backup-is-src

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

. $srcdir/../lang-default
. $srcdir/../envvar-check

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

echo a > a || framework_failure=1
echo a-tilde > a~ || framework_failure=1

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

# This cp command should exit nonzero.
cp --b=simple a~ a > out 2>&1 && fail=1

sed "s,cp:,XXX:," out > out2

cat > exp <<\EOF
XXX: backing up `a' would destroy source;  `a~' not copied
EOF

cmp out2 exp || fail=1

(exit $fail); exit