Hi all. Can anyone help me with scheduling tasks? I'm running Centos4.2 (updated via yum starting from 4.0). I know I have vixie-cron and anacron packages installed (came like that, from first install, I guess). I read the crontab syntax man page (man 5 crontab) and I made an entry as a normal user (using crontab -e) that looks like the following:
30 0 9 1 1 /bin/ls -F /home/jose > /home/jose/home-listing.txt
when I run the command "/bin/ls -F /home/jose > /home/jose/home-listing.txt" it produces a file named "home-listing.txt" in my home directory. However, if I delete the file and wait for the cron process to take place, the cron process never takes place at the exact time of scheduling. In fact I don't think it ever takes place because the file just does not appear. Am I doing something wrong? Can someone please help me! I really need to be able to schedule processes at *very* *specific* *times*. Anyone? Thank you.
On Monday 09 January 2006 00:51, Jose Alburquerque wrote:
Hi all. Can anyone help me with scheduling tasks? I'm running Centos4.2 (updated via yum starting from 4.0). I know I have vixie-cron and anacron packages installed (came like that, from first install, I guess). I read the crontab syntax man page (man 5 crontab) and I made an entry as a normal user (using crontab -e) that looks like the following:
30 0 9 1 1 /bin/ls -F /home/jose > /home/jose/home-listing.txt
when I run the command "/bin/ls -F /home/jose > /home/jose/home-listing.txt" it produces a file named "home-listing.txt" in my home directory. However, if I delete the file and wait for the cron process to take place, the cron process never takes place at the exact time of scheduling. In fact I don't think it ever takes place because the file just does not appear. Am I doing something wrong? Can someone please help me! I really need to be able to schedule processes at *very* *specific* *times*. Anyone? Thank you.
Looks good to me... are you sure you have permissions for the output file to be written? Is cron running? what is the output from /var/log/cron for that timeframe?
Peter.
On Mon, 2006-01-09 at 01:01 -0500, Peter Arremann wrote:
On Monday 09 January 2006 00:51, Jose Alburquerque wrote:
Hi all. Can anyone help me with scheduling tasks? I'm running Centos4.2 (updated via yum starting from 4.0). I know I have vixie-cron and anacron packages installed (came like that, from first install, I guess). I read the crontab syntax man page (man 5 crontab) and I made an entry as a normal user (using crontab -e) that looks like the following:
30 0 9 1 1 /bin/ls -F /home/jose > /home/jose/home-listing.txt
when I run the command "/bin/ls -F /home/jose > /home/jose/home-listing.txt" it produces a file named "home-listing.txt" in my home directory. However, if I delete the file and wait for the cron process to take place, the cron process never takes place at the exact time of scheduling. In fact I don't think it ever takes place because the file just does not appear. Am I doing something wrong? Can someone please help me! I really need to be able to schedule processes at *very* *specific* *times*. Anyone? Thank you.
Looks good to me... are you sure you have permissions for the output file to be written? Is cron running? what is the output from /var/log/cron for that timeframe?
right ... the time that would have run was ...
Monday, Jan 9, at 00:30 on the time zone set on your machine ... is that what you wanted.
Peter Arremann wrote:
Looks good to me... are you sure you have permissions for the output file to be written? Is cron running? what is the output from /var/log/cron for that timeframe?
Actually, by looking at the log (thanks for the info, I did not know!). I see that I booted my system on 1/8/2006 around 8:30pm and kept it up until 1:00am on 1/9/2006. I was experimenting with two Gui's for crontab (gnome-schedule and gnome-crontab) and now I can see that some test processes did execute (ie. the ls > /dev/null commands, which, of course did not provide any output so that I did not know if they executed!).
