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:This should no other side-effect than disabling CRLF/LF conversion, and requires no further configuration, including on new/old clones. |
:This should no other side-effect than disabling CRLF/LF conversion, and requires no further configuration, including on new/old clones. |
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=== Install Git Server with SSH / git-shell === |
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Here we access a central git server with ssh, and limit access by using the git shell <code>git-shell</code>. |
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Create the new user ''git'', using <code>git-shell</code> as shell. |
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<source lang=bash> |
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useradd --create-home --skel /dev/null --home-dir /home/git --shell /usr/bin/git-shell git |
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chmod 750 /home/git |
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</source> |
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;Note |
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:We choose {{file|/home/git}} as root for our repositories because it makes obvious that this folder must be backed up. Another possibility is to use {{file|/var/lib/git}}, the debian default; {{file|/var/git}}, to match {{file|var/www}} used in apache; {{file|/srv/git}} recommended in SELinux and ArchLinux. [http://serverfault.com/questions/432959/wheres-the-conventional-place-to-store-git-repositories-in-a-linux-file-system] |
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Create {{file|.ssh/authorized_keys}} file: |
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<source lang=bash> |
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mkdir .ssh; chmod 700 .ssh |
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touch .ssh/authorized_keys; chmod 600 .ssh/authorized_keys |
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chown -R git:git ~git |
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</source> |
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Add user public key to file above, but also make sure to add <code>no-agent-forwarding,no-port-forwarding,no-X11-forwarding </code> before each key to prevent port forwarding, etc. For instance: |
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<source lang=text> |
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no-agent-forwarding,no-port-forwarding,no-X11-forwarding ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCrpFEALD473OqeplM+qyBx+46KMquWK9utwNmvIy3iBatE4S2oFrHVjeQjSNNDK9qaVh2cHPNzzB0UkV9y174ZLn9qeatU032ieKgFfdTdgQCe88BM8eSiVxTkVWe/bawQwn0qqghPtQl7v6/Bof9H9pAGeWLPTfUFj/+CQTf2vevBZF7iuh/RhaokJ75EY29E2lMlAgfIsLv8OVt71LBJNzvXaZIvQgFn03et44UZuZpoqYlZZgAuVgJbHG88QRxcvciBl3H7adkphEkoGUn05JpG2G01Yw2orxpKuMAkCs6t+Z7LjzQhDe+vmKYC4ZUNr5APDwSUxovI3HWJ10Xv mip@home |
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</source> |
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== Commands == |
== Commands == |
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Revision as of 21:07, 11 July 2016
References
- Git Home
- Git Tutorial
- Git on Ubuntu
- Pro Git
- Git, from the bottom up
- Linux Greatest Invention
- Tech Talk: Linux Torvalds on git
- Git cheat sheet
- Remove Sensitive Data from Git
Example on how to usegit-filter-branchto delete files and propagates this upstream.
Things to look at
- Why arent you using git flow?
Quick overview of git-flow, a small to implement this git branching model - Visualize Git with SeeGit
Visual aid showing off the structure of a git repository in real time while issuing commands against the repository.
Git vs ...
- Mercurial vs Git — It's all in the branches
Comparing Hg with Git, by a long-time advocate of Git ;-) (see also [1]) - Mercurial, Subversion, and Wesley Snipes
Including several posts on various git-related topics. - More: [2], [3].
Git Usage Statistics
According to recent statistics, Git is growing faster than other DVCS system, and would be 10 times more used than e.g. Mercurial:
- GNOME Survey, Debian popularity, Stack Overflow, Programmers StackExchange (indicating 1 order of magnitude difference between Git and Hg in Ohloh and Eclipse survey).
Git on Windows
- http://superuser.com/questions/138669/why-is-tortoise-git-changing-my-file-permissions
Might requiregit config core.filemode false - Using cygwin git instead of msysgit with TortoiseGit
Tools
Git SVN
Subversion integration
See Git SVN page
Introduction
Git Features:
- Reliability
- Performance
- Distributed
Distributed
Originally from BitKeeper. Other distributed SCM is Mercurial.
- No single repository. Everybody always has his own copy of the repository. The repository content is pulled from other people's repository.
- No politics, no commit access control. All work is always done locally, so there is no need to define such politics.
Reliability
Every change, file, directory, etc. is cryptographically hashed (sha1sum).
- Easy corruption detection. Any tampering to a file or directory content (either malicious or because of hardware failure) is immediately detected.
- Easy distribution. Moreover because the repository is distributed all over the place, it is very easy to repair a given repository. You only need to drop all broken objects, and get all missing objects from a remote copy.
Performance
Very fast commit. Local repository
Terminology and Concepts
- gitrevisions
- A commit is a snapshot of your working tree at some point in time. A revision in git denotes either a given commit, or all commit that can be reached from that commit. There are different ways to name a commit (see also
man gitrevisions):- branchname — a branch name is an alias for most recent commit on that branch
- tagname — similar to a branch alias, but that does not change in time
- HEAD — currently checked out commit
- c82a22c — the SHA-1 hash id of the commit (can be truncated as long as it remains unique)
- name^ — the parent of commit name
- name^^ — the grand-parent of commit name (and so on)
- name^2 — the 2nd parent of commit name (and so on)
- name~10 — the 10th ancestor of commit name (same as name^^^^^^^^^^)
- name:path — reference a specific file/directory in a given commit
- name^{tree} — reference the tree held by a commit
- name1..name2 — a commit range, i.e. all commits reachable from name2 back to, but no including, name1 (if either name is omitted, use HEAD instead)
- name1...name2 — refers to all commits referenced by name1 or name2, but not by both. For
git diff, refers to all commits between name2 and the common ancestor of name1 and name2. - master.. — to review changes made to the current branch
- ..master — after a
fetch, to review all changes occured since lastrebaseormerge - --since="2 weeks ago" — all commits since a certain date
- --until=”1 week ago” — all commits up to a certain date
- --grep=pattern — all commits whose commit message matches the regular expression pattern.
- --committer=pattern — all commits whose committer matches the pattern
- --author=pattern — all commits whose author matches the pattern
- --no-merges — all commits in a range that have only one pattern (i.e. ignore all merge commits)
- detached head
- When HEAD is no longer a reference to anything (like ref: refs/heads/branch), but instead contains the actual hash of a commit.
git checkout -b newbranch # To attach HEAD back on a new branch...
- hunk
- individual change within a file (basically a file diff output is made of a sequence of one or more hunks).
Install
From packages
Install the following essential packages:
- git-core — the main program
- git-gui — a gui front-end
Optionally install also:
- git-doc — documentation
- gitweb — Web interface
- ViewGit — Another web interface
- gitosis — Project management:
- tig — a text-mode repository browser interface to git and color pager.
tig # launch browser
git show | tig # Use as pager. Colorize output of git-show
- gitview — Git Repository browser
- gitg — a Git repository browser targeting Gtk+ / GNOME Version delivered with Lucid/Maverick is a very old one. Compile from the sources to get the latest version. Alternatively the repository ppa:pasgui/ppa contains a more recent version.
