File: ps-watcher.in.in

package info (click to toggle)
ps-watcher 1.08-9
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 760 kB
  • sloc: sh: 2,907; perl: 1,281; makefile: 103
file content (1337 lines) | stat: -rwxr-xr-x 38,448 bytes parent folder | download | duplicates (6)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
#!@PERL@ -w
# -*- Perl -*-
use diagnostics;
my $vcid='$Id: ps-watcher.in.in,v 1.63 2009/02/19 16:57:31 rockyb Exp $ ';
# See usage subroutine or perlpod documentation below.

# Copyright (C) 2000, 2002, 2003, 2004, 2005, 2006, 2008 
# Rocky Bernstein, email: rocky@gnu.org
#
# This program is free software; you can
# redistribute it and/or modify it under the terms of the GNU General
# Public License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

use vars qw($program $ps_cmd $ps_cmdfull $ps_fullcmd_fmt @ps_vars $ps_dvars
	    $0 $logopened $ps_args_fmt $args
            $count $pid $command $ps_arg_opts $DEVNULL %opts $PIDFILE
           );

$PIDFILE = "/var/run/ps-watcher.pid";

use strict;
BEGIN { require 5.00503 }

sub usage($) {
  my ($full_help) = @_;

  print "
usage: 

   $program [OPTIONS..]

$program can be used to monitor various processes based on ps-like
information.

options: 
  --help              -- print this help and exit
  --doc               -- extract and print complete documentation and exit
  --version           -- show a CVS version string and exit
  --debug *n*         -- give debugging output. The higher the
                         number, the more the output
  --run | --norun     -- do/don't run actions
                         go through the motions as though we were going to
  --log  [*logfile*]  -- Set a log file for this program. If option given
                         but no logfile, then use STDERR. Default is 
                         no error log file.
  --syslog | --nosyslog
                      -- send or don't send error output to syslog
                         Default is to send to syslog.
  --config *cnf file* -- specify configuration file.

  --daemon | --nodaemon 
                      -- do or don't become a daemon. Default daemonize.
  --sleep  *time*     -- sleep interval between iterations. The default is
                         $opts{sleep_interval} seconds.
  --path path         -- executable search path to use in running commands

  --ps-prog *program* -- command that gets ps information. The default is:
                         $opts{ps_prog}
  --ps-pids-opt *ps opts* 
                      -- ps options that lists pids and commands. The
                         default is: $opts{ps_pid_opts}
";

  if ($full_help) {
      print "
General operation: 

Periodically a list of processes obtained via ps. More precisely
each item in the list contains the process name (just what's listed in
the \"command\" field, not the full command and arguments) and its
process id (pid). A configuration file specifies a list of Perl
regular-expression patterns to match the process names against. For
each match, a Perl expression specified for that pattern is
evaluated. The evaluated expression can refer to variables which are
set by ps and pertain to the matched process(es), for example the
amount memory consumed by the process, or the total elapsed time. Some
other variables are set by the program, such as the number of times
the process is running. If the Perl expression for a matched pattern
evaluates true, then an action can be run such as killing the program,
restarting it, or mailing an alert.

This program can be used to ensure a daemon hasn't died or ensure it
is not running too many times. It might be used to determine when a
process has consumed too many resources (for example due to a memory
leak).

The following variables can be used in patterns or actions:
\t".  '$' . join("\n\t\$", @ps_vars) .
"
  The following is a sample config file:

# Comments start with # or ; and go to the end of the line.

# The format for each entry is in Microsoft .INI form:
# [process-pattern]
# trigger = perl-expression
# action  = program-and-arguments-to-run

[httpd\$]
  trigger = \$count < 4
  action  = echo \"\$trigger fired -- You have \$count \$command sessions.\"

[em?cs]
trigger = \$vsz > 10
action  = echo \"Looks like you have a big \$command program: \$vsz KB\"

";
   }
   exit 100;
}

sub init();
sub podthis();
sub process_options();
sub show_version();
sub daemonize();
sub eval_trigger_action($$$);
sub make_the_rounds($);
sub elapsed2secs($);
sub logger($);
sub debug_log($$);
sub gather_psinfo();
sub read_config($);
sub check_config_file($);
sub run_trigger($$$);
sub check_pid();

init();
process_options();

# Unfurl the banner...
logger("Starting: $vcid");

my $cfg=read_config($opts{conf_file});

if (!defined($cfg)) {
  for my $line (@Config::IniFiles::errors) {
    logger($line);
  }
  exit 2;
}

if ($opts{daemon}) {
    if (! check_pid()) {
      exit 1;
    }
    if (! daemonize()) {
     exit 1;
    }
}

install_handlers();

do {
  make_the_rounds($cfg);
  sleep $opts{sleep_interval} if $opts{sleep_interval} > 0;
  check_config_file($opts{conf_file});
} until ($opts{sleep_interval} < 0) ;
if ($opts{syslog}) {
 use Sys::Syslog;
 closelog;
}
exit 0;

