tcjones@watdragon.waterloo.edu (Crocodile Dundee) (11/14/87)
Ooops. It turns out that under certain conditions "pipe" will do strange
things. This occurred when someone did the following
cat fred | pipe -o ">list1" "|sort>list2"
The script was copying its input to its output with
while read line
do
echo $line >> wherever
done
and this got totally mixed up when the input line contained a "*"
which was passed on to echo and expanded into all the filenames in the
directory. I should have used cat in the first place and all this wouldn't have
gone on. Anyway, here it is again, fixed (and faster due to cat).
Terry
# This is a shell archive. Remove anything before this line,
# then unpack it by saving it in a file and typing "sh file".
#
# Wrapped by watdragon!tcjones on Tue Nov 10 18:38:38 EST 1987
# Contents: pipe
echo x - pipe
sed 's/^@//' > "pipe" <<'@//E*O*F pipe//'
#!/bin/sh
#
# pipe -- multi-input, multi-output pipelining
#
# Terry Jones 19/10/87 (tcjones@watdragon)
#
#-------------------------------------------------------------------------------
# Department Of Computer Science, University Of Waterloo
# Waterloo Ontario Canada N2L 3G1
#
#{ihnp4,allegra,decvax,utzoo,utcsri,clyde}!watmath!watdragon!tcjones
#tcjones@dragon.waterloo.{cdn,edu} tcjones@WATER.bitnet
#tcjones%watdragon@waterloo.csnet [from oz, tcjones@dragon.waterloo.cdn@munnari]
#-------------------------------------------------------------------------------
#
myname=`basename $0`
if [ $# -eq 0 ]
then
cat > /dev/tty
exit 1
fi
def_shell=/bin/sh
if [ -z "$SHELL" ]
then
echo No '$SHELL' variable set, using $def_shell
SHELL=$def_shell
fi
cum_in=/tmp/pipe_$$
if [ -f $cum_in -a ! -w $cum_in ]
then
echo ${myname}: could not use temporary ${cum_in} - try again.
exit 1
fi
>$cum_in
tty=`tty`
IN=1
SOME_IN=0
SOME_OUT=0
ANY_OUT=0
while [ -n "$1" ]
do
case $1 in
-in|-i)
IN=1
SOME_IN=0
if [ "$SOME_OUT" = "0" ]
then
SOME_OUT=1
cat $cum_in
fi
shift;;
-out|-o)
IN=0
SOME_OUT=0
ANY_OUT=1
if [ "$SOME_IN" = "0" ]
then
SOME_IN=1
cat >> $cum_in
fi
shift;;
*)
if [ "$IN" = "1" ]
then
SOME_IN=1
if [ "$1" = "-" ]
then
cat >> $cum_in
else
echo $1 | $SHELL >> $cum_in
fi
else
SOME_OUT=1
if [ "$1" = "-" ]
then
cat $cum_in
else
eval "cat $cum_in" "$1"
fi
fi
shift;;
esac
done
if [ "$SOME_OUT" = "0" -o "$ANY_OUT" = "0" ]
then
cat $cum_in
fi
/bin/rm -f $cum_in
@//E*O*F pipe//
chmod u=rwx,g=,o= pipe
echo Inspecting for damage in transit...
temp=/tmp/shar$$; dtemp=/tmp/.shar$$
trap "rm -f $temp $dtemp; exit" 0 1 2 3 15
cat > $temp <<\!!!
103 207 2054 pipe
!!!
wc pipe | sed 's=[^ ]*/==' | diff -b $temp - >$dtemp
if [ -s $dtemp ]
then echo "Ouch [diff of wc output]:" ; cat $dtemp
else echo "No problems found."
-b -b