- qgit — A graphical interface to git repositories using QT
To install the repository:
sudo apt-add-repository ppa:pasgui/ppa
or alternatively, create a file /etc/apt/sources.list.d/pasgui-ppa-lucid.list (change lucid as necessary):
deb http://ppa.launchpad.net/pasgui/ppa/ubuntu lucid main
deb-src http://ppa.launchpad.net/pasgui/ppa/ubuntu lucid main
Then add the apt key:
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys F599ACE3
From sources
Get the sources with
git clone git://github.com/gitster/git.git # Use proxygit if behind a proxy
cd git
git checkout v1.7.8 # To use given version
Some dependencies must be installed:
sudo apt-get install autoconf zlib1g-dev libcurl4-openssl-dev expat asciidoc # More packages might be needed
sudo apt-get install docbook2x # For info pages
For cygwin:
- Install the packages above (or similar)
- install package docbook-xml45
- if needed (see INSTALL):
xmlcatalog --noout --add rewriteURI http://docbook.sourceforge.net/release/xsl/current /usr/share/sgml/docbook/xsl-stylesheets /etc/xml/catalog
xmlcatalog --noout --add rewriteURI http://www.oasis-open.org/docbook/xml/4.5/xsl/current /usr/share/sgml/docbook/xml-dtd-4.5 /etc/xml/catalog
- Add temporarily an executable script ~/bin/xmlto:
#! /bin/bash
/usr/bin/xmlto --skip-validation "$@"
To build and install (again, see INSTALL):
make configure # See also INSTALL
./configure --prefix=/usr/local # In // of existing package installation. /usr/local has precedence
make all doc info # 'info' optional, more dependencies
sudo make install install-doc install-html install-info # 'install-info' optional
Configuration
References:
- Git Community Boot - Customizing Git
- Git handy feedback on command-line
General
Global per-user configuration settings are stored in file ~/.gitconfig
- Add color to git output for all commmands:
- Define author/email
- Add some frequently used aliases:
- More aliases for submodules:
- Setup global .gitattributes file (for better tokenization with
git diff --color-words): - Some handy scripts:
- git-wtf displays the state of your repository in a readable and easy-to-scan format
- Global ~/.gitignore_global file (see [4]):
# Global .gitignore file that applies to all git repositories # # Add this file to git global config with # # git config --global core.excludesfile ~/.gitignore_global # Vim temp files .*.swp
Add this file with:
git config --global core.excludesfile ~/.gitignore_global
- Filter script to prevent running
git cleanin HOME directory:#! /bin/bash if [ -a /usr/local/bin/git ]; then ORIG_GIT=/usr/local/bin/git else ORIG_GIT=/usr/bin/git fi for c; do if [ "$c" = "clean" ]; then GIT_HOME="$HOME/.git" GIT_DIR="$($ORIG_GIT rev-parse --git-dir 2>/dev/null)" GIT_HOME_STAT=$(stat -c %i "$GIT_HOME") GIT_DIR_STAT=$(stat -c %i "$GIT_DIR") if [ "$GIT_HOME_STAT" = "$GIT_DIR_STAT" -o "$GIT_HOME" = "$GIT_DIR" ]; then echo "Can't invoke 'git clean' in HOME git repository!" exit 1 fi break # Break on 'clean' fi if [[ $c != -* || $c == -- ]]; then break # ... or on first non-option arg or -- fi done "$ORIG_GIT" "$@"
- Disable pager for
git log: - Enable auto-complete for git aliases
- Setting the tab width in git diff outputs [5]
- Use the credential helper to cache username / password when connecting to a remote via HTTPS [6]:
git config --global credential.helper cache # Setup cache with default timeout (900s) git config --global credential.helper 'cache --timeout=3600' # To change the default timeout
gitk and tcl/tk
- To solve the issue of ugly fonts (not anti-aliased besides other uglyness), install tk8.5 and force alternatives for wish (see [7]):
- To use Gnome GTK native look, install tileqt as tcl/qt theme (see [8], instructions from [9] ):
- Beautification of git gui
- Clearlooks theme from pysolfc
- Use clam built-in theme
- tile, providing Windows XP native look.
- Does not work on Ubuntu Precise (at least under VB). We get the message
X error of failed request: BadDrawable (invalid Pixmap or Window parameter)
sudo apt-get install tk8.5 sudo update-alternatives --config wish # select wish8.5
An alternative however is to use gitg.
# Install tileqt build deps sudo apt-get install tcl8.5-dev tk8.5-dev libqt4-dev checkinstall # Fetch, configure, build tileqt cd ~/tmp proxygit clone git://tktable.git.sourceforge.net/gitroot/tktable/tile-qt cd tile-qt # On UBUNTU LUCID: ./configure --with-tcl=/usr/lib/tcl8.5/ --with-tk=/usr/lib/tk8.5/ # On UBUNTU PRECISE (multi-arch), pick the correct arch: ./configure --with-tcl=/usr/lib/tcl8.5/ --with-tk=/usr/lib/tk8.5/ --with-qt-include=/usr/include/qt4 --with-qt-lib=/usr/lib/i386-linux-gnu ./configure --with-tcl=/usr/lib/tcl8.5/ --with-tk=/usr/lib/tk8.5/ --with-qt-include=/usr/include/qt4 --with-qt-lib=/usr/lib/x86_64-linux-gnu make sudo checkinstall # Answer questions until files are copied # Set 'tileqt' as default theme, and update system (w/o reboot) echo '*TkTheme: tileqt' >> ~/.Xresources xrdb -merge ~/Xresources
More info/themes:
Issues:
Hook - prevent non-fast-forwarded update
References:
Save this file as .git/hooks/update to install the hook. Edit configuration settings hooks.allownonffupdatemaster to allow / forbid (default) non-fast-forward update.
#!/bin/sh # # A hook to prevent non fast-forward update of 'master'. # # Config # ------ # hooks.allownonffupdatemaster # This boolean sets whether non-fast-forwarded update on master are allowed. # By default, they won't be to prevent history loss. # --- Command line refname="$1" oldrev="$2" newrev="$3" # --- Safety check if [ -z "$GIT_DIR" ]; then echo "Don't run this script from the command line." >&2 echo " (if you want, you could supply GIT_DIR then run" >&2 echo " $0 <ref> <oldrev> <newrev>)" >&2 exit 1 fi if [ -z "$refname" -o -z "$oldrev" -o -z "$newrev" ]; then echo "Usage: $0 <ref> <oldrev> <newrev>" >&2 exit 1 fi # --- Config allownonffupdatemaster=$(git config --bool hooks.allownonffupdatemaster) # echo "update hook: refname '$refname' oldrev '$oldrev' newrev '$newrev' allownonffupdatemaster '$allownonffupdatemaster'" case "$refname" in refs/heads/master) if [ "$allownonffupdatemaster" != "true" ]; then # update is not a fast-forward if there are commits that we can access from oldrev, but not from newrev is_non_ff=$(git rev-list $newrev..$oldrev|wc -l) if [ $is_non_ff -ne 0 ]; then echo "*** [hook] Non-fast-forward updates on master are not allowed, even if forced." exit 1 fi fi ;; *) # Anything else allowed exit 0 ;; esac # --- Finished exit 0
Install / Configure git-daemon
References:
- https://www.kernel.org/pub/software/scm/git/docs/git-daemon.html
- http://git-scm.com/book/en/Git-on-the-Server-Git-Daemon
git-daemon is the daemon that enables access to git repositories through the git: protocol (port 9418). It is easily installed thanks to package git-daemon-sysvinit:
sudo apt-get install git-daemon-sysvinit sudo vi /etc/default/git-daemon # Change user to 'git' sudo /etc/init.d/git-daemon start # Start daemon
By default you cannot access any git repository through git: protocol. You must explicitly list which repository are accessible:
cd ~git/git/project.git touch git-daemon-export-ok # This allow git-daemon to export this project sudo ln -sf ~git/git/project.git /var/cache/git/project.git # In addition, project must be listed in /var/cache/git
Note that base address for git-daemon is /var/cache. Hence, given example above, one would clone it with
git clone git://server/git/project.git.Write access are also refused by default. To allow them, you must edit the .git/config file:
cd ~git/git/project.git git config --add daemon.receivepack true # no hyphen in receivepack!
