head-c

实战Linux编程的原代码,希望对学驱动的人能有所帮助

#!/bin/sh
# exercize the fix of 2001-08-18, based on test case from Ian Bruce

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

pwd=`pwd`
tmp=head-c.$$
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 abc > in || framework_failure=1

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

fail=0

(head -c1; head -c1) < in > out || fail=1
case "`cat out`" in
  ab) ;;
  *) fail=1 ;;
esac

(exit $fail); exit