</div>\r
<h2>Author</h2>\r
<div class="sectionbody">\r
-<p>Written by Junio C Hamano 濱野 純 <junkio@cox.net></p>\r
+<p>Written by Junio C Hamano <gitster@pobox.com></p>\r
</div>\r
<h2>Documentation</h2>\r
<div class="sectionbody">\r
</div>\r
<div id="footer">\r
<div id="footer-text">\r
-Last updated 19-Jul-2007 02:09:44 UTC\r
+Last updated 24-Sep-2007 01:04:57 UTC\r
</div>\r
</div>\r
</body>\r
Author
------
-Written by Junio C Hamano 濱野 純 <junkio@cox.net>
+Written by Junio C Hamano <gitster@pobox.com>
Documentation
--------------
is efficient to access. The packed archive format (.pack) is\r
designed to be unpackable without having anything else, but for\r
random access, accompanied with the pack index file (.idx).</p>\r
+<p>Placing both in the pack/ subdirectory of $GIT_OBJECT_DIRECTORY (or\r
+any of the directories on $GIT_ALTERNATE_OBJECT_DIRECTORIES)\r
+enables git to read from such an archive.</p>\r
<p><em>git-unpack-objects</em> command can read the packed archive and\r
expand the objects contained in the pack into "one-file\r
one-object" format; this is typically done by the smart-pull\r
commands when a pack is created on-the-fly for efficient network\r
transport by their peers.</p>\r
-<p>Placing both in the pack/ subdirectory of $GIT_OBJECT_DIRECTORY (or\r
-any of the directories on $GIT_ALTERNATE_OBJECT_DIRECTORIES)\r
-enables git to read from such an archive.</p>\r
<p>In a packed archive, an object is either stored as a compressed\r
whole, or as a difference from some other object. The latter is\r
often called a delta.</p>\r
</div>\r
<div id="footer">\r
<div id="footer-text">\r
-Last updated 15-Sep-2007 07:45:32 UTC\r
+Last updated 24-Sep-2007 01:04:57 UTC\r
</div>\r
</div>\r
</body>\r
designed to be unpackable without having anything else, but for
random access, accompanied with the pack index file (.idx).
+Placing both in the pack/ subdirectory of $GIT_OBJECT_DIRECTORY (or
+any of the directories on $GIT_ALTERNATE_OBJECT_DIRECTORIES)
+enables git to read from such an archive.
+
'git-unpack-objects' command can read the packed archive and
expand the objects contained in the pack into "one-file
one-object" format; this is typically done by the smart-pull
commands when a pack is created on-the-fly for efficient network
transport by their peers.
-Placing both in the pack/ subdirectory of $GIT_OBJECT_DIRECTORY (or
-any of the directories on $GIT_ALTERNATE_OBJECT_DIRECTORIES)
-enables git to read from such an archive.
-
In a packed archive, an object is either stored as a compressed
whole, or as a difference from some other object. The latter is
often called a delta.
</div>\r
<h2>DESCRIPTION</h2>\r
<div class="sectionbody">\r
-<p>This program search the <tt>$GIT_OBJECT_DIR</tt> for all objects that currently\r
+<p>This program searches the <tt>$GIT_OBJECT_DIR</tt> for all objects that currently\r
exist in a pack file as well as the independent object directories.</p>\r
<p>All such extra objects are removed.</p>\r
<p>A pack is a collection of objects, individually compressed, with delta\r
</div>\r
<div id="footer">\r
<div id="footer-text">\r
-Last updated 19-Jul-2007 02:09:49 UTC\r
+Last updated 24-Sep-2007 01:04:58 UTC\r
</div>\r
</div>\r
</body>\r
DESCRIPTION
-----------
-This program search the `$GIT_OBJECT_DIR` for all objects that currently
+This program searches the `$GIT_OBJECT_DIR` for all objects that currently
exist in a pack file as well as the independent object directories.
All such extra objects are removed.
-<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Git User's Manual (for version 1.5.3 or newer)</title><link rel="stylesheet" href="docbook-xsl.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.69.1"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="book" lang="en"><div class="titlepage"><div><div><h1 class="title"><a name="id189136"></a>Git User's Manual (for version 1.5.3 or newer)</h1></div></div><hr></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="preface"><a href="#id264725">Preface</a></span></dt><dt><span class="chapter"><a href="#repositories-and-branches">1. Repositories and Branches</a></span></dt><dd><dl><dt><span class="section"><a href="#how-to-get-a-git-repository">How to get a git repository</a></span></dt><dt><span class="section"><a href="#how-to-check-out">How to check out a different version of a project</a></span></dt><dt><span class="section"><a href="#understanding-commits">Understanding History: Commits</a></span></dt><dd><dl><dt><span class="section"><a href="#understanding-reachability">Understanding history: commits, parents, and reachability</a></span></dt><dt><span class="section"><a href="#history-diagrams">Understanding history: History diagrams</a></span></dt><dt><span class="section"><a href="#what-is-a-branch">Understanding history: What is a branch?</a></span></dt></dl></dd><dt><span class="section"><a href="#manipulating-branches">Manipulating branches</a></span></dt><dt><span class="section"><a href="#detached-head">Examining an old version without creating a new branch</a></span></dt><dt><span class="section"><a href="#examining-remote-branches">Examining branches from a remote repository</a></span></dt><dt><span class="section"><a href="#how-git-stores-references">Naming branches, tags, and other references</a></span></dt><dt><span class="section"><a href="#Updating-a-repository-with-git-fetch">Updating a repository with git fetch</a></span></dt><dt><span class="section"><a href="#fetching-branches">Fetching branches from other repositories</a></span></dt></dl></dd><dt><span class="chapter"><a href="#exploring-git-history">2. Exploring git history</a></span></dt><dd><dl><dt><span class="section"><a href="#using-bisect">How to use bisect to find a regression</a></span></dt><dt><span class="section"><a href="#naming-commits">Naming commits</a></span></dt><dt><span class="section"><a href="#creating-tags">Creating tags</a></span></dt><dt><span class="section"><a href="#browsing-revisions">Browsing revisions</a></span></dt><dt><span class="section"><a href="#generating-diffs">Generating diffs</a></span></dt><dt><span class="section"><a href="#viewing-old-file-versions">Viewing old file versions</a></span></dt><dt><span class="section"><a href="#history-examples">Examples</a></span></dt><dd><dl><dt><span class="section"><a href="#counting-commits-on-a-branch">Counting the number of commits on a branch</a></span></dt><dt><span class="section"><a href="#checking-for-equal-branches">Check