CR/LF conversion
- To disable CR/LF completely, across all copies of the repositories, create a file .gitattributes in the root of the repository with the following as content [10]:
* -text
- This should no other side-effect than disabling CRLF/LF conversion, and requires no further configuration, including on new/old clones.
Install Git Server with SSH / git-shell
Here we access a central git server with ssh, and limit access by using the git shell
git-shell.Create the new user git, using
git-shellas shell.useradd --create-home --skel /dev/null --home-dir /home/git --shell /usr/bin/git-shell git chmod 750 /home/git
- Note
- We choose /home/git as root for our repositories because it makes obvious that this folder must be backed up. Another possibility is to use /var/lib/git, the debian default; /var/git, to match var/www used in apache; /srv/git recommended in SELinux and ArchLinux. [11]
Create .ssh/authorized_keys file:
mkdir .ssh; chmod 700 .ssh touch .ssh/authorized_keys; chmod 600 .ssh/authorized_keys chown -R git:git ~git
Add user public key to file above, but also make sure to add
no-agent-forwarding,no-port-forwarding,no-X11-forwardingbefore each key to prevent port forwarding, etc. For instance:no-agent-forwarding,no-port-forwarding,no-X11-forwarding ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCrpFEALD473OqeplM+qyBx+46KMquWK9utwNmvIy3iBatE4S2oFrHVjeQjSNNDK9qaVh2cHPNzzB0UkV9y174ZLn9qeatU032ieKgFfdTdgQCe88BM8eSiVxTkVWe/bawQwn0qqghPtQl7v6/Bof9H9pAGeWLPTfUFj/+CQTf2vevBZF7iuh/RhaokJ75EY29E2lMlAgfIsLv8OVt71LBJNzvXaZIvQgFn03et44UZuZpoqYlZZgAuVgJbHG88QRxcvciBl3H7adkphEkoGUn05JpG2G01Yw2orxpKuMAkCs6t+Z7LjzQhDe+vmKYC4ZUNr5APDwSUxovI3HWJ10Xv mip@home
Commands
Here we'll summarize how to use some of the Git commands
Frequently used & common command options
Option Valid for Description -p, -u, --patch log Generate patch -b log, diff, show Ignore whitespace changes --oneline log, show Show commit # + description on oneline -M log, diff, show Find renames --summary log, diff, show Show summary of changes (file creation, rename...) --name-status log, diff, show List file name and type of change (Add, Copied, Deleted, Modified, Renamed) git-add
git-add adds file contents to the index
git add -A # Stage all modified AND new files in current directory and recursively
git-archive
git-archive creates an archive of file from a named tree
# Duplicate current subtree at version commit in ~/tmp/project/sub # !!! DON'T FORGET *trailing slash* in --prefix git archive --prefix project/sub/ commit . | tar -x -C ~/tmp # Same as above git archive --prefix project/ commit sub | tar -x -C ~/tmp
git-blame
git blame -w file # Blame file, ignore whitespaces git blame file | sort | uniq -w 8 | egrep -o "^.{8}" # Show list of commits that produced file # (! actually a subset of git log)
git-branch
git-branch lists, creates, or deletes branches
# CREATE a local branch git branch newbranch # Create a new local branch 'newbranch' # ... use "git checkout newbranch" to check it out # TRACK a remote branch git branch --track sf origin/serverfix # Create a local branch 'sf' that tracks remote branch 'serverfix' git branch --set-upstream sf origin/serverfix # ... same, but when local branch 'sf' already exists # DELETE a branch git branch -d sf # Delete local branch 'sf' git branch -d -r origin/serverfix # Delete remote tracking branch 'serverfix' (see remark below) git remote prune origin # Prune all state remote tracking branch # MOVE a branch git branch -f branch commit # Move tip of an existing branch to a different commit # VIEW branches git branch --all # List ALL branches git branch --contains commit # List LOCAL branches that CONTAIN commit git branch --all --contains commit # List ALL branches that CONTAIN commit
Note:
- You can also track local branch (
git branch -t local1 local2), but is it useful? - Deleting remote tracking branch (
git branch -d -r) on the local repository only makes sense if the remote branch has been deleted on the remote, or if git-fetch has been configured not to import that branch anymore. So the best is simply to prune remote tracking branches automatically:
git remote prune origin # Remove all remote tracking branches that no longer exist on the remote (i.e. stale branches) git fetch --prune # After fetching, remove all remote tracking branches that no longer exist on the remote
git-checkout
git-checkout checkouts a branch or paths to the working tree.
# CHECKOUT a local branch git checkout mybranch # Checkout an existing branch # CREATE & CHECKOUT a local branch git checkout -b newbranch # Create a new local branch 'newbranch' and check it out # TRACK & CHECKOUT a remote branch git checkout --track origin/serverfix # Checkout a new local branch 'serverfix' to track remote branch 'serverfix' # (remember that this branch is called locally 'origin/serverfix') git checkout -b sf origin/serverfix # ... same as above, but the local branch is named 'sf' # Checkout <paths> from INDEX or COMMIT git checkout -- <paths...> # DISCARD changes git checkout COMMIT -- <paths...> # Same as "git reset commit -- path; git checkout -- path"
git-clean
git-clean removes untracked files from the working tree.
