In previous articles about the Git version control system, I provided a Git cheat sheet and showed how to fix mistakes in Git. In this article, however, I will show how to mine your Git log to find information on everything that happened in your repository: what happened, who did it, and when.
Git Log Tells All
You can run the git log command to see a complete commit history for your repository, from most recent to oldest. Run it with no options as shown here to display the commit hash, author, date, and comment.
$ git log commit baffcc6389f4499624f51dce3fe59864d0 Author: Dev Loper <firstname.lastname@example.org> Date: Fri Apr 15 12:46:47 2016 +0200 Fix loading the storage autoloader commit cc034cd893752f23f6e51b8fdd6425bd11e Author: Co Derr <email@example.com> Date: Fri Apr 15 12:01:13 2016 +0200 Move apitranslate to apiversiontranslate
The git log –state command adds a list of changed files to the git log output:
lib/private/version.php | 382 +++ lib/private/checkhttp.php | 753 +++++++ lib/private/username.php | 62 +++++++ lib/private/htaccess.php | 382 ----------- lib/private/apicheck.php | 753 -------------- lib/private/errortext.php | 62 ------- 6 files changed, 1197 insertions(+), 1197 deletions(-)
You can view all details of a single commit. This displays everything: date, committer, diff, and entire content of the commit.
$ git show baffcc63
Using git log –no-merges streamlines output by displaying only commits, and not merges. You can view only merges with git log –merges, and see who made the merges with git log –merges –author.
You can also view the diffs of the commits with the -p (patch) option:
$ git log -p commit faf693af499797735b9a6309d520fbf3fc90b268 Author: Com Mitter <firstname.lastname@example.org> Date: Fri Apr 15 12:04:45 2016 -0700 link to file.html describes configuration settings and examples for last three versions diff --git a/config.file b/config.file index c2671f9..86dffa2 100644 --- a/config.file +++ b/config.file @@ -430,14 +430,14 @@ $CONFIG = array(
You can limit the number of commits displayed, for example, diff only the most recent five commits with git log -p -5.
There is a graph view, which can be rather fun to trace on complex projects.
$ git log --graph | | * | commit 03fea9e18d613f844c111e6cbe03ad7f3b7 | Merge: 2fdd888 174af8e | | | Author: donym <email@example.com> | | | Date: Thu Feb 4 11:33:01 2016 -0800 | | | | | | Merge pull request #133 from repo/libs | | | | | | corrections to public api
View commits by name with git log –committer=carla and git log –author=carla. Substituting your own name, of course, or the name of anyone on the project. You may search for commits on a specific file:
$ git log -- path/tofile
Searching in Date Ranges
Add a date range to your search; this is a great tool for fine-tuning your searches:
$ git log --graph --author=carla --after="2015-06-15" / --before="2016-07-15" --no-merges -- path/tofile
You may use –after= and –before= by themselves.
Use the –oneline= option to create a streamlined summary of your commits in a time period. This makes a nice report to give your boss when he’s grumping how he never knows what you’re doing:
$ git log --author="layla" --after="1 week ago" --oneline 54ccc4e corrections to public api 40774df Update user README 5146605 Update dev docs a833ee3 Revert "advance version number" ff2247c Merge pull request #351 from eagle/backport_235 fa0ffa4 clarify temp storage location
You can also display a simplified history of a file:
$ git log -- path/tofile
Or, see all commits on a file, including renames:
$ git log --follow -- path/tofile
The Blame Game
Using git blame — path/tofile outputs a history of everyone who made commits on the file, with the date and changes. You can even narrow your search to a range of lines in the file:
$ git blame -L 5,15 -- path/tofile
Finding Content in Files
Suppose you want to hunt down everything related to the word “http”. You can do this in Git with git grep. It works just like plain grep, as in this case-insensitive search for http:
$ git grep -i http
Just like grep, this outputs a list of files and quotes the line your search term is found in. You can limit the results to filenames only with the -l option:
$ git grep -l http
Or, you can add the line number to the output with -n:
$ git grep -in http
You can search for a specific code snippet. This example looks for anything pertaining to “Apache”, and displays single-line commit summaries:
$ git log --oneline -S'Apache' a7b2056 corrections to htaccess 5b05e61 add warning to use only Apache 2.4 d539643 list Apache module dependencies f0b2428 list supported HTTP servers
And, remember, to save time and headaches, always consult the official Git documentation first.