出错时退出脚本

Question

我正在构建一个具有如下if函数的Shell脚本:

if jarsigner -verbose -keystore $keyst -keystore $pass $jar_file $kalias
then
    echo $jar_file signed sucessfully
else
    echo ERROR: Failed to sign $jar_file. Please recheck the variables
fi

...

我希望在显示错误消息后完成脚本的执行.我怎么能这样做？

Answer 1

如果你set -e输入一个脚本,脚本会在其中的任何命令失败时立即终止(即任何命令返回非零状态时).这不会让您编写自己的消息,但通常失败的命令自己的消息就足够了.

这种方法的优点在于它是自动的:您不会冒失去处理错误情况的风险.

状态由条件(例如if,&&或||)测试的命令不会终止脚本(否则条件将是无意义的).偶然命令的成语,其失败无关紧要command-that-may-fail || true.您也可以set -e关闭脚本的一部分set +e.

Answer 2

你在找exit？

这是最好的bash指南. http://tldp.org/LDP/abs/html/

在上下文中:

if jarsigner -verbose -keystore $keyst -keystore $pass $jar_file $kalias
then
    echo $jar_file signed sucessfully
else
    echo ERROR: Failed to sign $jar_file. Please recheck the variables 1>&2
    exit 1 # terminate and indicate error
fi

...

Answer 3

如果您希望能够处理的错误,而不是盲目地退出,而不是使用set -e,使用trap的ERR伪信号.

#!/bin/bash
f () {
    errorCode=$? # save the exit code as the first thing done in the trap function
    echo "error $errorCode"
    echo "the command executing at the time of the error was"
    echo "$BASH_COMMAND"
    echo "on line ${BASH_LINENO[0]}"
    # do some error handling, cleanup, logging, notification
    # $BASH_COMMAND contains the command that was being executed at the time of the trap
    # ${BASH_LINENO[0]} contains the line number in the script of that command
    # exit the script or return to try again, etc.
    exit $errorCode  # or use some other value or do return instead
}
trap f ERR
# do some stuff
false # returns 1 so it triggers the trap
# maybe do some other stuff

其他陷阱可以设置为处理其他信号,包括通常的Unix信号加上其他Bash伪信号RETURN和DEBUG.

Answer 4

这是做到这一点的方法:

#!/bin/sh

abort()
{
    echo >&2 '
***************
*** ABORTED ***
***************
'
    echo "An error occurred. Exiting..." >&2
    exit 1
}

trap 'abort' 0

set -e

# Add your script below....
# If an error occurs, the abort() function will be called.
#----------------------------------------------------------
# ===> Your script goes here
# Done!
trap : 0

echo >&2 '
************
*** DONE *** 
************
'