#!/usr/bin/perl
#
# Copyright (c) 1995-1996 Wolfram Schneider <wosch@FreeBSD.org>. Berlin.
# All rights reserved.
#
# 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.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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
#
# $FreeBSD$


$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] procname ...\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 }
}

&usage if $#ARGV < 0;		# no arguments
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;

undef %pidu;
undef %thiskill;

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;

	foreach $program (@ARGV) {
	    # quote meta characters
	    ($programMatch = $program) =~ s/(\W)/\\$1/g if $match;

            # match program name
	    if ($proc[$PROC_NAME] eq $program ||
		($match && $proc[$PROC_NAME] =~ /$programMatch/i)) {
		
		# id test
		if ($proc[$PROC_EUID] eq $id || # effective uid
		    $proc[$PROC_RUID] eq $id || # real uid
		    !$id)			# root
		{
		    push(@kill, $pid) if !$pidu{"$pid"};
		    $pidu{"$pid"} = $pid;
		    $thiskill{"$program"}++;
		} 
		
		# process exists, but does not belong to you
		else {
		    $notkillable{"$program"}++;
		}
	    }
	}
    }
    close STATUS;
}
closedir PROCFS;

# nothing found
foreach $program (@ARGV) {
    if (!$thiskill{"$program"}) {
	print STDERR "No processes matching ``$program''"; 
	print STDERR " belong to you" if $notkillable{"$program"};
	print STDERR "\n";
    }
}


# nothing found
exit(1) if $#kill < 0;

$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);