git clean -dfx # force + delete dirs + delete also ignored files
git-clone
git-clone is mainly used to create a local copy of a remote repository, or to create a bare repository (i.e. one without a working tree) for remote storage:
- Clone a remote repository:
- Create a bare repository for remote storage:
git clone git@griffin:repositories/myproject.git # Clone repository and create working tree in myproject/
git clone --bare myproject myproject.git # Create a bare clone of your repository, if not available yet scp -r myproject.git/ git@griffin:repositories/ # Copy the repository to server - requires SSH access rm -rf myproject.git # Delete local bare clone
The commandgit clone /dir/repo/project.gitis identical to running the following commands:git init # Create an empty repo git remote add -f origin /dir/repo/project.git # Add a remote repo called 'origin' and fetch git set-head -a # Set default remote branch for remote 'origin' automatically git checkout --track origin/master # Create a tracking branch 'master', and update working tree
Another equivalent option for last command is
git checkout -b origin origin/master(since the start-point is remote, git creates a tracking branch).Some variants:
- To get a local copy of a remote repository, but without changing the working tree (i.e. keeping all local changes), just change the last command to:
git init git remote add -f origin -m master /dir/repo/project.git git branch --track master origin/master # Branch 'master' set up to track remote branch 'master' from 'origin'
- To merge remote branch locally, but without creating a tracking branch, change the last command to :
# ... git merge origin/master # Merge
git-commit
git commit -m "commit message" # Gives immediately the commit message on the command-line git commit -a # Add all changes and commit in one pass git commit --amend # Amend tip current branch (message, add some files) - also for merge commits git commit -C <commit> # Reuse commit message from <commit>
Add the following line to your file ~/.gitconfig:
git config --global alias.ci 'commit'
Now you can use ci instead of commit:
git ci -m "commit message"
git-diff
git-diff shows changes between commits, commit and working tree, etc
Sample of useful options (some can be combined):
git diff --stat <commit> # Show changes summary as a graph (with + and -) git diff -b <commit> # Ignore whitespaces git diff -w <commit> # Ignore all whitespaces (remove them completely) git diff --name-only <commit> # Only list names of changed files git diff --relative[=<dir>] <commit> # Restrict changes to current (or given) directory and show relative pathname git diff -M --summary <commit> # Show summary of changes (incl. file creation), find renames
git-fetch
git-fetch downloads objects and refs from another repository.
git fetch -p # After fetching, remove any remote-tracking branches which no longer exist on the remote # (see also git remote prune origin)
git-filter-branch
git-filter-branch rewrites branches.
This command can be used for instance to rewrite / rebase a branch while changing the author/committer name/email (see [12] and [13]):
# Set the committer name to author name, for instance after a rebase git filter-branch --commit-filter ' export GIT_COMMITTER_NAME="$GIT_AUTHOR_NAME"; export GIT_COMMITTER_EMAIL="$GIT_AUTHOR_EMAIL"; export GIT_COMMITTER_DATE="$GIT_AUTHOR_DATE"; git commit-tree "$@"' -- basecommit..HEAD # Change the author/committer name for specific commit (e.g. if wrong email was used): git filter-branch --commit-filter ' if [ "$GIT_COMMITTER_NAME" = "<Old Name>" ]; then GIT_COMMITTER_NAME="<New Name>"; GIT_AUTHOR_NAME="<New Name>"; GIT_COMMITTER_EMAIL="<New Email>"; GIT_AUTHOR_EMAIL="<New Email>"; git commit-tree "$@"; else git commit-tree "$@"; fi' HEAD
Note that
basecommit..HEADcan easily be changed to other commit specification, like--since="1 year ago"Another example to remove sensitive files from repository (from [14]):
# Delete the file(s) git clone git@github.com:defunkt/github-gem.git cd github-gem/ git filter-branch --index-filter 'git rm --cached --ignore-unmatch pattern1 pattern2 ...' HEAD # .... Add --tag-name-filter "cat" to keep tags - will overwrite existing tags! # Push to origin git push origin master --force # Force cleanup (a safer method is to clone the repository and keep the clone if everything's fine) rm -rf .git/refs/original/ git reflog expire --expire=now --all git gc --prune=now git gc --aggressive --prune=now
Deleting a directory in all commits
# -- --all apply to all branches # filter-branch -f to ignore backup in refs/original/ git filter-branch -f --index-filter 'git rm --ignore-unmatch --cached -rfq shared/saves' -- --all
Moving a directory
# Rewrite revision history - Move directory (since we branched off master) git filter-branch --tree-filter 'mv subsystem/inc inc' master..HEAD
Applying on all branches
git filter-branch ... HEADwill only filter all commits that are reachable from HEAD. To filter all branches, simply replaceHEADby-- --all(see [15]):git filter-branch --tree-filter 'mv subsystem/inc inc' -- --all
Move a directory and symlink
Same as above but we want to keep a symlink to the new location. It appears we can't move and symlink at the same time because Git complains about following files through symlinks. So we proceed in 2 steps:
git filter-branch --tree-filter "moveit nfc4java bb/firmware_35g/option/jvm mv" nfcbase..HEAD git filter-branch --tree-filter "moveit nfc4java bb/firmware_35g/option/jvm ln" nfcbase..HEAD
moveit is a script in the path with the following code:
#! /bin/bash SRC=$1 DST=$2 PHASE=$3 # either 'mv' (1st phase) or 'ln' (2nd phase) if [ "$PHASE" = "mv" ]; then # 1st phase mv $SRC/nfc.h $DST/include/nfc.h mv $SRC/nfc.c $DST/src/nfc.c if [ -a $SRC/fri-lib ]; then rm -rf $DST/nfc-fri mv $SRC/fri-lib $DST/fri-lib else rm -rf $DST/nfc-fri mv $SRC/nfc-fri $DST/nfc-fri fi else # 2nd phase ln -sf ../$DST/include/nfc.h $SRC/nfc.h ln -sf ../$DST/src/nfc.c $SRC/nfc.c if [ -a $DST/fri-lib ]; then mv $DST/fri-lib $DST/nfc-fri ln -sf ../$DST/nfc-fri $SRC/fri-lib else ln -sf ../$DST/nfc-fri $SRC/nfc-fri fi fi
As a result the file / directory nfc.h, nfc.c, fri-lib, nfc-fri are moved from nfc4java/ to bb/firmware_35g/option/jvm, and symlinks are created in the source directory so these files / directories are still accessible.
Adding a CR/PR tag to each commmit
Say we need to add a CR/PR tag to each of our commit (like [CR_1234]), we can do it with:
git filter-branch -f --msg-filter "sed -r '1 s/$/ [CR_1234]/'" master..HEAD
git-grep
git-grep prints lines matching a pattern (see also Git Book)
# Find all occurences of pattern in all files committed since last year for i in $(git log --oneline --all --graph --since="1 year ago" | egrep -o " [a-h0-9]{7} "); do git grep pattern $i; done
Maybe a better solution from [16]:
git grep <regexp> $(git rev-list --all)
git-log
git-log shows commit logs.
