bash - 不存在文件上的 Shell 脚本源终止脚本

Question

考虑以下:

#!/bin/sh

# GNU bash, version 4.1.2(1)-release
echo "Start"
cd /path/does/not/exists # this does not terminate
source /path/does/not/exists

echo $?
echo "End"

结果:

Start
./test.sh: line 6: /path/does/not/exists: No such file or directory

为什么没有一个 echo 打印任何内容并且脚本终止？为什么只捕获 source 错误而不设置显式 set -e 并终止脚本？

Answer 1

在 posix 模式下运行时，如果作为 . 的参数命名的文件(又名 source)不存在，bash 将中止。请参阅:https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_18

If no readable file is found, a non-interactive shell shall abort; aninteractive shell shall write a diagnostic message to standard error,but this condition shall not be considered a syntax error.

因为您使用了 #!/bin/sh 作为 shebang，bash 是 running in posix mode .来自 bash 联机帮助页:

If bash is invoked with the name sh, it tries to mimic the startupbehavior of historical versions of sh as closely as possible, whileconforming to the POSIX standard as well.