Customer Support

Beware of the line endings in DOS vs unix.  I edited the crontab and
script files on DOS (with CR/LF endings) and unix expects just the LF. 
The symptom was the error:

/bin/sh: /ping/pingMonitor.py: bad interpreter: No such file or
directory

You can find utilities dos2unix and unix2dos to do the conversion.

Cheers,
Roger Burnham

Any output from a cron script (including stderr messages) is emailed to
your hosting account mailbox. If you do not want the mails, or the disk
space they use up, then have your cron script produce no output:

               /path/to/script &> /dev/null 

When trying to execute "lynx" from a cron, the cron was not executing
but was instead giving errors about "no such directory
/www/vhosts/m/myaccount.com" so I created such a path, making it lead
back to my home directory with a symlink like this:

    cd /
    mkdir www
    mkdir www/vhosts
    mkdir www/vhosts/m
    cd www/vhosts/m
    ln -s ../../../ myaccount.com

where "myaccount.com" is the domain name hosted here and "m" is the 1st
letter of that domain name

Here's a crontab that executes at 4:41AM on the 1st of each month and
deletes files in the logs directory that are more than 32 days old:

41 04 1 * * find /logs -ctime +32 -type f -exec rm -f \{\} \;

You CAN use a backtick operator in the command argument place in a
crontab.

However, percent signs (%) in the command must be escaped with a
backslash or else they will be interpreted as a newline.

From 'man crontab':
The ??sixth?? field (the rest of the line) specifies the command to be
run. The entire command portion of the line, up to a newline or %
character, will be executed by /bin/sh or by the shell specified in the
SHELL variable of the crontab file.
Percent-signs (%) in the command, unless escaped with backslash (\),
will be changed into newline characters, and all data after the first %
will be sent to the command as standard input. There is no way to split
a single command line onto multiple lines, like the shell?s trailing
"\".

so the following is valid:

15 3 * * 0,2-6 echo `date +\%a`

and

15 3 * * 0,2-6 echo $(date +\%a)

Failure to escape the backslash will result in a cron error:

/bin/sh: -c: line 1: unexpected EOF while looking for matching ``'
/bin/sh: -c: line 2: syntax error: unexpected end of file