From: Philip Oakley <philipoakley@iee.email>
Date: Sun, 08 Dec 2019 15:05:44 GMT
Subject: Re: How to determine age of HEAD commit
Message-ID: <74d4a783-6196-08ce-b600-2eb2cacecac7@iee.email>
In-Reply-To: <0a578dce37e8802b2022df80c336f61a264a33e3.camel@gammascience.co.uk>

Hi Roger,

On 08/12/2019 14:07, Roger Gammans wrote:
> On Sun, 2019-12-08 at 12:09 +0000, Philip Oakley wrote:
>> Is there a command that does return the numeric agedness of a commit
>> (e.g. now - commit_date, in seconds)?
> Hi
>
> I don't know a specific command for the age. But `git cat-file commit
> HEAD`, will give you the commit's timestamps in seconds from the the
> epoch. (Plus some timezone info).
>
> I can construct a bash script, shown below (warning: only had the most
> rudimentary testing), which turns that into an age. For your use case
> you might be better getting yesterdays unix-timestamp from date, if GNU
> date is available, and directly comparing it to the commit timestamp.
>
> ------
> #!/bin/bash
>
> now=$(date +"%s")
> commit=$(git cat-file commit HEAD | grep committer)
> commit=${commit##*>}
> commit=${commit%%+*}
> echo $(( $now-$commit ))
> #--------------
>
Thanks,
That has spurred me into looking at a few other ideas.
Unfortunately the script needs to run inside a DOS batch file as part of 
a Visual Studio pre-build step, hence the desire for a direct command.

That said I have now found, with a bit of rooting around, that

    `git log -1 --format=format:"%ct" HEAD`

does appear to give the right form of answer. Just need to see if I can 
fit it into the DOS pre-build script now ;-)
There may be extra tweaks needed.. (a merged pull has the pull date, but 
a fast forward pull has the original date)

Philip

Philip