# Evaluates the trigger and if that's true also performs
# an action. 1 is returned if the action was performed, 
# zero otherwise.
sub eval_trigger_action($$$) {
    my ($trigger,$action,$perl_action) = @_;
    my $etrigger=$trigger;
    # It is a pain to predeclare all of the variables assigned
    # by ps which is OS and ps specific. So we'll allow anything.
    # Likewise, we'll allow it occur in $action.
    no strict; 
    if ($trigger ne '1') {
	$etrigger =~ s/"/\\"/g;
	debug_log("trigger before substitution: $etrigger", 2);
	$etrigger = eval qq/"$trigger"/;
    }
    debug_log("trigger after substitution: $etrigger", 2);
    if (eval ($etrigger)) {
	if (defined($perl_action)) {
	    debug_log("running Perl_action: $perl_action", 2);
	    eval($perl_action) if $opts{run};
	}
	if (defined($action)) {
	    debug_log("action before substitution: $action", 2);
	    my $eaction=$action;
	    $eaction =~ s/"/\\"/g;
	    $eaction = eval qq/"$eaction"/;
	    debug_log("action after substitution: $eaction", 2);
	    my $output=`$eaction` if $opts{run};
	    chomp($output);
	    logger($output) if $output;
	}
	return 1;
    }
    return 0;
}

# Perform a round over the process_patterns comparing against the
# process info to see if anything's stirring.
sub make_the_rounds($) {
  my $cfg = $_[0];
  my @ps_info=gather_psinfo();
  foreach our $ps_pat ($cfg->Sections()) {
    debug_log("process pattern: /$ps_pat/", 1);
    my @selected_ps;
    my $in_prolog_epilog=0;
    my $trigger     = $cfg->val($ps_pat, 'trigger') || '1';
    my $action      = $cfg->val($ps_pat, 'action');
    my $perl_action = $cfg->val($ps_pat, 'perl-action');
    my $occurs      = $cfg->val($ps_pat, 'occurs') || "first";
    local $count;
    if ($ps_pat =~ /^\$PROLOG/ || $ps_pat =~ /\$EPILOG/) {
	# Set to run trigger below.
	$count  = @ps_info;
	$in_prolog_epilog=1;
    } else {
	@selected_ps = grep(/$ps_pat/, @ps_info);
	$count = @selected_ps; 
	debug_log("count for /$ps_pat/: $count", 2);
    }
    if ($in_prolog_epilog) {
	# execute trigger
	eval_trigger_action($trigger, $action, $perl_action);
    } elsif ($occurs =~ /none/i) {
      if ($count eq 0) {
	  # execute the trigger anyway
	  eval_trigger_action($trigger, $action, $perl_action);
      }
    } elsif ($count gt 0) {
    TRIGGER:
      foreach (@selected_ps) {
	next if !/\s*(\d+)\s+(\S+)/;
        local($pid, $command) = /\s*(\d+)\s+(\S+)/;
        if ($pid !~ /\d+/) {
          logger("Something wrong with ps format:\n$_");
          next;
        }

        my $ps_fullcmd = sprintf $ps_fullcmd_fmt, $pid;
        my @output     = `$ps_fullcmd`;
        my $output='';
	if (@output == 1) {
	  # Got one line of output - good.
	  $output=$output[0];
	  # Make sure though we don't just have a title line. 
	  # One of the fields should be just digits, e.g. ppid, uid, gud...
	  next if $output !~ m{\s+\d+\s+};
        } elsif (@output == 2 && @PS_NO_NULL_HEADER@) {
	  # Got two lines of output - we are running a ps where
          #  we can't remove the title line?
	  $output=$output[1];
        } elsif (@output > 1 && @PS_CAN_RETURN_MULTIPLE_LINES@) {
	  # Got multiple lines of output - we are running a ps which can
	  # do so. For example Solaris does this for a process that has many
	  # LWPs (light-weight processes).
	  $output=$output[0];
	} else {
          debug_log("Something wrong getting ps variables", 1);
	  next;
        }

	local $args = '';
	if ($ps_arg_opts) {
	  my $ps_argscmd = sprintf $ps_args_fmt, $pid;
          my @output     = `$ps_argscmd`;
	  if (@output == 1) {
  	    $args=$output[0];
          } elsif (@output == 2 && @PS_NO_NULL_HEADER@) {
	    $args=$output[1];
	  } else {
            debug_log("Something wrong with getting command arguments", 1);
          }
	}

        # Process may have disappeared. In this case we'll get no 
	# output.
	next if !$output;

        # Add ' ' so split will junk first ps_dvars $junk.
        $output = ' ' . $output;
        my $perl_ps_assign = "$ps_dvars = split(/\\s+/, \$output)";
        { 
          # It is a pain to predeclare all of the variables assigned
          # by ps which is OS and ps specific. So we'll allow anything.
          # Likewise, we'll allow it occur in $action.
          no strict; 

