hard-3

实战Linux编程的原代码,希望对学驱动的人能有所帮助

#!/bin/sh
# Ensure that using `cp --preserve=link' to copy hard-linked arguments
# onto existing destinations works, even when one of the link operations fails.
# This bug was fixed in coreutils-4.5.9.
# To exercise this bug is non-trivial:
# Set-up requires at least three hard-linked files.  In copying them,
# while preserving links, the initial copy must succeed, the attempt
# to create the second file via `link' must fail, and the final `link'
# (to create the third) must succeed.  Before the corresponding fix,
# the first and third destination files would not be linked.
#
# Note that this is nominally a test of `cp', yet it is in the tests/mv
# directory, because it requires use of the --preserve=link option that
# mv enables by default.

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

. $srcdir/../envvar-check
PRIV_CHECK_ARG=require-non-root . $srcdir/../priv-check

pwd=`pwd`
t0=`echo "$0"|sed 's,.*/,,'`.tmp; tmp=$t0/$$
trap 'status=$?; cd $pwd; chmod -R u+rwx $t0; 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
mkdir -p x dst/x || framework_failure=1
touch dst/x/b || framework_failure=1
chmod a-w dst/x
touch a || framework_failure=1
ln a x/b || framework_failure=1
ln a c || framework_failure=1

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

fail=0

# ======================================
# This must fail -- because x/b cannot be unlinked.
cp --preserve=link --parents a x/b c dst 2> /dev/null && fail=1

# Source files must remain.
test -f a || fail=1
test -f x/b || fail=1
test -f c || fail=1
cd dst

# Three destination files must exist.
test -f a || fail=1
test -f x/b || fail=1
test -f c || fail=1

# The i-node numbers of a and c must be the same.
ia=`ls -i a|sed 's/ a$//'`
ic=`ls -i c|sed 's/ c$//'`
test $ia = $ic || fail=1

# The i-node number of x/b must be different.
ib=`ls -i x/b|sed 's/ x.b$//'`
test $ia = $ib && fail=1

(exit $fail); exit $fail