same-file

实战Linux编程的原代码,希望对学驱动的人能有所帮助

#!/bin/sh
# Test some of cp's options and how cp handles situations in
# which a naive implementation might overwrite the source file.

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

. $srcdir/../lang-default

# Unset CDPATH.  Otherwise, output from the `cd dir' command
# can make this test fail.
(unset CDPATH) >/dev/null 2>&1 && unset CDPATH

VERSION_CONTROL=numbered; export VERSION_CONTROL

pwd=`pwd`
t0=`echo "$0"|sed 's,.*/,,'`.tmp;tmp=$t0/$$
trap 'status=$?; cd $pwd; exec 1>&2; rm -rf $t0 && exit $status' 0
trap '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 'failure in testing framework'
  exit 1
fi

actual=actual-$$
expected=expected-$$

exec 1> $actual

# FIXME: This should be bigger: like more than 8k
contents=XYZ

for args in 'foo symlink' 'symlink foo' 'foo foo' 'sl1 sl2' 'foo hardlink'; do
  for options in '' -d -f -df --rem -b -bd -bf -bdf \
		 -l -dl -fl -dfl -bl -bdl -bfl -bdfl; do
    case $args$options in
      # These tests are not portable.
      # They all involve making a hard link to a symbolic link.
      'symlink foo'-dfl)
	continue;;
      'symlink foo'-bdl)
	continue;;
      'symlink foo'-bdfl)
	continue;;
      'sl1 sl2'-dfl)
	continue;;
      'sl1 sl2'-bd*l)
	continue;;
      'sl1 sl2'-dl)
	continue;;
    esac
    rm -rf dir
    mkdir dir
    cd dir
    echo $contents > foo
    case "$args" in *symlink*) ln -s foo symlink ;; esac
    case "$args" in *hardlink*) ln foo hardlink ;; esac
    case "$args" in *sl1*) ln -s foo sl1;; esac
    case "$args" in *sl2*) ln -s foo sl2;; esac
    (
      (
	# echo 1>&2 cp $options $args
	cp $options $args 2>_err
	echo $? $options

	# Normalize the program name in the error output,
	# and put brackets around the output.
	test -s _err && echo "[`sed 's/^[^:][^:]*:/cp:/' _err`]"
	# Strip off all but the file names.
	# Omit the variable-width owner and group names.
	ls="`ls -gG --ignore=_err . \
	    | sed \
	        -e '/^total /d' \
		-e 's/^......................................//'`"
	echo "($ls)"
	# Make sure the original is unchanged and that
	# the destination is a copy.
	for f in $args; do
	  if test -f $f; then
	    case "`cat $f`" in
	      "$contents") ;;
	      *) echo cp FAILED;;
	    esac
	  else
	    echo symlink-loop
	  fi
	done
      ) | tr '\012' ' '
      echo
    ) | sed 's/  *$//'
    cd ..
  done
  echo
done

cat <<\EOF > $expected
1 [cp: `foo' and `symlink' are the same file] (foo symlink -> foo)
1 -d [cp: `foo' and `symlink' are the same file] (foo symlink -> foo)
1 -f [cp: `foo' and `symlink' are the same file] (foo symlink -> foo)
1 -df [cp: `foo' and `symlink' are the same file] (foo symlink -> foo)
0 --rem (foo symlink)
0 -b (foo symlink symlink.~1~ -> foo)
0 -bd (foo symlink symlink.~1~ -> foo)
0 -bf (foo symlink symlink.~1~ -> foo)
0 -bdf (foo symlink symlink.~1~ -> foo)
0 -l (foo symlink -> foo)
0 -dl (foo symlink -> foo)
0 -fl (foo symlink -> foo)
0 -dfl (foo symlink)
0 -bl (foo symlink -> foo)
0 -bdl (foo symlink symlink.~1~ -> foo)
0 -bfl (foo symlink -> foo)
0 -bdfl (foo symlink symlink.~1~ -> foo)

