Shell Programming and Scripting

so i have to perform a certain task at set times. for instance, i need to run a job at 12:30am every night, and other jobs, i only need to have them run on saturdays.

how do i manipulate the date command to give me the epoch equivalence of what 12:30am would be every day?

im looking for a simple command that can just output to me what the epoch time would be.

something along the lines of:

Code:

WhatTime=12:30am,daily
date -d@${WhatTime}

Code:

WhatTimeDay=12:00am,Saturday
date -d@${WhatTimeDay}

The goal here is to submit the epoch time produced by the above command to a program and the program will know to run the job at the time specified, whether it be daily or on specific days.

This is to run on a Linux or SunOS box.

please advise.

Have you consider just using cron.

I am also not clear on what you mean by "epoch time". A lot of computer time mechanisms are based on "seconds since epoch"

I agree, just use cron. You want to run a jon at 12:30 every night? Just put it in crontab.

Anyway, each 12:30am is a different epoch second every night. The epoch started as midnight Jan 1, 1970 and has been incrementing ever since. The Linux date command can do what you asked...

Code:

$
$ date --date "1/1/1970 00:00:00" +%s
18000
$ date -u --date "1/1/1970 00:00:00" +%s
0
$

I had to use -u to get GMT time.

i am using cron. but based on how things are set up, there's several devices i need to perform a function on and each device has different times the job has to run on them.

epochtime is basically the equivalence of a changing date.

for instance, if i have to run a job on deviceA at 12:30am every day and on deviceB every Saturday at 12:00am, how do i get the epoch time of that?

deviceA is just one of many devices in a file.

Code:

deviceA,12:30am-daily
deviceB,12:00am-Saturday

i'd like to replace the second field with the equivalent epoch time.