the repository, the cache and the working fileset and those that
interrogate and compare them.
+There are also some ancilliary programs that can be viewed as useful
+aids for using the core commands but which are unlikely to be used by
+SCMs layered over git.
+
Manipulation commands
~~~~~~~~~~~~~~~~~~~~~
-link:git-apply-patch-script.html[git-apply-patch-script]::
- Sample script to apply the diffs from git-diff-*
-
link:git-checkout-cache.html[git-checkout-cache]::
Copy files from the cache to the working directory
link:git-commit-tree.html[git-commit-tree]::
Creates a new commit object
-link:git-convert-cache.html[git-convert-cache]::
- Converts old-style GIT repository
-
-link:git-http-pull.html[git-http-pull]::
- Downloads a remote GIT repository via HTTP
-
link:git-init-db.html[git-init-db]::
Creates an empty git object database
-link:git-local-pull.html[git-local-pull]::
- Duplicates another GIT repository on a local system
-
link:git-merge-base.html[git-merge-base]::
Finds as good a common ancestor as possible for a merge
-link:git-merge-one-file-script.html[git-merge-one-file-script]::
- The standard helper program to use with "git-merge-cache"
-
link:git-mktag.html[git-mktag]::
Creates a tag object
-link:git-prune-script.html[git-prune-script]::
- Prunes all unreachable objects from the object database
-
-link:git-pull-script.html[git-pull-script]::
- Script used by Linus to pull and merge a remote repository
-
link:git-read-tree.html[git-read-tree]::
Reads tree information into the directory cache
-link:git-resolve-script.html[git-resolve-script]::
- Script used to merge two trees
-
-link:git-rpull.html[git-rpull]::
- Pulls from a remote repository over ssh connection
-
-link:git-tag-script.html[git-tag-script]::
- An example script to create a tag object signed with GPG
-
link:git-update-cache.html[git-update-cache]::
Modifies the index or directory cache
link:git-diff-tree.html[git-diff-tree]::
Compares the content and mode of blobs found via two tree objects
-link:git-diff-tree-helper.html[git-diff-tree-helper]::
- Generates patch format output for git-diff-*
-
link:git-export.html[git-export]::
Exports each commit and a diff against each of its parents
link:git-rev-tree.html[git-rev-tree]::
Provides the revision tree for one or more commits
-link:git-rpush.html[git-rpush]::
- Helper "server-side" program used by git-rpull
-
link:git-tar-tree.html[git-tar-tree]::
Creates a tar archive of the files in the named tree
touch the working file set - but in general they don't
+Ancilliary Commands
+-------------------
+Manipulators:
+
+link:git-apply-patch-script.html[git-apply-patch-script]::
+ Sample script to apply the diffs from git-diff-*
+
+link:git-convert-cache.html[git-convert-cache]::
+ Converts old-style GIT repository
+
+link:git-http-pull.html[git-http-pull]::
+ Downloads a remote GIT repository via HTTP
+
+link:git-local-pull.html[git-local-pull]::
+ Duplicates another GIT repository on a local system
+
+link:git-merge-one-file-script.html[git-merge-one-file-script]::
+ The standard helper program to use with "git-merge-cache"
+
+link:git-pull-script.html[git-pull-script]::
+ Script used by Linus to pull and merge a remote repository
+
+link:git-prune-script.html[git-prune-script]::
+ Prunes all unreachable objects from the object database
+
+link:git-resolve-script.html[git-resolve-script]::
+ Script used to merge two trees
+
+link:git-tag-script.html[git-tag-script]::
+ An example script to create a tag object signed with GPG
+
+link:git-rpull.html[git-rpull]::
+ Pulls from a remote repository over ssh connection
+
+Interogators:
+
+link:git-diff-tree-helper.html[git-diff-tree-helper]::
+ Generates patch format output for git-diff-*
+
+link:git-rpush.html[git-rpush]::
+ Helper "server-side" program used by git-rpull
+
+
+
Terminology
-----------
see README for description
Indicates a filename - always relative to the root of
the tree structure GIT_INDEX_FILE describes.
