Hi all,

I am new in linux and i was trying to excute one perl file using cron. but it is not going to excute after 1 minute.

I created two files

1-
==============test.cron===============
0,1,30,45 * * * * /usr/local/cron/test.pl
==============End test.cron file=========

2-
===============test.pl================
#!/usr/bin/perl

use DBI;

my $db_host = '10.0.0.20';
my $db_user = 'linux';
my $db_pass = '123456';
my $db_name = 'auto';

my $db = "dbi:mysql:dbname=${db_name};host=${db_host}";

$dbh = DBI->connect($db, $db_user, $db_pass,
{ RaiseError => 1, AutoCommit => 0 }
) || die "Error connecting to the database";

$dbh->do("INSERT INTO test(name)
VALUES(?)", undef,"Thanx for insert");

=================== End of test.pl file =======

When i start the crontab it is started successfully from the following commond

[root@localhost cron]# crontab test.cron

[root@localhost cron]# crontab -l
# DO NOT EDIT THIS FILE - edit the master and reinstall.
# (test.cron installed on Fri Jul 29 20:07:46 2005)
# (Cron version -- $Id: crontab.c,v 2.13 1994/01/17 03:20:37 vixie Exp $)
0,1,30,45 * * * * /usr/local/cron/test.pl[root@localhost cron]#


And the perl file is ok if i am using perl test.pl the all scripts of perl is working fine.

Can anyone tell me where i am doing the wrong.

Thank You

I don't understand exactly what the problem is. You say it's executing correctly with 'crontab.test' ?

If you use 'crontab -e' you can edit your crontab and make it a permanent cron job under whatever user you might be logged in as.

I'm not sure what the problem is that you are trying to state.

It is not excuting with crontab.test but the same perl file can be excuted successfully with perl commond on console.

Okay, I understand now, thank you.

I just referred to the man page for crontab. If I read it correctly, 0,1,30,45.... will cause it to execute at the top of the hour, 1 minute past the hour, 30 minutes past the hour, and 45 minutes past the hour.

And it sounded like you wanted it to run 1 minute after running 'crontab crontab.test'. See the difference?

I'm not sure how to get cron to do that actually. You can set it to run every minute for the test:
*/1 * * * *

Thanx andey,

But i am really sorry to say that i tested with the your given time interval format. But no more luck.

i tested with also like :

*/1 * * * * perl /usr/local/cron/test.pl

and
*/1 * * * * /usr/local/cron/test.pl

But no luck.

Okay.. perhaps you could try this for troubleshooting:

*/1 * * * * /usr/local/cron/test.pl_>>$HOME/crontest.log_2>&1

and then keep an eye on that log real-time with:
tail -f $HOME/crontest.log

I would like to think that you'd at least get some kind of error message every minute using that crontab. I used underscores there to indicate spaces. Make sure you don't use the underscores.

Hello Andy,

I did the following modification in my test.cron file.

*/1 * * * * /usr/local/cron/test.pl >/tmp/perll.log 2>&1

And i restart the machine, after that it start to work. but when i am trying crontab -l i found that it is using KCron. I cannot see any log in perll.log file.


How i can make the format to execute test.pl file every seconds?

You have to use _two_ angle brackets (before the '/tmp/perll.log'), so your log will be appended. With only one, the log file will be recreated each time it is written to.


It's working now? But no logging? I use Dillon's cron. I don't know anything Kcron. You should be able to see whatever crontab is currently being used by 'crontab -l' and also, on my system anyway, all the crontabs are stored in /var/spool/cron

Read thru the man page for crontab, or search Google. I don't know if it's possible; I don't recall seeing any options for seconds. I don't have any more information for you, but I wish you luck finding the solution.

Hi Andy,

Thank you very much for your kind of help and company. really i a approciate it.

I am going to search about the seconds. if i will find anything let you know.

Thank You