我正在写一个shell脚本,需要检查终端应用程序是否已安装。我想使用TRY/CATCH命令来做到这一点,除非有更整洁的方法。


当前回答

借用肖恩·梅奥的回答,你可以这样做

function check {
EXITCODE=$?
if [ "$EXITCODE" -ne "0" ]; then
    #this is the catch part
    echo "uh oh"
    exit $EXITCODE
fi
}

YOUR COMMAND HERE
check
YOUR COMMAND HERE
check
YOUR COMMAND HERE
check
YOUR COMMAND HERE
check

效果很好

其他回答

你可以使用trap:

try {block A} catch {block B} finally {block C}

翻译:

(
  set -Ee
  function _catch {
    block B
    exit 0  # optional; use if you don't want to propagate (rethrow) error to outer shell
  }
  function _finally {
    block C
  }
  trap _catch ERR
  trap _finally EXIT
  block A
)

Bash中有TRY CATCH命令吗?

不。

Bash不像在许多编程语言中那样拥有那么多奢侈的东西。

bash中没有try/catch;但是,可以使用&&或||实现类似的行为。

使用| |:

如果command1失败,则command2按如下方式运行

command1 || command2

类似地,使用&&,如果command1成功,command2将运行

try/catch最接近的近似如下

{ # try

    command1 &&
    #save your output

} || { # catch
    # save log for exception 
}

此外,bash还包含一些错误处理机制

set -e

如果任何简单的命令失败,它将停止脚本。

还有为什么不是if…else。它是你最好的朋友。

根据我在这里找到的一些答案,我为自己的项目制作了一个小的帮助文件:

trycatch.sh

#!/bin/bash

function try()
{
    [[ $- = *e* ]]; SAVED_OPT_E=$?
    set +e
}

function throw()
{
    exit $1
}

function catch()
{
    export ex_code=$?
    (( $SAVED_OPT_E )) && set +e
    return $ex_code
}

function throwErrors()
{
    set -e
}

function ignoreErrors()
{
    set +e
}

下面是它在使用中的示例:

#!/bin/bash
export AnException=100
export AnotherException=101

# start with a try
try
(   # open a subshell !!!
    echo "do something"
    [ someErrorCondition ] && throw $AnException

    echo "do something more"
    executeCommandThatMightFail || throw $AnotherException

    throwErrors # automaticatly end the try block, if command-result is non-null
    echo "now on to something completely different"
    executeCommandThatMightFail

    echo "it's a wonder we came so far"
    executeCommandThatFailsForSure || true # ignore a single failing command

    ignoreErrors # ignore failures of commands until further notice
    executeCommand1ThatFailsForSure
    local result = $(executeCommand2ThatFailsForSure)
    [ result != "expected error" ] && throw $AnException # ok, if it's not an expected error, we want to bail out!
    executeCommand3ThatFailsForSure

    # make sure to clear $ex_code, otherwise catch * will run
    # echo "finished" does the trick for this example
    echo "finished"
)
# directly after closing the subshell you need to connect a group to the catch using ||
catch || {
    # now you can handle
    case $ex_code in
        $AnException)
            echo "AnException was thrown"
        ;;
        $AnotherException)
            echo "AnotherException was thrown"
        ;;
        *)
            echo "An unexpected exception was thrown"
            throw $ex_code # you can rethrow the "exception" causing the script to exit if not caught
        ;;
    esac
}

我用了一个非常简单的方法:

try() {
    "$@" || (e=$?; echo "$@" > /dev/stderr; exit $e)
}

你可以:

#!/bin/bash
if <command> ; then # TRY
    <do-whatever-you-want>
else # CATCH
    echo 'Exception'
    <do-whatever-you-want>
fi