: '
: A program to cause vi to fill its buffer from standard input through
: a (high speed) named pipe.  This will work on system V and SUN 3.x unix
: For systems where the named pipe can not be created, a TMP file will be
: used with corresponding lack of efficiency. Vi will read its command
: input from /dev/tty.
:
: Usage: pvi [-f|-u] [viflags]
:	-f forces the use of a file rather than a named pipe
:	-u implies -f but causes the cat to run unbuffered (-u)
:	viflags are passed to vi after the -R (read-only) flag
:
: Usage example:  co -p foo | pvi
:
: Author: Corey Satten, Corey@fluke, 5/7/87
: http://staff.washington.edu/corey
: '
TMP=/tmp/pipe$$; cat=/bin/cat; mknod=/etc/mknod; rm=/bin/rm

trap "$rm -f $TMP; exit 0" 0 1 2 13 15
case "$1" in
    -f) FFLAG=1; shift;;
    -u) FFLAG=1; CATFLAG=-u; shift;;
    *)  $mknod $TMP p >/dev/null 2>&1;;
esac				# Doesn't seem to return a useful status
if [ -w $TMP -a -z "$FFLAG" ] ;then
    exec 4<&0			# Extreme wizardry, (copy stdin to FD #4)
    $cat <&4 > $TMP &		# so that cat can run in the background
    vi -R ${1+"$@"} $TMP </dev/tty
else
    $cat $CATFLAG - > $TMP	# Can't make the pipe?  Just use a file.
    vi -R ${1+"$@"} $TMP </dev/tty
fi