Bash command for comparing two dates

Completely Clueless · 03-25-2013, 12:00 PM

Hi all,

Is there a command in Bash that allows one to compare the current date grabbed from the network with another one specified in a script file?
I cannot use cron since the hardware in question will not be running constantly and anacron from what I can see doesn't parse dates at all; merely intervals which isn't sufficient in this case.

Any ideas; suggestions for workarounds?

thanks, cc.

H_TeXMeX_H · 03-25-2013, 01:12 PM

Yes, the 'date' command is what you want.

Here are some examples:
http://unix.stackexchange.com/questi...te-differences

you can search for more. It depends on what exactly you want to calculate.

Completely Clueless · 03-25-2013, 01:56 PM

Quote:

Originally Posted by H_TeXMeX_H

Yes, the 'date' command is what you want.

Here are some examples:
http://unix.stackexchange.com/questi...te-differences

you can search for more. It depends on what exactly you want to calculate.

Thank you, TM. I had no idea "date" was so versatile! How the hell do you find all this stuff? My searches never seem to bear any fruit.

H_TeXMeX_H · 03-25-2013, 01:59 PM

It wasn't that easy to find. You're lucking I was looking for exactly the same thing just yesterday for a script I was making.

Habitual · 03-25-2013, 02:27 PM

http://www.linuxquestions.org/questi...es-4175454050/

short version:

Code:

echo $((($(date +%s -d "June 5, 2013")-$(date +%s -d "June 5, 1960"))/86400)) days.

19358 days.

Habitual · 03-25-2013, 02:34 PM

Quote:

Originally Posted by Completely Clueless

How the hell do you find all this stuff?

sadly, it is the old standby answer "RTFM".
in "man bash" and "man date" to be specific.

w1k0 · 03-25-2013, 06:34 PM

See: that thread.