Date: Thu, 26 Jan 2012 10:39:20 -0500 From: Michael Scheidell <scheidell@freebsd.org> To: <perl@freebsd.org> Cc: ports@freebsd.org Subject: what is maxcmdlen? $0 len? Message-ID: <4F2173A8.5010803@freebsd.org>
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(followups set to ports@)
I am trying to track down a persistent bug in swatch.
swatch sets y $commandLineString = $0 . ' ' . join(' ', @ARGV);
, and if the len of the cmdargs is > (x?), then ps gets borked, rc
scripts can't find it (so service status won't work), service restart
won' t kill old one, so it just keep adding new instances.
perldoc says:
http://perldoc.perl.org/perlvar.html
"Note that there are platform-specific limitations on the maximum length
of $0 . In the most extreme case it may be limited to the space occupied
by the original $0 ."
(but, I searched and could not find it)
best I can tell, this number is 251. (possibly 255)
(in swatch.rc, swatch_flags -gt 222 chars), so, swatch_flags, then len
of command (/usr/local/bin/swatch), some spacing, the '(perl)' at end...
and something else.
other than putting something like this in rc file, is there a way to
tell, on a platform by platform basis, what this number is?
should I send patches to swatch upstream to prevent this from happening?
notes:
swatch_1_flags='-c /usr/local/etc/swatch-hackertrap.conf
--tail-file=/var/log/eventlog_this_is_an_incredable_log_file_that_should_cause_big_problems_yes_an_op_would_never_do_this_but_it_is_so_I_can_test_if_problem_is_log_file_arg_or_log_cmd_arg_or_a_lot_of_files_or_some_thing_in_between_and_or.log
--tail-args=-Fn0 --daemon --script-dir=/tmp/
--pid-file=/var/run/swatch_1.pid'
swatch_enable="YES"
ps -auxww | grep swatch
root 86920 0.0 0.7 7496 6960 ?? Is 9:33AM 0:00.01
/usr/local/bin/perl /tmp//.swatch_script.86918
./swatch status
329
swatch is not running.
./swatch status
223
swatch is not running.
./swatch status
222
swatch is running as pid 98668.
--
Michael Scheidell, CTO
o: 561-999-5000
d: 561-948-2259
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