bash 在 shell 脚本中捕获失败
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Catch failure in shell script
提问by Mild Fuzz
Pretty new to shell scripting. I am trying to do the following:
shell 脚本编写非常新。我正在尝试执行以下操作：
#!/bin/bash
unzip myfile.zip
#do stuff if unzip successful
I know that I can just chain the commands together in with &&but there is quite a chunk, it would not be terribly maintainable.
我知道我可以将命令链接在一起，&&但是有相当多的块，它不会非常易于维护。
回答by
You can use the exit status of the command explicitly in the test:
您可以在测试中明确使用命令的退出状态：
if ! unzip myfile.zip &> /dev/null; then
# handle error
fi
回答by fedorqui 'SO stop harming'
You can use $?. It returns:
- 0 if the command was successfully executed.
- !0 if the command was unsuccessful.
您可以使用$?. 它返回：
- 0 如果命令成功执行。
- !0 如果命令不成功。
So you can do
所以你可以做
#!/bin/bash
unzip myfile.zip
if [ "$?" -eq 0 ]; then
#do stuff on unzip successful
fi
Test
测试
$ cat a
hello
$ echo $?
0
$ cat b
cat: b: No such file or directory
$ echo $?
1
回答by Mild Fuzz
The variable $?contains the exit status of the previous command. A successful exit status for (most) commands is (usually) 0, so just check for that...
该变量$?包含上一个命令的退出状态。（大多数）命令的成功退出状态是（通常）0，所以只需检查一下......
#!/bin/bash
unzip myfile.zip
if [ $? == 0 ]
then
# Do something
fi
回答by Grzegorz ?ur
If you want the shell to check the result of the executed commands and stop interpretation when something returns non-zero value you can add set -ewhich means Exit immediately if a command exits with a non-zero status.I'm using this often in scripts.
如果您希望 shell 检查执行命令的结果并在某些返回非零值时停止解释，您可以添加set -e这意味着如果命令以非零状态退出，则立即退出。我经常在脚本中使用它。
#!/bin/sh
set -e
# here goes the rest