git log # Standard history log git log -5 # Limit to 5 commits git log -- file # List commits affecting file git log -p -- file # History log, show patch/diff for file git log -p -M -- file # ... idem, but find also renames git log --summary -M -- file # Condensed summary with renames git log --stat -1 # Show diff-stat for last commit git log -w master.. --stat -- $(find . -name "*.java") # Show all changes to java files since branching off master git log -p topic..HEAD -- . # Show all changes done in current dir that are not in topic branch git log --all --ancestry-path A.. # Show all commits that are descendants of A (also with gitk)
Some handy aliases:
[alias] # h like history h = log --oneline --graph --decorate -45 ha = log --oneline --graph --decorate -45 --all # l like log ;-) l = log --pretty=tformat:\"%C(yellow)%h %Cblue%an %Cgreen%cr %Cred%d %Creset%s\" --graph -45 la = log --pretty=tformat:\"%C(yellow)%h %Cblue%an %Cgreen%cr %Cred%d %Creset%s\" --graph -45 --all
View history of a single files, across copy and renames:
git l --follow -- file # Show all commits that modified file (incl. renames) # (includes commits that deleted lines, unlike blame) git log -b --follow -p -- file # ... same, show patch and ignore blanks
CAUTION! —
git logwill not show any differences for merge commits! To fix that, use options-m,-cor--cc(see [17]):git log -p <commit> # SHOW NOTHING!!! git log -p -m <commit> # Show 2 diffs, one for each parent git log -p -c <commit> # ... Same as above, but simultaneously git log -p --cc <commit> # ... Same as above, but remove hunks that are identical to one of the parent
CAUTION! —
git log --oneline --graphoutput can be misleading! Overlooking the graph may give the impression that a given commit is in some branch where actually it is in another branch. Look at the asterisks (*) carefully!. Example:* | 2dbfa34 frq05215 4 weeks ago Integration implementation... * | cd1d5a7 beq03416 4 weeks ago Merged head of trunk into... |\ \ * | | 84fb520 frq05215 4 weeks ago Integration implementation... # This commit is not in same branch as 0eef5c7! | | | * 0eef5c7 beq03416 4 weeks ago relaxed the rate adaptation... | | |/ | | * b998ebd nxp12661 4 weeks ago [PT_TLMT2086] Changed bool_t type into J9bool_t...
git-pull
git-pull fetches from and merges with another repository or a local branch.
git pull -p # After fetching, remove any remote-tracking branches which no longer exist on the remote # (see also git remote prune)
git-push
git push updates remote refs along with associated objects. In layman english, git push basically pushes changes to the remote repository, possibly creating, updating, deleting branches, objects or references.
# PUBLISH a local branch (for TRACKing) # git push [remotename] [localbranch]:[remotebranch] git push # Push current branch to remote git push origin # Push all matching branches to remote git push origin serverfix # Push a local branch 'serverfix' to remote (create it if necessary) git push -u origin serverfix # ... same but also set upstream reference for TRACKING git push -u origin serverfix:serverfix # ... same as above git push -u origin serverfix:coolfix # ... same but call the branch 'coolfix' on the remote # DELETE a branch git push origin :serverfix # Delete remote branch 'serverfix' on 'origin' # (basically this means push nothing to remote branch 'serverfix')
git-rebase
git-rebase forward-port local commits to the updated upstream head.
git rebase master # Rebase current branch to master branch git rebase master topic # Rebase branch topic to branch master. Same as # git checkout topic # git rebase master git rebase master topic --onto newbase # Same as above, but instead write the commits at dest git rebase --committer-date-is-author-date master # ... keep original (author) date for new commits
git-reflog
git reflog manages reflog information. This is very handy to repair mistakes, or to recover lost commits (e.g. after modifying the head of a branch that was the only reference to a given commit)
git refloggit-remote
Add another remote to an existing repository. Using
git remote set-headandgit branchone call also set up automatically origin/HEAD and set tracking branches. For instance the following is equivalent to what's done bygit clone:git remote add -f origin git@griffin:repositories/my_project.git # Add remote repository and fetch automatically git remote set-head -a origin # Set origin/HEAD automatically - see man git-remote, set-head git branch --set-upstream master origin # Set master to track head (here origin/master) branch from origin
- git-remote set-head
- Sets / deletes the default branch for a remote. For remote origin, this creates the reference refs/remotes/origin/HEAD with content ref: refs/remotes/origin/master if default branch is master.
Use set-head to follow the changes in another branch than the default one:
git remote set-head origin -a # Set default remote branch for remote 'origin' automatically git diff origin # -> Will show difference with origin/master (if 'master' is the default) git remote set-head origin exoticbranch # ... or set it to a different branch (here 'exoticbranch') git diff origin # -> Now will show diff with origin/exoticbranch
git-reset
git reset has two purposes:
- commit paths... → Index
Copy paths... from HEAD (or given commit) to index (working tree left unchanged), or - branch head → commit
Move current branch head to HEAD (or given commit), and optionally update index and/or working tree.
Modes are:
mode index working tree preserve local changes --soft Yes --mixed (default) reset Yes --hard reset reset No --merge reset keep if idx = commit, else
reset if idx = tree, else
abortNo
(fully staged changes are lost)--keep reset keep if HEAD = commit, else
reset if HEAD = tree, else
abortYes Note:
- git reset copies the old head to ORIG_HEAD.
- Use
git checkout <commit> -- <paths...>to copy paths... from a given commit to the index and working tree in one go. - Caution! — Don't move the head of a branch if changes have been already published, or this will create many merge conflicts.
- Caution! — git reset --hard is a dangerous command. Prefer one of its alternatives, like:
Commit any changes first git commit -a -m "snapshot WIP" git reset --hard~3
Stash the changes git stash git reset --hard HEAD~3 # ... git reset --hard HEAD@{1} # or ORIG_HEAD git stash apply
Idem & don't change master too early git stash git checkout -b new-branch HEAD~3 ... git branch -D master git branch -m new-branch master
Some use cases (seeman git-resetfor details):- Undo a commit and redo
git commit ... git reset --soft HEAD^ edit git commit -a -c ORIG_HEAD # or -C
- Undo commits permanently
git commit ... git reset --hard HEAD~3
- Undo a commit, making it a topic branch
git branch topic/wip git reset --hard HEAD~3 # or --mixed git checkout topic/wip # or -m topic/wip
- Undo a merge or pull
git pull # conflicts git reset --hard git pull . topic/branch # no conflict git reset --hard ORIG_HEAD
- Undo a merge or pull inside a dirty work tree
git pull git reset --merge ORIG_HEAD
- Interrupted workflow
git checkout feature #work work work git commit -a -m "snapshot WIP" git checkout master #fix fix fix git commit git checkout feature git reset HEAD^ # or --soft
- Reset a single file in the index
git add foo.c git reset -- foo.c
git-show
git-show shows various types of objects.
git show --stat <commit> # Show commit; for merge, show *combined* commit git show -b -R <commit> # Show reverse patch, ignoring blanks (handy for reversing commit by hand) git show <treeish>:<file> # Show file at given commit (see also 'git checkout') git show -s <commit> # Show commit, but suppress diff output (like 'git log -1')
git-submodule
See Submodules section.
