cron entry error

capeme · October 25, 2006, 2:38pm

I am using the following cron entry to run a cron job every 4 hours and
it is rejecting it:

0 */4 * * * /home/location/scriptname

When I put this entry in cron is errors with: 0481-079 reached a symbol that is not expected.

This is an AIX 5.3 system

Any ideas?

Thanks

BOFH · October 25, 2006, 2:41pm

Hey, you only need to post the question once. Either it'll get answered or it won't but posting it more than once won't help and will just indicate you don't know where to post your question.

Carl

capeme · October 25, 2006, 3:06pm

I thought this was a better forum after I posted it on the other. I figured different users in this then the other.
sorry

aigles · October 26, 2006, 2:40am

The syntax of the second field is invalid : */4
You must indicate the hours explicitly

0 0,4,8,12,16,20 * * * /home/location/scriptname

From crontab man page

The crontab File Entry Format

A crontab file contains entries for each cron job. Entries are separated by
newline characters. Each crontab file entry contains six fields separated by
spaces or tabs in the following form:

minute hour day_of_month month weekday command

These fields accept the following values:

minute 0 through 59

hour 0 through 23

day_of_month 1 through 31

month 1 through 12

weekday 0 through 6 for Sunday through Saturday

command a shell command

You must specify a value for each field. Except for the command field, these
fields can contain the following:

o A number in the specified range. To run a command in May, specify 5 in the
month field.
o Two numbers separated by a dash to indicate an inclusive range. To run a
cron job on Tuesday through Friday, place 2-5 in the weekday field.
o A list of numbers separated by commas. To run a command on the first and
last day of January, you would specify 1,31 in the day_of_month field.
o An * (asterisk), meaning all allowed values. To run a job every hour,
specify an asterisk in the hour field.

Note: Any character preceeded by a backslash (including the %) causes that
character to be treated literally. The specification of days may be made by
two fields (day of the month and day of the week). If you specify both as a
list of elements, both are adhered to. For example, the following entry:
0 0 1,15 * 1 command

would run command on the first and fifteenth days of each month, as well as
every Monday. To specify days by only one field, the other field should
contain an * .

Jean-Pierre.

srikanthus2002 · October 26, 2006, 3:22am

and you can check the log file for the same ( if any errors)

/var/cron/log/

mahendramahendr · October 26, 2006, 4:29am

I have also read somewhere that */4 works in cron, but in solaris it never worked for me... don't use this method.

BOFH · October 26, 2006, 9:05am

Yea, it works in Linux but not in Solaris, AIX or any of the "real" Unices. While I've been mucking around with Linux since 1994 or so (Slackware), I was a production Solaris admin before I worked on production Linux boxes.

Carl