sysv

实战Linux编程的原代码,希望对学驱动的人能有所帮助

#!/bin/sh
# make sure `sum -s' works for input whose sum of bytes is larger than 2^32

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

case "$PERL" in
  *'missing perl')
  echo 1>&2 "$0: configure didn't find a usable version of Perl, so can't run this test"
  exit 77
  ;;
esac

# Avoid a problem when run in a UTF-8 locale.
# Otherwise, Perl would try to (and fail to) interpret
# each string below as a sequence of multi-byte characters.
LC_ALL=C
export LC_ALL

pwd=`pwd`
tmp=sum-s.$$
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

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

fail=0

# FYI, 16843009 is floor (2^32 / 255).

# aka: perl -e 'print chr(255) x 16843009'
$PERL -e '$s = chr(255) x 65537; foreach (1..257) {print $s}' \
  | sum -s > out || fail=1
cat > exp <<\EOF
65535 32897
EOF
cmp out exp || fail=1
test $fail = 1 && diff out exp 2> /dev/null

rm -f out exp

# aka: perl -e 'print chr(255) x 16843010'
$PERL -e '$s = chr(255) x 65537; foreach (1..257) {print $s}; print chr(255)' \
  | sum -s > out || fail=1
cat > exp <<\EOF
254 32897
EOF
cmp out exp || fail=1
test $fail = 1 && diff out exp 2> /dev/null

(exit $fail); exit