Submodules
References:
- Summary of command 'git submodule'
git submodule add git submodule status git submodule init git submodule deinit git submodule update [--init] [--recursive] git submodule summary [--cached] [--files] # See also 'git diff --submodule=log' git submodule foreach git submodule sync
- Clone a project with submodules
git clone <project_url> # First clone parent project. submodule folders will be present but empty git submodule init # Init local configuration file git submodule update # Fetch all data from submodule project, and check out appropriate commit git clone <project_url> git submodule update --init # Idem, one command less git clone --recursive <project_url> # Same as above, all in one step
- Add a submodule into an existing project
git submodule add <public_url> [submodulename]
- To use another, private, URL to pull from locally, use
git config submodule.<submodulename>.url <private_url>
- Diff with pretty submodules info
git diff --submodule # View commit changes in submodules git config --global diff.submodule log # To avoid typing --submodule everytime
- Updating a local submodule to get upstream changes
cd <submodulename> git fetch git merge origin/master # or git merge --ff-only
or simpler
git submodule update --remote [submodulename] # Update one or all submodules
By default, commands above will update the checkout to the 'master' branch of submodule directory. To track a different branch do
git config -f .submodules submodule.<submodulename>.branch <branchname> # for everyone checking out parent project git config submodule.<submodulename>.branch <branchname> # locally only
Git status can also show a summary of changes (new commit)
git config status.submodulesummary 1 # Tell git-status to show summary of changes git status
- Update submodule and merge / rebase
git submodule update --remote --merge git submodule update --remote --rebase
- Publishing submodules changes
Make sure to push new commits in submodules first before updating the parent.
git push --recurse-submodules=check # Check that submodule remote contains the necessary commit git push --recurse-submodules=ondemand # Push missing submodules commit to remote if necessary
See also option 'submodule.<name>.fetchRecurseSubmodules' to have either options above by default
- Update submodule url
- Edit .gitmodules, then run
git submodule sync git submodule update
- Tips
- Run a command in all submodules
git submodule foreach 'git stash' git submodule foreach 'git checkout -b featureA' git diff; git submodule foreach 'git diff'
- Useful aliases
git config alias.sdiff '!' "git diff && git submodule foreach 'git diff'" git config alias.spush 'push --recurse-submodules=on-demand" git config alias.supdate 'submodule update --remote --merge'
- Pits
- Committing changes in a submodule in detached head state, then updating the module to a different commit. The new commit was not pushed to repo with a branch and so is lost. It can be recovered by looking into the reflog. Suggestion:
- Only checkout tags in submodules. Let senior dev update and test changes in submodules. Also, submodules must be stand-alone projects that can be tested and developed separately.
Tips
Frequently Used Commands
git commit -a # Add all changes and commit in one pass git commit --amend # Amend tip current branch (message, add some files) - also for merge commits
Working the Git Way
- Check project diff before
commit -a: - Give
git commita directory argument instead of using-a: - Clean up an ugly sequence of commits ([18]). Better than hunk-based commit because (1) each stage can be tested individually, (2) intermediate commits may contain changes that is not in the final one.
- First make sure that the ugly sequence is on some temporary branch target (what we aim for), and that end result is good and clean.
- Switch back to starting point, and do:
- Edit diff file, to select only those changes we want to include in a first commit. Then do a
git-apply diff - Test, finalize the last changes before commits, and diff against target if necessary.
- Commit, and repeat from step 2.
- When done, branch target can be removed
- Use
gitkto get a graphical visualisation of current commit, or some subsets. For instance - Use
git stashto save the current state of the working tree (see [19]). - Forgot to add some files in the previous commit? Mistyped the commit message? Use
git commit --amend:
git diff # First see what's in the working tree (or git status) git commit -a # Commit all changes
git commit fs/ # Commit all changes in directory fs
git diff -R target > diff # diff to target
vi diff git-apply diff # Must be in project root dir
# test test test git diff -R target > diff # if necessary
gitk # View current commit and all ancestors gitk master.. # View changes to current branch (i.e. reachable from HEAD, excluding master)
git stash # Save current work in working tree ... # (whatever, including git reset --hard...) git stash apply # Bring back changes in working tree
git commit # Oups! forgot one file git add somefile # ... Add the missing file git commit --amend # ... and replace the previous commit
Word-by-word diffs
Reference:
- Blog [20] and [21]
- Manpage gitattributes(5)
- Manpage git-diff(1)
Add the following alias to your ~/.gitconfig file:
[alias] wdiff = diff --color-words wshow = show --color-words
Now you can have word-by-word diffs / shows:
git wdiff fname git show
Improving tokenization in diffs
Diffs can even be further improved thanks to the use of the .gitattributes file in your repository. For instance:
*.tex diff=tex *.h diff=cpp *.c diff=cpp *.cpp diff=cpp
One can also define filters that would clean files before checkin/checkout.
Show Git Branch in Prompt
Links:
The simplest is to add
$(__git_ps1)to variable PS1 in file ~/.bashrc. Alternatively one can use\[\e[31m\]$(__git_ps1 " (%s)")\[\e[0m\]to prepad a space when branch name is displayed and use red color.#PS1 in cygwin PS1='\[\e]0;\w\a\]\n\[\e[32m\]\u@\h \[\e[33m\]\w\[\e[31m\]$(__git_ps1 " (%s)")\[\e[0m\]\n\$ '
Undoing / Reverting a commit
- See [22] (stackoverflow.com)
Undoing last commit
The much simpler
git commit --amend:git add ... git rm ... git commit --amend # Current index state will be used for new commit
The usual
reset / add / commitsequence:git commit ... git reset --soft HEAD^ # Move back to previous commit, keep current changes # edit edit edit... git add ... # Add modified files git commit -c ORIG_HEAD # Commit, reedit old comment as base (-C to reuse w/o editing)
Reverting a past commit
Use
git revert ...:git revert -n HEAD # Revert last commit, don't commit yet git revert -n 1234567 # Revert a given commit, don't commit yet git commit ...
Revert with Cherry Picking changes
The easiest is to reuse the patch method as explained by Linus above in Working the Git Way:
git show -b -R <commit> > diff # Get a revert patch vi diff # Edit the patch as necessary git apply diff # Apply the patch
Housekeeping / compress repository
Repack repository:
git repack -adf git repack -adF # Also repack already packed objects - rarely needed # Complete sequence include garbage collect rm -rf .git/refs/original/ # remove the old reference backup used for rebase git reflog expire --expire=now --all # tell git that all reflog objects expire now git gc --prune=now # first prune everything git gc --aggressive --prune=now # ... then again and pack objects together
Squashing Merge Commits
Let's assume we have this situation, and we want to squash the 2 merge commits M1 and M2 (see [23]).
Initial situation Final situation X --- Y --------- M1 -------- M2 (my-feature) / / / / / / a --- b --- c --- d --- e --- f (stable)
→ X --- Y --------------------- M2' (my-feature) / / / / a --- b --- c --- d --- e --- f (stable)
Easy solution:
git checkout my-feature git reset --soft Y git rev-parse f > .git/MERGE_HEAD git commit
Result is commit M2', identical to M2 above.
Finding files
Using
git ls-filesit is very easy and fast to locate a file in a git repository:git ls-files # List all files in the repository git ls-files *.c # List all files with .d suffix git ls-files */gcc.mk # Find a specific file
Cloning to/from a Server using SSH
- Standard peer-2-peer clone
The standard method is simply to use the
clonecommand:git clone user@server:repositories/myproject
This assumes one has SSH access to user@server.
