backup-1

实战Linux编程的原代码,希望对学驱动的人能有所帮助

#!/bin/sh

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

pwd=`pwd`
t0=`echo "$0"|sed 's,.*/,,'`.tmp; tmp=$t0/$$
trap 'status=$?; cd $pwd; 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

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

suffix=.b
file=b1.$$
file_backup="$file$suffix"
temp_files="$file $file_backup"
rm -f $temp_files

fail=0
echo test > $file || fail=1

# Specify both version control and suffix so the environment variables
# (possibly set by the user running these tests) aren't used.
cp --force --backup=simple --suffix=$suffix $file $file \
  || fail=1

test -f $file || fail=1
test -f $file_backup || fail=1
cmp $file $file_backup > /dev/null || fail=1

(exit $fail); exit