whether two branches point at the same history</a></span></dt><dt><span class="section"><a href="#finding-tagged-descendants">Find first tagged version including a given fix</a></span></dt><dt><span class="section"><a href="#showing-commits-unique-to-a-branch">Showing commits unique to a given branch</a></span></dt><dt><span class="section"><a href="#making-a-release">Creating a changelog and tarball for a software release</a></span></dt><dt><span class="section"><a href="#Finding-comments-with-given-content">Finding commits referencing a file with given content</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="#Developing-with-git">3. Developing with git</a></span></dt><dd><dl><dt><span class="section"><a href="#telling-git-your-name">Telling git your name</a></span></dt><dt><span class="section"><a href="#creating-a-new-repository">Creating a new repository</a></span></dt><dt><span class="section"><a href="#how-to-make-a-commit">How to make a commit</a></span></dt><dt><span class="section"><a href="#creating-good-commit-messages">Creating good commit messages</a></span></dt><dt><span class="section"><a href="#ignoring-files">Ignoring files</a></span></dt><dt><span class="section"><a href="#how-to-merge">How to merge</a></span></dt><dt><span class="section"><a href="#resolving-a-merge">Resolving a merge</a></span></dt><dd><dl><dt><span class="section"><a href="#conflict-resolution">Getting conflict-resolution help during a merge</a></span></dt></dl></dd><dt><span class="section"><a href="#undoing-a-merge">Undoing a merge</a></span></dt><dt><span class="section"><a href="#fast-forwards">Fast-forward merges</a></span></dt><dt><span class="section"><a href="#fixing-mistakes">Fixing mistakes</a></span></dt><dd><dl><dt><span class="section"><a href="#reverting-a-commit">Fixing a mistake with a new commit</a></span></dt><dt><span class="section"><a href="#fixing-a-mistake-by-editing-history">Fixing a mistake by editing history</a></span></dt><dt><span class="section"><a href="#checkout-of-path">Checking out an old version of a file</a></span></dt><dt><span class="section"><a href="#interrupted-work">Temporarily setting aside work in progress</a></span></dt></dl></dd><dt><span class="section"><a href="#ensuring-good-performance">Ensuring good performance</a></span></dt><dt><span class="section"><a href="#ensuring-reliability">Ensuring reliability</a></span></dt><dd><dl><dt><span class="section"><a href="#checking-for-corruption">Checking the repository for corruption</a></span></dt><dt><span class="section"><a href="#recovering-lost-changes">Recovering lost changes</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="#sharing-development">4. Sharing development with others</a></span></dt><dd><dl><dt><span class="section"><a href="#getting-updates-with-git-pull">Getting updates with git pull</a></span></dt><dt><span class="section"><a href="#submitting-patches">Submitting patches to a project</a></span></dt><dt><span class="section"><a href="#importing-patches">Importing patches to a project</a></span></dt><dt><span class="section"><a href="#public-repositories">Public git repositories</a></span></dt><dd><dl><dt><span class="section"><a href="#setting-up-a-public-repository">Setting up a public repository</a></span></dt><dt><span class="section"><a href="#exporting-via-git">Exporting a git repository via the git protocol</a></span></dt><dt><span class="section"><a href="#exporting-via-http">Exporting a git repository via http</a></span></dt><dt><span class="section"><a href="#pushing-changes-to-a-public-repository">Pushing changes to a public repository</a></span></dt><dt><span class="section"><a href="#setting-up-a-shared-repository">Setting up a shared repository</a></span></dt><dt><span class="section"><a href="#setting-up-gitweb">Allowing web browsing of a repository</a></span></dt></dl></dd><dt><span class="section"><a href="#sharing-development-examples">Examples</a></span></dt><dd><dl><dt><span class="section"><a href="#maintaining-topic-branches">Maintaining topic branches for a Linux subsystem maintainer</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="#cleaning-up-history">5. Rewriting history and maintaining patch series</a></span></dt><dd><dl><dt><span class="section"><a href="#patch-series">Creating the perfect patch series</a></span></dt><dt><span class="section"><a href="#using-git-rebase">Keeping a patch series up to date using git-rebase</a></span></dt><dt><span class="section"><a href="#modifying-one-commit">Modifying a single commit</a></span></dt><dt><span class="section"><a href="#reordering-patch-series">Reordering or selecting from a patch series</a></span></dt><dt><span class="section"><a href="#patch-series-tools">Other tools</a></span></dt><dt><span class="section"><a href="#problems-with-rewriting-history">Problems with rewriting history</a></span></dt></dl></dd><dt><span class="chapter"><a href="#advanced-branch-management">6. Advanced branch management</a></span></dt><dd><dl><dt><span class="section"><a href="#fetching-individual-branches">Fetching individual branches</a></span></dt><dt><span class="section"><a href="#fetch-fast-forwards">git fetch and fast-forwards</a></span></dt><dt><span class="section"><a href="#forcing-fetch">Forcing git fetch to do non-fast-forward updates</a></span></dt><dt><span class="section"><a href="#remote-branch-configuration">Configuring remote branches</a></span></dt></dl></dd><dt><span class="chapter"><a href="#git-concepts">7. Git concepts</a></span></dt><dd><dl><dt><span class="section"><a href="#the-object-database">The Object Database</a></span></dt><dd><dl><dt><span class="section"><a href="#commit-object">Commit Object</a></span></dt><dt><span class="section"><a href="#tree-object">Tree Object</a></span></dt><dt><span class="section"><a href="#blob-object">Blob Object</a></span></dt><dt><span class="section"><a href="#trust">Trust</a></span></dt><dt><span class="section"><a href="#tag-object">Tag Object</a></span></dt><dt><span class="section"><a href="#pack-files">How git stores objects efficiently: pack files</a></span></dt><dt><span class="section"><a href="#dangling-objects">Dangling objects</a></span></dt></dl></dd><dt><span class="section"><a href="#the-index">The index</a></span></dt></dl></dd><dt><span class="chapter"><a href="#
