The git log command is a Git tool which is used to examine a repository's history and find a particular version of a project. It lists and filters the project history and searches for specific changes. The git log only works on the committed history in comparison with git status, which also works on the working directory and the staging area. The git blame command is used to examine the contents of a file line by line and see when each line was last modified and who the author of the modifications was. The output format of git blame can be altered with various command line options.
Online Git hosting solutions like Bitbucket offer blame views, which offer a superior user experience to command line git blame usage. Git blame and git log can be used in combination to help discover the history of a file's contents. The git log command has some similar blame functionality, to learn more visit the git logoverview page. The git blame command is a versatile troubleshooting utility that has extensive usage options.
The high-level function of git blame is the display of author metadata attached to specific committed lines in a file. This is used to examine specific points of a file's history and get context as to who the last author was that modified the line. This is used to explore the history of specific code and answer questions about what, how, and why the code was added to a repository. In the commit history view, a history of commits for the repository in the default branch is displayed, in reverse chronological order of the commit date. You can view the commit history of a different branch by choosing the view selector button and then choosing a branch from the list. If you are using tags in your repository, you can view a commit with a specific tag and its parents by choosing that tag in the view selector button.
The git blame command displays the details of the author who last modified or added each line of code in a given file along with the commit id of modification. The commit id can be used with the git log command to get details of the commit. A repository contains the history, the different versions over time and all different branches and tags. In Git each copy of the repository is a complete repository. If the repository is not a bare repository, it allows you to checkout revisions into your working tree and to capture changes by creating new commits. Bare repositories are only changed by transporting changes from other repositories.
Once you enter some text in the search box, a dropdown provides the choice to search in the current repo or all of GitHub. GitHub searches the contents of files (described as "Code"), commit messages, and issues. Take advantage of the search hits across these different domains.
Again, this is a powerful way to zoom in on specific lines of code, revisit an interesting time in project history, or re-discover a conversation thread. Recently, I saw a developer on the team trying to figure out who removed a file, when it was, and why it was removed. This seems like a useful time for git blame but that works based on lines in a file; it doesn't help with stuff that isn't there any more. If you look at the log with no arguments, then you will see a long list of all the changes on the current branch.
The commit operation, created a new version of your files in the local repository inside the .git folder. If you need to visualise the Git history, git log --graph can be more helpful than a simple git log. There are many ways to customise it, but if you just want to have a compact overview of your commit history you should try the command above. When multiple bulk commits were added over time, it takes quite some effort to add a --ignore-rev for each of them in order to get a 'clean' output for git blame. Luckily, git also provides a way to make this easier on us.
In your repository, create a file to hold commit hashes of commits to be ignored by git blame. Naming this file .git-blame-ignore-revs seems to be a common convention. The -p or –patch option shows the author details and changes in the code in the commit of commit id provided.
This output shows us that content from the README was added or modified 3 times by 3 different authors. It was originally added in commit cb20237cc by Mr.doob. In this example, git log has also been prepended with the --pretty-format option. This option converts the default output format of git log into one that matches the format of git log.
For more information on usage and configuration options visit the git log page. The default execution of git blame will simply output the commands help menu. For this example, we will operate on the README.MD file. It is a common open source software practice to include a README file in the root of a git repository as documentation source for the project.
If you specify the --mixed parameter , thegit reset command moves the HEAD pointer and resets the staging area to the new HEAD. Any file change between the original commit and the one you reset to shows up as modifications in your working tree. Use this option to remove commits but keep all the work you have done. You can do additional changes, stage changes and commit again.
We use the git blame command to display the authorial information for each commit. It helps us track bugs and find which commits produced the error. On a higher level, git blame inspects specific points in repo history, obtains information on who last committed, and what they really changed. While git blame displays the last author that modified a line, often times you will want to know when a line was originally added.
It requires a combination of the -w, -C, and -M options. It can be far more convenient to use the git logcommand. The git filter-branch command allows you to rewrite the Git commit history. This can be done for selected branches and you can apply custom filters on each revision. This creates different hashes for all modified commits.
This implies that you get new IDs for all commits based on any rewritten commit. Assume that a user has a local feature branch and wants to push it to a branch on the remote repository. However, the branch has evolved and therefore pushing is not possible. Now it is good practice to fetch the latest state of the branch from the remote repository.
Afterwards you rebase the local feature branch onto the remote tracking branch. The git show command allows to see and retrieve files from branches, commits and tags. It allows seeing the status of these files in the selected branch, commit or tag without checking them out into your working tree. In Git, this feature is called git blame or git annotate. The git blame command allows you to see which commit and author modified a file on a per line base.
