CronJob not running

Question

I have setup cronjob for root user in ubuntu environment as follows by typing crontab -e

  34 11 * * * sh /srv/www/live/CronJobs/daily.sh
  0 08 * * 2 sh /srv/www/live/CronJobs/weekly.sh
  0 08 1 * * sh /srv/www/live/CronJobs/monthly.sh

But the cronjon do not run. I have tried checking if the cronjob is running using

pgrep cron

and that gives process id 3033.The shell scrip is calls python file and is used to send email. Running the python file is ok. There's no error in it but the cron doesn't run. The daily.sh file has following code in it.

python /srv/www/live/CronJobs/daily.py
python /srv/www/live/CronJobs/notification_email.py
python /srv/www/live/CronJobs/log_kpi.py

Answer 1

Sometimes the command that cron needs to run is in a directory where cron has no access, typically on systems where users' home directories' permissions are 700 and the command is in that directory.

Answer 2

Another reason crontab will fail: Special handling of the % character.

From the man file:

The entire command portion of the line, up to a newline or a
"%" character, will be executed by /bin/sh or by the shell specified
in the SHELL variable of the cronfile.  A "%" character in the
command, unless escaped with a backslash (\), will be changed into
newline characters, and all data after the first % will be sent to
the command as standard input.

In my particular case, I was using date --date="7 days ago" "+%Y-%m-%d" to produce parameters to my script, and it was failing silently. I finally found out what was going on when I checked syslog and saw my command was truncated at the % symbol. You need to escape it like this:

date --date="7 days ago" "+\%Y-\%m-\%d"

See here for more details:

http://www.ducea.com/2008/11/12/using-the-character-in-crontab-entries/