low-level-operations">8. Low-level git operations</a></span></dt><dd><dl><dt><span class="section"><a href="#object-manipulation">Object access and manipulation</a></span></dt><dt><span class="section"><a href="#the-workflow">The Workflow</a></span></dt><dd><dl><dt><span class="section"><a href="#working-directory-to-index">working directory -> index</a></span></dt><dt><span class="section"><a href="#index-to-object-database">index -> object database</a></span></dt><dt><span class="section"><a href="#object-database-to-index">object database -> index</a></span></dt><dt><span class="section"><a href="#index-to-working-directory">index -> working directory</a></span></dt><dt><span class="section"><a href="#tying-it-all-together">Tying it all together</a></span></dt></dl></dd><dt><span class="section"><a href="#examining-the-data">Examining the data</a></span></dt><dt><span class="section"><a href="#merging-multiple-trees">Merging multiple trees</a></span></dt><dt><span class="section"><a href="#merging-multiple-trees-2">Merging multiple trees, continued</a></span></dt></dl></dd><dt><span class="chapter"><a href="#hacking-git">9. Hacking git</a></span></dt><dd><dl><dt><span class="section"><a href="#object-details">Object storage format</a></span></dt><dt><span class="section"><a href="#birdview-on-the-source-code">A birds-eye view of Git's source code</a></span></dt></dl></dd><dt><span class="chapter"><a href="#glossary">10. GIT Glossary</a></span></dt><dt><span class="appendix"><a href="#git-quick-start">A. Git Quick Reference</a></span></dt><dd><dl><dt><span class="section"><a href="#quick-creating-a-new-repository">Creating a new repository</a></span></dt><dt><span class="section"><a href="#managing-branches">Managing branches</a></span></dt><dt><span class="section"><a href="#exploring-history">Exploring history</a></span></dt><dt><span class="section"><a href="#making-changes">Making changes</a></span></dt><dt><span class="section"><a href="#merging">Merging</a></span></dt><dt><span class="section"><a href="#sharing-your-changes">Sharing your changes</a></span></dt><dt><span class="section"><a href="#repository-maintenance">Repository maintenance</a></span></dt></dl></dd><dt><span class="appendix"><a href="#todo">B. Notes and todo list for this manual</a></span></dt></dl></div><div class="preface" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="id264725"></a>Preface</h2></div></div></div><p>Git is a fast distributed revision control system.</p><p>This manual is designed to be readable by someone with basic UNIX
+<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Git User's Manual (for version 1.5.3 or newer)</title><link rel="stylesheet" href="docbook-xsl.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.69.1"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="book" lang="en"><div class="titlepage"><div><div><h1 class="title"><a name="id189136"></a>Git User's Manual (for version 1.5.3 or newer)</h1></div></div><hr></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="preface"><a href="#id264725">Preface</a></span></dt><dt><span class="chapter"><a href="#repositories-and-branches">1. Repositories and Branches</a></span></dt><dd><dl><dt><span class="section"><a href="#how-to-get-a-git-repository">How to get a git repository</a></span></dt><dt><span class="section"><a href="#how-to-check-out">How to check out a different version of a project</a></span></dt><dt><span class="section"><a href="#understanding-commits">Understanding History: Commits</a></span></dt><dd><dl><dt><span class="section"><a href="#understanding-reachability">Understanding history: commits, parents, and reachability</a></span></dt><dt><span class="section"><a href="#history-diagrams">Understanding history: History diagrams</a></span></dt><dt><span class="section"><a href="#what-is-a-branch">Understanding history: What is a branch?</a></span></dt></dl></dd><dt><span class="section"><a href="#manipulating-branches">Manipulating branches</a></span></dt><dt><span class="section"><a href="#detached-head">Examining an old version without creating a new branch</a></span></dt><dt><span class="section"><a href="#examining-remote-branches">Examining branches from a remote repository</a></span></dt><dt><span class="section"><a href="#how-git-stores-references">Naming branches, tags, and other references</a></span></dt><dt><span class="section"><a href="#Updating-a-repository-with-git-fetch">Updating a repository with git fetch</a></span></dt><dt><span class="section"><a href="#fetching-branches">Fetching branches from other repositories</a></span></dt></dl></dd><dt><span class="chapter"><a href="#exploring-git-history">2. Exploring git history</a></span></dt><dd><dl><dt><span class="section"><a href="#using-bisect">How to use bisect to find a regression</a></span></dt><dt><span class="section"><a href="#naming-commits">Naming commits</a></span></dt><dt><span class="section"><a href="#creating-tags">Creating tags</a></span></dt><dt><span class="section"><a href="#browsing-revisions">Browsing revisions</a></span></dt><dt><span class="section"><a href="#generating-diffs">Generating diffs</a></span></dt><dt><span class="section"><a href="#viewing-old-file-versions">Viewing old file versions</a></span></dt><dt><span class="section"><a href="#history-examples">Examples</a></span></dt><dd><dl><dt><span class="section"><a href="#counting-commits-on-a-branch">Counting the number of commits on a branch</a></span></dt><dt><span class="section"><a href="#checking-for-equal-branches">Check whether two branches point at the same history</a></span></dt><dt><span class="section"><a href="#finding-tagged-descendants">Find first tagged version including a given fix</a></span></dt><dt><span class="section"><a href="#showing-commits-unique-to-a-branch">Showing commits unique to a given branch</a></span></dt><dt><span class="section"><a href="#making-a-release">Creating a changelog and tarball for a software release</a></span></dt><dt><span class="section"><a href="#Finding-comments-with-given-content">Finding commits referencing a file with given content</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="#Developing-with-git">3. Developing with git</a></span></dt><dd><dl><dt><span class="section"><a href="#telling-git-your-name">Telling git your name</a></span></dt><dt><span class="section"><a href="#creating-a-new-repository">Creating a new repository</a></span></dt><dt><span class="section"><a href="#how-to-make-a-commit">How to make a commit</a></span></dt><dt><span class="section"><a href="#creating-good-commit-messages">Creating