- Bare central repo - SSH access to client
If the clone is not meant to be used locally, but only as a central repository that other users will clone from, it is better to create a bare repository:
git clone --bare user@server:repositories/myproject myproject.git
By default,
cloneadds the source server as remote. This is usually not necessary:cd myproject.git git remote remove origin
Another method is to use
git fetchin that case (which does not create a remote):git init --bare myproject.git cd myproject.git git fetch user@server:repositories/myproject "*:*" # Fetch from local repository
- Bare central repo - restricted access from client
Usual, the central git server can't access to remote clients, and also, only offers restricted access from client (via SSH
git-shellfor instance). In that case, the method is to create an empty bare repository on the server (either via console or via some web interface):ssh git@griffin cd repositories git init --bare myproject.git
And then, from the client, add the server as a remote and push all references:
git remote add git@griffin:repositories myproject.git git push --all origin
- Bare central repo - full access from client
In this method, we create a local bare copy, and then copy it to the remote server.
git clone --bare myproject myproject.git # Create a bare clone of your repository, if not available yet cd myproject.git git remote remove origin cd .. scp -r myproject.git/ git@griffin:repositories/ # Copy the repository to server - requires full SSH access rm -rf myproject.git # Delete local bare clone
Alternatively, one can transfer the repository using another user, but then access conditions and file ownership must be corrected.
See git-clone below for more details.
Cloning from a Server using SSH (limited access)
Reference: [27]
Say you have an SSH access to a server but git-core is not installed you you can't install it yourself (for instance on a shared hosting server). You can still use git but it requires some "hacking":
- First copy the executables from package git-core, directory /usr/bin to some directory on the server where you have write access (say private/bin). Note that somes files are actually symlinks: private/bin/: -rwxr-xr-x user webusers git* lrwxrwxrwx user webusers git-receive-pack -> git* -rwxr-xr-x user webusers git-shell* lrwxrwxrwx user webusers git-upload-archive -> git* -rwxr-xr-x user webusers git-upload-pack*
- Clone from the server using -u command-line switch:
- Edit the local myproject/.git/config file to add the lines marked with a +:
[remote "origin"] fetch = +refs/heads/*:refs/remotes/origin/* url = user@server:private/git/myproject.git + uploadpack = /path/to/private/bin/git-upload-pack + receivepack = /path/to/private/bin/git-receive-pack
git clone -u </path/to/private/bin/git-upload-pack> user@server:private/git/myproject.git
Using a remote with custom port
Just use the generic address ssh://username@hostname:port/...
git clone ssh://username@hostname:22222/home/git/repo/myrepo git remote add origin ssh://username@hostname:22222/home/git/repo/myrepo
Mirroring
Reference: [28]
Cloning from a Server using git: Protocol over a Proxy
The referenced links propose some script. Here another variant. Add this script to your path (say ~/bin/proxygit):
#!/bin/bash # proxygit - git through http proxy # # Usage: proxygit [options] COMMAND [ARGS] # Setup Git HTTP proxy variable GIT_PROXY_COMMAND and call git with the given parameters. # The proxy settings are read from env variable $http_proxy # # Note: # - Requires package socat # - $GIT_PROXY_COMMAND must not be defined if [ -n "$GIT_PROXY_COMMAND" ]; then PROXY=$(echo $http_proxy|sed -r 's!(http://)?([^/:]*):([0-9]*)/?!\2!') PROXYPORT=$(echo $http_proxy|sed -r 's!(http://)?([^/:]*):([0-9]*)/?!\3!') exec /usr/bin/socat - "PROXY:$PROXY:$1:$2,proxyport=$PROXYPORT" else export GIT_PROXY_COMMAND="$0" exec git "$@" fi
Work with local and remote branches
Let's assume you have already a remote repository setup, like you would obtain if you clone a remote repository:
git clone user@server:repositories/project.git
By issuing this command, git will automatically:
- Create a local repository, clone of the remote one
- Call the remote repository origin
- Create a local branch master, and
- Configure it to track the branch master on origin. That remote branch is called locally origin/master.
The following commands can be used to create, track, delete local and remote branches.
# CREATE a local branch git branch newbranch # Create a new local branch 'newbranch' # ... use "git checkout newbranch" to check it out # CREATE & CHECKOUT a local branch git checkout -b newbranch # Create a new local branch 'newbranch' and check it out # PUBLISH a local branch (for TRACKing) # git push [remotename] [localbranch]:[remotebranch] git push origin serverfix # Push a local branch 'serverfix' to remote (create it if necessary) git push -u origin serverfix # ... same but also set upstream reference for TRACKING git push -u origin serverfix:serverfix # ... same as above git push -u origin serverfix:coolfix # ... same but call the branch 'coolfix' on the remote # TRACK a remote branch git branch --track sf origin/serverfix # Create a local branch 'sf' that tracks remote branch 'serverfix' git branch --set-upstream sf origin/serverfix # ... same, but when local branch 'sf' already exists # TRACK & CHECKOUT a remote branch git checkout --track origin/serverfix # Checkout a new local branch 'serverfix' to track remote branch 'serverfix' # (remember that this branch is called locally 'origin/serverfix') git checkout -b sf origin/serverfix # ... same as above, but the local branch is named 'sf' # FETCH / UPDATE from remote git fetch git fetch --prune # After fetching, remove any remote tracking branches that no longer exist on the remote # FETCH from & MERGE with remote git pull git pull --prune # After fetching, remove any remote tracking branches that no longer exist on the remote # DELETE a branch git branch -d sf # Delete local branch 'sf' git branch -d -r origin/serverfix # Delete remote tracking branch 'serverfix' git push origin :serverfix # Delete branch 'serverfix' on 'origin' # (basically this means push nothing to remote 'serverfix')
In summary:
- Use
git branchto create, update, delete branches on the local repository. - Use
git checkoutto checkout (possibly new) local branches. - Use
git pushto update the remote, possibly publishing or deleting branches.
Define a diff textconv filter
This applies a diff filter, but only for
git diffandgit logcommands:- Edit file ~/.gitattributes, add (! no quotes around the diff parameter)
*.adr diff=bookmarks_adr
- Edit file ~/.gitconfig, add
[diff "bookmarks_adr"] textconv = sed -r '/NAME=|URL=|SHORT NAME=/!d'
Duplicate a work tree at a given commit without duplicating the .git repo
This can be done with
git archive, which is a bit like thesvn exportfunction of svn:# create current subtree at version commit in ~/tmp/project/sub # !!! DON'T FORGET *trailing slash* in --prefix git archive --prefix project/sub/ commit . | tar -x -C ~/tmp # Same as above git archive --prefix project/ commit sub | tar -x -C ~/tmp
Pushing to a non-bare repository
(see [31])
Let's consider we have
- 2 repositories,
- one on a machine work and
- another one on a machine home,
- we cannot push to home because it is not visible
By default it is not possible to push to work because it is not a bare repository. However it is possible to push to another branch than the current one:
# On machine home, pushing to branch 'from-home' on work git push work HEAD:from-home # On machine work git merge from-home
We can configure home to always push master to branch from-home on remote work:
git config remote.work.push +master:from-home
Fetch a single branch from a remote
Say you have a big remote repository, and you want to only fetch a single branch from it so that to save disk space. This is easily done as follows:
git remote add <remote> <url> git fetch <remote> <remotebranch <localbranch> # This will fetch branch <remotebranch> from <remote> and call it <localbranch> locally
Restore file timestamp
Creation / modification timestamps are not kept by Git, but one can set the file timestamp to e.g. commit timestamp using the following script (from [32]):
for FILE in $(git ls-files) do TIME=$(git log --pretty=format:%cd -n 1 --date=iso $FILE) TIME=$(date -j -f '%Y-%m-%d %H:%M:%S %z' "$TIME" +%Y%m%d%H%M.%S) touch -m -t $TIME $FILE done
Import commits from another repo easily
The easiest is to export the commits as patches with
git format-patch, and then import then back.cd repo1 git format-patch HEAD~3.. cd ../repo2 git am ../repo1/00*
Backup a GitHub repository
First create the repository [33]:
git clone --mirror git://github.com/user/project.git
Then to update:
git --git-dir project.git remote update
Change active branch in a bare repository
if you want the default branch to be something other than master, you need to do this [34]:
git symbolic-ref HEAD refs/heads/mybranch
Which will update the HEAD file in your repository so that it contains:
ref: refs/heads/mybranchThis is well documented in the git-symbolic-ref.