	  # Escape backticks so that we don't inadvertently run
	  # the program. For example there could be a process named
	  # `/tmp/evilcommand` (with backticks). Thanks to Randal
	  # Schwartz for noticing the problem.
	  # Not sure if there are other things to watch out for.
	  # Although the Perl Cookbook suggests how to make system,
	  # safe, it is silent about making eval safe.
	  $command =~ s/`/\\`/g;

          if (eval ($perl_ps_assign)) {
	      my $evaled = eval_trigger_action($trigger, $action, 
					       $perl_action);
	      last TRIGGER if $evaled && $occurs eq 'first-trigger';
	      last TRIGGER if $occurs eq 'first';
          } else {
            logger("Something wrong with perl assignment: $perl_ps_assign");
            last TRIGGER;
	  }
        } # no strict
      } # foreach
    } # if $count
  }
}

# Initailize various variables variously.
sub init() {

  use File::Basename;
  $program          = basename($0); # Who am I today, anyway? 

  $DEVNULL = '/dev/null'; # And what do we do about non Unix?

  use constant MINS   => 60;
  use constant HOURS  => 60*60;
  use constant DAYS   => HOURS * 24;

  $opts{debug}        = 0;  # no debugging
  $opts{run}          = 1;  # run actions
  $opts{syslog}       = 1;  # Log errors to syslog
  $opts{logfile}      = $DEVNULL;  
  $opts{daemon}       = 1;  # Run as daemon;
  $opts{ps_prog}      = '/bin/ps';   # Where is ps? 
  $opts{ps_pid_opts}  = '@PS_PID_OPTS@';   # How do I get pids and commands?

  $ps_arg_opts  = '@PS_ARGS@';       # How do I get full process command?

  # List of all the fields from ps we will be able to use. Don't need
  # to list variables listed above. 
  @ps_vars = qw ( @PS_VARS@ 
);

  # Convert the above into an argument list like
  # ($junk, $user, ... )
  # The first argument ($junk) will be null and thrown out.
  $ps_dvars = '($junk,$' . join(',$', @ps_vars) . ')';

  $opts{sleep_interval} = 300;

}

# The bane of programming.
sub process_options() {
  use Getopt::Long;
  my(@opt_cf);
  $Getopt::Long::autoabbrev = 1;
  my($newstyle_config);

  my ($help, $long_help, $show_version);

  my $result = &GetOptions
    (
     'help'         => \$help,
     'doc'          => \$long_help,
     'version'      => \$show_version,
     'config=s'     => \$opts{conf_file},
     'debug=i'      => \$opts{debug}, 
     'path=s'       => \$ENV{PATH},
     'ps-pid-opts=s'=> \$opts{ps_pid_opts},
     'ps-prog=s'    => \$opts{ps_prog},
     'sleep=i'      => \$opts{sleep_interval},
     'log:s'        => \$opts{logfile},
     'syslog!'      => \$opts{syslog}, 
     'run!'         => \$opts{run}, 
     'daemon!'      => \$opts{daemon}, 
    );

  show_version() if $show_version;
  usage(1) if $help;
  podthis() if $long_help;

  # However specifying a configuration file is not. 
  # Nor can we deal with multiple configuration files or tolerate
  # option-processing errors. 
  usage(0) if !$result;

  # The option-specifier "--config" is optional...
  if (@ARGV && !defined($opts{conf_file})) {
    $opts{conf_file} = shift(@ARGV);
  } 
  
  # However we do have to give exactly one configurtion file. 
  if (!defined($opts{conf_file}) || @ARGV != 0) {
    print STDERR "$program: Please specify exactly one configuration file.\n";
    usage(0);
  }

  $ps_cmd = "$opts{ps_prog} $opts{ps_pid_opts}"; 
  my $ps_vars;
  if (@PS_CUSTOM_HEADER@) {
   $ps_vars = join('= -o ', @ps_vars) . '=';
  } else {
   $ps_vars = join(' -o ', @ps_vars);
  }

  if ('@PS_FULLCMD_FMT@') {
      $ps_fullcmd_fmt  = "@PS_FULLCMD_FMT@";
  } else {
      $ps_fullcmd_fmt  = "$opts{ps_prog} -p %d -o $ps_vars";
  }
  if ('@PS_ARGS_FMT@') {
      $ps_args_fmt     = "@PS_ARGS_FMT@";
  } else {
      $ps_args_fmt     = "$opts{ps_prog} -p %d $ps_arg_opts";
  }

  open STDIN, $DEVNULL   or die "Can't read $DEVNULL: $!";
  if ($opts{logfile} ne '') {
      open STDOUT, ">>$opts{logfile}" or 
	  die "Can't write STDOUT to $opts{logfile}: $!";
      open STDERR, ">>&STDOUT" or 
	  die "Can't write STDERR to $opts{logfile}: $!";
  }
}

