[mharc.git] / bin / logcmd

#!/usr/bin/perl -w
##------------------------------------------------------------------------##
##  File:
##      $Id: logcmd,v 1.1 2002/10/01 22:49:46 ehood Exp $
##  Author:
##      Earl Hood       earl@earlhood.com
##  Description:
##	Program to log the output of a program.
##	POD at __END__.
##------------------------------------------------------------------------##
##    Copyright (C) 2002   Earl Hood, earl@earlhood.com
##
##    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., 59 Temple Place - Suite 330, Boston, MA
##    02111-1307, USA
##------------------------------------------------------------------------##

package Devtools::locmd;

use strict;
use Getopt::Long;
use POSIX;

my $our_name = 'logcmd';
my @cmd = ( );
my $cmd_name = "";
my $time_fmt = '%Y-%m-%d %H:%M:%S';

my $first_time = 1;
my $log_file = '-';
my $log_fh;
my $child_pid;

MAIN: {
  my @mailto   = ( );
  my ($help, $man);

  GetOptions(
    'log=s'	  => \$log_file,
    'mailto=s@'	  => \@mailto,	# not implemented, yet
    'time-fmt=s'  => \$time_fmt,

    'help'	  => \$help,
    'man'	  => \$man,
  ) || die qq/ERROR: Use -help for usage information\n/;
  usage(1, 0)  if ($help);
  usage(2, 0)  if ($man);

  if (!@ARGV) {
    die qq/ERROR: No command specified\n/;
  }
  ($cmd_name = $ARGV[0]) =~ s/.*\///;
  @cmd = @ARGV;

  $child_pid = open(CMD, "-|");
  if ($child_pid) {   # parent
    {
      local @SIG{'PIPE','TERM','INT'} = (sub {
	log_line($our_name, $$, "Caught signal: SIG$_[0]\n");
      }) x 3;

      while (<CMD>) {
	log_line($cmd_name, $child_pid, $_);
      }
    }
    if (!close(CMD)) {
      log_line($our_name, $$, qq/Non-zero exit for [$child_pid]: $?\n/);
    }
    log_close();

  } else {      # child
    open(STDERR, '>&STDOUT');
    exec(@cmd) || die qq/ERROR: Cannot exec "@cmd": $!\n/;
  }

} # End: MAIN

##=========================================================================##

sub format_time {
  POSIX::strftime($time_fmt, localtime);
}

sub log_line  {
  my $label = shift;
  my $pid   = shift;
  my $line  = shift;
  my $have_newline = $line =~ /\n\Z/;
  my $eol = ($have_newline) ? "" : "\n";
  if ($first_time) {
    $first_time = 0;
    log_open($log_file);
    print $log_fh join('', '[',format_time(),']',' [',$$,'] ',$our_name,': ',
			   "Command: [$child_pid] @cmd\n");
  }
  print $log_fh join('', '[',format_time(),']',' [',$pid,'] ',$label,': ',
			  $line,$eol);
}

sub log_open {
  my $file = shift;
  if (!defined($file) || $file eq '-') {
    $log_fh = \*STDOUT;
  } else {
    open(LOG, ">>$file") ||
	die qq/ERROR: Unable to open "$file" for appending: $!\n/;
    $log_fh = \*LOG;
  }
}

sub log_close {
  if (!$first_time) {
    if ($log_fh != \*STDOUT) {
      close($log_fh) ||
	  warn qq/Warning: Problem closing log file: $!\n/;
    }
  }
}

sub usage {
  require Pod::Usage;
  my $verbose   = shift || 0;
  my $exit_code	= shift;

  if ($verbose == 0) {
    Pod::Usage::pod2usage(-verbose => $verbose);
  } else {
    my $pager = $ENV{'PAGER'} || 'more';
    local(*PAGER);
    my $fh = (-t STDOUT && open(PAGER, "|$pager")) ? \*PAGER : \*STDOUT;
    Pod::Usage::pod2usage(-verbose => $verbose,
                          -output  => $fh);
    close(PAGER)  if ($fh == \*PAGER);
  }
  defined($exit_code) && exit($exit_code);
}

##=========================================================================##
__END__

=head1 NAME

logcmd - Log the output of a program.

=head1 SYNOPSIS

  logcmd [options] -- <command> [command-args ...]

