Script to run every hr

[Allanm]

Hi!

I am having problems with the attached script when it runs at midnight (next day)...otherwise it runs fine.

Can you suggest what change I can make to run it every 5 mins past the hr successfully.

I don't want to use if statement though and I am running this thru cron.

Thanks,
Allan.

[James R. Ferguson]

Hi Allan:

Am I missing something? Why not 'cron' your script like this (?):

5 * * * * /path_to_script

Regards!

...JRF...

[Allanm]

Thats what I did but it broke when it ran at 00:05.

[James R. Ferguson · Accepted solution]

Hi (again) Allan:

Instead of fiddling around with time computations over midnight, use this Perl snippet:

# perl -MPOSIX -le 'print strftime "%Y%m%d %H",localtime(time()-3600)'
20090224 15

You can use the same 'date' formatting directives you are used to using. This code uses 3600 seconds or ONE hour ago.

Regards!

...JRF...

[Patrick Wallek]

>>Thats what I did but it broke when it ran at 00:05.

Broke how?

>>I am having problems with the attached

What kind of problems?

What does it do or not do when it runs after midnight?

[Patrick Wallek]

PRESENTHR=`date '+%H'`
LASTHR=`expr $PRESENTHR - 1`

The problem is the above expressions.

When you run this during the midnight hour, which is the '0' hour, and you subtract 1 from, you get '-1'.

You need some logic to determine that '-1' should actually be hour 23 from yesterday. (I think JRF covers this in his response above.)

[Allanm]

Thanks so much JRF/Patrick.

Just for my knowledge how would I handle this through "date" command.

Thanks
Allan

[James R. Ferguson]

Hi (again) Allan:

> Just for my knowledge how would I handle this through "date" command

You would have to subtract your one-hour from the hour field and if that is negative, back off by one day; maybe to the previous month; and perhaps to the previous year...

Hence, why reinvent the wheel...

One helpful piece if you insist on taking this route, might be to install the GNU 'date' command which can do :

# date -d yesterday

Regards!

...JRF...

[Steven E. Protter]

Shalom,

A Clay's Date Hammer can be useful in these type of situations:

http://mirrors.develooper.com/hpux/caljd-2.25.sh

http://mirrors.develooper.com/hpux/caljd-2.2.pl

I ported it to Linux (A 1 line shell change), if you need.

Regards,

SEP