good commit messages</a></span></dt><dt><span class="section"><a href="#ignoring-files">Ignoring files</a></span></dt><dt><span class="section"><a href="#how-to-merge">How to merge</a></span></dt><dt><span class="section"><a href="#resolving-a-merge">Resolving a merge</a></span></dt><dd><dl><dt><span class="section"><a href="#conflict-resolution">Getting conflict-resolution help during a merge</a></span></dt></dl></dd><dt><span class="section"><a href="#undoing-a-merge">Undoing a merge</a></span></dt><dt><span class="section"><a href="#fast-forwards">Fast-forward merges</a></span></dt><dt><span class="section"><a href="#fixing-mistakes">Fixing mistakes</a></span></dt><dd><dl><dt><span class="section"><a href="#reverting-a-commit">Fixing a mistake with a new commit</a></span></dt><dt><span class="section"><a href="#fixing-a-mistake-by-editing-history">Fixing a mistake by editing history</a></span></dt><dt><span class="section"><a href="#checkout-of-path">Checking out an old version of a file</a></span></dt><dt><span class="section"><a href="#interrupted-work">Temporarily setting aside work in progress</a></span></dt></dl></dd><dt><span class="section"><a href="#ensuring-good-performance">Ensuring good performance</a></span></dt><dt><span class="section"><a href="#ensuring-reliability">Ensuring reliability</a></span></dt><dd><dl><dt><span class="section"><a href="#checking-for-corruption">Checking the repository for corruption</a></span></dt><dt><span class="section"><a href="#recovering-lost-changes">Recovering lost changes</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="#sharing-development">4. Sharing development with others</a></span></dt><dd><dl><dt><span class="section"><a href="#getting-updates-with-git-pull">Getting updates with git pull</a></span></dt><dt><span class="section"><a href="#submitting-patches">Submitting patches to a project</a></span></dt><dt><span class="section"><a href="#importing-patches">Importing patches to a project</a></span></dt><dt><span class="section"><a href="#public-repositories">Public git repositories</a></span></dt><dd><dl><dt><span class="section"><a href="#setting-up-a-public-repository">Setting up a public repository</a></span></dt><dt><span class="section"><a href="#exporting-via-git">Exporting a git repository via the git protocol</a></span></dt><dt><span class="section"><a href="#exporting-via-http">Exporting a git repository via http</a></span></dt><dt><span class="section"><a href="#pushing-changes-to-a-public-repository">Pushing changes to a public repository</a></span></dt><dt><span class="section"><a href="#setting-up-a-shared-repository">Setting up a shared repository</a></span></dt><dt><span class="section"><a href="#setting-up-gitweb">Allowing web browsing of a repository</a></span></dt></dl></dd><dt><span class="section"><a href="#sharing-development-examples">Examples</a></span></dt><dd><dl><dt><span class="section"><a href="#maintaining-topic-branches">Maintaining topic branches for a Linux subsystem maintainer</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="#cleaning-up-history">5. Rewriting history and maintaining patch series</a></span></dt><dd><dl><dt><span class="section"><a href="#patch-series">Creating the perfect patch series</a></span></dt><dt><span class="section"><a href="#using-git-rebase">Keeping a patch series up to date using git-rebase</a></span></dt><dt><span class="section"><a href="#modifying-one-commit">Modifying a single commit</a></span></dt><dt><span class="section"><a href="#reordering-patch-series">Reordering or selecting from a patch series</a></span></dt><dt><span class="section"><a href="#patch-series-tools">Other tools</a></span></dt><dt><span class="section"><a href="#problems-with-rewriting-history">Problems with rewriting history</a></span></dt></dl></dd><dt><span class="chapter"><a href="#advanced-branch-management">6. Advanced branch management</a></span></dt><dd><dl><dt><span class="section"><a href="#fetching-individual-branches">Fetching individual branches</a></span></dt><dt><span class="section"><a href="#fetch-fast-forwards">git fetch and fast-forwards</a></span></dt><dt><span class="section"><a href="#forcing-fetch">Forcing git fetch to do non-fast-forward updates</a></span></dt><dt><span class="section"><a href="#remote-branch-configuration">Configuring remote branches</a></span></dt></dl></dd><dt><span class="chapter"><a href="#git-concepts">7. Git concepts</a></span></dt><dd><dl><dt><span class="section"><a href="#the-object-database">The Object Database</a></span></dt><dd><dl><dt><span class="section"><a href="#commit-object">Commit Object</a></span></dt><dt><span class="section"><a href="#tree-object">Tree Object</a></span></dt><dt><span class="section"><a href="#blob-object">Blob Object</a></span></dt><dt><span class="section"><a href="#trust">Trust</a></span></dt><dt><span class="section"><a href="#tag-object">Tag Object</a></span></dt><dt><span class="section"><a href="#pack-files">How git stores objects efficiently: pack files</a></span></dt><dt><span class="section"><a href="#dangling-objects">Dangling objects</a></span></dt></dl></dd><dt><span class="section"><a href="#the-index">The index</a></span></dt></dl></dd><dt><span class="chapter"><a href="#
submodules">8. Submodules</a></span></dt><dd><dl><dt><span class="section"><a href="#id279663">Pitfalls with submodules</a></span></dt></dl></dd><dt><span class="chapter"><a href="#low-level-operations">9. Low-level git operations</a></span></dt><dd><dl><dt><span class="section"><a href="#object-manipulation">Object access and manipulation</a></span></dt><dt><span class="section"><a href="#the-workflow">The Workflow</a></span></dt><dd><dl><dt><span class="section"><a href="#working-directory-to-index">working directory -> index</a></span></dt><dt><span class="section"><a href="#index-to-object-database">index -> object database</a></span></dt><dt><span class="section"><a href="#object-database-to-index">object database -> index</a></span></dt><dt><span class="section"><a href="#index-to-working-directory">index -> working directory</a></span></dt><dt><span class="section"><a href="#tying-it-all-together">Tying it all together</a></span></dt></dl></dd><dt><span class="section"><a href="#examining-the-data">Examining the data</a></span></dt><dt><span class="section"><a href="#merging-multiple-trees">Merging multiple trees</a></span></dt><dt><span class="section"><a href="#merging-multiple-trees-2">Merging