1 [cp: `symlink' and `foo' are the same file] (foo symlink -> foo)
1 -d [cp: `symlink' and `foo' are the same file] (foo symlink -> foo)
1 -f [cp: `symlink' and `foo' are the same file] (foo symlink -> foo)
1 -df [cp: `symlink' and `foo' are the same file] (foo symlink -> foo)
1 --rem [cp: `symlink' and `foo' are the same file] (foo symlink -> foo)
1 -b [cp: `symlink' and `foo' are the same file] (foo symlink -> foo)
0 -bd (foo -> foo foo.~1~ symlink -> foo) symlink-loop symlink-loop
1 -bf [cp: `symlink' and `foo' are the same file] (foo symlink -> foo)
0 -bdf (foo -> foo foo.~1~ symlink -> foo) symlink-loop symlink-loop
0 -l (foo symlink -> foo)
0 -dl (foo symlink -> foo)
0 -fl (foo symlink -> foo)
0 -bl (foo symlink -> foo)
0 -bfl (foo symlink -> foo)

1 [cp: `foo' and `foo' are the same file] (foo)
1 -d [cp: `foo' and `foo' are the same file] (foo)
1 -f [cp: `foo' and `foo' are the same file] (foo)
1 -df [cp: `foo' and `foo' are the same file] (foo)
1 --rem [cp: `foo' and `foo' are the same file] (foo)
1 -b [cp: `foo' and `foo' are the same file] (foo)
1 -bd [cp: `foo' and `foo' are the same file] (foo)
0 -bf (foo foo.~1~)
0 -bdf (foo foo.~1~)
0 -l (foo)
0 -dl (foo)
0 -fl (foo)
0 -dfl (foo)
0 -bl (foo)
0 -bdl (foo)
0 -bfl (foo foo.~1~)
0 -bdfl (foo foo.~1~)

1 [cp: `sl1' and `sl2' are the same file] (foo sl1 -> foo sl2 -> foo)
0 -d (foo sl1 -> foo sl2 -> foo)
1 -f [cp: `sl1' and `sl2' are the same file] (foo sl1 -> foo sl2 -> foo)
0 -df (foo sl1 -> foo sl2 -> foo)
0 --rem (foo sl1 -> foo sl2)
0 -b (foo sl1 -> foo sl2 sl2.~1~ -> foo)
0 -bd (foo sl1 -> foo sl2 -> foo sl2.~1~ -> foo)
0 -bf (foo sl1 -> foo sl2 sl2.~1~ -> foo)
0 -bdf (foo sl1 -> foo sl2 -> foo sl2.~1~ -> foo)
0 -l (foo sl1 -> foo sl2 -> foo)
0 -fl (foo sl1 -> foo sl2 -> foo)
0 -bl (foo sl1 -> foo sl2 -> foo)
0 -bfl (foo sl1 -> foo sl2 -> foo)

1 [cp: `foo' and `hardlink' are the same file] (foo hardlink)
1 -d [cp: `foo' and `hardlink' are the same file] (foo hardlink)
1 -f [cp: `foo' and `hardlink' are the same file] (foo hardlink)
1 -df [cp: `foo' and `hardlink' are the same file] (foo hardlink)
0 --rem (foo hardlink)
0 -b (foo hardlink hardlink.~1~)
0 -bd (foo hardlink hardlink.~1~)
0 -bf (foo hardlink hardlink.~1~)
0 -bdf (foo hardlink hardlink.~1~)
0 -l (foo hardlink)
0 -dl (foo hardlink)
0 -fl (foo hardlink)
0 -dfl (foo hardlink)
0 -bl (foo hardlink)
0 -bdl (foo hardlink)
0 -bfl (foo hardlink)
0 -bdfl (foo hardlink)

EOF

fail=0;

# Some folks don't have diff.
cmp $expected $actual \
  || { diff -c $expected $actual 1>&2; fail=1; }

(exit $fail); exit