to-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
# Make sure that the copying code used in an inter-partition
# move unlinks a destination symlink before opening it.

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

. $srcdir/setup
. $srcdir/../envvar-check

if test -z "$other_partition_tmpdir"; then
  exit 77
fi

rem_file="$other_partition_tmpdir/file"
rem_symlink="$other_partition_tmpdir/symlink"
file=to-sym-$$

fail=0

trap 'rm -fr $file $other_partition_tmpdir; exit $fail' 0 1 2 3 15

framework_failure=0
rm -f $file || framework_failure=1
echo local > $file || framework_failure=1
echo remote > $rem_file || framework_failure=1
ln -s $rem_file $rem_symlink || framework_failure=1

if test $framework_failure = 1; then
  echo 'failure in testing framework'
  exit 1
fi

# This mv command should succeed, unlinking the symlink
# before copying.
mv $file $rem_symlink || fail=1

# Make sure $file is gone.
test -f $file && fail=1

# Make sure $rem_file is unmodified.
test `cat $rem_file` = remote || fail=1

exit $fail