multiple trees, continued</a></span></dt></dl></dd><dt><span class="chapter"><a href="#hacking-git">10. Hacking git</a></span></dt><dd><dl><dt><span class="section"><a href="#object-details">Object storage format</a></span></dt><dt><span class="section"><a href="#birdview-on-the-source-code">A birds-eye view of Git's source code</a></span></dt></dl></dd><dt><span class="chapter"><a href="#glossary">11. GIT Glossary</a></span></dt><dt><span class="appendix"><a href="#git-quick-start">A. Git Quick Reference</a></span></dt><dd><dl><dt><span class="section"><a href="#quick-creating-a-new-repository">Creating a new repository</a></span></dt><dt><span class="section"><a href="#managing-branches">Managing branches</a></span></dt><dt><span class="section"><a href="#exploring-history">Exploring history</a></span></dt><dt><span class="section"><a href="#making-changes">Making changes</a></span></dt><dt><span class="section"><a href="#merging">Merging</a></span></dt><dt><span class="section"><a href="#sharing-your-changes">Sharing your changes</a></span></dt><dt><span class="section"><a href="#repository-maintenance">Repository maintenance</a></span></dt></dl></dd><dt><span class="appendix"><a href="#todo">B. Notes and todo list for this manual</a></span></dt></dl></div><div class="preface" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="id264725"></a>Preface</h2></div></div></div><p>Git is a fast distributed revision control system.</p><p>This manual is designed to be readable by someone with basic UNIX
command-line skills, but no previous knowledge of git.</p><p><a href="#repositories-and-branches" title="Chapter 1. Repositories and Branches">Chapter 1, <i>Repositories and Branches</i></a> and <a href="#exploring-git-history" title="Chapter 2. Exploring git history">Chapter 2, <i>Exploring git history</i></a> explain how
to fetch and study a project using git—read these chapters to learn how
to build and test a particular version of a software project, search for
</li><li>
"origin/master" is short for "refs/remotes/origin/master".
</li></ul></div><p>The full name is occasionally useful if, for example, there ever
-exists a tag and a branch with the same name.</p><p>As another useful shortcut, the "HEAD" of a repository can be referred
+exists a tag and a branch with the same name.</p><p>(Newly created refs are actually stored in the .git/refs directory,
+under the path given by their name. However, for efficiency reasons
+they may also be packed together in a single file; see
+<a href="git-pack-refs.html" target="_top">git-pack-refs(1)</a>).</p><p>As another useful shortcut, the "HEAD" of a repository can be referred
to just using the name of that repository. So, for example, "origin"
is usually a shortcut for the HEAD branch in the repository "origin".</p><p>For the complete list of paths which git checks for references, and
the order it uses to decide which to choose when there are multiple
git checkout $1 && git pull . origin<br>
;;<br>
origin)<br>
- before=$(cat .git/refs/remotes/origin/master)<br>
+ before=$(git rev-parse refs/remotes/origin/master)<br>
git fetch origin<br>
- after=$(cat .git/refs/remotes/origin/master)<br>
+ after=$(git rev-parse refs/remotes/origin/master)<br>
if [ $before != $after ]<br>
then<br>
git log $before..$after | git shortlog<br>
exit 1<br>
}<br>
<br>
-if [ ! -f .git/refs/heads/"$1" ]<br>
-then<br>
+git show-ref -q --verify -- refs/heads/"$1" || {<br>
echo "Can't see branch <$1>" 1>&2<br>
usage<br>
-fi<br>
+}<br>
<br>
case "$2" in<br>
test|release)<br>
git log test..release<br>
fi<br>
<br>
-for branch in `ls .git/refs/heads`<br>
+for branch in `git show-ref --heads | sed 's|^.*/||'`<br>
do<br>
if [ $branch = test -o $branch = release ]<br>
then<br>
-----END PGP SIGNATURE-----</p></div><p>See the <a href="git-tag.html" target="_top">git-tag(1)</a> command to learn how to create and verify tag
objects. (Note that <a href="git-tag.html" target="_top">git-tag(1)</a> can also be used to create
"lightweight tags", which are not tag objects at all, but just simple
-references
in .git/refs/tags/).</p></div><div class="section" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="pack-files"></a>How git stores objects efficiently: pack files</h3></div></div></div><p>Newly created objects are initially created in a file named after the
+references
whose names begin with "refs/tags/").</p></div><div class="section" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="pack-files"></a>How git stores objects efficiently: pack files</h3></div></div></div><p>Newly created objects are initially created in a file named after the
object's SHA1 hash (stored in .git/objects).</p><p>Unfortunately this system becomes inefficient once a project has a
lot of objects. Try this on an old project:</p><div class="literallayout"><p>$ git count-objects<br>
6930 objects, 47620 kilobytes</p></div><p>The first number is the number of objects which are kept in
number, and will take on values other than 0 for files with merge
conflicts.</p></li></ol></div><p>The index is thus a sort of temporary staging area, which is filled with
a tree which you are in the process of working on.</p><p>If you blow the index away entirely, you generally haven't lost any
-information as long as you have the name of the tree that it described.</p></div></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="low-level-operations"></a>Chapter 8. Low-level git operations</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="#object-manipulation">Object access and manipulation</a></span></dt><dt><span class="section"><a href="#the-workflow">The Workflow</a></span></dt><dd><dl><dt><span class="section"><a href="#working-directory-to-index">working directory -> index</a></span></dt><dt><span class="section"><a href="#index-to-object-database">index -> object database</a></span></dt><dt><span class="section"><a href="#object-database-to-index">object database -> index</a></span></dt><dt><span class="section"><a href="#index-to-working-directory">index -> working directory</a></span></dt><dt><span class="section"><a href="#tying-it-all-together">Tying it all together</a></span></dt></dl></dd><dt><span class="section"><a href="#examining-the-data">Examining the data</a></span></dt><dt><span class="section"><a href="#merging-multiple-trees">Merging multiple trees</a></span></dt><dt><span class="section"><a href="#merging-multiple-trees-2">Merging multiple trees, continued</a></span></dt></dl></div><p>Many of the higher-level commands were originally implemented as shell
