GIT(1) ====== v0.1, May 2005 //////////////////////// Please note that this document is in asciidoc format. http://www.methods.co.nz/asciidoc/index.html You should be able to read it but be aware that there is some minor typographical bludgeoning to allow the production of clean man and html output. (eg in some synopsis lines the '*' character is preceded by a '\' and there are one or two '+' characters) //////////////////////// NAME ---- git - the stupid content tracker SYNOPSIS -------- 'git-' DESCRIPTION ----------- This is reference information for the core git commands. The link:README[] contains much useful definition and clarification info - read that first. And of the commands, I suggest reading 'git-update-cache' and 'git-read-tree' first - I wish I had! David Greaves 08/05/05 Updated by Junio C Hamano on 2005-05-05 to reflect recent changes. Commands Overview ----------------- The git commands can helpfully be split into those that manipulate the repository, the cache and the working fileset and those that interrogate and compare them. 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-write-blob.html[git-write-blob]:: Creates a blob from a file link:git-write-tree.html[git-write-tree]:: Creates a tree from the current cache Interrogation commands ~~~~~~~~~~~~~~~~~~~~~~ link:git-cat-file.html[git-cat-file]:: Provide content or type information for repository objects link:git-check-files.html[git-check-files]:: Verify a list of files are up-to-date link:git-diff-cache.html[git-diff-cache]:: Compares content and mode of blobs between the cache and repository link:git-diff-files.html[git-diff-files]:: Compares files in the working tree and the 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-fsck-cache.html[git-fsck-cache]:: Verifies the connectivity and validity of the objects in the database link:git-ls-files.html[git-ls-files]:: Information about files in the cache/working directory link:git-ls-tree.html[git-ls-tree]:: Displays a tree object in human readable form link:git-merge-cache.html[git-merge-cache]:: Runs a merge for files needing merging link:git-rev-list.html[git-rev-list]:: Lists commit objects in reverse chronological order 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 link:git-unpack-file.html[git-unpack-file]:: Creates a temporary file with a blob's contents The interrogate commands may create files - and you can force them to touch the working file set - but in general they don't Terminology ----------- see README for description Identifier terminology ---------------------- :: Indicates any object sha1 identifier :: Indicates a blob object sha1 identifier :: Indicates a tree object sha1 identifier :: Indicates a commit object sha1 identifier :: Indicates a tree, commit or tag object sha1 identifier. A command that takes a argument ultimately wants to operate on a object but automatically dereferences and that points at a . :: Indicates that an object type is required. Currently one of: blob/tree/commit/tag :: Indicates a filename - always relative to the root of the tree structure GIT_INDEX_FILE describes. Terminology ----------- Each line contains terms used interchangeably object database, .git directory directory cache, index id, sha1, sha1-id, sha1 hash type, tag blob, blob object tree, tree object commit, commit object parent root object changeset Environment Variables --------------------- 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' NAME ---- git-apply-patch-script - Sample script to apply the diffs from git-diff-* SYNOPSIS -------- 'git-apply-patch-script' DESCRIPTION ----------- This is a sample script to be used via the 'GIT_EXTERNAL_DIFF' environment variable to apply the differences that the "git-diff-*" family of commands report to the current work tree. NAME ---- git-cat-file - Provide content or type information for repository objects SYNOPSIS -------- 'git-cat-file' (-t | ) DESCRIPTION ----------- Provides content or type of objects in the repository. The type is required if '-t' is not being used to find the object type. OPTIONS ------- :: The sha1 identifier of the object. -t:: Instead of the content, show the object type identified by . :: Typically this matches the real type of but asking for a type that can trivially dereferenced from the given is also permitted. An example is to ask for a "tree" with being a commit object that contains it, or to ask for a "blob" with being a tag object that points at it. OUTPUT ------ If '-t' is specified, one of the . Otherwise the raw (though uncompressed) contents of the will be returned. NAME ---- git-check-files - Verify a list of files are up-to-date SYNOPSIS -------- 'git-check-files' ... DESCRIPTION ----------- Check that a list of files are up-to-date between the filesystem and the cache. Used to verify a patch target before doing a patch. Files that do not exist on the filesystem are considered up-to-date (whether or not they are in the cache). Emits an error message on failure: preparing to update existing file not in cache:: exists but is not in the cache preparing to update