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Diffstat (limited to 'Documentation/git-checkout.txt')
| -rw-r--r-- | Documentation/git-checkout.txt | 338 |
1 files changed, 270 insertions, 68 deletions
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt index 880763d391..e108b0f74b 100644 --- a/Documentation/git-checkout.txt +++ b/Documentation/git-checkout.txt @@ -3,15 +3,18 @@ git-checkout(1) NAME ---- -git-checkout - Checkout a branch or paths to the working tree +git-checkout - Switch branches or restore working tree files SYNOPSIS -------- [verse] 'git checkout' [-q] [-f] [-m] [<branch>] +'git checkout' [-q] [-f] [-m] --detach [<branch>] +'git checkout' [-q] [-f] [-m] [--detach] <commit> 'git checkout' [-q] [-f] [-m] [[-b|-B|--orphan] <new_branch>] [<start_point>] 'git checkout' [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] [--] <paths>... -'git checkout' --patch [<tree-ish>] [--] [<paths>...] +'git checkout' [<tree-ish>] [--] <pathspec>... +'git checkout' (-p|--patch) [<tree-ish>] [--] [<paths>...] DESCRIPTION ----------- @@ -20,17 +23,34 @@ or the specified tree. If no paths are given, 'git checkout' will also update `HEAD` to set the specified branch as the current branch. -'git checkout' [<branch>]:: +'git checkout' <branch>:: + To prepare for working on <branch>, switch to it by updating + the index and the files in the working tree, and by pointing + HEAD at the branch. Local modifications to the files in the + working tree are kept, so that they can be committed to the + <branch>. ++ +If <branch> is not found but there does exist a tracking branch in +exactly one remote (call it <remote>) with a matching name, treat as +equivalent to ++ +------------ +$ git checkout -b <branch> --track <remote>/<branch> +------------ ++ +You could omit <branch>, in which case the command degenerates to +"check out the current branch", which is a glorified no-op with +rather expensive side-effects to show only the tracking information, +if exists, for the current branch. + 'git checkout' -b|-B <new_branch> [<start point>]:: - This form switches branches by updating the index, working - tree, and HEAD to reflect the specified branch. -+ -If `-b` is given, a new branch is created as if linkgit:git-branch[1] -were called and then checked out; in this case you can -use the `--track` or `--no-track` options, which will be passed to -'git branch'. As a convenience, `--track` without `-b` implies branch -creation; see the description of `--track` below. + Specifying `-b` causes a new branch to be created as if + linkgit:git-branch[1] were called and then checked out. In + this case you can use the `--track` or `--no-track` options, + which will be passed to 'git branch'. As a convenience, + `--track` without `-b` implies branch creation; see the + description of `--track` below. + If `-B` is given, <new_branch> is created if it doesn't exist; otherwise, it is reset. This is the transactional equivalent of @@ -43,16 +63,29 @@ $ git checkout <branch> that is to say, the branch is not reset/created unless "git checkout" is successful. -'git checkout' [--patch] [<tree-ish>] [--] <pathspec>...:: +'git checkout' --detach [<branch>]:: +'git checkout' [--detach] <commit>:: - When <paths> or `--patch` are given, 'git checkout' does *not* - switch branches. It updates the named paths in the working tree - from the index file or from a named <tree-ish> (most often a - commit). In this case, the `-b` and `--track` options are - meaningless and giving either of them results in an error. The - <tree-ish> argument can be used to specify a specific tree-ish - (i.e. commit, tag or tree) to update the index for the given - paths before updating the working tree. + Prepare to work on top of <commit>, by detaching HEAD at it + (see "DETACHED HEAD" section), and updating the index and the + files in the working tree. Local modifications to the files + in the working tree are kept, so that the resulting working + tree will be the state recorded in the commit plus the local + modifications. ++ +When the <commit> argument is a branch name, the `--detach` option can +be used to detach HEAD at the tip of the branch (`git checkout +<branch>` would check out that branch without detaching HEAD). ++ +Omitting <branch> detaches HEAD at the tip of the current branch. + +'git checkout' [<tree-ish>] [--] <pathspec>...:: + + Overwrite paths in the working tree by replacing with the + contents in the index or in the <tree-ish> (most often a + commit). When a <tree-ish> is given, the paths that + match the <pathspec> are updated both in the index and in + the working tree. + The index may contain unmerged entries because of a previous failed merge. By default, if you try to check out such an entry from the index, the @@ -62,12 +95,26 @@ specific side of the merge can be checked out of the index by using `--ours` or `--theirs`. With `-m`, changes made to the working tree file can be discarded to re-create the original conflicted merge result. +'git checkout' (-p|--patch) [<tree-ish>] [--] [<pathspec>...]:: + This is similar to the "check out paths to the working tree + from either the index or from a tree-ish" mode described + above, but lets you use the interactive interface to show + the "diff" output and choose which hunks to use in the + result. See below for the description of `--patch` option. + + OPTIONS ------- -q:: --quiet:: Quiet, suppress feedback messages. +--[no-]progress:: + Progress status is reported on the standard error stream + by default when it is attached to a terminal, unless `--quiet` + is specified. This flag enables progress reporting even if not + attached to a terminal, regardless of `--quiet`. + -f:: --force:: When switching branches, proceed even if the index or the @@ -81,12 +128,27 @@ entries; instead, unmerged entries are ignored. --theirs:: When checking out paths from the index, check out stage #2 ('ours') or #3 ('theirs') for unmerged paths. - --b:: ++ +Note that during `git rebase` and `git pull --rebase`, 'ours' and +'theirs' may appear swapped; `--ours` gives the version from the +branch the changes are rebased onto, while `--theirs` gives the +version from the branch that holds your work that is being rebased. ++ +This is because `rebase` is used in a workflow that treats the +history at the remote as the shared canonical one, and treats the +work done on the branch you are rebasing as the third-party work to +be integrated, and you are temporarily assuming the role of the +keeper of the canonical history during the rebase. As the keeper of +the canonical history, you need to view the history from the remote +as `ours` (i.e. "our shared canonical history"), while what you did +on your side branch as `theirs` (i.e. "one contributor's work on top +of it"). + +-b <new_branch>:: Create a new branch named <new_branch> and start it at <start_point>; see linkgit:git-branch[1] for details. --B:: +-B <new_branch>:: Creates the branch <new_branch> and start it at <start_point>; if it already exists, then reset it to <start_point>. This is equivalent to running "git branch" with "-f"; see @@ -97,25 +159,32 @@ entries; instead, unmerged entries are ignored. When creating a new branch, set up "upstream" configuration. See "--track" in linkgit:git-branch[1] for details. + -If no '-b' option is given, the name of the new branch will be -derived from the remote-tracking branch. If "remotes/" or "refs/remotes/" -is prefixed it is stripped away, and then the part up to the -next slash (which would be the nickname of the remote) is removed. +If no `-b` option is given, the name of the new branch will be +derived from the remote-tracking branch, by looking at the local part of +the refspec configured for the corresponding remote, and then stripping +the initial part up to the "*". This would tell us to use "hack" as the local branch when branching off of "origin/hack" (or "remotes/origin/hack", or even "refs/remotes/origin/hack"). If the given name has no slash, or the above guessing results in an empty name, the guessing is aborted. You can -explicitly give a name with '-b' in such a case. +explicitly give a name with `-b` in such a case. --no-track:: Do not set up "upstream" configuration, even if the - branch.autosetupmerge configuration variable is true. + branch.autoSetupMerge configuration variable is true. -l:: Create the new branch's reflog; see linkgit:git-branch[1] for details. ---orphan:: +--detach:: + Rather than checking out a branch to work on it, check out a + commit for inspection and discardable experiments. + This is the default behavior of "git checkout <commit>" when + <commit> is not a branch name. See the "DETACHED HEAD" section + below for details. + +--orphan <new_branch>:: Create a new 'orphan' branch, named <new_branch>, started from <start_point> and switch to it. The first commit made on this new branch will have no parents and it will be the root of a new @@ -140,6 +209,12 @@ branch by running "git rm -rf ." from the top level of the working tree. Afterwards you will be ready to prepare your new files, repopulating the working