+information as long as you have the name of the tree that it described.</p></div></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="submodules"></a>Chapter 8. Submodules</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="#id279663">Pitfalls with submodules</a></span></dt></dl></div><p>This tutorial explains how to create and publish a repository with submodules
+using the <a href="git-submodule.html" target="_top">git-submodule(1)</a> command.</p><p>Submodules maintain their own identity; the submodule support just stores the
+submodule repository location and commit ID, so other developers who clone the
+superproject can easily clone all the submodules at the same revision.</p><p>To see how submodule support works, create (for example) four example
+repositories that can be used later as a submodule:</p><div class="literallayout"><p>$ mkdir ~/git<br>
+$ cd ~/git<br>
+$ for i in a b c d<br>
+do<br>
+ mkdir $i<br>
+ cd $i<br>
+ git init<br>
+ echo "module $i" > $i.txt<br>
+ git add $i.txt<br>
+ git commit -m "Initial commit, submodule $i"<br>
+ cd ..<br>
+done</p></div><p>Now create the superproject and add all the submodules:</p><div class="literallayout"><p>$ mkdir super<br>
+$ cd super<br>
+$ git init<br>
+$ for i in a b c d<br>
+do<br>
+ git submodule add ~/git/$i<br>
+done</p></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>Do not use local URLs here if you plan to publish your superproject!</p></div><p>See what files <code class="literal">git submodule</code> created:</p><div class="literallayout"><p>$ ls -a<br>
+. .. .git .gitmodules a b c d</p></div><p>The <code class="literal">git submodule add</code> command does a couple of things:</p><div class="itemizedlist"><ul type="disc"><li>
+It clones the submodule under the current directory and by default checks out
+ the master branch.
+</li><li>
+It adds the submodule's clone path to the <code class="literal">.gitmodules</code> file and adds this
+ file to the index, ready to be committed.
+</li><li>
+It adds the submodule's current commit ID to the index, ready to be
+ committed.
+</li></ul></div><p>Commit the superproject:</p><div class="literallayout"><p>$ git commit -m "Add submodules a, b, c and d."</p></div><p>Now clone the superproject:</p><div class="literallayout"><p>$ cd ..<br>
+$ git clone super cloned<br>
+$ cd cloned</p></div><p>The submodule directories are there, but they're empty:</p><div class="literallayout"><p>$ ls -a a<br>
+. ..<br>
+$ git submodule status<br>
+-d266b9873ad50488163457f025db7cdd9683d88b a<br>
+-e81d457da15309b4fef4249aba9b50187999670d b<br>
+-c1536a972b9affea0f16e0680ba87332dc059146 c<br>
+-d96249ff5d57de5de093e6baff9e0aafa5276a74 d</p></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>The commit object names shown above would be different for you, but they
+should match the HEAD commit object names of your repositories. You can check
+it by running <code class="literal">git ls-remote ../a</code>.</p></div><p>Pulling down the submodules is a two-step process. First run <code class="literal">git submodule
+init</code> to add the submodule repository URLs to <code class="literal">.git/config</code>:</p><div class="literallayout"><p>$ git submodule init</p></div><p>Now use <code class="literal">git submodule update</code> to clone the repositories and check out the
+commits specified in the superproject:</p><div class="literallayout"><p>$ git submodule update<br>
+$ cd a<br>
+$ ls -a<br>
+. .. .git a.txt</p></div><p>One major difference between <code class="literal">git submodule update</code> and <code class="literal">git submodule add</code> is
+that <code class="literal">git submodule update</code> checks out a specific commit, rather than the tip
+of a branch. It's like checking out a tag: the head is detached, so you're not
+working on a branch.</p><div class="literallayout"><p>$ git branch<br>
+* (no branch)<br>
+ master</p></div><p>If you want to make a change within a submodule and you have a detached head,
+then you should create or checkout a branch, make your changes, publish the
+change within the submodule, and then update the superproject to reference the
+new commit:</p><div class="literallayout"><p>$ git checkout master</p></div><p>or</p><div class="literallayout"><p>$ git checkout -b fix-up</p></div><p>then</p><div class="literallayout"><p>$ echo "adding a line again" >> a.txt<br>
+$ git commit -a -m "Updated the submodule from within the superproject."<br>
+$ git push<br>
+$ cd ..<br>
+$ git diff<br>
+diff --git a/a b/a<br>
+index d266b98..261dfac 160000<br>
+--- a/a<br>
++++ b/a<br>
+@@ -1 +1 @@<br>
+-Subproject commit d266b9873ad50488163457f025db7cdd9683d88b<br>
++Subproject commit 261dfac35cb99d380eb966e102c1197139f7fa24<br>
+$ git add a<br>
+$ git commit -m "Updated submodule a."<br>
+$ git push</p></div><p>You have to run <code class="literal">git submodule update</code> after <code class="literal">git pull</code> if you want to update
+submodules, too.</p><div class="section" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id279663"></a>Pitfalls with submodules</h2></div></div></div><p>Always publish the submodule change before publishing the change to the
+superproject that references it. If you forget to publish the submodule change,
+others won't be able to clone the repository:</p><div class="literallayout"><p>$ cd ~/git/super/a<br>
+$ echo i added another line to this file >> a.txt<br>
+$ git commit -a -m "doing it wrong this time"<br>
+$ cd ..<br>
+$ git add a<br>
+$ git commit -m "Updated submodule a again."<br>
+$ git push<br>
+$ cd ~/git/cloned<br>
+$ git pull<br>
+$ git submodule update<br>
+error: pathspec '261dfac35cb99d380eb966e102c1197139f7fa24' did not match any file(s) known to git.<br>
+Did you forget to 'git add'?<br>
+Unable to checkout '261dfac35cb99d380eb966e102c1197139f7fa24' in submodule path 'a'</p></div><p>You also should not rewind branches in a submodule beyond commits that were
+ever recorded in any superproject.</p><p>It's not safe to run <code class="literal">git submodule update</code> if you've made and committed
+changes within a submodule without checking out a branch first. They will be
+silently overwritten:</p><div class="literallayout"><p>$ cat a.txt<br>
+module a<br>
+$ echo line added from private2 >> a.txt<br>
+$ git commit -a -m "line added inside private2"<br>
+$ cd ..<br>