Here's the /var/log/cron entries for the relevant times:
Jan 8 22:39:20 sweety crond[3794]: (CRON) STARTUP (V5.0) Jan 8 22:39:21 sweety anacron[3830]: Anacron 2.3 started on 2006-01-08 Jan 8 22:39:21 sweety anacron[3830]: Normal exit (0 jobs run) Jan 8 23:01:01 sweety crond[5154]: (root) CMD (run-parts /etc/cron.hourly) Jan 9 00:01:01 sweety crond[5355]: (root) CMD (run-parts /etc/cron.hourly) Jan 9 00:01:03 sweety /usr/bin/crontab[5356]: (jose) LIST (jose) Jan 9 00:01:20 sweety /usr/bin/crontab[5367]: (jose) LIST (jose) Jan 9 00:04:53 sweety /usr/bin/crontab[5415]: (jose) REPLACE (jose) Jan 9 00:04:53 sweety /usr/bin/crontab[5416]: (jose) LIST (jose) Jan 9 00:05:01 sweety crond[3794]: (jose) RELOAD (cron/jose) Jan 9 00:05:09 sweety /usr/bin/crontab[5421]: (jose) REPLACE (jose) Jan 9 00:05:09 sweety /usr/bin/crontab[5424]: (jose) LIST (jose) Jan 9 00:06:01 sweety crond[3794]: (jose) RELOAD (cron/jose) Jan 9 00:06:01 sweety crond[5436]: (jose) CMD (ls >/dev/null 2>&1 # Untitled, /usr/share/pixmaps/nautilus/Bluecurve/i-executable.png) Jan 9 00:17:24 sweety /usr/bin/crontab[5555]: (jose) REPLACE (jose) Jan 9 00:17:24 sweety /usr/bin/crontab[5558]: (jose) LIST (jose) Jan 9 00:17:57 sweety /usr/bin/crontab[5565]: (jose) REPLACE (jose) Jan 9 00:17:57 sweety /usr/bin/crontab[5566]: (jose) LIST (jose) Jan 9 00:18:01 sweety crond[3794]: (jose) RELOAD (cron/jose) Jan 9 00:19:45 sweety /usr/bin/crontab[5579]: (jose) REPLACE (jose) Jan 9 00:19:45 sweety /usr/bin/crontab[5580]: (jose) LIST (jose) Jan 9 00:20:01 sweety crond[3794]: (jose) RELOAD (cron/jose) Jan 9 00:20:01 sweety crond[5582]: (jose) CMD (ls >/dev/null 2>&1 # Untitled, /usr/share/pixmaps/nautilus/Bluecurve/i-executable.png) Jan 9 00:20:45 sweety crontab[5589]: (jose) BEGIN EDIT (jose) Jan 9 00:21:14 sweety crontab[5589]: (jose) END EDIT (jose) Jan 9 00:22:06 sweety crontab[5597]: (jose) BEGIN EDIT (jose) Jan 9 00:22:23 sweety crontab[5597]: (jose) END EDIT (jose) Jan 9 00:24:02 sweety crontab[5630]: (root) BEGIN EDIT (root) Jan 9 00:24:04 sweety crontab[5630]: (root) END EDIT (root) Jan 9 00:24:10 sweety crontab[5634]: (jose) BEGIN EDIT (jose) Jan 9 00:24:34 sweety crontab[5634]: (jose) REPLACE (jose) Jan 9 00:24:34 sweety crontab[5634]: (jose) END EDIT (jose) Jan 9 00:25:01 sweety crond[3794]: (jose) RELOAD (cron/jose) Jan 9 00:25:59 sweety crontab[5645]: (jose) BEGIN EDIT (jose) Jan 9 00:26:21 sweety crontab[5645]: (jose) END EDIT (jose) Jan 9 00:26:38 sweety /usr/bin/crontab[5654]: (jose) LIST (jose) Jan 9 00:26:54 sweety /usr/bin/crontab[5657]: (jose) LIST (jose) Jan 9 00:27:06 sweety crontab[5663]: (jose) BEGIN EDIT (jose) Jan 9 00:27:35 sweety crontab[5663]: (jose) REPLACE (jose) Jan 9 00:27:35 sweety crontab[5663]: (jose) END EDIT (jose) Jan 9 00:27:43 sweety /usr/bin/crontab[5670]: (jose) LIST (jose) Jan 9 00:28:01 sweety crond[3794]: (jose) RELOAD (cron/jose) Jan 9 00:30:54 sweety /usr/bin/crontab[5709]: (jose) REPLACE (jose) Jan 9 00:30:54 sweety /usr/bin/crontab[5710]: (jose) LIST (jose) Jan 9 00:31:01 sweety crond[3794]: (jose) RELOAD (cron/jose) Jan 9 00:32:01 sweety crontab[5717]: (jose) BEGIN EDIT (jose) Jan 9 00:32:05 sweety crontab[5717]: (jose) END EDIT (jose) Jan 9 00:36:12 sweety crontab[5738]: (jose) BEGIN EDIT (jose) Jan 9 00:41:29 sweety crontab[5738]: (jose) REPLACE (jose) Jan 9 00:41:29 sweety crontab[5738]: (jose) END EDIT (jose) Jan 9 00:42:01 sweety crond[3794]: (jose) RELOAD (cron/jose)
