dangling-symlink

实战Linux编程的原代码,希望对学驱动的人能有所帮助

#!/bin/sh
# rm should not prompt before removing a dangling symlink.
# Likewise for a non-dangling symlink.
# But for fileutils-4.1.9, it would do the former and
# for fileutils-4.1.10 the latter.

if test "$VERBOSE" = yes; then
  set -x
  rm --version
fi

pwd=`pwd`
t0=`echo "$0"|sed 's,.*/,,'`.tmp; tmp=$t0/$$
trap 'status=$?; cd $pwd; chmod -R u+rwx $t0; rm -rf $t0 && exit $status' 0
trap '(exit $?); exit' 1 2 13 15

framework_failure=0
mkdir -p $tmp || framework_failure=1
cd $tmp || framework_failure=1
ln -s no-file dangle
ln -s / symlink

if test $framework_failure = 1; then
  echo "$0: failure in testing framework" 1>&2
  (exit 1); exit
fi

fail=0

rm --presume-input-tty dangle symlink &
pid=$!
# The buggy rm (fileutils-4.1.9) would hang here, waiting for input.

# Give the working rm a chance to remove the file.
sleep 1

# The file must no longer exist.
ls -l dangle > /dev/null 2>&1 && fail=1
ls -l symlink > /dev/null 2>&1 && fail=1

kill $pid > /dev/null 2>&1

(exit $fail); exit