# Signal handling..
sub install_handlers {
  $SIG{'QUIT'} = \&terminate;
  $SIG{'TERM'} = \&terminate;
  $SIG{'INT'}  = \&terminate;
  $SIG{'HUP'}  = \&null_handler;
  $SIG{'USR1'} = \&debug_up_handler;
  $SIG{'USR2'} = \&debug_down_handler;
}

# Used perhaps to break out of a deep sleep.
sub null_handler {
  my($signo) = @_;
  logger("Received signal: ${signo}");
}

# Increase verbosity of debugging.
sub debug_up_handler {
  my($signo) = @_;
  $opts{debug}++;
  logger("Received signal: ${signo}. Increasing debugging to $opts{debug}.");
}

# Decrease verbosity of debugging.
sub debug_down_handler {
  my($signo) = @_;
  $opts{debug}--;
  logger("Received signal: ${signo}. Decreasing debugging to $opts{debug}.");
}

# Signal handler to go down recording the signal.
sub terminate {
  my($signo) = @_;
  use Config;
  if (defined $Config{sig_name}) {
      my $i = 0; 
      my @signame;
      my %sig;
      foreach my $name (split(' ', $Config{sig_name})) {
	  $signame[$i] = $name;
	  $sig{$name} = $i;
	  $i++;
      }
      $signo = $sig{$signo} if exists($sig{$signo});
      if ($signo =~ m{\A\d+\Z} ) {
	  logger("Going down on $signame[$signo] (${signo}) signal. " .
		 "Have a nice day!");
      } 
  } else {
      logger("Going down on signal ${signo}). Have a nice day!");
  }

  $signo = 15 if $signo !~ m{\A\d+\Z};
  if ($opts{syslog}) {
      use Sys::Syslog;
      closelog;
  }
  exit $signo;
};

# Utility function for parsing/converting elapsed time into seconds.
sub elapsed2secs($) {
  $_ = $_[0];

  # Handle formats like:
  # 1-08:34:37  -- One day, 8 hours, 34 minutes, 37 seconds
  #   20:40:34  -- 20 hours, 40 minutes, 34 seconds
  #       0:00  -- 0 seconds.

  # 1-08:34.37  -- One day, 8 hours, 34 minutes, 37 seconds
  #   20:40.34  -- 20 hours, 40 minutes, 34 seconds
  #       5.03  -- 5 minutes, 3 seconds.
  #          5  -- 5 seconds.

  # Some easy cases.
  return -1 if !defined($_) || m{\A\s*\Z};
  return $_ if m{\A\d+\Z};

  # Originally had as one pattern and optional 
  # arguments but i got compaints about using
  # uninitialized variables even with "no diagonstics". Would rather
  # switch than fight.
  my $min_secs_pat = '(\d{1,2})[:.](\d\d)';
  if (m{
      (\d{1,2})-          # The number of days. e.g. 1- or 19- or blank
      (\d{1,2})[:.]       # The number of hrs. e.g. 01: or 23: or blank
      $min_secs_pat
      }x) {
      my ($days, $hours, $minutes, $secs) = ($1, $2, $3, $4);
      return ($days*DAYS + $hours*HOURS + $minutes*MINS + $secs);
  } elsif (m{
	   (\d{1,2})[:.]  # The number of hrs. e.g. 01: or 23: or blank
	   $min_secs_pat
	   }x) {
      my ($hours, $minutes, $secs) = ($1, $2, $3);
      return ($hours*HOURS + $minutes*MINS + $secs);
  } elsif (m{$min_secs_pat}) {
    my ($minutes, $secs) = ($1, $2);
    return ($minutes*MINS + $secs);
  } else {
    logger("Error in converting $_ to seconds");
    return -1;
  }
}

# Return time and PID as string in a common format
sub timestring() { 
    my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = 
	localtime(time);
    $mon++; 
    return sprintf( "%.2d/%.2d/%.2d %.2d:%.2d:%.2d %s[$$]", 
		    $mon, $mday, $year%100, $hour, $min, $sec, $program); 
}

