git equivalent of svn r-number

[Graham Perrin]

<https://diigo.com/0jd4h9> for an annotated view of 
<https://lists.freebsd.org/pipermail/freebsd-current/2020-December/077990.html>

The ASCII lines drawn by Ed Maste are pleasingly accurate.

The Git commit counts have a c prefix; the Git hashes have a g prefix.

I have a one-line command, to run whenever I prepare for an update to 
FreeBSD-CURRENT, that produces output such as this:

----

Sun Jan  3 10:20:03 GMT 2021
FreeBSD 13.0-CURRENT
shell: /bin/csh

Looking up portsnap.FreeBSD.org mirrors... 4 mirrors found.
Fetching snapshot tag from ipv4.aws.portsnap.freebsd.org... done.
Latest snapshot on server matches what we already have.
No updates needed.
Ports tree is already up to date.

Already up to date.
freebsd/main (FreeBSD-CURRENT) Git commit count: 572
freebsd/main Git hash: 82397d791966b09d344251bc709cd9db2b3a1902
<https://cgit.freebsd.org/src/commit/?id=82397d791966b09d344251bc709cd9db2b3a1902>
– in context: 
<https://cgit.freebsd.org/src/log/?qt=range&q=82397d791966b09d344251bc709cd9db2b3a1902>

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The relevant post is in Reddit but I'll not link to it until after I 
have finished testing. Probably a few hours from now.