echo $?可以获取上一条命令的exit code。 但是如果bash脚本中设置了set -e,那么如果命令的exit code不为0,当前bash脚本会直接退出。这种情况下如果要获取命令的exit code而不退出,需要让该命令在一个新的shell中执行: set -e ret=$(bash -c 'bash test2.sh; echo $?') echo $ret...
格式:trap "commands" EXIT 退出时执行commands指定的命令。( A trap on EXIT is executed before the shell terminates.) 退出码(exit status,或exit code)的约定: 0表示成功(Zero - Success) 非0表示失败(Non-Zero - Failure) 2表示用法不当(Incorrect Usage) 127表示命令没有找到(Command Not Found) 126...
echo “Command failed with exit code: $exit_code” fi “` 在这个例子中,我们使用了ls命令来示范。脚本首先执行ls命令,然后使用$?获取ls命令的返回值并将其赋值给变量exit_code。接下来,使用if语句判断exit_code的值,如果等于0,则打印”Command executed successfully”,否则打印”Command failed with exit code...
<view class="text-grey text-xs"> <button v-if="item.isLeave === 0">离厂解绑</button...
{//假如程序替换失败//关于打印的错误信息:也可以自定义,格式跟着标准走if(WEXITSTATUS(status)==168)printf("%s: Error - %s\n",argv[0],"The directive is not yet defined");}else//如果子进程被异常终止,打印相关信息printf("process run fail! [code_dump]:%d [exit_signal]:%d\n",(status>>7...
While ShellCheck is mostly intended for interactive use, it can easily be added to builds or test suites. It makes canonical use of exit codes, so you can just add ashellcheckcommand as part of the process. For example, in a Makefile: ...
# 假设在终端输入 bash bash_tutorial.sh -a 1 -b 2 -c yes a=0; b=0; c="zero" # 变量初始化, 一行定义多个变量, 通过 ';' 分割开 # 定义函数提示正确用法 usage() { echo "Usage: bash $0 -a <a_meaning> -b <b_meaning> [-c <c_meaning>]" # '[ ]' 表示参数可选 exit 1 }...
Use the command “2>/dev/null” to send standard error outputs to /dev/null to suppress an error code. Also, when you combine the OR operation and the suppressed error output, a non-existing file or command can return as “0”. The OR operation (|| exit 0) provides a fallback, ou...
When you execute a command or run a script, you receive an exit code. An exit code is a system response that reports success, an error, or another condit...
Once you execute the script in the terminal, run “echo $?” to get the return code on exit: ./comparison.sh echo$? The “comparison.sh” is executed successfully. That’s why terminals show zero as the return code. Similarly, you will get non-zero as the successful execution of the...