# log error to syslog and print to STDERR.
sub logger($) {
  my($msg) = shift;

  if ($opts{syslog}) {
    if (!$logopened) {
      use Sys::Syslog;
      $logopened++;
      openlog($program,'cons,pid', 'err');
    }
    syslog('info', $msg);
  }
  if (defined($opts{logfile}) && $opts{logfile} ne $DEVNULL) {
    my $ts=timestring();
    print STDERR "$ts: $msg\n";
  }
}

sub debug_log($$) {
  my($msg, $level) = @_;
  logger("** debug ** $msg") if $opts{debug} >= $level;
}

sub gather_psinfo() {
  my @output=`$ps_cmd`;
  return @output;
}

# Show the CVS version id string and quit.
sub show_version() {
  print "$vcid
Copyright (C) 2000, 2002, 2003, 2004, 2006, 2008 Rocky Bernstein.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
";
  exit 10;
}

sub check_pid() {
  if (-f $PIDFILE) {
    if (open(PID,$PIDFILE)) {
      my $pid = <PID>;
      if (!close(PID)) {
        logger("Unable to close file handle PID for file '$PIDFILE': $!");
        return;
      }
      if (-f "/proc/$pid/stat") {
        if (open(FH,"/proc/$pid/stat")) {
          my $line = <FH>;
          if (!close(FH)) {
            logger("Unable to close file handle FH for file '/proc/$pid/stat': $!");
            return;
          }
          if ($line =~ /\d+[^(]*\((.*)\)\s*/) {
            my $process = $1;
            if ($process =~ /^$program$/) {
              logger("$program already running at PID $pid; exiting.");
              exit(0);
            }
          }
        } else {
          logger("Unable to open file handle FH for file '/proc/$pid/stat': $!");
          return;
        }
      } else {
        logger("Removing stale PID file.");
        unlink($PIDFILE);
      }
    }else{
      logger("Unable to open file handle PID for file '$PIDFILE': $!");
      return;
    }
  }
  return 1;
}

sub daemonize() {
  chdir '/'                 or die "Can't chdir to /: $!";
  defined(my $pid = fork)   or die "Can't fork: $!";
  exit 0 if $pid;
  if (open(FH,">$PIDFILE")) {
    print FH $$;
    if (!close(FH)) {
      logger("Unable to close file handle FH for file '$PIDFILE': $!");
      return;
    }
  } else {
    logger("Unable to open file handle FH for file '$PIDFILE': $!");
    return;
  }
  use POSIX qw(setsid);
  setsid()                  or die "Can't start a new session: $!";
  umask 0;
  return 1;
}

# Time configuration file was last read.
my $conf_time;

# Read a configuration file.
sub read_config($) {
  use Config::IniFiles;
  my($cf)=@_;
  if (!-f $cf || !-r _ || -z _ || !-T _) {
    logger("Unusable config file: <$cf>");
    return undef;
  } 

  # Save time we read the configuration file so we can check back
  # later to see if it changed.

  my($dev, $ino, $mode, $nlink, $uid, $gid, $rdev, $size,
     $atime, $mtime, $ctime) = stat $cf;
  $conf_time = $mtime;

  return new Config::IniFiles( -file => $cf );
}

# Check to see if any configuration file has changed 
# since the last time this routime was called.
# Updates global $conf_time.
sub check_config_file($) {
  my ($conf_file) = @_;
  my($dev, $ino, $mode, $nlink, $uid, $gid, $rdev, $size,
     $atime, $mtime, $ctime) = stat $opts{conf_file}; 
  if ( defined($conf_time) && defined($mtime) && $conf_time < $mtime ) { 
    logger("Configuration file $conf_file modified; re-reading...");
    $cfg = read_config($conf_file);
  }
}

sub run_trigger($$$) {
  my($trigger, $action, $count) = @_;
  my $etrigger=$trigger;
  if ($trigger ne '1') {
    $etrigger =~ s/"/\\"/g;
    debug_log("trigger before substitution: $etrigger", 2);
    $etrigger = eval qq/"$trigger"/;
  }
  debug_log("trigger after substitution: $etrigger", 2);
  if (eval ($etrigger)) {
    debug_log("action before substitution: $action", 2);
    my $eaction=$action;
    $eaction =~ s/"/\\"/g;
    $eaction = eval qq/"$eaction"/;
    debug_log("action after substitution: $eaction", 2);
    my $output=`$eaction` if $opts{run};
    chomp($output);
    logger($output) if $output;
  }
}

sub podthis() {
  use Pod::Text;
  $^W = 0;
  pod2text $0;
  exit 101;
}

#--------------------------------------------------
=pod

=head1 NAME

@PACKAGE@ - monitors various processes based on ps-like information.


=head1 SYNOPSIS

B<@PACKAGE@> [I<options>...]
            [C<--config>] I<config-file>

=head1 DESCRIPTION

Periodically a list of processes obtained via C<ps>. More precisely
each item in the list contains the process name (just what's listed in
the "cmd" field, not the full command and arguments) and its process
id (pid). A configuration file specifies a list of Perl
regular-expression patterns to match the processes against. For each
match, a Perl expression specified for that pattern is evaluated. The
evaluated expression can refer to variables which are set by ps and
pertain to the matched process(es), for example the amount memory
consumed by the process, or the total elapsed time. Some other
variables are set by the program, such as the number of times the
process is running. If the Perl expression for a matched pattern
evaluates true, then an action can be run such as killing the program,
restarting it, or mailing an alert, or running some arbitrary Perl
code.

