Shell Programming and Scripting

Hi Experts,

below similar thread i posted earlier. Although i wish to know ur suggestion newly.

I want to run a script every 1 minute. I tried with Crontab. But the problem is cron send every 1 mins invertal- mail to the user mailbox.

meanwhile, some expert telling me it is not wise to run short interval in crontab.

What could be best way to run this type of short interval without getting any problem in systm.

//purple

If you want crontab to run without sending email, make the command not generate any output. Many commands have a -q or --quiet switch to make them not generate output. Otherwise you can redirect the output to a file or /dev/null.

Code:

some_command arg1 arg2 >/dev/null 2>/dev/null

But instead of using cron, if you are willing to accept sloppy timing, you can just keep one script running constantly and put it to sleep for a minute.

Code:

#!/bin/bash
while true; do
    some_command arg1 arg2
    sleep 60
done

This assumes you have it running in a dedicated shell and you stay logged in. But if you want to log out and let run, you can use screen (install the screen package if you don't have it--it's quite valuable).

There's no need for sloppy timing:

Code:

while :
do
    sleep 60 & pid=$!
    some_command arg1 arg2
    wait $pid
done

There's no need for screen. Use nohup and put it in the background.

cfajohnson ,
what's a 'sloppy timing' in the previous solution?

It executes the command every 60 seconds plus the time it takes to execute the command.

sorry, I must be thick-sculled - I'm having hard time parsing this sentence.
Chris, could you elaborate a little bit more and why your other suggestion is any better.
In 2 words or less.....

The command is initiated 60 seconds AFTER it last ran. If it requires 12 seconds to run, it will, in essence, run every 72 seconds.