=head1 DESCRIPTION

B<logcmd> logs the output of a program.  This program is useful
for logging program output for programs that do not have a built-in
logging facility.

Typical usage is to use B<logcmd> in crontabs to log any command
output to a file instead of mail automatically being sent to the
crontab owner.

When invoking B<logcmd>, you B<must> use "C<-->" to separate the
B<logcmd> and its options from the command you are invoking.  For
example,

  logcmd -log out.log -- some-cmd arg1 arg2 arg3

This tells B<logcmd> to run "C<some-cmd arg1 arg2 arg3>" and have
any output goto C<out.log>.

Each line logged will be preceded by a timestamp, the process ID, and
the name of the command.  Also, before the first log message for a command
is printed, B<logcmd> will print out a line giving the full command-line
of the command invoked.  Example:

  [2002-07-30 14:52:13] [25392] logcmd: Command: [25393] mhonarc -quiet -out out /var/archiver/mail
  [2002-07-30 14:52:13] [25393] mhonarc: 
  [2002-07-30 14:52:13] [25393] mhonarc: Warning: Unrecognized character set: utf-8
  [2002-07-30 14:52:13] [25393] mhonarc:          Message-Id: <1022714308.2028.1.camel@xxx.xxx.xxx>
  [2002-07-30 14:52:13] [25393] mhonarc:          Message Number: 00367
  [2002-07-30 14:52:13] [25393] mhonarc: 
  [2002-07-30 14:52:13] [25393] mhonarc: Warning: Unrecognized character set: utf-8
  [2002-07-30 14:52:13] [25393] mhonarc:          Message-Id: <1022716087.2028.3.camel@xxx.xxx.xxx>
  [2002-07-30 14:52:13] [25393] mhonarc:          Message Number: 00368
  [2002-07-30 14:52:14] [25393] mhonarc: 
  [2002-07-30 14:52:14] [25393] mhonarc: Warning: Unrecognized character set: utf-8
  [2002-07-30 14:52:14] [25393] mhonarc:          Message-Id: <1024365245.9394.0.camel@xxx.xxx.xxx>
  [2002-07-30 14:52:14] [25393] mhonarc:          Message Number: 00398


=head1 OPTIONS

=over

=item C<-help>

Display SYNOPSIS and OPTIONS sections.

=item C<-log> I<pathname>

Command output will be logged to I<pathname>.  If this option is
not specified, then standard out is used.

=item C<-man>

Display manpage.

=item C<-time-fmt> I<fmt>

Date/time format to use when printing time before each logged line.
The format string should be in C<strftime>(3) format.  If this
option is not specified, then "C<%Y-%m-%d %H:%M:%S>" is used.

=item C<-->

Terminate option processing for B<logcmd>.  Any arguments after
C<--> comprise the command that B<logcmd> should execute.

=back

=head1 EXAMPLES

The following is an example crontab entries of a user that has
any output of commands goto a personal log file:

  0 2 * * * logcmd -log $HOME/log/cron.log -- $HOME/bin/clean_account
  0 3 * * * logcmd -log $HOME/log/cron.log -- $HOME/bin/pack_mail

=head1 LIMITATIONS

=over

=item *

B<logcmd> performs no file locking on the log file specified.  To help
minimize that a single output line to the log does not get broken up
due to multiple writers, the entire line is dumped in a single call
to Perl's C<print> operator.

=back

=head1 DEPENDENCIES

C<Getopt::Long>, C<POSIX>.

=head1 AUTHOR

Earl Hood, earl@earlhood.com

This program comes with ABSOLUTELY NO WARRANTY and may be copied only
under the terms of the GNU General Public License.

