not used.
11 
12     If the directory is not found, and the shell option `cdable_vars' is set,
13     the word is assumed to be  a variable name.  If that variable has a value,
14     its value is used for DIR.
15 
16     Options:
17         -L      force symbolic links to be followed
18         -P      use the physical directory structure without following symbolic
19         links
20         -e      if the -P option is supplied, and the current working directory
21         cannot be determined successfully, exit with a non-zero status
22 
23     The default is to follow symbolic links, as if `-L' were specified.
24 
25     Exit Status:
26     Returns 0 if the directory is changed, and if $PWD is set successfully when
27     -P is used; non-zero otherwise.

posted on 2019-04-01 10:18 国民时代阅读(343) 评论(0) 编辑收藏举报

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