+Symbolic Identifiers
+--------------------
+Any git comand accepting any <object> can also use the following symbolic notation:
+
+HEAD::
+ indicates the head of the repository (ie the contents of `$GIT_DIR/HEAD`)
+<tag>::
+ a valid tag 'name'+
+ (ie the contents of `$GIT_DIR/refs/tags/<tag>`)
+<head>::
+ a valid head 'name'+
+ (ie the contents of `$GIT_DIR/refs/heads/<head>`)
+<snap>::
+ a valid snapshot 'name'+
+ (ie the contents of `$GIT_DIR/refs/snap/<snap>`)
+
+
+File/Directory Structure
+------------------------
+The git-core manipulates the following areas in the directory:
+
+ .git/ The base (overridden with $GIT_DIR)
+ objects/ The object base (overridden with $GIT_OBJECT_DIRECTORY)
+ ??/ 'First 2 chars of object' directories
+
+It can interrogate (but never updates) the following areas:
+
+ refs/ Directories containing symbolic names for objects
+ (each file contains the hex SHA1 + newline)
+ heads/ Commits which are heads of various sorts
+ tags/ Tags, by the tag name (or some local renaming of it)
+ snap/ ????
+ ... Everything else isn't shared
+ HEAD Symlink to refs/heads/<something>
+
+Higher level SCMs may provide and manage additional information in the
+GIT_DIR.
+
Terminology
-----------
Each line contains terms used interchangeably
---------------------
Various git commands use the following environment variables:
-- 'GIT_AUTHOR_NAME'
-- 'GIT_AUTHOR_EMAIL'
-- 'GIT_AUTHOR_DATE'
-- 'GIT_COMMITTER_NAME'
-- 'GIT_COMMITTER_EMAIL'
-- 'GIT_DIFF_OPTS'
-- 'GIT_EXTERNAL_DIFF'
-- 'GIT_INDEX_FILE'
-- 'GIT_OBJECT_DIRECTORY'
-- 'GIT_ALTERNATE_OBJECT_DIRECTORIES'
-
+The git Repository
+~~~~~~~~~~~~~~~~~~
+These environment variables apply to 'all' core git commands. Nb: it
+is worth noting that they may be used/overridden by SCMS sitting above
+git so take care if using Cogito etc
+
+'GIT_INDEX_FILE'::
+ This environment allows the specification of an alternate
+ cache/index file. If not specified, the default of
+ `$GIT_DIR/index` is used.
+
+'GIT_OBJECT_DIRECTORY'::
+ If the object storage directory is specified via this
+ environment variable then the sha1 directories are created
+ underneath - otherwise the default `$GIT_DIR/objects`
+ directory is used.
+
+'GIT_ALTERNATE_OBJECT_DIRECTORIES'::
+ Due to the immutable nature of git objects, old objects can be
+ archived into shared, read-only directories. This variable
+ specifies a ":" seperated list of git object directories which
+ can be used to search for git objects. New objects will not be
+ written to these directories.
+
+'GIT_DIR'::
+ If the 'GIT_DIR' environment variable is set then it specifies
+ a path to use instead of `./.git` for the base of the
+ repository.
+
+git Commits
+~~~~~~~~~~~
+'GIT_AUTHOR_NAME'::
+'GIT_AUTHOR_EMAIL'::
+'GIT_AUTHOR_DATE'::
+'GIT_COMMITTER_NAME'::
+'GIT_COMMITTER_EMAIL'::
+ see link:git-commit-tree.html[git-commit-tree]
+
+git Diffs
+~~~~~~~~~
+GIT_DIFF_OPTS::
+GIT_EXTERNAL_DIFF::
+ see the "generating patches" section in :
+ link:git-diff-cache.html[git-diff-cache];
+ link:git-diff-files.html[git-diff-files];
+ link:git-diff-tree.html[git-diff-tree]
Author
------