Comments on: do you know crontab?

By: d.ksyte

d.ksyte — Sat, 14 Jun 2008 14:14:20 +0000

I was also caught out and didn’t see it would run on the hour as well as minute 59. I put it into Cron Sandbox at HxPI and got back…

Sat 14 Jun 2008 1407 UTC
Forward Schedule
Sat 14 Jun 2008 1457
Sat 14 Jun 2008 1500
Sat 14 Jun 2008 1557
Sat 14 Jun 2008 1600
Sat 14 Jun 2008 1657
Sat 14 Jun 2008 1700

By: Marcin Gryszkalis

Marcin Gryszkalis — Thu, 17 Apr 2008 01:12:46 +0000

Sorry, the comment seems to get broken Let’s try again:

Every crontab field specifies range, ie.
5 is 5-5 range
5-10 is 5-10 range
* is min-max range (for minutes it’s 0-59)

/n specifies step within range, like in
for (i=begin; i<=end; i+=step)

then */57 means
for (i=0; i<=59; i+=57)

By: Marcin Gryszkalis

Marcin Gryszkalis — Thu, 17 Apr 2008 01:09:19 +0000

Every crontab field specifies range, ie.
5 is 5-5 range
5-10 is 5-10 range
* is min-max range (for minutes it’s 0-59)

/n specifies step within range, like in
for (i=begin; i<=end; i+=step)

then */57 means
for (i=0; idow_star’ and ‘e->dom_star’. yes, it’s bizarre.
* like many bizarre things, it’s the standard.
*/

By: sinx

sinx — Wed, 16 Apr 2008 21:51:59 +0000

Hello,

I using vixie-cron, from Portage (using Gentoo):

[I] sys-process/vixie-cron
Available versions: 4.1-r9 4.1-r10 {debug pam selinux}
Installed versions: 4.1-r10(02:19:38 2007-10-14)(pam -debug -selinux)
Homepage: ftp://ftp.isc.org/isc/cron/
Description: Paul Vixie’s cron daemon, a fully featured crond implementation

*/57 * * * * root date >> /root/test_cron.txt

Generated:

Wed Apr 16 21:57:02 CEST 2008
Wed Apr 16 22:00:01 CEST 2008
Wed Apr 16 22:57:01 CEST 2008
Wed Apr 16 23:00:01 CEST 2008

At the begining i thought that it will run this date command only XX:57:00 but now i see it’s also run at each hour.