file not uptodate in cache:: on disk is not up-to-date with the cache Exits with a status code indicating success if all files are up-to-date. see also: link:git-update-cache.html[git-update-cache] NAME ---- git-checkout-cache - Copy files from the cache to the working directory SYNOPSIS -------- 'git-checkout-cache' [-q] [-a] [-f] [-n] [--prefix=] [--] ... DESCRIPTION ----------- Will copy all files listed from the cache to the working directory (not overwriting existing files). OPTIONS ------- -q:: be quiet if files exist or are not in the cache -f:: forces overwrite of existing files -a:: checks out all files in the cache (will then continue to process listed files). -n:: Don't checkout new files, only refresh files already checked out. --prefix=:: When creating files, prepend (usually a directory including a trailing /) --:: Do not interpret any more arguments as options. Note that the order of the flags matters: git-checkout-cache -a -f file.c will first check out all files listed in the cache (but not overwrite any old ones), and then force-checkout `file.c` a second time (ie that one *will* overwrite any old contents with the same filename). Also, just doing "git-checkout-cache" does nothing. You probably meant "git-checkout-cache -a". And if you want to force it, you want "git-checkout-cache -f -a". Intuitiveness is not the goal here. Repeatability is. The reason for the "no arguments means no work" thing is that from scripts you are supposed to be able to do things like: find . -name '*.h' -print0 | xargs -0 git-checkout-cache -f -- which will force all existing `*.h` files to be replaced with their cached copies. If an empty command line implied "all", then this would force-refresh everything in the cache, which was not the point. To update and refresh only the files already checked out: git-checkout-cache -n -f -a && git-update-cache --ignore-missing --refresh Oh, and the "--" is just a good idea when you know the rest will be filenames. Just so that you wouldn't have a filename of "-a" causing problems (not possible in the above example, but get used to it in scripting!). The prefix ability basically makes it trivial to use git-checkout-cache as an "export as tree" function. Just read the desired tree into the index, and do a git-checkout-cache --prefix=git-export-dir/ -a and git-checkout-cache will "export" the cache into the specified directory. NOTE The final "/" is important. The exported name is literally just prefixed with the specified string, so you can also do something like git-checkout-cache --prefix=.merged- Makefile to check out the currently cached copy of `Makefile` into the file `.merged-Makefile` NAME ---- git-commit-tree - Creates a new commit object SYNOPSIS -------- 'git-commit-tree' [-p ]\ < changelog DESCRIPTION ----------- Creates a new commit object based on the provided tree object and emits the new commit object id on stdout. If no parent is given then it is considered to be an initial tree. A commit object usually has 1 parent (a commit after a change) or up to 16 parents. More than one parent represents a merge of branches that led to them. While a tree represents a particular directory state of a working directory, a commit represents that state in "time", and explains how to get there. Normally a commit would identify a new "HEAD" state, and while git doesn't care where you save the note about that state, in practice we tend to just write the result to the file `.git/HEAD`, so that we can always see what the last committed state was. OPTIONS ------- :: An existing tree object -p :: Each '-p' indicates a the id of a parent commit object. Commit Information ------------------ A commit encapsulates: - all parent object ids - author name, email and date - committer name and email and the commit time. If not provided, "git-commit-tree" uses your name, hostname and domain to provide author and committer info. This can be overridden using the following environment variables. GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE GIT_COMMITTER_NAME GIT_COMMITTER_EMAIL (nb <,> and '\n's are stripped) A commit comment is read from stdin (max 999 chars). If a changelog entry is not provided via '<' redirection, "git-commit-tree" will just wait for one to be entered and terminated with ^D see also: link:git-write-tree.html[git-write-tree] NAME ---- git-convert-cache - Converts old-style GIT repository SYNOPSIS -------- 'git-convert-cache' DESCRIPTION ----------- Converts old-style GIT repository to the latest format NAME ---- git-diff-cache - Compares content and mode of blobs between the cache and repository SYNOPSIS -------- 'git-diff-cache' [-p] [-r] [-z] [-m] [--cached] DESCRIPTION ----------- Compares the content and mode of the blobs found via a tree object with the content of the current cache and, optionally ignoring the stat state of the file on disk. OPTIONS ------- :: The id of a tree object to diff against. -p:: Generate patch (see section on generating patches) -r:: This flag does not mean anything. It is there only to match "git-diff-tree". Unlike "git-diff-tree", "git-diff-cache" always looks at all the subdirectories. -z:: \0 line termination on output --cached:: do not consider the on-disk file at all -m:: By default, files recorded in the index but not checked out are reported as deleted. This flag makes "git-diff-cache" say that all non-checked-out files are up to date. Output format ------------- include::diff-format.txt[] Operating Modes --------------- You can choose whether you want to trust the index file entirely (using the '--cached' flag) or ask the diff logic to show any files that don't match the stat state as being "tentatively changed". Both of these operations are very useful indeed. Cached Mode ----------- If '--cached' is specified, it allows you to ask: show me the differences between HEAD and the current index contents (the ones I'd write with a "git-write-tree") For example, let's say that you have worked on your index file, and are ready to commit. You want to see eactly *what* you are going to commit is without having to write a new tree object and compare it that way, and to do that, you just do git-diff-cache --cached $(cat .git/HEAD) Example: let's say I had renamed `commit.c` to `git-commit.c`, and I had done an "git-update-cache" to make that effective in the index file. "git-diff-files" wouldn't show anything at all, since the index file matches my working directory. But doing a "git-diff-cache" does: torvalds@ppc970:~/git> git-diff-cache --cached $(cat .git/HEAD) -100644 blob 4161aecc6700a2eb579e842af0b7f22b98443f74 commit.c +100644 blob 4161aecc6700a2eb579e842af0b7f22b98443f74 git-commit.c You can trivially see that the above is a rename. In fact, "git-diff-cache --cached" *should* always be entirely equivalent to actually doing a "git-write-tree" and comparing that. Except this one is much nicer for the case where you just want to check where you are. So doing a "git-diff-cache --cached" is basically very useful when you are asking yourself "what have I already marked for being committed, and what's the difference to a previous tree". Non-cached Mode --------------- The "non-cached" mode takes a different approach, and is potentially the more useful of the two in that what it does can't be emulated with a "git-write-tree" + "git-diff-tree". Thus that's the default mode. The non-cached version asks the question: show me the differences between HEAD and the currently checked out tree - index contents _and_ files that aren't up-to-date which is obviously a very useful question too, since that tells you what you *could* commit. Again, the output matches the "git-diff-tree -r" output to a tee, but with a twist. The twist is that if some file doesn't match the cache, we don't have a backing store thing for it, and we use the magic "all-zero" sha1 to show that. So let's say that you have edited `kernel/sched.c`, but have not actually done a "git-update-cache" on it yet - there is no "object" associated with the new state, and you get: torvalds@ppc970:~/v2.6/linux> git-diff-cache $(cat .git/HEAD ) *100644->100664 blob 7476bb......->000000...... kernel/sched.c ie it shows that the tree has changed, and that `kernel/sched.c` has is not up-to-date and may contain new stuff. The all-zero sha1 means that to get the real diff, you need to look at the object in the working directory directly rather than do an object-to-object diff. NOTE! As with other commands of this type, "git-diff-cache" does not actually look at the contents of the file at all. So maybe `kernel/sched.c` hasn't actually changed, and it's just that you touched it. In either case, it's a note that you need to "git-upate-cache" it to make the cache be in sync. NOTE 2! You can have a mixture of files show up as "has been updated" and "is still dirty in the working directory" together. You can always tell which file is in which state, since the "has been updated" ones show a valid sha1, and the "not in sync with the index" ones will always have the special all-zero sha1. NAME ---- git-diff-files - Compares files in the working tree and the cache SYNOPSIS -------- 'git-diff-files' [-p] [-q] [-r] [-z] [...] DESCRIPTION ----------- Compares the files in the working tree and the cache. When paths are specified, compares only those named paths. Otherwise all entries in the cache are compared. The output format is the same as "git-diff-cache" and "git-diff-tree". OPTIONS ------- -p:: generate patch (see section on generating patches). -q:: Remain silent even on nonexisting files -r:: This flag does not mean anything. It is there only to match git-diff-tree. Unlike git-diff-tree, git-diff-files always looks at all the subdirectories. Output format ------------- include::diff-format.txt[] NAME ---- git-diff-tree - Compares the content and mode of blobs found via two tree objects SYNOPSIS -------- 'git-diff-tree' [-p] [-r] [-z] [--stdin] [-m] [-s] [-v] []\* DESCRIPTION ----------- Compares the content and mode of the blobs found via two tree objects. Note that "git-diff-tree" can use the tree encapsulated in a commit object. OPTIONS ------- :: The id of a tree