Bash Script-Fu
Some tips on how to use Git in scripts.
It is recommended to only use Git's Plumbing and Porcelain commands:
- Plumbing
- Commands not meant to be used on the command-line, but as building blocks in scripts to build more powerful command
- Porcelain
- More user-friendly commmands, but that are guaranteed not to change in the future
- Get commit of current or any branch
git rev-parse HEAD git rev-parse branchname
- Get current branch name
- The recommended way is to use
git symbolic-ref(see [35])
branch="$(git symbolic-ref HEAD 2>/dev/null)" || branch="(no branch)" branch=${branch##refs/heads/}
- Get .git directory location
We can use function
__gitdir, but it requires to be exported first. Add to ~/.bashrc or ~/.profile:export -f __gitdir
Alternatively one can also use [36]:
GITDIR=$(git rev-parse --git-dir)
- Get root directory location
GITROOT=$(git rev-parse --show-toplevel)
- List all references
#List all references that starts with "refs/remotes/tags" git-for-each-ref refs/remotes/tags #Loop on these references git-for-each-ref refs/remotes/tags | cut -d / -f 4- | while read REF do echo $REF done
- Detect whether current tree is dirty (from [37])
if ( ! git diff-index --quiet HEAD ); then echo Your tree is dirty! Aborting... exit 1 fi
Tools
Git-Annex
git-annex allows managing files with git, without checking the file contents into git. While that may seem paradoxical, it is useful when dealing with files larger than git can currently easily handle, whether due to limitations in memory, time, or disk space.
Troubleshoot
Out of memory - fetch
I get the following message under cygwin (WinXP SP3, cygwin 1.7.9-1, git 1.7.5.1-1, perl 5.10.1-5), while doing a
git svn fetch:git svn fetch # . . . # . . . # Out of memory during "large" request for 268439552 bytes, total sbrk() is 311015424 bytes at /usr/lib/perl5/vendor_perl/5.10/Git.pm line 908, <GEN1> line 615.
Solution is to increase Cygwin's maximum memory. Setting /HKLM/Software/Cygwin/heap_chunk_in_mb to 1024 (1GB) fixed the problem. Indeed Cygwin can only allocate 384MB for a process, and process ended up using more than 480MB... (see also [38])
Out of memory - gc / repack
$ git gc --prune --aggressive Counting objects: 58668, done. Delta compression using up to 2 threads. fatal: Out of memory, malloc failed (tried to allocate 65795137 bytes) error: failed to run repack
Warning! — Seems that
git gc --aggressivehas it's own settings for repack window. See git-gc.Settings / configuration we can play on to help in solving that problem:
- pack.window and pack.depth, which control how objects are stored using delta compression. window basically defines how far repack will look for making deltas, and depth controls the depth when nesting deltas.
- pack.windowmemory will automatically tune down the values of pack.window and pack.depth when the memory limit is reached. This helps for repositories with both big and small files, allowing to still benefit from a large window with small objects while controling memory usage for big objects.
- core.bigFileThreshold set the maximum size of objects manipulated for repack. Any object bigger than this threshold will not be repacked and simply stored deflated.
- pack.threads set the number of threads used by repack (it seems that memory limit is set per thread)
- Increase the amount of virtual & physical memory
- Use a 64-bit OS
Settings examples:
- My settings (got an out of memory - suboptimal pack warning during
git gc --prune --aggressivethough): - Tim's Settings:
- Settings on QNAP (ARM-based NAS):
pack.windowmemory = 700m # Default 0 (no limit) pack.packsizelimit = 1g # Default unlimited # No pack.threads settings core.bigFileThreshold = 256m # Default 512m
pack.windowmemory = 256m pack.packsizelimit = 1g pack.threads = 1 core.bigFileThreshold = 256m
sudo git config --system pack.windowmemory 128m sudo git config --system pack.packsizelimit 1g sudo git config --system pack.threads 1 sudo git config --system core.bigFileThreshold 256m
Some references:
- git-repack manual page
- git-config manual page
- reduce threads [39]
- reduce repack window [40])
Broken Pipe error code 13 on git svn fetch
This error is most likely due to network disconnection. Solution so far is to fetch repeatedly in a for loop:
for i in 1..50 ; do git svn fetch; done
Corporate SSL proxy
Cloning a repository over a HTTPS through an corporate proxy that intercepts SSL request will fail with the error:
git clone https://github.com/kien/ctrlp.vim.git ctrlp.vim # Cloning into 'ctrlp.vim'... # fatal: unable to access 'https://github.com/kien/ctrlp.vim.git/': SSL certificate # problem: unable to get local issuer certificate
The solution:
- Disable SSL certificate verification [41]
git config --global http.sslVerify false
- Add corporate certificate [42].
git config --global color.ui true
git config --global user.name "Your Name"
git config --global user.email you@example.com
git config --global alias.st 'status'
git config --global alias.ci 'commit'
git config --global alias.co 'checkout'
git config --global alias.br 'branch'
git config --global alias.ls 'ls-files'
git config --global alias.last 'log -1 HEAD'
# h like history
git config --global alias.h 'log --oneline --graph --decorate -45'
git config --global alias.ha 'log --oneline --graph --decorate -45 --all'
# l like log ;-)
git config --global alias.l 'log --pretty=tformat:\"%C(yellow)%h %Cblue%an %Cgreen%cr %Cred%d %Creset%s\" --graph -45'
git config --global alias.la 'log --pretty=tformat:\"%C(yellow)%h %Cblue%an %Cgreen%cr %Cred%d %Creset%s\" --graph -45 --all'
git config --global alias.dc 'diff --cached'
git config --global alias.wdiff 'diff --color-words'
git config --global alias.wshow 'show --color-words'
git config --global alias.sst '!git status && git submodule foreach git status'
git config --global alias.sdiff '!git diff $@ && git submodule foreach git diff $@'
git config --global alias.sclean '!git clean $@ && git submodule foreach git clean $@'
git config --global alias.sreset '!git reset $@ && git submodule foreach git reset $@'
git config --global alias.sh '!git h -1 && git submodule foreach git h -1'
git config --global core.attributesfile '~/.gitattributes'
Content of ~/.gitattributes:
*.c diff=cpp
*.cpp diff=cpp
git config --global pager.log false # Can be enabled back with 'git -l log'
alias g=git
alias gg='git -p'
complete -F _git g # Enable auto-complete for these aliases too
complete -F _git gg
git config --global core.pager 'less -x1,5'