Question

how to use if/then statements in crontab?

Asked by: weihk

Hello,

I'm new to unix shell programming. I was wondering if there is a way to use if/then statements in crontab? If so, can you please give me an example, or the problem I'm working on is reading a file for a specific line (ex: hello there) and if it is read more than 2 times then execute a reboot of that particular server.

The code below is what I have so far but not sure how to fully utilize the if/then statement. Thanks for your help.

*/5 * * * * awk '{if($15 ~/XFMRDPAD/) shutdown -i6}' StructureService_PR.log

                                  
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Asked On
2009-05-26 at 15:18:42ID24439824
Tags

unix

Topics

Unix Networking

,

Unix Systems Programming

Participating Experts
3
Points
500
Comments
5

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Answers

 

by: gheistPosted on 2009-05-26 at 15:22:55ID: 24478287

You should not reboot UNIX automatically.

Specifying full path to commands helps in crontab.
No "if" statements in your command line, just gawk syntax.

 

by: climbgunksPosted on 2009-05-26 at 15:40:54ID: 24478436

if you really want to use awk, you could do it like this.    Actually, once c == 2 you could go ahead and call shutdown if you wanted....

awk '{if ($15 ~ /XFMRDPAD/) c++ } END { if (c > 1) system("shutdown -i6") }' StructureService_PR.log


I agree w/ the warning about automatic reboots.....

 

by: gheistPosted on 2009-05-26 at 22:15:59ID: 24480029

This could be of more value when scripting in cron and avoiding reboots:
http://www.experts-exchange.com/Programming/Languages/Scripting/Shell/Q_24326078.html

 

by: weihkPosted on 2009-05-27 at 10:56:47ID: 24485758

i found out that i'm suppose to stop the IS (integration server) using this command:
call vtadmin stop server /StructureService_PR/initial/StructureService_IS

and reboot the project using this command:
call vtadmin start project /Projects/StructureService_PR/initial

can i just replace the "shutdown -i6" with those commands? or how will i be able to implement it into the code? thank you

 

by: docbertPosted on 2009-06-10 at 22:36:36ID: 24598980

Trying to put too much information into cron is a bad idea from the perspective of maintainability.

Configure cron to run a single script, and then put whatever commands/logic you need into the script - either in standard Bourne shell, or Perl/Python/etc - whatever you prefer.

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