+$ git submodule update<br>
+Submodule path 'a': checked out 'd266b9873ad50488163457f025db7cdd9683d88b'<br>
+$ cd a<br>
+$ cat a.txt<br>
+module a</p></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>The changes are still visible in the submodule's reflog.</p></div><p>This is not the case if you did not commit your changes.</p></div></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="low-level-operations"></a>Chapter 9. Low-level git operations</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="#object-manipulation">Object access and manipulation</a></span></dt><dt><span class="section"><a href="#the-workflow">The Workflow</a></span></dt><dd><dl><dt><span class="section"><a href="#working-directory-to-index">working directory -> index</a></span></dt><dt><span class="section"><a href="#index-to-object-database">index -> object database</a></span></dt><dt><span class="section"><a href="#object-database-to-index">object database -> index</a></span></dt><dt><span class="section"><a href="#index-to-working-directory">index -> working directory</a></span></dt><dt><span class="section"><a href="#tying-it-all-together">Tying it all together</a></span></dt></dl></dd><dt><span class="section"><a href="#examining-the-data">Examining the data</a></span></dt><dt><span class="section"><a href="#merging-multiple-trees">Merging multiple trees</a></span></dt><dt><span class="section"><a href="#merging-multiple-trees-2">Merging multiple trees, continued</a></span></dt></dl></div><p>Many of the higher-level commands were originally implemented as shell
scripts using a smaller core of low-level git commands. These can still
be useful when doing unusual things with git, or just as a way to
understand its inner workings.</p><div class="section" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="object-manipulation"></a>Object access and manipulation</h2></div></div></div><p>The <a href="git-cat-file.html" target="_top">git-cat-file(1)</a> command can show the contents of any object,
to help you understand what conceptually happens under the hood.
In practice, nobody, not even git itself, uses three <code class="literal">git-cat-file</code>
for this. There is <code class="literal">git-merge-index</code> program that extracts the
-stages to temporary files and calls a "merge" script on it:</p><div class="literallayout"><p>$ git-merge-index git-merge-one-file hello.c</p></div><p>and that is what higher level <code class="literal">git merge -s resolve</code> is implemented with.</p></div></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="hacking-git"></a>Chapter
9. Hacking git</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="#object-details">Object storage format</a></span></dt><dt><span class="section"><a href="#birdview-on-the-source-code">A birds-eye view of Git's source code</a></span></dt></dl></div><p>This chapter covers internal details of the git implementation which
+stages to temporary files and calls a "merge" script on it:</p><div class="literallayout"><p>$ git-merge-index git-merge-one-file hello.c</p></div><p>and that is what higher level <code class="literal">git merge -s resolve</code> is implemented with.</p></div></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="hacking-git"></a>Chapter
10. Hacking git</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="#object-details">Object storage format</a></span></dt><dt><span class="section"><a href="#birdview-on-the-source-code">A birds-eye view of Git's source code</a></span></dt></dl></div><p>This chapter covers internal details of the git implementation which
probably only git developers need to understand.</p><div class="section" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="object-details"></a>Object storage format</h2></div></div></div><p>All objects have a statically determined "type" which identifies the
format of the object (i.e. how it is used, and how it can refer to other
objects). There are currently four different object types: "blob",
and see that it is in commit 18449ab0… Now just copy this object name,
and paste it into the command line</p><div class="literallayout"><p>$ git show 18449ab0</p></div><p>Voila.</p><p>Another example: Find out what to do in order to make some script a
builtin:</p><div class="literallayout"><p>$ git log --no-merges --diff-filter=A builtin-*.c</p></div><p>You see, Git is actually the best tool to find out about the source of Git
-itself!</p></div></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="glossary"></a>Chapter 1
0. GIT Glossary</h2></div></div></div><div class="variablelist"><dl><dt><span class="term">
+itself!</p></div></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="glossary"></a>Chapter 1
1. GIT Glossary</h2></div></div></div><div class="variablelist"><dl><dt><span class="term">
<a name="def_alternate_object_database"></a>alternate object database
</span></dt><dd>
Via the alternates mechanism, a <a href="#def_repository">repository</a>
The full name is occasionally useful if, for example, there ever
exists a tag and a branch with the same name.
+(Newly created refs are actually stored in the .git/refs directory,
+under the path given by their name. However, for efficiency reasons
+they may also be packed together in a single file; see
+gitlink:git-pack-refs[1]).
+
As another useful shortcut, the "HEAD" of a repository can be referred
to just using the name of that repository. So, for example, "origin"
is usually a shortcut for the HEAD branch in the repository "origin".
git checkout $1 && git pull . origin
;;
origin)
- before=$(cat .git/refs/remotes/origin/master)
+ before=$(git rev-parse refs/remotes/origin/master)
git fetch origin
- after=$(cat .git/refs/remotes/origin/master)
+ after=$(git rev-parse refs/remotes/origin/master)
if [ $before != $after ]
then
git log $before..$after | git shortlog
exit 1
}
-if [ ! -f .git/refs/heads/"$1" ]
-then
+git show-ref -q --verify -- refs/heads/"$1" || {
echo "Can't see branch <$1>" 1>&2
usage
-fi
+}
case "$2" in
test|release)
git log test..release
fi
-for branch in `ls .git/refs/heads`
+for branch in `git show-ref --heads | sed 's|^.*/||'`
do
if [ $branch = test -o $branch = release ]
then
See the gitlink:git-tag[1] command to learn how to create and verify tag
objects. (Note that gitlink:git-tag[1] can also be used to create
"lightweight tags", which are not tag objects at all, but just simple
-references in .git/refs/tags/).
+references whose names begin with "refs/tags/").
