#! /usr/bin/perl
##
## $Id: par.in 2096 2009-06-17 21:49:46Z heas $
##
## rancid 2.3.3
## Copyright (c) 1997-2008 by Terrapin Communications, Inc.
## All rights reserved.
##
## This code is derived from software contributed to and maintained by
## Terrapin Communications, Inc. by Henry Kilmer, John Heasley, Andrew Partan,
## Pete Whiting, Austin Schutz, and Andrew Fort.
##
## 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 Terrapin Communications,
##        Inc. and its contributors for RANCID.
## 4. Neither the name of Terrapin Communications, Inc. nor the names of its
##    contributors may be used to endorse or promote products derived from
##    this software without specific prior written permission.
## 5. It is requested that non-binding fixes and modifications be contributed
##    back to Terrapin Communications, Inc.
##
## THIS SOFTWARE IS PROVIDED BY Terrapin Communications, INC. 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 COMPANY 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.
#
# PAR - parallel processing of command
#
# par -q -n # -l logfile -c command -x -d
#   -q = quiet mode (don't log anything to the logfiles)
#   -n # = number of processes to run at once (default = 3)
#   -l logfile = logfile to store par logging into (.0-.n)
#   -c command = command to run (can also be in the list
#                of routers begining with a :
#   -x = view par logs as they run through xterms
#   -i = run commands through interactive xterms
#   -d = print debugging to stderr
#   -p # = pause # seconds between forks, default 0.
#   -f = no file or STDIN, just run a quantity of $command.
#                This precludes passing different args to each process.
#   -e = exec args split by spaces rather than use sh -c
#
# par takes a list of items to run a command on.  If the list entry begins
# with a ":" the remainder of the line is the command to run ("{}" will be
# replaced with each subsequent item in the list.  If the list entry begins
# with a "#", the entry is ignored.  If a command is defined (either with
# the -c or with a : line) any entry thereafter will be applied to the
# command by replacing the {} brackets.  In no cammand is defined, then each
# line is assumed to be a command to be run.
#
use Getopt::Std;
getopts('p:n:l:c:fixedqV');
if ($opt_V) {
    print "rancid 2.3.3\n";
    exit(0);
}
$procs=$opt_n;  $procs=3 if(!$procs);
$command=$opt_c;   #$command="{}" if(!$command);
$parlog=$opt_l; $parlog="par.log.".time() if(!$parlog);
$debug=$opt_d;
$no_file=$opt_f ? 1 : 0;
$pause_time = $opt_p ? $opt_p : 0;

if ($opt_q && ($opt_x || $opt_l)) {
    print STDERR "-q nullifies -x and -l\n";
    exit(1);
}

$signalled=0;

sub handler {
    $signalled++;
    print STDERR "Received signal - ending run ($signalled).\n";
    if($signalled>1) {
	printf(STDERR "Ok - killing $id!\n");
	kill 9, 0;
        exit(1);
    }
}

$SIG{'INT'} = 'handler';
$SIG{'TERM'} = 'handler';
$SIG{'QUIT'} = 'handler';

sub start {
    local($cmd,$logfile)=@_;
    unless ($id=fork) {
	if (!$opt_q) {
	    local($date)=scalar localtime;
	    open(LOG,">>$logfile");
	    print(LOG "!!!!!!!\n!$date: $cmd\n!!!!!!!\n");
	    close(LOG);
	    exec "($cmd) >>$logfile";
	} else {
            if($opt_e) {
                # Don't use sh -c.
	        exec split(/\s+/, $cmd);
            }
	    exec "($cmd)";
	}
        exit 0;
    }
    print STDERR "Starting $cmd: process id=$id logfile=$logfile\n" if ($debug);
    $id;
}

sub finish {
    if(($id=wait)>0){
        $logfile=$log{$id};
        print STDERR "$id finished (logfile $logfile)\n" if($logfile && $debug);
        $logfile;
    }
}

sub watchf {
    local($log)=@_;
    unless(fork) { exec "xterm -e tail -f $log" ; exit 1; }
}

# this does not work, $_ doesnt end up with <>
#for($i=0; ($no_file && $i<$procs) || (! $no_file && <> ) ;$i++) {
for($i=0; ($no_file || ($_=<>)) ;$i++) {
    chop;
    if (/^\#/){$i--;next;}
    if ($opt_c == "" && /^:(.*)$/) {
	$command=$1;$i--;next;
    }
    if ($i<$procs) {
	$logfile="running.$i"; $logfile="$parlog.$i" if (!$opt_q);
    } else {
	$logfile=finish;
    }
    last if $signalled;
    if ($logfile) {
        $cmd = $command;
        $cmd =~ s/\{\}/$_/g;
	$cmd = "xterm -e $cmd" if ($opt_i);
        $id=start($cmd,$logfile);
	watchf($logfile) if($opt_x);
        $log{$id} = $logfile;
    }
    print STDERR "$i/$procs: $_: id=$id, log=$log{$id}\n" if ($debug);
    sleep($pause_time) if ($pause_time);
}

if($signalled && !eof) {
    $i--;
    print STDERR "Signalled - not running these:\n$_\n";
    while(<>){print STDERR;}
} else {
    print STDERR "All work assigned.  Waiting for remaining processes.\n" if ($debug);
}
$procs=$i if ($i<$procs);
while($procs) {
    $procs-- if(finish);
}
print STDERR "Complete\n" if ($debug);