=cut
Commit	Line	Data
2ea8f66b IK	1	#!/usr/bin/perl -w
	2	##------------------------------------------------------------------------##
	3	## File:
	4	## $Id: logcmd,v 1.1 2002/10/01 22:49:46 ehood Exp $
	5	## Author:
	6	## Earl Hood earl@earlhood.com
	7	## Description:
	8	## Program to log the output of a program.
	9	## POD at __END__.
	10	##------------------------------------------------------------------------##
	11	## Copyright (C) 2002 Earl Hood, earl@earlhood.com
	12	##
	13	## This program is free software; you can redistribute it and/or modify
	14	## it under the terms of the GNU General Public License as published by
	15	## the Free Software Foundation; either version 2 of the License, or
	16	## (at your option) any later version.
	17	##
	18	## This program is distributed in the hope that it will be useful,
	19	## but WITHOUT ANY WARRANTY; without even the implied warranty of
	20	## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	21	## GNU General Public License for more details.
	22	##
	23	## You should have received a copy of the GNU General Public License
	24	## along with this program; if not, write to the Free Software
	25	## Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
	26	## 02111-1307, USA
	27	##------------------------------------------------------------------------##
	28
	29	package Devtools::locmd;
	30
	31	use strict;
	32	use Getopt::Long;
	33	use POSIX;
	34
	35	my $our_name = 'logcmd';
	36	my @cmd = ( );
	37	my $cmd_name = "";
	38	my $time_fmt = '%Y-%m-%d %H:%M:%S';
	39
	40	my $first_time = 1;
	41	my $log_file = '-';
	42	my $log_fh;
	43	my $child_pid;
	44
	45	MAIN: {
	46	my @mailto = ( );
	47	my ($help, $man);
	48
	49	GetOptions(
	50	'log=s' => \$log_file,
	51	'mailto=s@' => \@mailto, # not implemented, yet
	52	'time-fmt=s' => \$time_fmt,
	53
	54	'help' => \$help,
	55	'man' => \$man,
	56	) \|\| die qq/ERROR: Use -help for usage information\n/;
	57	usage(1, 0) if ($help);
	58	usage(2, 0) if ($man);
	59
	60	if (!@ARGV) {
	61	die qq/ERROR: No command specified\n/;
	62	}
	63	($cmd_name = $ARGV[0]) =~ s/.*\///;
	64	@cmd = @ARGV;
65
66	$child_pid = open(CMD, "-\|");
67	if ($child_pid) { # parent
68	{
69	local @SIG{'PIPE','TERM','INT'} = (sub {
70	log_line($our_name, $$, "Caught signal: SIG$_[0]\n");
71	}) x 3;
72
73	while (<CMD>) {
74	log_line($cmd_name, $child_pid, $_);
75	}
76	}
77	if (!close(CMD)) {
78	log_line($our_name, $$, qq/Non-zero exit for [$child_pid]: $?\n/);
79	}
80	log_close();
81
82	} else { # child
83	open(STDERR, '>&STDOUT');
84	exec(@cmd) \|\| die qq/ERROR: Cannot exec "@cmd": $!\n/;
85	}
86
87	} # End: MAIN
88
89	##=========================================================================##
90
91	sub format_time {
92	POSIX::strftime($time_fmt, localtime);
93	}
94
95	sub log_line {
96	my $label = shift;
97	my $pid = shift;
98	my $line = shift;
99	my $have_newline = $line =~ /\n\Z/;
100	my $eol = ($have_newline) ? "" : "\n";
101	if ($first_time) {
102	$first_time = 0;
103	log_open($log_file);
104	print $log_fh join('', '[',format_time(),']',' [',$$,'] ',$our_name,': ',
105	"Command: [$child_pid] @cmd\n");
106	}
107	print $log_fh join('', '[',format_time(),']',' [',$pid,'] ',$label,': ',
108	$line,$eol);
109	}
110
111	sub log_open {
112	my $file = shift;
113	if (!defined($file) \|\| $file eq '-') {
114	$log_fh = \*STDOUT;
115	} else {
116	open(LOG, ">>$file") \|\|
117	die qq/ERROR: Unable to open "$file" for appending: $!\n/;
118	$log_fh = \*LOG;
119	}
120	}
121
122	sub log_close {
123	if (!$first_time) {
124	if ($log_fh != \*STDOUT) {
125	close($log_fh) \|\|
126	warn qq/Warning: Problem closing log file: $!\n/;
127	}
128	}
129	}
130
131	sub usage {
132	require Pod::Usage;
133	my $verbose = shift \|\| 0;
134	my $exit_code = shift;
135
136	if ($verbose == 0) {
137	Pod::Usage::pod2usage(-verbose => $verbose);
138	} else {
139	my $pager = $ENV{'PAGER'} \|\| 'more';
140	local(*PAGER);
141	my $fh = (-t STDOUT && open(PAGER, "\|$pager")) ? \PAGER : \STDOUT;