[[pack-files]]
How git stores objects efficiently: pack files
If you blow the index away entirely, you generally haven't lost any
information as long as you have the name of the tree that it described.
+[[submodules]]
+Submodules
+==========
+
+This tutorial explains how to create and publish a repository with submodules
+using the gitlink:git-submodule[1] command.
+
+Submodules maintain their own identity; the submodule support just stores the
+submodule repository location and commit ID, so other developers who clone the
+superproject can easily clone all the submodules at the same revision.
+
+To see how submodule support works, create (for example) four example
+repositories that can be used later as a submodule:
+
+-------------------------------------------------
+$ mkdir ~/git
+$ cd ~/git
+$ for i in a b c d
+do
+ mkdir $i
+ cd $i
+ git init
+ echo "module $i" > $i.txt
+ git add $i.txt
+ git commit -m "Initial commit, submodule $i"
+ cd ..
+done
+-------------------------------------------------
+
+Now create the superproject and add all the submodules:
+
+-------------------------------------------------
+$ mkdir super
+$ cd super
+$ git init
+$ for i in a b c d
+do
+ git submodule add ~/git/$i
+done
+-------------------------------------------------
+
+NOTE: Do not use local URLs here if you plan to publish your superproject!
+
+See what files `git submodule` created:
+
+-------------------------------------------------
+$ ls -a
+. .. .git .gitmodules a b c d
+-------------------------------------------------
+
+The `git submodule add` command does a couple of things:
+
+- It clones the submodule under the current directory and by default checks out
+ the master branch.
+- It adds the submodule's clone path to the `.gitmodules` file and adds this
+ file to the index, ready to be committed.
+- It adds the submodule's current commit ID to the index, ready to be
+ committed.
+
+Commit the superproject:
+
+-------------------------------------------------
+$ git commit -m "Add submodules a, b, c and d."
+-------------------------------------------------
+
+Now clone the superproject:
+
+-------------------------------------------------
+$ cd ..
+$ git clone super cloned
+$ cd cloned
+-------------------------------------------------
+
+The submodule directories are there, but they're empty:
+
+-------------------------------------------------
+$ ls -a a
+. ..
+$ git submodule status
+-d266b9873ad50488163457f025db7cdd9683d88b a
+-e81d457da15309b4fef4249aba9b50187999670d b
+-c1536a972b9affea0f16e0680ba87332dc059146 c
+-d96249ff5d57de5de093e6baff9e0aafa5276a74 d
+-------------------------------------------------
+
+NOTE: The commit object names shown above would be different for you, but they
+should match the HEAD commit object names of your repositories. You can check
+it by running `git ls-remote ../a`.
+
+Pulling down the submodules is a two-step process. First run `git submodule
+init` to add the submodule repository URLs to `.git/config`:
+
+-------------------------------------------------
+$ git submodule init
+-------------------------------------------------
+
+Now use `git submodule update` to clone the repositories and check out the
+commits specified in the superproject:
+
+-------------------------------------------------
+$ git submodule update
+$ cd a
+$ ls -a
+. .. .git a.txt
+-------------------------------------------------
+
+One major difference between `git submodule update` and `git submodule add` is
+that `git submodule update` checks out a specific commit, rather than the tip
+of a branch. It's like checking out a tag: the head is detached, so you're not
+working on a branch.
+
+-------------------------------------------------
+$ git branch
+* (no branch)
+ master
+-------------------------------------------------
+
+If you want to make a change within a submodule and you have a detached head,
+then you should create or checkout a branch, make your changes, publish the
+change within the submodule, and then update the superproject to reference the
+new commit:
+
+-------------------------------------------------
+$ git checkout master
+-------------------------------------------------
+
+or
+
+-------------------------------------------------
+$ git checkout -b fix-up
+-------------------------------------------------
+
+then
+
+-------------------------------------------------
+$ echo "adding a line again" >> a.txt
+$ git commit -a -m "Updated the submodule from within the superproject."
+$ git push
+$ cd ..
+$ git diff
+diff --git a/a b/a
+index d266b98..261dfac 160000
+--- a/a
++++ b/a
+@@ -1 +1 @@
+-Subproject commit d266b9873ad50488163457f025db7cdd9683d88b
++Subproject commit 261dfac35cb99d380eb966e102c1197139f7fa24
+$ git add a
+$ git commit -m "Updated submodule a."
+$ git push
+-------------------------------------------------
+
+You have to run `git submodule update` after `git pull` if you want to update
+submodules, too.
+
+Pitfalls with submodules
+------------------------
+
+Always publish the submodule change before publishing the change to the
+superproject that references it. If you forget to publish the submodule change,
+others won't be able to clone the repository:
+
+-------------------------------------------------
+$ cd ~/git/super/a
+$ echo i added another line to this file >> a.txt
+$ git commit -a -m "doing it wrong this time"
+$ cd ..
+$ git add a
+$ git commit -m "Updated submodule a again."
+$ git push
+$ cd ~/git/cloned
+$ git pull
+$ git submodule update
+error: pathspec '261dfac35cb99d380eb966e102c1197139f7fa24' did not match any file(s) known to git.
+Did you forget to 'git add'?
+Unable to checkout '261dfac35cb99d380eb966e102c1197139f7fa24' in submodule path 'a'
+-------------------------------------------------
+
+You also should not rewind branches in a submodule beyond commits that were
+ever recorded in any superproject.
+
+It's not safe to run `git submodule update` if you've made and committed
+changes within a submodule without checking out a branch first. They will be
+silently overwritten:
+
+-------------------------------------------------
+$ cat a.txt
+module a
+$ echo line added from private2 >> a.txt
+$ git commit -a -m "line added inside private2"
+$ cd ..
+$ git submodule update
+Submodule path 'a': checked out 'd266b9873ad50488163457f025db7cdd9683d88b'
+$ cd a
+$ cat a.txt
+module a
+-------------------------------------------------
+
+NOTE: The changes are still visible in the submodule's reflog.
+
+This is not the case if you did not commit your changes.
+
[[low-level-operations]]
Low-level git operations
========================
projects / git.git / commitdiff