tree, by copying them from elsewhere, extracting a tarball, etc. +--ignore-skip-worktree-bits:: + In sparse checkout mode, `git checkout -- <paths>` would + update only entries matched by <paths> and sparse patterns + in $GIT_DIR/info/sparse-checkout. This option ignores + the sparse patterns and adds back any files in <paths>. + -m:: --merge:: When switching branches, @@ -162,7 +237,7 @@ the conflicted merge in the specified paths. --conflict=<style>:: The same as --merge option above, but changes the way the conflicting hunks are presented, overriding the - merge.conflictstyle configuration variable. Possible values are + merge.conflictStyle configuration variable. Possible values are "merge" (default) and "diff3" (in addition to what is shown by "merge" style, shows the original contents). @@ -174,7 +249,21 @@ the conflicted merge in the specified paths. working tree (and if a <tree-ish> was specified, the index). + This means that you can use `git checkout -p` to selectively discard -edits from your current working tree. +edits from your current working tree. See the ``Interactive Mode'' +section of linkgit:git-add[1] to learn how to operate the `--patch` mode. + +--ignore-other-worktrees:: + `git checkout` refuses when the wanted ref is already checked + out by another worktree. This option makes it check the ref + out anyway. In other words, the ref can be held by more than one + worktree. + +--[no-]recurse-submodules:: + Using --recurse-submodules will update the content of all initialized + submodules according to the commit recorded in the superproject. If + local modifications in a submodule would be overwritten the checkout + will fail unless `-f` is used. If nothing (or --no-recurse-submodules) + is used, the work trees of submodules will not be updated. <branch>:: Branch to checkout; if it refers to a branch (i.e., a name that, @@ -183,11 +272,11 @@ edits from your current working tree. commit, your HEAD becomes "detached" and you are no longer on any branch (see below for details). + -As a special case, the `"@\{-N\}"` syntax for the N-th last branch -checks out the branch (instead of detaching). You may also specify -`-` which is synonymous with `"@\{-1\}"`. +As a special case, the `"@{-N}"` syntax for the N-th last branch/commit +checks out branches (instead of detaching). You may also specify +`-` which is synonymous with `"@{-1}"`. + -As a further special case, you may use `"A\...B"` as a shortcut for the +As a further special case, you may use `"A...B"` as a shortcut for the merge base of `A` and `B` if there is exactly one merge base. You can leave out at most one of `A` and `B`, in which case it defaults to `HEAD`. @@ -204,42 +293,152 @@ leave out at most one of `A` and `B`, in which case it defaults to `HEAD`. -Detached HEAD +DETACHED HEAD ------------- +HEAD normally refers to a named branch (e.g. 'master'). Meanwhile, each +branch refers to a specific commit. Let's look at a repo with three +commits, one of them tagged, and with branch 'master' checked out: + +------------ + HEAD (refers to branch 'master') + | + v +a---b---c branch 'master' (refers to commit 'c') + ^ + | + tag 'v2.0' (refers to commit 'b') +------------ + +When a commit is created in this state, the branch is updated to refer to +the new commit. Specifically, 'git commit' creates a new commit 'd', whose +parent is commit 'c', and then updates branch 'master' to refer to new +commit 'd'. HEAD still refers to branch 'master' and so indirectly now refers +to commit 'd': + +------------ +$ edit; git add; git commit + + HEAD (refers to branch 'master') + | + v +a---b---c---d branch 'master' (refers to commit 'd') + ^ + | + tag 'v2.0' (refers to commit 'b') +------------ -It is sometimes useful to be able to 'checkout' a commit that is -not at the tip of one of your branches. The most obvious -example is to check out the commit at a tagged official release -point, like this: +It is sometimes useful to be able to checkout a commit that is not at +the tip of any named branch, or even to create a new commit that is not +referenced by a named branch. Let's look at what happens when we +checkout commit 'b' (here we show two ways this may be done): ------------ -$ git checkout v2.6.18 +$ git checkout v2.0 # or +$ git checkout master^^ + + HEAD (refers to commit 'b') + | + v +a---b---c---d branch 'master' (refers to commit 'd') + ^ + | + tag 'v2.0' (refers to commit 'b') ------------ -Earlier versions of git did not allow this and asked you to -create a temporary branch using the `-b` option, but