object. :: If provided, the results are limited to a subset of files matching one of these prefix strings. ie file matches `/^||.../` Note that pattern does not provide any wildcard or regexp features. -p:: generate patch (see section on generating patches). For git-diff-tree, this flag implies '-r' as well. -r:: recurse -z:: \0 line termination on output --stdin:: When '--stdin' is specified, the command does not take arguments from the command line. Instead, it reads either one or a pair of separated with a single space from its standard input. + When a single commit is given on one line of such input, it compares the commit with its parents. The following flags further affects its behaviour. This does not apply to the case where two separated with a single space are given. -m:: By default, "git-diff-tree --stdin" does not show differences for merge commits. With this flag, it shows differences to that commit from all of its parents. -s:: By default, "git-diff-tree --stdin" shows differences, either in machine-readable form (without '-p') or in patch form (with '-p'). This output can be supressed. It is only useful with '-v' flag. -v:: This flag causes "git-diff-tree --stdin" to also show the commit message before the differences. Limiting Output --------------- If you're only interested in differences in a subset of files, for example some architecture-specific files, you might do: git-diff-tree -r arch/ia64 include/asm-ia64 and it will only show you what changed in those two directories. Or if you are searching for what changed in just `kernel/sched.c`, just do git-diff-tree -r kernel/sched.c and it will ignore all differences to other files. The pattern is always the prefix, and is matched exactly. There are no wildcards. Even stricter, it has to match complete path comonent. I.e. "foo" does not pick up `foobar.h`. "foo" does match `foo/bar.h` so it can be used to name subdirectories. An example of normal usage is: torvalds@ppc970:~/git> git-diff-tree 5319e4...... *100664->100664 blob ac348b.......->a01513....... git-fsck-cache.c which tells you that the last commit changed just one file (it's from this one: commit 3c6f7ca19ad4043e9e72fa94106f352897e651a8 tree 5319e4d609cdd282069cc4dce33c1db559539b03 parent b4e628ea30d5ab3606119d2ea5caeab141d38df7 author Linus Torvalds Sat Apr 9 12:02:30 2005 committer Linus Torvalds Sat Apr 9 12:02:30 2005 Make "git-fsck-cache" print out all the root commits it finds. Once I do the reference tracking, I'll also make it print out all the HEAD commits it finds, which is even more interesting. in case you care). Output format ------------- include::diff-format.txt[] NAME ---- git-diff-tree-helper - Generates patch format output for git-diff-* SYNOPSIS -------- 'git-diff-tree-helper' [-z] [-R] DESCRIPTION ----------- Reads output from "git-diff-cache", "git-diff-tree" and "git-diff-files" and generates patch format output. OPTIONS ------- -z:: \0 line termination on input -R:: Output diff in reverse. This is useful for displaying output from "git-diff-cache" which always compares tree with cache or working file. E.g. git-diff-cache | git-diff-tree-helper -R file.c + would show a diff to bring the working file back to what is in the . See also the section on generating patches in link:git-diff-cache.html[git-diff-cache] NAME ---- git-export - Exports each commit and a diff against each of its parents SYNOPSIS -------- 'git-export' top [base] DESCRIPTION ----------- Exports each commit and diff against each of its parents, between top and base. If base is not specified it exports everything. NAME ---- git-fsck-cache - Verifies the connectivity and validity of the objects in the database SYNOPSIS -------- 'git-fsck-cache' [--tags] [--root] [[--unreachable] [--cache] \*] DESCRIPTION ----------- Verifies the connectivity and validity of the objects in the database. OPTIONS ------- :: An object to treat as the head of an unreachability trace. --unreachable:: Print out objects that exist but that aren't readable from any of the specified head nodes. --root:: Report root nodes. --tags:: Report tags. --cache:: Consider any object recorded in the cache also as a head node for an unreachability trace. It tests SHA1 and general object sanity, and it does full tracking of the resulting reachability and everything else. It prints out any corruption it finds (missing or bad objects), and if you use the '--unreachable' flag it will also print out objects that exist but that aren't readable from any of the specified head nodes. So for example git-fsck-cache --unreachable $(cat .git/HEAD) or, for Cogito users: git-fsck-cache --unreachable $(cat .git/refs/heads/*) will do quite a _lot_ of verification on the tree. There are a few extra validity tests to be added (make sure that tree objects are sorted properly etc), but on the whole if "git-fsck-cache" is happy, you do have a valid tree. Any corrupt objects you will have to find in backups or other archives (ie you can just remove them and do an "rsync" with some other site in the hopes that somebody else has the object you