Some things you might want to watch a daemon or process for:

=over 2

=item *

check that it is running (hasn't died)

=item *

ensure it is not running too many times

=item *

isn't consuming too much memory (perhaps a memory leak), or I/O

=back

Some actions you might want to take:

=over 2

=item *

restart a process

=item *

kill off rampant processes

=item *

send an alert about any of the conditions listed above

=back

Depending on options specfied, this program can be run as a daemon,
run once (which is suitable as a C<cron> job), or run not as a daemon
but still continuously (which may be handy in testing the program or
your configuration).

=head2 OPTIONS

=over 4

=item --help

Print a usage message on standard error and exit with a return code
of 100.

Z<>

=item --doc

Extact the full documentation that you are reading now, print it and
exit with a return code of 101.

Z<>

=item --version

Print the version release on standard output and exit with a return
code of 10.

Z<>

=item --debug I<number> 

Give debugging output. The higher the number, the more the output. The
default is 0 = none. 2 is the most debugging output.

=item [--config] I<configuration file>

Specify configuration file. .

See L<CONFIGURATION FILE FORMAT> below for information on the format
of the configuration file and L<EXAMPLE CONFIGURATION> for a complete
example of a configuration file.

Z<>

=item --log [I<log file>]

Send or don't send error and debugging output to a log file. If option
is given but no logfile is specified, then use STDERR. The default is
no error log file.  See also --syslog below.

Z<>

=item --syslog | --nosyslog

Send or don't send error and debugging output to syslog. The default
is to syslog error and debug output.

Z<>

=item --daemon | --nodaemon

Run or don't as a daemon.

Z<>

=item --path I<search-path>

Specify the executable search path used in running commands.

=item --ps-prog I<program>

One can specify the command that gives ps information. By default, the
command is F<@PS@>.

Z<>

=item --run | --norun  

do/don't run actions go through the motions as though we were going
to. This may be useful in debugging.

Z<>

=item --sleep I<interval in seconds>

It is expected that one might want to run @PACKAGE@ over and over
again. In such instances one can specify the amount of time between
iterations with this option.

If a negative number is specified the program is run only once.

Z<>

=back

=head2 CONFIGURATION FILE MODIFICATION AND SIGNAL HANDLING

Periodically @PACKAGE@ checks to see if the configuration file
that it was run against has changed. If so, the program rereads the
configuration file.

More precisely, the checks are done after waking up from a slumber.
If the sleep interval is long (or if you are impatient), you can
probably force the program to wake up using a HUP signal.

At any time you can increase the level of debug output by sending a
USR1 signal to the @PACKAGE@ process. Similarly you can decrease the
level of debug output by sending the process a USR2 signal.

It is recommended that you terminate @PACKAGE@ via an INT, TERM, or QUIT
signal.

=head1 CONFIGURATION FILE FORMAT

The format of a configuration file is a series of fully qualified
filenames enclosed in square brackets followed by a number of
parameter lines. Each parameter line has a parameter name followed by
an "equal" sign and finally value. That is:

 # This is a comment line
 ; So is this.
 [process-pattern1]
  parameter1 = value1
  parameter2 = value2

 [process-pattern2]
  parameter1 = value3
  parameter2 = value4

Comments start with # or ; and take effect to the end of the line.

This should be familiar to those who have worked with text-readible
Microsoft C<.INI> files.

Note process patterns, (F<process-pattern1> and F<process-pattern2>
above) must be unique. If there are times when you may want to
refer to the same process, one can be creative to make these unique.
e.g. F<cron> and F<[c]ron> which refer to the same process even
though they I<appear> to be different.

As quoted directly from the Config::IniFiles documentation:

Multiline or multivalued fields may also be defined ala UNIX
"here document" syntax:

  Parameter=<<EOT
  value/line 1
  value/line 2
  EOT

You may use any string you want in place of "EOT".  Note
that what follows the "<<" and what appears at the end of
the text I<must> match exactly, including any trailing
whitespace.

There are two special "process patterns": $PROLOG and $EPILOG, the
former should appear first and the latter last.

You can put perl code to initialize variables here and do cleanup
actions in these sections using "perl-action." 

A description of parameters names, their meanings and potential values
follows.

=over

=item trigger

This parameter specifies the condition on which a process action is
fired.  The condition is evaluated with Perl eval() and should
therefore return something which is equivalent to "true" in a Perl
expression.

If no trigger is given in a section, true or 1 is assumed and
the action is unconditionally triggered.

Example: 

  # Match if httpd has not spawned enough (<4) times. NFS and databases
  # daemons typically spawn child processes.  Since the program
  # matches against the command names, not commands and arguments,
  # something like: ps -ef | grep httpd won't match the below.
  # If you want to match against the command with arguments, see
  # the example with $args below.
  [httpd$]
  trigger = $count <= 4

=item occurs

This parameter specifies how many times an action should be performed
on processes matching the section trigger. Acceptable values are
"every", "first", "first-trigger", and "none".

