bash source 文件末尾有一个退出命令

Question

cat >file1.sh <<'EOF_FILE1'
  echo 'before source'
  source 'file2.sh'
  echo 'after source'
  func1
EOF_FILE1

cat >file2.sh <<'EOF_FILE2'
  echo 'test script'
  func1() {
    echo 'func1 starts'
    exit
  }
  exit
EOF_FILE2

bash file1.sh

预期输出是:

before source
test script
after source
func1 starts

实际输出为:

before source
test script

由于 exit 命令，“after source”丢失了。有没有办法解决这个问题，因为我无法从代码中删除 exit？

Answer 1

虽然最好的方法是编写旨在获取而不是执行的脚本，但如果您出于某种原因不能这样做，您可以考虑 在source命令之前将exit别名到return，如下所示:

shopt -s expand_aliases  # enable alias expansion (off by default in noninteractive shells)
alias exit=return        # ...and alias 'exit' to 'return'

source 'file2.sh'        # source in your file which incorrectly uses 'exit' at top-level
unalias exit             # disable the alias...
echo 'after source'
func1

---

如果您希望函数中的 exit 在该函数被调用时仍然有效，可以使事情变得更复杂一些:

maybe_exit() {
  local last_retval=$?                 # preserve exit's behavior of defaulting to $?
  [[ $do_not_really_exit ]] && return  # abort if flag is set
  (( $# )) && exit "$@"                # if arguments are given, pass them through
  exit "$last_retval"                  # otherwise, use the $? we captured above
}

shopt -s expand_aliases  # enable alias expansion (off by default in noninteractive shells)
alias exit=maybe_exit    # ...and alias 'exit' to 'maybe_exit'

do_not_really_exit=1     # set a flag telling maybe_exit not to really exit
source 'file2.sh'        # source in your file which incorrectly uses 'exit' at top-level
unset do_not_really_exit # clear that flag...
unalias exit             # disable the alias...
echo 'after source'
func1