equals

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 chmod mode arguments of the form A=B work properly.
# Before fileutils-4.1.2, some of them didn't.

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

pwd=`pwd`
tmp=equals.$$
trap 'status=$?; cd $pwd; rm -rf $tmp && exit $status' 0
trap '(exit $?); exit' 1 2 13 15

framework_failure=0
mkdir $tmp || framework_failure=1
cd $tmp || framework_failure=1
touch f || framework_failure=1

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

fail=0

expected_u=-rwx------
expected_g=----rwx---
expected_o=-------rwx

for src in u g o; do
  for dest in u g o; do
    test $dest = $src && continue
    chmod a=,$src=rwx,$dest=$src,$src= f || fail=1
    set _ `ls -l f`; shift; actual_perms=$1
    expected_perms=`eval 'echo \$expected_'$dest`
    test "$actual_perms" = "$expected_perms" || fail=1
  done
done

(exit $fail); exit