我写 init.d 得出的经验是不要写 init.d http://chloerei.com/2014/12/15/foreman/

不过这不能解决楼主的问题。

#1 楼 @xiaoronglv 我觉得应该是多余的，从定义上来看。

Exit immediately if a pipeline (see Pipelines), which may consist of a single simple command (see Simple Commands), a subshell command enclosed in parentheses (see Command Grouping), or one of the commands executed as part of a command list enclosed by braces (see Command Grouping) returns a non-zero status. The shell does not exit if the command that fails is part of the command list immediately following a while or until keyword, part of the test in an if statement, part of any command executed in a && or || list except the command following the final && or ||, any command in a pipeline but the last, or if the command’s return status is being inverted with !. A trap on ERR, if set, is executed before the shell exits.

This option applies to the shell environment and each subshell environment separately (see Command Execution Environment), and may cause subshells to exit before executing all the commands in the subshell.

• sh 的 cd 错误是 exit code 是 2
• bash 的 cd 错误 exit code 是 1

这个脚本的作者通过 cd $APP_ROOT || exit 1 把错误从 2 改为 1

荣耀归给 @zgm

#3 楼 @serco

作者把 exit code 从 2 改为 1，貌似意义不大。就是 debug 时方便一些。