force

实战Linux编程的原代码,希望对学驱动的人能有所帮助

#!/bin/sh
# move a file onto itself

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

ff=mvforce
ff2=mvforce2

framework_failure=0
rm -f $ff $ff2 || framework_failure=1
echo force-contents > $ff || framework_failure=1
ln $ff $ff2 || framework_failure=1

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

# Make sure we get English translations.
. $srcdir/../lang-default

# This mv command should exit nonzero.
mv $ff $ff > out 2>&1 && fail=1

cat > exp <<EOF
mv: \`$ff' and \`$ff' are the same file
EOF

cmp out exp || fail=1
test `cat $ff` = force-contents || fail=1

# This should succeed, even though the source and destination
# device and inodes are the same.
mv $ff $ff2 || fail=1

rm -fr out exp $ff $ff2

exit $fail