Script that will look the same as Cron Post: 303037692

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Top Forums Shell Programming and Scripting Script that will look the same as Cron Post 303037692 by meister29 on Friday 9th of August 2019 11:31:40 AM

08-09-2019

Registered User

Quote:

Originally Posted by drysdalk

Hello,

OK, here's a quick hacked-together version of a script that more-or-less does what crond would do. As Neo has mentioned however, this is not the best idea, as you're kind of needlessly re-inventing something that already exists and which will definitely do a far better job than this shell script. If the customer/client/maintainer/whoever actively doesn't want you running scheduled tasks on the server, then they're not going to be happy about you doing it no matter how you go about doing it. Alternatively if you have a hard requirement to run scheduled tasks and the customer just doesn't want you installing software, then you need to have a conversation with your customer explaining that they need to install crond to enable you to do the work that you've been asked to do, otherwise you can't do it. If the job you need to do has a 100% requirement for scheduled tasks, then whoever provides this system either has to install or let you install crond, or they need to accept that the job can't be done since they won't let you have the tools you need to do it.

Anyway - bearing in mind all the above caveats (and the potential no doubt for bugs and issues that could be lurking with this approach), here's a quickly knocked-together script that would do more or less what you need.

Code:

$ cat cron.tab
Fri,16,13,echo "It's thirteen minutes past four !"
Fri,16,15,echo "It's quarter past four !"
$ cat script3.sh
#!/bin/bash

crontab=/home/unixforum/282472/cron.tab

while true
do
        while read cron
        do
                runday=`echo "$cron" | /usr/bin/awk -F, '{print $1}'`
                runhour=`echo "$cron" | /usr/bin/awk -F, '{print $2}'`
                runminute=`echo "$cron" | /usr/bin/awk -F, '{print $3}'`
                runcommand=`echo "$cron" | /usr/bin/awk -F, '{print $4}'`

                nowday=`/usr/bin/date +%a`
                nowhour=`/usr/bin/date +%H`
                nowminute=`/usr/bin/date +%M`

                if [ "$runday" == "$nowday" ] && [ "$runhour" == "$nowhour" ] && [ "$runminute" == "$nowminute" ]
                then
                        /usr/bin/date
                        $runcommand
                fi
        done < "$crontab"

        /usr/bin/sleep 60
done

$ date
Fri Aug  9 16:11:14 BST 2019
$ ./script3.sh
Fri Aug  9 16:13:16 BST 2019
"It's thirteen minutes past four !"
Fri Aug  9 16:15:16 BST 2019
"It's quarter past four !"
^C
$

thank you very much sir. i will take note of that. from here i will create my own. thx thx..

meister29

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LEARN ABOUT BSD

uupoll

UUPOLL(8)						      System Manager's Manual							 UUPOLL(8)

NAME

       uupoll - poll a remote UUCP site

SYNOPSIS

       uupoll [ -ggrade ] [ -n ] system

DESCRIPTION

       Uupoll is used to force a poll of a remote system. It queues a null job for the remote system and then invokes uucico(8).

       The following options are available:

       -ggrade Only send jobs of grade grade or higher on this call.

       -n      Queue the null job, but do not invoke uucico.

       Uupoll is usually run by cron(5) or by a user who wants to hurry a job along. A typical entry in crontab could be:

	    0	 0,8,16    *	*    *	  /usr/bin/uupoll ihnp4
	    0	 4,12,20   *	*    *	  /usr/bin/uupoll ucbvax
       This will poll ihnp4 at midnight, 0800, and 1600, and ucbvax at 0400, noon, and 2000.

       If the local machine is already running uucico every hour and has a limited number of outgoing modems, a more elegant approach might be:

	    0	 0,8,16    *	*    *	  /usr/bin/uupoll -n ihnp4
	    0	 4,12,20   *	*    *	  /usr/bin/uupoll -n ucbvax
	    5	 *	   *	*    *	  /usr/sbin/uucico -r1
       This will queue null jobs for the remote sites at the top of hour; they will be processed by uucico when it runs five minutes later.

FILES

       /etc/uucp/	  UUCP internal files
       /usr/spool/uucp/   Spool directory

SEE ALSO

       uucp(1), uux(1), uucico(8)

4.3 Berkeley Distribution					 October 23, 1996							 UUPOLL(8)

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