Setting the occurs value to "none" causes the the trigger to be
evaluated when there are no matching processes.  Although one might
think "$count == 0" in the action expression would do the same thing,
currently as coded this does not work.

Setting the occurs value to "first" causes the process-pattern rule to
be finished after handling the first rule that matches, whether or not the
trigger evaluated to true.

Setting the occurs value to "first-trigger" causes the process-pattern
rule to be finished after handling the first rule that matches I<and>
the trigger evaluates to true.

If the item parameter is not specified, "first" is assumed.

Examples:

  [.]
  occurs = first
  action = echo "You have $count processes running"

  # Note in the above since there is no trigger specified,
  #   occurs = first
  # is the same thing as 
  #   occurs = first-trigger

  [.?]
  trigger = $vsz > 1000
  occurs  = every
  action  = echo "Large program $command matches $ps_pat: $vsz KB"

  # Fire if /usr/sbin/syslogd is not running.
  # Since the program matches against the command names, not commands and
  # arguments, something like: 
  #   ps -ef | grep /usr/sbin/syslogd
  # won't match the below.
  [(/usr/sbin/)?syslogd]
  occurs = none
  action = /etc/init.d/syslogd start

=item action

This specifies the action, a command that gets run by the system
shell, when the trigger condition is evaluated to be true.

Example:

 action = /etc/init.d/market_loader.init restart

=item perl-action

This specifies Perl statements to be eval'd. This can be especially
useful in conjunction with $PROLOG and $EPILOG sections to make tests
across collections of process and do things which @PACKAGE@
would otherwise not be able to do.

Example:

  # A Perl variable initialization.
  # Since @PACKAGE@ runs as a daemon it's a good idea
  # to (re)initialize variables before each run.
  [$PROLOG]
    perl-action = $root_procs=0;

  # Keep track of how many root processes we are running
  [.*]
    perl-action = $root_procs++ if $uid == 0
    occurs  = every

  # Show this count.
  [$EPILOG]
    action  = echo "I counted $root_procs root processes"

=back

=head2 EXPANDED VARIABLES IN TRIGGER/ACTION CLAUSES

Any variables defined in the program can be used in pattern or
action parameters. For example, C<$program> can be used to refer to 
the name of this program @PACKAGE@.

The following variables can be used in either the pattern or action
fields.

=over

=item $action

A string containing the text of the action to run.

Z<>

=item $perl_action

A string containing the text of the perl_action to run.

Z<>

=item $ps_pat

The Perl regular expression specified in the beginning of the section.

Z<>

=item $command

The command that matched $ps_pat.

The Perl regular expression specified in the beginning of the section.
Normally processes will not have funny characters in them. Just in
case, backticks in $command are escaped.

Example: 

  # List processes other than emacs (which is a known pig) that use lots
  # of virtual memory

  [.*]
  trigger = $command !~ /emacs$/ && $vsz > 10
  action  = echo \"Looks like you have a big \$command program: \$vsz KB\"

Z<>

=item $count

The number of times the pattern matched. Presumably the number of
processes of this class running.

Z<>

=item $trigger

A string containing the text of the trigger.

=back

A list of variables specific to this program or fields commonly found in
C<ps> output is listed below followed by a description of the more
common ones. See also C<ps> for a more complete
description of the meaning of the field.

 @PS_VARS@

Beware though, in some situations ps can return multiple lines for a
single process and we will use just one of these in the trigger. In
particular, Solaris's C<ps> will return a line for each LWP (light-weight
process). So on Solaris, if a trigger uses variable lwp, it may or may
not match depending on which single line of the multiple C<ps> lines is
used.

Z<>

=over 

=item $args

The command along with its command arguments. It is possible that this
is might get truncated at certain length (if ps does likewise as is
the case on Solaris). 

Z<>

=item $ppid

The parent process id.

Z<>

=item $stime

The start time of the process.

Z<>

=item $etime

The end time of the process.

Z<>

=item $pmem

The process memory.

Z<>

=item $pcpu

The percent CPU utilization.

Z<>

=item $tty

The controlling tty.

Z<>

=item $vsz

Virtual memory size of the process

=back

=head2 OTHER THINGS IN TRIGGER CLAUSES

To make testing against elapsed time easier, a function C<elapse2sec()>
has been written to parse and convert elapsed time strings in the 
format C<dd-hh:mm:ss> and a number of seconds.