have corrupted). Of course, "valid tree" doesn't mean that it wasn't generated by some evil person, and the end result might be crap. Git is a revision tracking system, not a quality assurance system ;) Extracted Diagnostics --------------------- expect dangling commits - potential heads - due to lack of head information:: You haven't specified any nodes as heads so it won't be possible to differentiate between un-parented commits and root nodes. missing sha1 directory '':: The directory holding the sha1 objects is missing. unreachable :: The object , isn't actually referred to directly or indirectly in any of the trees or commits seen. This can mean that there's another root node that you're not specifying or that the tree is corrupt. If you haven't missed a root node then you might as well delete unreachable nodes since they can't be used. missing :: The object , is referred to but isn't present in the database. dangling :: The object , is present in the database but never 'directly' used. A dangling commit could be a root node. warning: git-fsck-cache: tree has full pathnames in it:: And it shouldn't... sha1 mismatch :: The database has an object who's sha1 doesn't match the database value. This indicates a serious data integrity problem. (note: this error occured during early git development when the database format changed.) Environment Variables --------------------- GIT_OBJECT_DIRECTORY:: used to specify the object database root (usually .git/objects) GIT_INDEX_FILE:: used to specify the cache NAME ---- git-http-pull - Downloads a remote GIT repository via HTTP SYNOPSIS -------- 'git-http-pull' [-c] [-t] [-a] [-v] commit-id url DESCRIPTION ----------- Downloads a remote GIT repository via HTTP. -c:: Get the commit objects. -t:: Get trees associated with the commit objects. -a:: Get all the objects. -v:: Report what is downloaded. NAME ---- git-init-db - Creates an empty git object database SYNOPSIS -------- 'git-init-db' DESCRIPTION ----------- This simply creates an empty git object database - basically a `.git` directory and `.git/object/??/` directories. If the object storage directory is specified via the 'GIT_OBJECT_DIRECTORY' environment variable then the sha1 directories are created underneath - otherwise the default `.git/objects` directory is used. "git-init-db" won't hurt an existing repository. NAME ---- git-local-pull - Duplicates another GIT repository on a local system SYNOPSIS -------- 'git-local-pull' [-c] [-t] [-a] [-l] [-s] [-n] [-v] commit-id path DESCRIPTION ----------- Duplicates another GIT repository on a local system. OPTIONS ------- -c:: Get the commit objects. -t:: Get trees associated with the commit objects. -a:: Get all the objects. -v:: Report what is downloaded. NAME ---- git-ls-files - Information about files in the cache/working directory SYNOPSIS -------- 'git-ls-files' [-z] [-t] (--[cached|deleted|others|ignored|stage|unmerged])\* (-[c|d|o|i|s|u])\* [-x |--exclude=] [-X |--exclude-from=] DESCRIPTION ----------- This merges the file listing in the directory cache index with the actual working directory list, and shows different combinations of the two. One or more of the options below may be used to determine the files shown: OPTIONS ------- -c|--cached:: Show cached files in the output (default) -d|--deleted:: Show deleted files in the output -o|--others:: Show other files in the output -i|--ignored:: Show ignored files in the output Note the this also reverses any exclude list present. -s|--stage:: Show stage files in the output -u|--unmerged:: Show unmerged files in the output (forces --stage) -z:: \0 line termination on output -x|--exclude=:: Skips files matching pattern. Note that pattern is a shell wildcard pattern. -X|--exclude-from=:: exclude patterns are read from ; 1 per line. Allows the use of the famous dontdiff file as follows to find out about uncommitted files just as dontdiff is used with the diff command: git-ls-files --others --exclude-from=dontdiff -t:: Identify the file status with the following tags (followed by a space) at the start of each line: H cached M unmerged R removed/deleted ? other Output ------ show files just outputs the filename unless '--stage' is specified in which case it outputs: [ ] "git-ls-files --unmerged" and "git-ls-files --stage" can be used to examine detailed information on unmerged paths. For an unmerged path, instead of recording a single mode/SHA1 pair, the dircache records up to three such pairs; one from tree O in stage 1, A in stage 2, and B in stage 3. This information can be used by the user (or Cogito) to see what should eventually be recorded at the path. (see read-cache for more information on state) see also: link:read-cache.html[read-cache] NAME ---- git-ls-tree - Displays a tree object in human readable form SYNOPSIS -------- 'git-ls-tree' [-r] [-z] DESCRIPTION ----------- Converts the tree object to a human readable (and script processable) form. OPTIONS ------- :: Id of a tree. -r:: recurse into sub-trees -z:: \0 line termination on output Output Format ------------- \t \t \t NAME ---- git-merge-base - Finds as good a common ancestor as possible for a merge SYNOPSIS -------- 'git-merge-base' DESCRIPTION ----------- "git-merge-base" finds as good a common ancestor as possible. Given a selection of equally good common ancestors it should not be relied on to decide in any particular way. The "git-merge-base" algorithm is still in flux - use the source... NAME ---- git-merge-cache - Runs a merge for files needing merging SYNOPSIS -------- 'git-merge-cache' (-a | -- | \*) DESCRIPTION ----------- This looks up the (s) in the cache and, if there are any merge entries, passes the SHA1 hash for those files as arguments 1, 2, 3 (empty argument if no file), and as argument 4. File modes for the three files are passed as arguments 5, 6 and 7. OPTIONS ------- --:: Interpret all future arguments as filenames. -a:: Run merge against all files in the cache that need merging. If "git-merge-cache" is called with multiple s (or -a) then it processes them in turn only stopping if merge returns a non-zero exit code. Typically this is run with the a script calling the merge command from the RCS package. A sample script called "git-merge-one-file-script" is included in the ditribution. ALERT ALERT ALERT! The git "merge object order" is different from the RCS "merge" program merge object order. In the above ordering, the original is first. But the argument order to the 3-way merge program "merge" is to have the original in the middle. Don't ask me why. Examples: torvalds@ppc970:~/merge-test> git-merge-cache cat MM This is MM from the original tree. # original This is modified MM in the branch A. # merge1 This is modified MM in the branch B. # merge2 This is modified MM in the branch B. # current contents or torvalds@ppc970:~/merge-test> git-merge-cache cat AA MM cat: : No such file or directory This is added AA in the branch A. This is added AA in the branch B. This is added AA in the branch B. fatal: merge program failed where the latter example shows how "git-merge-cache" will stop trying to merge once anything has returned an error (ie "cat" returned an error for the AA file, because it didn't exist in the original, and thus "git-merge-cache" didn't even try to merge the MM thing). NAME ---- git-merge-one-file-script - The standard helper program to use with "git-merge-cache" SYNOPSIS -------- 'git-merge-one-file-script' DESCRIPTION ----------- This is the standard helper program to use with "git-merge-cache" to resolve a merge after the trivial merge done with "git-read-tree -m". NAME ---- git-mktag - Creates a tag object SYNOPSIS -------- 'git-mktag' DESCRIPTION ----------- Reads a tag contents from its standard input and creates a tag object. The input must be a well formed tag object. NAME ---- git-prune-script - Prunes all unreachable objects from the object database SYNOPSIS -------- 'git-prune-script' DESCRIPTION ----------- This runs "git-fsck-cache --unreachable" program using the heads specified on the command line (or `.git/refs/heads/\*` and `.git/refs/tags/\*` if none is specified), and prunes all unreachable objects from the object database. NAME ---- git-pull-script - Script used by Linus to pull and merge a remote repository SYNOPSIS -------- 'git-pull-script' DESCRIPTION ----------- This script is used by Linus to pull from a remote repository and perform a merge. NAME ---- git-read-tree - Reads tree information into the directory cache SYNOPSIS -------- 'git-read-tree' ( | -m [ ])" DESCRIPTION ----------- Reads the tree information given by into the directory cache, but does not actually _update_ any of the files it "caches". (see: git-checkout-cache) Optionally, it can merge a tree into the cache or perform a 3-way merge. Trivial merges are done by "git-read-tree" itself. Only conflicting paths will be in unmerged state when "git-read-tree" returns. OPTIONS ------- -m:: Perform a merge, not just a read :: The id of the tree object(s) to be read/merged. Merging ------- If '-m' is specified, "git-read-tree" performs 2 kinds of merge, a single tree merge if only 1 tree is given or a 3-way merge if 3 trees are provided. Single Tree Merge ~~~~~~~~~~~~~~~~~ If only 1 tree is specified, git-read-tree operates as if the user did not specify '-m', except that if the original cache has an entry for a given pathname; and the contents of the path matches with the tree being read, the stat info from the cache is used. (In other words, the cache's stat()s take precedence over the merged tree's) That means that if you do a "git-read-tree -m " followed by a "git-checkout-cache -f -a", the "git-checkout-cache" only checks out the stuff that really changed. This is used to avoid unnecessary false hits when "git-diff-files" is run after git-read-tree. 3-Way Merge ~~~~~~~~~~~ Each "index" entry has two bits worth of "stage" state. stage 0 is the normal one, and is the only one you'd see in any kind of normal use. However, when you do "git-read-tree" with three trees, the "stage" starts out at 1. This means that you can do git-read-tree -m and you will end up with an index with all of the entries in "stage1", all of the entries in "stage2" and all of the entries in "stage3". Furthermore, "git-read-tree" has special-case logic that says: if you see a file that matches in all respects in the following states, it "collapses" back to "stage0": - stage 2 and 3 are the same; take one or the other (it makes no difference - the same work has been done on stage 2 and 3) - stage 1 and stage 2 are the same and stage 3 is different; take stage 3 (some work has been done on stage 3) - stage 1 and stage 3 are the same and stage 2 is different take stage 2 (some work has been done on stage 2) The "git-write-tree" command refuses to write a nonsensical tree, and it will complain about unmerged entries if it sees a single entry that is not stage 0. Ok, this all sounds like a collection of totally nonsensical rules, but it's actually exactly what you want in order to do a fast merge. The different stages represent the "result tree" (stage 0, aka "merged"), the original tree (stage 1, aka "orig"), and the two trees you are trying to merge (stage 2 and 3 respectively). In fact, the way "git-read-tree" works, it's entirely agnostic about how you assign the stages, and you could really assign them any which way, and the above is just a suggested way to do it (except since "git-write-tree" refuses to write anything but stage0 entries, it makes sense to always consider stage 0 to be the "full merge" state). So what happens? Try it out. Select the original tree, and two trees to merge, and look how it works: - if a file exists in identical format in all three trees, it will automatically collapse to "merged" state by the new git-read-tree. - a file that has _any_ difference what-so-ever in the three trees will stay as separate entries in the index. It's up to "script policy" to determine how to remove the non-0 stages, and insert a merged version. But since the index is always sorted, they're easy to find: they'll be clustered together. - the index file saves and restores with all this information, so you can merge things incrementally, but as long as it has entries in stages 1/2/3 (ie "unmerged entries") you can't write the result. So now the merge algorithm ends up being really simple: * you walk the index in order, and ignore all entries of stage 0, since they've already been done. * if you find a "stage1", but no matching "stage2" or "stage3", you know it's been removed from both trees (it only existed in the original tree), and you remove that entry. * if you find a matching "stage2" and "stage3" tree, you remove one of them, and turn the other into a "stage0" entry. Remove any matching "stage1" entry if it exists too. .. all the normal trivial rules .. Incidentally - it also means that you don't even have to have a separate subdirectory for this. All the information literally is in the index file, which is a temporary thing anyway. There is no need to worry about what is in the working directory, since it is never shown and never used. see also: link:git-write-tree.html[git-write-tree], link:git-ls-files.html[git-ls-files] NAME ---- git-resolve-script - Script used to merge two trees SYNOPSIS -------- 'git-resolve-script' DESCRIPTION ----------- This script is used by Linus to merge two trees. NAME ---- git-rev-list - Lists commit objects in reverse chronological order SYNOPSIS -------- 'git-rev-list' DESCRIPTION ----------- Lists commit objects in reverse chronological order starting at the given commit, taking ancestry relationship into account. This is useful to produce human-readable log output. NAME ---- git-rev-tree - Provides the revision tree for one or more commits SYNOPSIS -------- 'git-rev-tree' [--edges] [--cache ] [^] [[^]] DESCRIPTION ----------- Provides the revision tree for one or more commits. OPTIONS ------- --edges:: Show edges (ie places where the marking changes between parent and child) --cache :: Use the specified file as a cache from a previous git-rev-list run to speed things up. Note that this "cache" is totally different concept from the directory index. Also this option is not implemented yet. [^]:: The commit id to trace (a leading caret means to ignore this commit-id and below) Output ------ : [: ]\* :: Date in 'seconds since epoch' :: id of commit object :: id of each parent commit object (>1 indicates a merge) :: The flags are read as a bitmask representing each commit provided on the commandline. eg: given the command: $ git-rev-tree The output: :5 means that is reachable from (1) and (4) A revtree can get quite large. "git-rev-tree" will eventually allow you to cache previous state so that you don't have to follow the whole thing down. So the change difference between two commits is literally git-rev-tree [commit-id1] > commit1-revtree git-rev-tree [commit-id2] > commit2-revtree join -t : commit1-revtree commit2-revtree > common-revisions (this is also how to find the most common parent - you'd look at just the head revisions - the ones that aren't referred to by other revisions - in "common-revision", and figure out the best one. I think.) NAME ---- git-rpull - Pulls from