NAME¶
Schedule::At - OS independent interface to the Unix 'at' command
SYNOPSIS¶
require Schedule::At;
Schedule::At::add(TIME => $string, COMMAND => $string [, TAG =>$string]);
Schedule::At::add(TIME => $string, COMMAND => \@array [, TAG =>$string]);
Schedule::At::add(TIME => $string, FILE => $string)
%jobs = Schedule::At::getJobs();
%jobs = Schedule::At::getJobs(JOBID => $string);
%jobs = Schedule::At::getJobs(TAG => $string);
Schedule::At::readJobs(JOBID => $string);
Schedule::At::readJobs(TAG => $string);
Schedule::At::remove(JOBID => $string);
Schedule::At::remove(TAG => $string);
DESCRIPTION¶
This modules provides an OS independent interface to 'at', the Unix command that
allows you to execute commands at a specified time.
- Schedule::At::add
- Adds a new job to the at queue.
You have to specify a TIME and a command to execute. The TIME
has a common format: YYYYMMDDHHmm where YYYY is the year (4
digits), MM the month (01-12), DD is the day (01-31),
HH the hour (00-23) and mm the minutes.
The command is passed with the COMMAND or the FILE parameter.
COMMAND can be used to pass the command as an string, or an array
of commands, and FILE to read the commands from a file.
The optional parameter TAG serves as an application specific way to
identify a job or a set of jobs.
Returns 0 on success or a value != 0 if an error occurred.
- Schedule::At::readJobs
- Read the job content identified by the JOBID or
TAG parameters.
Returns a hash of JOBID => $string where $string is the the job content.
As the operating systems usually add a few environment settings, the
content is longer than the command provided when adding the job.
- Schedule::At::remove
- Remove an at job.
You identify the job to be deleted using the JOBID parameter (an
opaque string returned by the getJobs subroutine). You can also specify a
job or a set of jobs to delete with the TAG parameter, removing all
the jobs that have the same tag (as specified with the add subroutine).
Used with JOBID, returns 0 on success or a value != 0 if an error occurred.
Used with TAG, returns a hash reference where the keys are the JOBID of
the jobs found and the values indicate the success of the remove
operation.
- Schedule::At::getJobs
- Called with no params returns a hash with all the current
jobs or dies if an error has occurred. It's possible to specify the
TAG or JOBID parameters so only matching jobs are returned.
For each job the key is a JOBID (an OS dependent string that shouldn't be
interpreted), and the value is a hash reference.
This hash reference points to a hash with the keys:
- TIME
- An OS dependent string specifying the time to execute the
command
- TAG
- The tag specified in the Schedule::At::add subroutine
Configuration Variables¶
- •
- $Schedule::At::SHELL
This variable can be used to specify shell for execution of the scheduled
command. Can be useful for example when scheduling from CGI script and the
account of the user under which httpd runs is locked by using '/bin/false'
or similar as a shell.
EXAMPLES¶
use Schedule::At;
# 1
Schedule::At::add (TIME => '199801181530', COMMAND => 'ls',
TAG => 'ScheduleAt');
# 2
@cmdlist = ("ls", "echo hello world");
Schedule::At::add (TIME => '199801181630', COMMAND => \@cmdlist,
TAG => 'ScheduleAt');
# 3
Schedule::At::add (TIME => '199801181730', COMMAND => 'df');
# This will remove #1 and #2 but no #3
Schedule::At::remove (TAG => 'ScheduleAt');
my %atJobs = Schedule::At::getJobs();
foreach my $job (values %atJobs) {
print "\t", $job->{JOBID}, "\t", $job->{TIME}, ' ',
($job->{TAG} || ''), "\n";
}
AUTHOR¶
Jose A. Rodriguez (jose AT rodriguez.jp)