procUtils.pm - common process/program utility methods and attributes.
use EWS::procUtils;
$pInfo = new EWS::procUtils(-debug => 1,
-io => $baseIO);
###############################################################
$pInfo->createDaemon('myLogFile')) || die "Unable to create daemon";
@pidList = $pInfo->getMatchingPIDs;
@pidList = $pInfo->getProgramPIDs($pInfo->programName);
###############################################################
eval
{
local $SIG{ALRM} = sub {die "sigalrm"};
local $SIG{INT} = sub {die "sigint" };
local $SIG{KILL} = sub {die "sigkill"};
alarm 30; # 30 seconds to perform task
...<task steps>...
alarm 0; # stop timer when complete.
};
$pResult = $pInfo->checkEval($@);
die "alarm timeout" if ($pResult == 1);
die "keyboard interrupt" if ($pResult == 2);
die "killed" if ($pResult == 3);
die "unknown/other interrupt" if ($pResult > 3);
###############################################################
$SIG{INT} = \$pInfo->catchInterrupt;
$SIG{KILL} = \$pInfo->catchKill;
$pInfo->Interrupt(0);
...<perform task>...
die "Interrupted" if ($pInfo->Interrupt > 0);
EWS::procUtils.pm is an object oriented perl module which contains several commonly used process/program utility methods and attributes.
Methods are included to:
create a daemon from the running process,
get a list of current PIDs which match a given program (application) name,
catch SIGALRM, SIGINT, SIGKILL interrupts,
process eval result code.
Exposed Attributes include:
Current (calling) program name and name parts,
regex used to parse program (application) names,
Version and Revision strings.
$pInfo = new EWS::procUtils(%parameters);
Enter:
%parameters = parameter hash (see below).
Exit:
returns a blessed reference to a new procUtils object.
parameters are of the form:
-arg => value
acceptable values are:
-debug => 1 = debug messages
-io => baseIO object
(refer to EWS::baseIO documentation).
-trace => deprecated -- refer to -io
Convert this process to a daemon.
Enter:
$stdFile = file name to redirect std output to.
Exit:
result code: 0 = running as a daemon.
1 = no rights to root directory.
2 = unable to redirect STD files
3 = unable to fork
4 = unable to start new session
Example:
use procUtils;
$pInfo = new EWS::procUtils(-debug=>0);
$pInfo->createDaemon($logFileName)) || die "Unable to create daemon";
Return list of PIDs with same program name as this.
Enter:
None.
Exit:
@pidList if successful.
undef if not successful.
Note: the returned list does not include the current process.
Example:
use procUtils;
$pInfo = new EWS::procUtils(-debug=>0);
@pidList = $pInfo->getMatchingPIDs;
Return list of PIDs with $program name.
Enter:
$program = name to search schedule for.
Exit:
@pidList = list of pid's in list mode,
$pidList = count of pid's in scalar mode.
undef if not successful.
Note: the returned list does not include the current process.
Example:
use procUtils;
$pInfo = new EWS::procUtils(-debug=>0);
@pidList = $pInfo->getProgramPIDs('myProgramName');
Close current STDERR error file.
Enter:
none.
Exit:
1 if successful
0 if unable to open STDERR
Redirect STDERR to $errorFile.
Enter:
$errorFile = error file name.
Exit:
1 if successful
0 if unable to open STDERR
SIGnal handler for alarm (SIGALRM)
Enter:
$signame = interrupt signal name
Exit:
none.
Increments $interrupt to indicate interrupt has been received.
Example:
$SIG{ALRM} = \$pInfo->catchAlarm;
$pInfo->Interrupt(0); # setting $SIG will cause an interrupt, so clear it.
alarm 30; # set 30 seconds to perform task
...<perform task>...
alarm 0;
die "Interrupted" if ($pInfo->Interrupt > 0);
SIGnal handler for keyboard INTerrupt (SIGINT)
Enter:
$signame = interrupt signal name
Exit:
none.
Increments $interrupt to indicate interrupt has been received.
Example:
$SIG{INT} = \$pInfo->catchInterrupt;
$pInfo->Interrupt(0); # setting $SIG will cause an interrupt, so clear it.
...<perform task>...
die "Interrupted" if ($pInfo->Interrupt > 0);
SIGnal handler for kill INTerrupt (SIGKILL)
Enter:
$signame = interrupt signal name
Exit:
none.
Increments $interrupt to indicate interrupt has been received.
Example:
$SIG{KILL} = \$pInfo->catchKill;
$pInfo->Interrupt(0); # setting $SIG will cause an interrupt, so clear it.
...<perform task>...
die "Killed" if ($pInfo->Interrupt > 0);
Check eval result. Assumes that sigalrm, sigint and sigkill are known.
Enter:
$result = result to check
Exit:
0 = no error
1 = sigalrm
2 = sigint
3 = sigkill
4 = unknown
Example:
eval
{
local $SIG{ALRM} = sub {die "sigalrm"};
local $SIG{INT} = sub {die "sigint" };
local $SIG{KILL} = sub {die "sigkill"};
alarm 30; # 30 seconds to perform task
...<task steps>...
alarm 0; # stop timer when complete.
};
$pResult = $pInfo->checkEval($@);
die "alarm timeout" if ($pResult == 1);
die "keyboard interrupt" if ($pResult == 2);
die "killed" if ($pResult == 3);
die "unknown/other interrupt" if ($pResult > 3);
Set/get internal interrupt counter. The internal interrupt counter is incremented each time a supported SIGnal occurs.
Enter:
$interrupt = value to set interrupt counter to
= undef to not change setting
Exit:
$interrupt = current interrupt counter value.
Set/get the regex used to parse file names by the getMatchingPIDs and getProgramPIDs methods. Returns current value.
Enter:
$regex = regex to use in parsing file names,
undef to not change.
Exit:
$regex = current regex contents.
Returns the running process ($$) program.
Enter:
None.
Exit:
$name = program (without execution path or type)
Returns the running process ($$) program name.
Enter:
None.
Exit:
$name = program name (without execution path)
Returns the running process ($$) program path name.
Enter:
None.
Exit:
$path = program path name (without program or type)
The Revision method returns the revision number of procUtils.pm:
$revision = $pInfo->Revision;
Enter:
none.
Exit:
current revision string.
The Version method returns the version number of procUtils.pm:
$version = $pInfo->Version;
Enter:
none.
Exit:
current version string.
EWS::Trace provides a simple trace debug facility.
Version 0.0.2 4/24/2002
procUtils.pm is available at
http://www.geocities.com/jaywheeler.geo/perl/Source/procUtils.pm
or as a g-zip'ed tarball at
http://www.geocities.com/jaywheeler.geo/perl/Source/procUtils.tgz
Visit EarthWalk Software at Geocities:
http://www.geocities.com/jaywheeler.geo
Jay Wheeler, EarthWalk Software.
procUtils.pm is copyright Š 2002. EarthWalk Software.
This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.
This library 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA