General developer forum

I think the vote currently just shows that people who don't need keywords don't want them.

Binary files were already being treated as -kb (we explicitly specify a long list by file extension)

I'm not sure about setting everything to -kb all the time. It makes sense to me but are there any gotchas? Any other opinions?

Hi Anthony,

It is useful, and Git has a mechanism that is often used for exactly that. We call it "git describe" -- it gives you a unique name for the tree. And what people do is use that identifier in the script that grabs the daily snapshots. And people use it also to make the name of the snapshot file.

For example, in Moodle, we would add it into our top-level version.php. It is a unique identifier that...

• If it matches a tag (the case of a release) -- then it is the name of the tag.

• Otherwise, it counts patches since that tag, and adds a unique identifier for the commit.

For example, you would have

• For a release: moodle-v1.9.8.tar.gz with version.php defining $gitver='v1.9.8'

• For a snapshot: moodle-v1.9.8-23-gf5b223a.tar.gz and version.php defining $gitver='v1.9.8-23-gf5b223a'

The first case tells you it's straight from a release. The second case tells you it's a snapshot, 23 commits after v1.9.8, and it tells you the exact ID of the commit.

Remove the leading 'g' and you get f5b223a . Tell git

git checkout f5b223a

and you can peruse the exact contents of that tree. Want to make a temp branch (locally) to work on that problem?

git checkout -b tmpbranch f5b223a

Want to see the history?

gitk f5b223a

Note: the "patches since the tag" count is to help us humans visualise. Given the distributed version of git, many different branches could have a 23rd patch on top of v1.9.8 .

The real info is in the commit identifier.

(For example, I am running git v1.6.3.1-26-gf5b223a )

A feel sure that git should be able to work out which version of a file you have got, even if it is slightly modified, just from the file contents.

After much struggling, here is my best attempt:

(I downloaded moodlelib.php from http://cvs.moodle.org/contrib/patches/activity_locking/lib/ and put it in my lib folder as a test.)

Then, in that folder, I ran the following command line:


git log --format=format:'echo %H; git diff -b --shortstat %H moodlelib.php; echo' MOODLE_19_STABLE moodlelib.php | sh


What that does is works back through the history of moodlelib.php (git log ... moodlelib.php).

It uses the --format option of git log to generate another git command for each version in history: git diff -b --shortstat ... moodlelib.php. That counts then number of lines of different between two version of the file, ignoring whitespace changes.

Then we pipe that to sh, to actually execute the commands we have constructed. The extra echos output the commit name, and an blank line.


The output starts looking like:
503b8b480a39ef4817dd2abf77dba0ff476ddce5
1 files changed, 2198 insertions(+), 4506 deletions(-)

e92e4b8ab0ad9f1c8c89c4de0fc02190fa196410
1 files changed, 2198 insertions(+), 4500 deletions(-)

47e32d2955229f205743a0a84de951095fb1cd49
1 files changed, 2198 insertions(+), 4500 deletions(-)

...

and the numbers gradually count down (at the rate of several versions per second) until you get to

...

8ee1b0afabbeb4b18b0c699e826d6e110b4ac7b6
1 files changed, 98 insertions(+), 55 deletions(-)

373da1d463846a48392cae937013e36daf8ad46b
1 files changed, 90 insertions(+), 59 deletions(-)

b78fbdac9df4db1504731e534256a7148f3b5e62
1 files changed, 90 insertions(+), 19 deletions(-)

3a61ccbe0a07c65d2671f3b25ccea3ea8719ca25
1 files changed, 95 insertions(+), 20 deletions(-)

a40803130b5ce31f466efef6cbeb2141a3f292db
1 files changed, 108 insertions(+), 21 deletions(-)

...


So the minimum point there, b78fbdac9df4 is probably the revision that they started editing.

One problem with the CVS $id$ tag is that it is specific to a repository. If I copy the code from Moodle, and then stick it in another CVS repository, and then someone copies it from my CVS repository, the $id$ tag will contain the version number from my own repository, and will be meaningless, if not misleading, to someone who wants to compare with the main Moodle repository.