Some constants for the number of seconds in a minute, hour, or day
have also been defined. These are referred to as C<MINS>, C<HOURS>,
and C<DAYS> respectively and they have the expected definitions:

  use constant MINS   => 60;
  use constant HOURS  => 60*60;
  use constant DAYS   => HOURS * 24;

Here is an example of the use of C<elapsed2sec()>:

  # Which processes have been running for more than 3 hours?
  # Also note use of builtin-function elapsed2secs, variable $etime
  # and builtin-function HOURS
  [.]
    trigger = elapsed2secs('$etime') > 1*DAYS
    action  = echo "$command has been running more than 1 day ($etime)"
    occurs  = every

Please note the quotes around '$etime'.

=head1 EXAMPLE CONFIGURATION

  # Comments start with # or ; and go to the end of the line.

  # The format for each entry is in Microsoft .INI form:
  # [process-pattern]
  # trigger = perl-expression
  # action  = program-and-arguments-to-run

  [httpd$]
    trigger = $count < 4
    action  = echo "$trigger fired -- You have $count httpd sessions."

  [.]
  trigger = $vsz > 10
  action  = echo "Looks like you have a big $command program: $vsz KB"

  # Unfortunately we have use a different pattern below. (Here we use
  # ".?" instead of ".".) In effect the the two patterns mean
  # test every process.
  [.?]
    trigger = elapsed2secs('$etime') > 2*MINS && $pcpu > 40
    occurs  = every
    action  = <<EOT
     echo "$command used $pcpu% CPU for the last $etime seconds" | /bin/mail root
     kill -TERM $pid
  EOT

  # Scripts don't show as the script name as the command name on some
  # operating systems.  Rather the name of the interpreter is listed
  # (e.g. bash or perl) Here's how you can match against a script.
  # BSD/OS is an exception: it does give the script name rather than
  # the interpreter name.
  [/usr/bin/perl]
    trigger = \$args !~ /ps-watcher/
    occurs  = every
    action  = echo "***found perl program ${pid}:\n $args"

=head1 Using $PROLOG for getting non-ps information

Here is an example to show how to use ps-watcher to do something not
really possible from ps: check to see if a I<port> is active.  We make
use of lsof to check port 3333 and the $PROLOG make sure it runs.

  [$PROLOG]
    occurs  = first
    trigger = { \$x=`lsof -i :3333 >/dev/null 2>&1`; \$? >> 8 }
    action  = <<EOT
    put-your-favorite-command-here arg1 arg2 ...
  EOT

=head1 SECURITY CONSIDERATIONS

Any daemon such as this one which is sufficiently flexible is a
security risk. The configuration file allows arbitrary commands to be
run. In particular if this daemon is run as root and the configuration
file is not protected so that it can't be modified, a bad person could
have their programs run as root.

There's nothing in the ps command or ps-watcher, that requires one to
run this daemon as root. 

So as with all daemons, one needs to take usual security precautions
that a careful sysadmin/maintainer of a computer would. If you can run
any daemon as an unprivileged user (or with no privileges), do it!  If
not, set the permissions on the configuration file and the directory
it lives in. 

This program can also run chrooted and there is a C<--path> option
that is available which can be used to set the executable search path.
All commands used by @PACKAGE@ are fully qualified, and I generally
give a full execution path in my configuration file, so consider using
the option C<--path=''>.

Commands that need to be run as root you can run via C<sudo>.  I often
run process accounting which tracks all commands run. Tripwire may be
useful to track changed configuration files.

=head1 TROUBLESHOOTING

To debug a configuration file the following options are useful:

   @PACKAGE@ --log --nodaemon --sleep -1 --debug 2 *config-file*

For even more information and control try running the above under the
perl debugger, e.g.

   perl -d @PACKAGE@ --log --nodaemon --sleep -1 --debug 2 *config-file*

=head1 BUGS

Well, some of these are not so much a bug in @PACKAGE@ so much as a
challenge to getting @PACKAGE@ to do what you want it to do. 

One common problem people run in into is understanding exactly what
the process variables mean. The manual page L<ps(1)> should be of
help, but I've found some of the descriptions either a bit vague or
just plain lacking.

Sometimes one will see this error message when debug tracing is turned on:

  ** debug ** Something wrong getting ps variables

This just means that the process died between the time @PACKAGE@ first
saw the existence of the process and the time that it queried
variables.

=head1 SEE ALSO

See also L<ps(1)> and L<syslogd(8)>.

Another cool program doing ps-like things is C<xps>. Well okay, it's
another program I distributed. It shows the process tree dynamically
updated using X Motif and tries to display the output "attractively"
but fast. You can the find the homepage at
L<http://motif-pstree.sourceforge.net> and it download via
L<http://prdownloads.sourceforge.net/motif-pstree?sort_by=date&sort=desc>

=head1 AUTHOR

Rocky Bernstein (rocky@gnu.org)

=head1 COPYRIGHT

  Copyright (C) 2000, 2002, 2003, 2004, 2005, 2006, 2008
  Rocky Bernstein, email: rocky@gnu.org.
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.