I have this in my OMake files:

if $(test -e .git)
  GIT_COMMIT = 'Some "$(shell git rev-parse HEAD)"'
  export
else
  GIT_COMMIT = 'None'
  export

I also define VERSION manually, but ideally I should extract the version
from my opam file.

Given those, I use m4 as follows to generate an About module for most of my
projects.

m4 -D VERSION=$(VERSION) -D GIT_COMMIT=$(GIT_COMMIT) about.ml.m4 > about.ml

$ cat about.ml.m4
(** General information about this project. *)

(** Version: [VERSION] *)
let version = "VERSION"

(** Git commit if known: [GIT_COMMIT] *)
let git_commit = GIT_COMMIT



On Sat, Oct 17, 2015 at 3:22 AM, Gabriel Scherer <gabriel.scherer@gmail.com>
wrote:

> For reference, an ocamlbuild version would look like this:
>
> open Ocamlbuild_plugin
>
> let () = dispatch (function
>   | After_rules ->
>      rule "version file"
>           ~prod:"version.ml"
>           ~doc:"generate a file with version information:
>                 Version.commit is the HEAD commit at the time of building,
>                 Version.tag is the name of the last git tag"
>           (fun _env _build ->
>            let trim = "tr -d '\r\n'" in
>            let commit = run_and_read ("git rev-parse HEAD |" ^ trim) in
>            let tag = run_and_read ("git describe --abbrev=0 --tags |" ^
> trim) in
>            let code = Printf.sprintf
>                         "let commit = %S\n\
>                          let tag = %S\n"
>                         commit tag in
>            Echo ([code], "version.ml");
>           )
>   | _ -> ()
> );;
>
> On Fri, Oct 16, 2015 at 9:29 PM, Basile Starynkevitch
> <basile@starynkevitch.net> wrote:
> > On 10/16/2015 08:24 PM, David CHEMOUIL wrote:
> >>
> >> Hi,
> >>
> >> I am looking for a self-contained, to the point, documentation or
> tutorial
> >> detailing steps, or even commands and scripts to run in order to
> release and
> >> publish an OCaml-programmed piece of software.
> >
> >
> >>
> >> So common tasks we'd like to automate are quite simple: adding the
> commit
> >> number and/or a build number in the OCaml source code (e.g. to display
> it
> >> when running the program),
> >
> >
> > This is not specific to Ocaml. It is a matter of build process.
> >
> > Assuming a Linux system, you might have some rule in your Makefile
> similar
> > to the (untested) one below:
> >
> > ML_SOURCES=$(wildcard [a-z]*.ml)
> > ML_INTERFACES=$(wildcard [a-z]*.mli)
> > MD5SUM= md5sum
> >
> > _timestamp.ml:
> >     date +'let my_timestamp="%c";;' > _timestamp.tmp
> >
> >     (echo -n 'let my_lastgitcommit ="' ; \
> >        git log --format=oneline --abbrev=12 --abbrev-commit -q  \
> >          | head -1 | tr -d '\n\r\f\"' ; \
> >        echo '";;') >> _timestamp.tmp
> >     (echo -n 'let my_checksum ="'; cat $(sort $(ML_SOURCES)) $(sort
> > $(ML_INTERFACES))| $(MD5SUM) | cut -d' ' -f1 | tr -d '\n\r\f\"\\' ; echo
> > '";') >> _timestamp.tmp
> >     mv _timestamp.tmp _timestamp.ml
> >
> > Cheers
> >
> > --
> > Basile STARYNKEVITCH         http://starynkevitch.net/Basile/
> > email: basile<at>starynkevitch<dot>net mobile: +33 6 8501 2359
> > 8, rue de la Faiencerie, 92340 Bourg La Reine, France
> > *** opinions {are only mine, sont seulement les miennes} ***
> >
> >
> >
> > --
> > Caml-list mailing list.  Subscription management and archives:
> > https://sympa.inria.fr/sympa/arc/caml-list
> > Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
> > Bug reports: http://caml.inria.fr/bin/caml-bugs
>
> --
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>