That is very useful to identify the person or the commit which introduced a change. Viewing the history of commits for a branch might also help you understand the difference between branches. If you use tagging, you can also quickly view the commit that was labeled with a tag and the parents of that tagged commit. At the command line, you can use Git to view details about the commits in a local repo or a CodeCommit repository. Here, git blame shows the contents of the file including line numbers on the right.
On the left of each line, git blame shows the commit hash, the author who is responsible for this commit, the date & time of the commit. A commit may change multiple lines of code in a source file. A commit may change only a single line of code in a source file.
So, the same commit hash may appear for multiple lines. One of the downsides to working on a project for a long time is that it's hard to remember why changes get made. While a line might have been changed yesterday it's reason for existing might be hidden from you directly. This article will explain how to view the previous commits for a line so you can determine why it was added/change/whatever. To list all original commits in-which a specific code piece was added or modified execute git log with the -S option.
Append the -S option with the code you are looking for. Let's take one of the lines from the README output above to use as an example. Let us take the text "CSS3D and WebGL renderers" from Line 12 of the README output. If you checkout a commit or a tag, you are in the so-called detached HEAD mode.
If you commit changes in this mode, you have no branch which points to this commit. After you checkout a branch you cannot see the commit you did in detached head mode in the git log command. In general using the stash command should be the exception in using Git. Typically, you would create new branches for new features and switch between branches. You can also commit frequently in your local Git repository and use interactive rebase to combine these commits later before pushing them to another Git repository. In some cases simply using git blame is not sufficient in order to see all details of certain changes.
You can navigate to the file location in the target git repository and use the gitk command to see all commits of a file in a clear UI. The git diff command allows you to compare changes between commits, the staging area and working tree, etc. Via an optional third parameter you can specify a path to filter the displayed changes path can be a file or directorygit diff .
Using Git as a single user is one thing but when you're on a team of people — usually with a mix of backgrounds and technologies — Git can become both a blessing and a curse. It can be powerful for sharing the same codebase, getting code reviews, and seeing progress of the whole team. But at the same time, everyone needs to have a shared understanding of how the team intends to use it. In the extreme case that git reflog is unable to help you get your files back (e.g. if you ran a hard reset with staged files), there's one more trick up your sleeve. Every change is stored in .git/objects which on an active project would be full of files and impossible to decipher.
There is, however, a git command called git fsck which is used to verify integrity within a repository. We are able to use this command with the --lost-found flag to find all files that are not related to a commit; these files are called a "dangling blob". This contrasts with git log which is everything that has changed over time for the particular branch.
Some people get confused between git blame and git log. However, if you only want to display the metadata of the person who performed the commit, then git blame should be your command of choice. This causes git to automatically ignore the commits specified in that file for every call to git blame.
Be aware however that git currently gives an error when this setting is configured globally but a repository has no .git-blame-ignore-revs file yet. I hope that this is considered a bug and will be fixed in an upcoming version. In order to demonstrate git blame we need a repository with some history. We will use the open source project git-blame-example.
This open source project is a simple repository that contains a README.md file which has a few commits from different authors. The first step of our git blame usage example is to git clone the example repository. Afterwards add the affected file to the staging area and commit the result. You can also push the integrated changes now to the remote repository.
The git fetch command updates your remote-tracking branches, i.e., it updates the local copy of branches stored in a remote repository. The following command updates the remote-tracking branches from the repository called origin. The git log command shows the history of the Git repository. If no commit reference is specified it starts from the commit referred to by the HEAD pointer.
To test the git pull in your example Git repositories, switch to other non-bare local repository. Pull in the recent changes from the remote repository. Afterwards make some changes and push them again to your remote repository. Adding a file to the .gitignore file does not remove the file from the repository history. If the file should also be removed from the history, have a look at the git filter-branch command which allows you to rewrite the commit history. See Using the git filter branch command (filter-branch) for details.
This revision can be retrieved later, for example, if you want to see the source code of an older version. Each commit object contains the author and the committer. This makes it possible to identify who did the change. The author did the change and the committer applied the change to the Git repository. This is common for contributions to open source projects. Says that Harry last modified readme.txtin revision 5, understand that this subcommand is by default very picky about what constitutes a change.
Perhaps his changes were the result of blindly running a whitespace cleanup script on this file. You might need to examine the specific differences and related log message to understand exactly what Harry did to this file in revision 5. Can be set to false to disable click actions on the CodeLens. Additionally, these integrations provide commands to copy the url of or open files, commits, branches, and the repository on the remote provider. A long-standing objection to making bulk changes to code using automated tools (e.g. to conform to a given code style) is that it clutters the output of git blame.
