#!/usr/bin/perl
#
# Copyright (c) 1995 Wolfram Schneider, Berlin
# All rights reserved. Alle Rechte vorbehalten.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. All advertising materials mentioning features or use of this software
#    must display the following acknowledgement:
#    This product includes software developed by Wolfram Schneider
# 4. The name of the author may not be used to endorse or promote products
#    derived from this software without specific prior written permission
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# killall - kill processes by name
#
# $Id: killall.pl,v 1.3 1996/02/03 22:52:27 wosch Exp $
#

$ENV{'PATH'} = '/bin:/usr/bin'; # security
$procfs = '/proc';
$signal = 'SIGTERM';		# default signal for kill
$debug = 0;
$match = 0;			# 0 match exactly program name
$show = 0;			# do nothings

# see /sys/miscfs/procfs/procfs_status.c
$PROC_NAME =  0;
$PROC_EUID = 11;
$PROC_RUID = 12;

sub usage {
    $! = 2;
    die "killall [-?|-help] [-d] [-l] [-m] [-s] [-SIGNAL] program\n";
}

$id = $<;			# real uid of this process / your id
while ($_ = $ARGV[0], /^-/) {
    shift @ARGV;
    if	  (/^--$/)		    { $_ = $ARGV[0]; last }
    elsif (/^-(h|help|\?)$/)	    { &usage }
    elsif (/^-[dv]$/)		    { $debug++ }
    elsif (/^-l$/)		    { exec 'kill', '-l' }
    elsif (/^-m$/)		    { $match = 1 }
    elsif (/^-s$/)		    { $show = 1 }
    elsif (/^-([a-z][a-z0-9]+|[0-9]+)$/i) { $signal = $1 }
    elsif (/^-/)		    { &usage }
}

$program = $_; &usage unless $program;


die "Maybe $procfs is not mounted\n" unless -e "$procfs/0/status";
opendir(PROCFS, "$procfs") || die "$procfs $!\n";
print "  PID  EUID  RUID COMMAND\n" if $debug > 1;

# quote meta characters
($programMatch = $program) =~ s/(\W)/\\$1/g;

foreach (sort{$a <=> $b} grep(/^[0-9]/, readdir(PROCFS))) {
    $status = "$procfs/$_/status";
    $pid = $_;
    next if $pid == $$;		# don't kill yourself

    open(STATUS, "$status") || next; # process maybe already terminated
    while(<STATUS>) {
	@proc = split;

	printf "%5d %5d %5d %s\n", $pid, $proc[$PROC_EUID],
	$proc[$PROC_RUID], $proc[$PROC_NAME] if $debug > 1;

	if ( # match program name
	    ($proc[$PROC_NAME] eq $program ||
	     ($match && $proc[$PROC_NAME] =~ /$programMatch/oi)
	     ) &&
	    # id test
	    ($proc[$PROC_EUID] eq $id || # effective uid
	     $proc[$PROC_RUID] eq $id || # real uid
	     !$id))			 # root
	{
	    push(@kill, $pid);
	}
    }
    close STATUS;
}
closedir PROCFS;

if ($#kill < 0) {		# nothing found
    warn "No matching processes ``$program''.\n";
    exit(1);
}

$signal =~ y/a-z/A-Z/;		# signal name in upper case
$signal =~ s/^SIG//;		# strip a leading SIG if present
print "kill -$signal @kill\n" if $debug || $show;

$cnt = kill ($signal, @kill) unless $show; # kill processes
exit(0) if $show || $cnt == $#kill + 1;
exit(1);