#!/bin/ksh
# @(#) psf.ksh 1.0 93/11/19
# 93/11/09 John H. DuBois III (john@armory.com)
# 93/11/19 Get rid of c, p, r codes at end of PIDs
#          Use $(ps) instead of ps|read so that leading whitespace isn't lost
#          Added options (-h and -x)

name=${0##*/}
Usage="Usage: $name [-hx] file ..."

typeset -i i=0 j numfiles debug=0

alias istrue="test 0 -ne"
alias isfalse="test 0 -eq"

while getopts :hx opt; do
    case $opt in
    h)
	echo \
"$name: list processes using files.
$Usage
A ps line is printed for any process that has any of the named files open.
Options:
-h: Print this help.
-x: Turn on debugging."
	exit 0
	;;
    x)
	debug=1
	;;
    +?)
	print -u2 "$name: options should not be preceded by a '+'."
	exit 1
	;;
    :)
        print -r -u2 -- \
        "$name: Option '$OPTARG' requires a value.  Use -h for help."
        exit 1
        ;;
    ?) 
	print -u2 "$name: $OPTARG: bad option.  Use -h for help."
	exit 1
	;;
    esac
done
 
# remove args that were options
let OPTIND=OPTIND-1
shift $OPTIND

if [ $# -lt 1 ]; then
    print -u2 "$Usage\nUse -h for help."
    exit
fi

# Generate process ID list
OIFS=$IFS
# Need to get error output with standard output so that we can
# keep process lists associated with files
fuser $* 2>&1 | while read file proclist; do
    set -- $proclist
    if [ -z "$proclist" ]; then
	print -u2 "$file no processes"
    elif [[ "$1" != [0-9]* ]]; then
	# If a word starting with anything other than a digit is printed
	# after a  file name, it is the start of an error message
	print -u2 "$file $proclist"
    else
	istrue debug && print -u2 "$file $proclist"
	files[i]=${file%:}

	j=0
	unset pids[*]
	for pid; do
	    pids[j]=${pid%[!0-9]}	# get rid of file use code (c, p, r)
	    let j+=1
	done
	# Make the PID list be an egrep pattern: pid1|pid2|pid3...
	IFS=\|
	procpat[i]="${pids[*]}"
	IFS=$OIFS

	allprocs="$allprocs ${pids[*]}"
	let i+=1
    fi
done
istrue debug && print "PIDs: $allprocs"
[ i -lt 1 ] && exit
numfiles=i

# Set ps args.  Use -e instead of -fp because ps has a 20 proc limit
set -- $allprocs
[ $# -le 20 ] && set -- -fp "$allprocs" || set -- -fe

# Get ps output for each process ID
IFS="
"
# Use this instead of read because read always strips leading whitespace
set -- $(ps "$@")
IFS=$OIFS
for line in "$@"; do
    set -- $line
    pid=$2
    i=0
    while [ i -lt numfiles ]; do
	if eval [[ $pid = "@(${procpat[i]})" ]]; then
	    pslines[i]="${pslines[i]}
$line"
	fi
	let i+=1
    done
done

# Print output by filename
i=0
while [ i -lt numfiles ]; do
    print "${files[i]}:${pslines[i]}"
    let i+=1
done