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)

perl v5.32.0                                       2021-01-03                                            At(3pm)