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Linux shell 中“../”是什么意思？

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Linux shell 中“../”是什么意思？

我有一个 shell 脚本，它不能执行， ./script.sh但是需要. ./script.sh执行。

./和之间有什么区别. ./？我在 Windows 上使用 MSYS2 环境。请注意点之间的空格。我知道 和 的作用../，但这并不能解决问题，因为我与可执行文件位于同一目录中。

输出如下：

终端输出

答案1

.是 Bash 和其他多个 POSIX shell 中的源运算符：

$ help .
.: . filename [arguments]
    Execute commands from a file in the current shell.

    Read and execute commands from FILENAME in the current shell.  The
    entries in $PATH are used to find the directory containing FILENAME.
    If any ARGUMENTS are supplied, they become the positional parameters
    when FILENAME is executed.

    Exit Status:
    Returns the status of the last command executed in FILENAME; fails if
    FILENAME cannot be read.

. ./script这样做总是更安全，. script因为. 默认情况下搜索 PATH，并且您可能会遇到名称冲突：

$ echo echo hi > script
$ . script
bash: .: /usr/bin/script: cannot execute binary file
$ . ./script
hi

并且因为有些 shell 默认不搜索当前目录：

$ mv script script-to-be-sourced
$ dash
$ . script-to-be-sourced
dash: 1: .: script-to-be-sourced: not found

答案2

两者完全不同，无法比较。

./表示当前目录。

. ./没有任何意义，运行会打印以下错误：

-bash: .: ./: is a directory

然而，它需要被分解成两部分：

  • 命令.​
  • 参数./​

该.命令是 shell 内置命令，与该命令同义source。它以文件而非目录作为参数，因此会出现上述错误。

您可能见过的一个非常命令的示例是以下命令：

$ . ~/.bashrc

这正是

$ source ~/.bashrc

你可以找到他们的手动的通过运行

man bash-builtins

        .  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,  filenames  in  PATH  are  used to find the directory containing
              filename.  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.

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