update

Linux下文件工具。

#!/bin/sh
# make sure --update works as advertised

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

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

pwd=`pwd`
tmp=mv-update.$$
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
echo old > old || framework_failure=1
touch -d yesterday old || framework_failure=1
echo new > new || framework_failure=1

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

fail=0

for cp_or_mv in cp mv; do
  # This is a no-op.
  $cp_or_mv --update old new || fail=1
  case "`cat new`" in new) ;; *) fail=1 ;; esac
  case "`cat old`" in old) ;; *) fail=1 ;; esac
done

# This will actually perform the rename.
mv --update new old || fail=1
test -f new && fail=1
case "`cat old`" in new) ;; *) fail=1 ;; esac

# Restore initial conditions.
echo old > old || fail=1
touch -d yesterday old || fail=1
echo new > new || fail=1

# This will actually perform the copy.
cp --update new old || fail=1
case "`cat old`" in new) ;; *) fail=1 ;; esac
case "`cat new`" in new) ;; *) fail=1 ;; esac

(exit $fail); exit