求帮助，12.10，判断符号[]在shell中用法。

[astolia]

ubuntu上，如果不去改sh的链接对象，sh xxx就等同于dash xxx也就是用dash来执行脚本。#!这行只有直接用文件名运行时才有效
你想写通用点，就只用=来比较

a shell builtin就是shell的内建命令。要查shell的manpage。
source的通用程度也不高，dash就不认。最好还是用 . 替代
man bash中可以查到

代码： 全选

        .  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 exe‐
              cuted 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  posi‐
              tional  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.

第一句就说明是在当前shell环境下执行，也就是相当于你直接在shell中输入脚本中的所有内容。你脚本不管输入什么最后都会执行exit语句，在shell中执行exit当然就会退出了

[super_art]

ubuntu上，如果不去改sh的链接对象，sh xxx就等同于dash xxx也就是用dash来执行脚本。#!这行只有直接用文件名运行时才有效
你想写通用点，就只用=来比较

a shell builtin就是shell的内建命令。要查shell的manpage。
source的通用程度也不高，dash就不认。最好还是用 . 替代
man bash中可以查到

代码： 全选

        .  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 exe‐
              cuted 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  posi‐
              tional  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.

第一句就说明是在当前shell环境下执行，也就是相当于你直接在shell中输入脚本中的所有内容。你脚本不管输入什么最后都会执行exit语句，在shell中执行exit当然就会退出了

谢谢！