a remote repository over ssh connection SYNOPSIS -------- 'git-rpull' [-c] [-t] [-a] [-v] commit-id url DESCRIPTION ----------- Pulls from a remote repository over ssh connection, invoking git-rpush on the other end. OPTIONS ------- -c:: Get the commit objects. -t:: Get trees associated with the commit objects. -a:: Get all the objects. -v:: Report what is downloaded. NAME ---- git-rpush - Helper "server-side" program used by git-rpull SYNOPSIS -------- 'git-rpush' DESCRIPTION ----------- Helper "server-side" program used by git-rpull. NAME ---- git-tag-script - An example script to create a tag object signed with GPG SYNOPSIS -------- 'git-tag-script' DESCRIPTION ----------- This is an example script that uses "git-mktag" to create a tag object signed with GPG. NAME ---- git-tar-tree - Creates a tar archive of the files in the named tree SYNOPSIS -------- 'git-tar-tree' [ ] DESCRIPTION ----------- Creates a tar archive containing the tree structure for the named tree. When is specified it is added as a leading path as the files in the generated tar archive. NAME ---- git-unpack-file - Creates a temporary file with a blob's contents SYNOPSIS -------- 'git-unpack-file' DESCRIPTION ----------- Creates a file holding the contents of the blob specified by sha1. It returns the name of the temporary file in the following format: .merge_file_XXXXX OPTIONS ------- :: Must be a blob id NAME ---- git-update-cache - Modifies the index or directory cache SYNOPSIS -------- 'git-update-cache' [--add] [--remove] [--refresh] [--replace] [--ignore-missing] [--force-remove ] [--cacheinfo ]\* [--] []\* DESCRIPTION ----------- Modifies the index or directory cache. Each file mentioned is updated into the cache and any 'unmerged' or 'needs updating' state is cleared. The way "git-update-cache" handles files it is told about can be modified using the various options: OPTIONS ------- --add:: If a specified file isn't in the cache already then it's added. Default behaviour is to ignore new files. --remove:: If a specified file is in the cache but is missing then it's removed. Default behaviour is to ignore removed file. --refresh:: Looks at the current cache and checks to see if merges or updates are needed by checking stat() information. --ignore-missing:: Ignores missing files during a --refresh --cacheinfo :: Directly insert the specified info into the cache. --force-remove:: Remove the file from the index even when the working directory still has such a file. --replace:: By default, when a file `path` exists in the index, git-update-cache refuses an attempt to add `path/file`. Similarly if a file `path/file` exists, a file `path` cannot be added. With --replace flag, existing entries that conflicts with the entry being added are automatically removed with warning messages. --:: Do not interpret any more arguments as options. :: Files to act on. Note that files begining with '.' are discarded. This includes `./file` and `dir/./file`. If you don't want this, then use cleaner names. The same applies to directories ending '/' and paths with '//' Using --refresh --------------- '--refresh' does not calculate a new sha1 file or bring the cache up-to-date for mode/content changes. But what it *does* do is to "re-match" the stat information of a file with the cache, so that you can refresh the cache for a file that hasn't been changed but where the stat entry is out of date. For example, you'd want to do this after doing a "git-read-tree", to link up the stat cache details with the proper files. Using --cacheinfo ----------------- '--cacheinfo' is used to register a file that is not in the current working directory. This is useful for minimum-checkout merging. To pretend you have a file with mode and sha1 at path, say: $ git-update-cache --cacheinfo mode sha1 path To update and refresh only the files already checked out: git-checkout-cache -n -f -a && git-update-cache --ignore-missing --refresh NAME ---- git-write-blob - Creates a blob from a file SYNOPSIS -------- 'git-write-blob' DESCRIPTION ----------- Writes the contents of the named file (which can be outside of the work tree) as a blob into the object database, and reports its object ID to its standard output. This is used by "git-merge-one-file-script" to update the cache without modifying files in the work tree. NAME ---- git-write-tree - Creates a tree from the current cache SYNOPSIS -------- 'git-write-tree' DESCRIPTION ----------- Creates a tree object using the current cache. The cache must be merged. Conceptually, "git-write-tree" sync()s the current directory cache contents into a set of tree files. In order to have that match what is actually in your directory right now, you need to have done a "git-update-cache" phase before you did the "git-write-tree". //////////////////////////////////////////////////////////////// Producing man pages and html To create a set of html pages run: perl split-docs.pl -html < core-git.txt To create a set of man pages run: perl split-docs.pl -man < core-git.txt ////////////////////////////////////////////////////////////////