This morning I experimented again and found out that the command does execute. I changed my crontab entry to read:
00 9 9 1 1 /bin/ls -F /home/jose > /home/jose/new-home-listing.txt
and in fact, the command did execute. Later, I tried changed the entry to read:
05 11 9 1 1 /bin/ls -F /home/jose > /home/jose/new-home-listing.txt
(I did this one minute before the process was supposed to execute at 11:04 as you can see in log output below). But the process did not execute. I think it has to do with how much time in advance the task is scheduled. Am I right? Here's my log output for today:
Jan 9 08:40:07 sweety crond[3713]: (CRON) STARTUP (V5.0) Jan 9 08:40:08 sweety anacron[3749]: Anacron 2.3 started on 2006-01-09 Jan 9 08:40:09 sweety anacron[3749]: Will run job `cron.daily' in 65 min. Jan 9 08:40:09 sweety anacron[3749]: Jobs will be executed sequentially Jan 9 08:52:21 sweety crontab[5474]: (jose) BEGIN EDIT (jose) Jan 9 08:52:46 sweety crontab[5474]: (jose) END EDIT (jose) Jan 9 08:56:38 sweety crontab[5489]: (jose) BEGIN EDIT (jose) Jan 9 08:57:02 sweety crontab[5489]: (jose) REPLACE (jose) Jan 9 08:57:02 sweety crontab[5489]: (jose) END EDIT (jose) Jan 9 08:58:01 sweety crond[3713]: (jose) RELOAD (cron/jose) Jan 9 08:59:28 sweety crontab[5528]: (jose) LIST (jose) Jan 9 09:00:01 sweety crond[5533]: (jose) CMD (/bin/ls -F /home/jose > /home/jose/home-listing.txt) Jan 9 09:01:01 sweety crond[5539]: (root) CMD (run-parts /etc/cron.hourly) Jan 9 09:45:07 sweety anacron[3749]: Job `cron.daily' started Jan 9 09:45:52 sweety anacron[6122]: Updated timestamp for job `cron.daily' to 2006-01-09 Jan 9 09:48:58 sweety anacron[3749]: Job `cron.daily' terminated Jan 9 09:48:58 sweety anacron[3749]: Normal exit (1 jobs run) Jan 9 10:01:01 sweety crond[6262]: (root) CMD (run-parts /etc/cron.hourly) Jan 9 11:01:01 sweety crond[6451]: (root) CMD (run-parts /etc/cron.hourly) Jan 9 11:03:54 sweety crontab[6461]: (jose) BEGIN EDIT (jose) Jan 9 11:04:23 sweety crontab[6461]: (jose) REPLACE (jose) Jan 9 11:04:23 sweety crontab[6461]: (jose) END EDIT (jose) Jan 9 11:05:01 sweety crond[3713]: (jose) RELOAD (cron/jose)
But thanks so much Peter, your answer led me the right way.
-Jose
On Sun, 2006-01-08 at 23:51, Jose Alburquerque wrote:
Hi all. Can anyone help me with scheduling tasks? I'm running Centos4.2 (updated via yum starting from 4.0). I know I have vixie-cron and anacron packages installed (came like that, from first install, I guess). I read the crontab syntax man page (man 5 crontab) and I made an entry as a normal user (using crontab -e) that looks like the following:
30 0 9 1 1 /bin/ls -F /home/jose > /home/jose/home-listing.txt
That looks right for today, but normally you would only specify one or the other of the day/month or day-of-week items and use * for the others.
-
Johnny Hughes -
Jose Alburquerque -
Les Mikesell -
Peter Arremann