142	Pod::Usage::pod2usage(-verbose => $verbose,
143	-output => $fh);
144	close(PAGER) if ($fh == \*PAGER);
145	}
146	defined($exit_code) && exit($exit_code);
147	}
148
149	##=========================================================================##
150	__END__
151
152	=head1 NAME
153
154	logcmd - Log the output of a program.
155
156	=head1 SYNOPSIS
157
158	logcmd [options] -- <command> [command-args ...]
159
160	=head1 DESCRIPTION
161
162	B<logcmd> logs the output of a program. This program is useful
163	for logging program output for programs that do not have a built-in
164	logging facility.
165
166	Typical usage is to use B<logcmd> in crontabs to log any command
167	output to a file instead of mail automatically being sent to the
168	crontab owner.
169
170	When invoking B<logcmd>, you B<must> use "C<-->" to separate the
171	B<logcmd> and its options from the command you are invoking. For
172	example,
173
174	logcmd -log out.log -- some-cmd arg1 arg2 arg3
175
176	This tells B<logcmd> to run "C<some-cmd arg1 arg2 arg3>" and have
177	any output goto C<out.log>.
178
179	Each line logged will be preceded by a timestamp, the process ID, and
180	the name of the command. Also, before the first log message for a command
181	is printed, B<logcmd> will print out a line giving the full command-line
182	of the command invoked. Example:
183
184	[2002-07-30 14:52:13] [25392] logcmd: Command: [25393] mhonarc -quiet -out out /var/archiver/mail
185	[2002-07-30 14:52:13] [25393] mhonarc:
186	[2002-07-30 14:52:13] [25393] mhonarc: Warning: Unrecognized character set: utf-8
187	[2002-07-30 14:52:13] [25393] mhonarc: Message-Id: <1022714308.2028.1.camel@xxx.xxx.xxx>
188	[2002-07-30 14:52:13] [25393] mhonarc: Message Number: 00367
189	[2002-07-30 14:52:13] [25393] mhonarc:
190	[2002-07-30 14:52:13] [25393] mhonarc: Warning: Unrecognized character set: utf-8
191	[2002-07-30 14:52:13] [25393] mhonarc: Message-Id: <1022716087.2028.3.camel@xxx.xxx.xxx>
192	[2002-07-30 14:52:13] [25393] mhonarc: Message Number: 00368
193	[2002-07-30 14:52:14] [25393] mhonarc:
194	[2002-07-30 14:52:14] [25393] mhonarc: Warning: Unrecognized character set: utf-8
195	[2002-07-30 14:52:14] [25393] mhonarc: Message-Id: <1024365245.9394.0.camel@xxx.xxx.xxx>
196	[2002-07-30 14:52:14] [25393] mhonarc: Message Number: 00398
197
198
199	=head1 OPTIONS
200
201	=over
202
203	=item C<-help>
204
205	Display SYNOPSIS and OPTIONS sections.
206
207	=item C<-log> I<pathname>
208
209	Command output will be logged to I<pathname>. If this option is
210	not specified, then standard out is used.
211
212	=item C<-man>
213
214	Display manpage.
215
216	=item C<-time-fmt> I<fmt>
217
218	Date/time format to use when printing time before each logged line.
219	The format string should be in C<strftime>(3) format. If this
220	option is not specified, then "C<%Y-%m-%d %H:%M:%S>" is used.
221
222	=item C<-->
223
224	Terminate option processing for B<logcmd>. Any arguments after
225	C<--> comprise the command that B<logcmd> should execute.
226
227	=back
228
229	=head1 EXAMPLES
230
231	The following is an example crontab entries of a user that has
232	any output of commands goto a personal log file:
233
234	0 2 * * * logcmd -log $HOME/log/cron.log -- $HOME/bin/clean_account
235	0 3 * * * logcmd -log $HOME/log/cron.log -- $HOME/bin/pack_mail
236
237	=head1 LIMITATIONS
238
239	=over
240
241	=item *
242
243	B<logcmd> performs no file locking on the log file specified. To help
244	minimize that a single output line to the log does not get broken up
245	due to multiple writers, the entire line is dumped in a single call
246	to Perl's C<print> operator.
247
248	=back
249
250	=head1 DEPENDENCIES
251
252	C<Getopt::Long>, C<POSIX>.
253
254	=head1 AUTHOR
255
256	Earl Hood, earl@earlhood.com
257
258	This program comes with ABSOLUTELY NO WARRANTY and may be copied only
259	under the terms of the GNU General Public License.
260
261	=cut
262