====== Git cribsheet ======
/* ~~REDIRECT>:crib:git~~ */
{{tag> crib git}}
This is a [[cribsheets|personal cribsheet]] intended for my own use. If it's useful to you, great, but it doesn't cover the subject exhaustively.

===== Resources for beginners =====

  * Atlassian provide some good (and Bitbucket-agnostic) learning paths:
    * [[https://www.atlassian.com/git/tutorials/what-is-version-control|Introduction to Git]]
    * [[https://www.atlassian.com/git/tutorials/setting-up-a-repository|Understanding Git commands]]
    * [[https://www.atlassian.com/git/tutorials/syncing|Collaborating with Git]]
  * [[https://www.amazon.co.uk/Rys-Git-Tutorial-Ryan-Hodson-ebook/dp/B00QFIA5OC/|Ry's Git Tutorial]] is a good, free ebook.


===== Undo =====
==== Unstage file ====
  * ''git reset %%--%% <filename>''

==== Discard local change to file ====
  * ''git checkout %%--%% <filename>''

==== Discard all local changes ====
  * ''git fetch''
  * ''git checkout <branch>''
  * ''git reset %%--%%hard origin/<branch>''

This is a specific form of ''git reset %%--%%hard <commit>'' which resets your current branch to ''<commit>''. ''origin/<branch>'' here refers to the HEAD commit of that branch at origin.

==== Revert ====

  * ''git revert ref_spec''
Git revert undoes a **single** specified commit, making the changes necessary to do so at the HEAD of your current branch.


===== Branches =====
==== Get existing remote branch ====

https://stackoverflow.com/questions/9537392/git-fetch-remote-branch
  * ''git checkout %%--%%track origin/remote_branch_name''

==== Auto setup remote branch when pushing new local branch ====

https://medium.com/@anjusha.khandavalli/auto-setup-remote-branch-with-push-autosetupremote-892ddd7644
  * ''git config --global --add --bool push.autoSetupRemote true''
==== Branch deletion ====

=== Local branches ===
  ** ''git branch -d <branch_name>''
  .. ''-D'' to force deletion in the presence of local-only changes

=== Remote branches ===
https://stackoverflow.com/questions/2003505/how-do-i-delete-a-git-branch-locally-and-remotely
  ** ''git push -d origin <branch>''
  .. (Substitute ''origin'' for a different remote name if required).
=== Obsolete tracking branches ===
https://stackoverflow.com/questions/7726949/remove-tracking-branches-no-longer-on-remote
  * ''git remote prune origin''
  * ''git branch -vv | awk '/: gone]/{print $1}' | xargs -r git branch -d''
===== List conflicted files =====
  * ''git diff %%--%%name-only %%--%%diff-filter=U''
Show //unmerged// files in the diff between the working tree and the index (staging area for next commit).

===== Configuration =====
==== Config files ====
git has [[https://www.theserverside.com/blog/Coffee-Talk-Java-News-Stories-and-Opinions/Where-system-global-and-local-Windows-Git-config-files-are-saved|three config files]]. In Windows:
  * system-wide ("system") -- ''gitconfig'' in the git install folder's ''mingw64\etc'' subdirectory (probably ''C:\Program Files\Git\mingw64\etc'')
  * per-user ("global") --  ''.gitconfig'' in the root of the user's local profile
  * per-repo ("local") -- ''config'' in the repo's ''.git'' folder 
Settings are overridden by values in more narrowly-scoped config (e.g. if the same property is set at user and repo level, the repo level takes precedence).

=== Can't find them? ===
Inspect properties to see where their values are set:
  * ''git config %%--%%list %%--%%show-origin''
or just edit them (using the [[#editor|configured editor]]) via the command line:
  * ''git config %%--%%edit %%--%%system''  
  * ''git config %%--%%edit %%--%%global''  
  * ''git config %%--%%edit %%--%%local''  

==== Settings ====
https://www.atlassian.com/git/tutorials/setting-up-a-repository/git-config covers a lot of possible settings.
=== Editor ===
In Git for Windows, by default the mighty [[https://www.vim.org/|vim]]. If that's not your cup of tea:
  * ''git config %%--%%global core.editor %%"%%'C:/Program Files/Notepad++/notepad++.exe' -multiInst -notabbar -nosession -noPlugin%%"%%''

=== Terminal colours ===
Here's a possible config setup (thanks [[https://nathanhoad.net/how-to-colours-in-git/|Nathan Hoad]]!)
<code>[color]
  ui = auto
[color "branch"]
  current = yellow reverse
  local = yellow
  remote = green
[color "diff"]
  meta = yellow bold
  frag = magenta bold
  old = red bold
  new = green bold
[color "status"]
  added = green bold
  changed = yellow bold
  untracked = magenta bold</code>
To set these up via the command line (e.g. for current branch as above):
  * ''git config %%--%%global color.branch.current %%"%%yellow reverse%%"%%''


=== Unable to get local issuer certificate  ===

  ** To disable verification:
  .. ''git config %%--%%global http.sslVerify false''
  .. This is ill-advised as it [[https://stackoverflow.com/questions/23885449/unable-to-resolve-unable-to-get-local-issuer-certificate-using-git-on-windows/38460722|opens you up to man-in-the-middle attacks]].

=== Long file names ===

From https://stackoverflow.com/questions/22575662/filename-too-long-in-git-for-windows.

Git for Windows compiled with msys has a limit of 260 characters for a filename -- this is a limitation of msys, not Git. (Git's filename length limit is 4096 characters. Work around this by setting ''core.longpaths'' to true:

''git config %%--%%system core.longpaths true''

===== GitHub =====
==== Update fork from origin ====

  -- Go to your forked repo
  -- Pull requests -> New pull request. This compares your fork to its origin as if to merge it back to its originating repo.
  -- Change the base repo to be your fork. This turns it into a branch comparison within the fork -- click compare across forks to be able to see the originating repo again.
  -- Change the head repo to the originating repo. You might need to wait for the screen to refresh if the originating repo has moved on a lot.
  -- Create the pull request and merge it


===== Useful links =====

  * https://mirrors.edge.kernel.org/pub/software/scm/git/docs/user-manual.html#git-concepts
  * http://git-school.github.io/visualizing-git/