bash - 在 bash 脚本中，将所有错误视为成功退出(除了最后一个错误)的最佳方法是什么？

Question

假设你有一个 bash 脚本

#!/bin/bash

echo "hello" > hello
echo "world" > world

diff hello world

如果任何 echo 失败，则退出并返回状态代码 0。
diff 应该正常退出，无论它返回什么退出代码

Answer 1

最佳实践是明确地进行错误处理(也就是说，“手动”)。请参阅BashFAQ #105讨论为什么以及如何更自动化的方法容易出错(如果匆忙的话，可以跳过上面的寓言进行下面的练习)。

#!/bin/bash

echo "hello" > hello || exit 0
echo "world" > world || exit 0

# the shell will exit with the status of the last command by default
diff hello world

也就是说，如果您确实想要信任 shell 的内置错误检测，您可以这样做:

#!/bin/bash

# DON'T DO THIS if your logic is at all nontrivial, or if you can't answer all the exercise
# questions at http://mywiki.wooledge.org/BashFAQ/105 correctly.

trap 'exit 0' ERR     # Start handling errors by exiting with status 0
echo "hello" > hello
echo "world" > world
trap - ERR            # Remove the ERR trap, falling back to default behavior

diff hello world