starting from -version 1.5.0, the above command 'detaches' your HEAD from the -current branch and directly points at the commit named by the tag -(`v2.6.18` in the example above). +Notice that regardless of which checkout command we use, HEAD now refers +directly to commit 'b'. This is known as being in detached HEAD state. +It means simply that HEAD refers to a specific commit, as opposed to +referring to a named branch. Let's see what happens when we create a commit: -You can use all git commands while in this state. You can use -`git reset --hard $othercommit` to further move around, for -example. You can make changes and create a new commit on top of -a detached HEAD. You can even create a merge by using `git -merge $othercommit`. +------------ +$ edit; git add; git commit + + HEAD (refers to commit 'e') + | + v + e + / +a---b---c---d branch 'master' (refers to commit 'd') + ^ + | + tag 'v2.0' (refers to commit 'b') +------------ + +There is now a new commit 'e', but it is referenced only by HEAD. We can +of course add yet another commit in this state: + +------------ +$ edit; git add; git commit + + HEAD (refers to commit 'f') + | + v + e---f + / +a---b---c---d branch 'master' (refers to commit 'd') + ^ + | + tag 'v2.0' (refers to commit 'b') +------------ + +In fact, we can perform all the normal Git operations. But, let's look +at what happens when we then checkout master: + +------------ +$ git checkout master + + HEAD (refers to branch 'master') + e---f | + / v +a---b---c---d branch 'master' (refers to commit 'd') + ^ + | + tag 'v2.0' (refers to commit 'b') +------------ + +It is important to realize that at this point nothing refers to commit +'f'. Eventually commit 'f' (and by extension commit 'e') will be deleted +by the routine Git garbage collection process, unless we create a reference +before that happens. If we have not yet moved away from commit 'f', +any of these will create a reference to it: + +------------ +$ git checkout -b foo <1> +$ git branch foo <2> +$ git tag foo <3> +------------ + +<1> creates a new branch 'foo', which refers to commit 'f', and then +updates HEAD to refer to branch 'foo'. In other words, we'll no longer +be in detached HEAD state after this command. + +<2> similarly creates a new branch 'foo', which refers to commit 'f', +but leaves HEAD detached. + +<3> creates a new tag 'foo', which refers to commit 'f', +leaving HEAD detached. -The state you are in while your HEAD is detached is not recorded -by any branch (which is natural --- you are not on any branch). -What this means is that you can discard your temporary commits -and merges by switching back to an existing branch (e.g. `git -checkout master`), and a later `git prune` or `git gc` would -garbage-collect them. If you did this by mistake, you can ask -the reflog for HEAD where you were, e.g. +If we have moved away from commit 'f', then we must first recover its object +name (typically by using git reflog), and then we can create a reference to +it. For example, to see the last two commits to which HEAD referred, we +can use either of these commands: ------------ +$ git reflog -2 HEAD # or $ git log -g -2 HEAD ------------ +ARGUMENT DISAMBIGUATION +----------------------- + +When there is only one argument given and it is not `--` (e.g. "git +checkout abc"), and when the argument is both a valid `<tree-ish>` +(e.g. a branch "abc" exists) and a valid `<pathspec>` (e.g. a file +or a directory whose name is "abc" exists), Git would usually ask +you to disambiguate. Because checking out a branch is so common an +operation, however, "git checkout abc" takes "abc" as a `<tree-ish>` +in such a situation. Use `git checkout -- <pathspec>` if you want +to checkout these paths out of the index. EXAMPLES -------- @@ -259,6 +458,18 @@ $ git checkout hello.c <3> <2> take a file out of another commit <3> restore hello.c from the index + +If you want to check out _all_ C source files out of the index, +you can say ++ +------------ +$ git checkout -- '*.c' +------------ ++ +Note the quotes around `*.c`. The file `hello.c` will also be +checked out, even though it is no longer in the working tree, +because the file globbing is used to match entries in the index +(not in the working tree by the shell). ++ If you have an unfortunate branch that is named `hello.c`, this step would be confused as an instruction to switch to that branch. You should instead write: @@ -315,15 +526,6 @@ $ edit frotz $ git add frotz ------------ - -Author ------- -Written by Linus Torvalds <torvalds@osdl.org> - -Documentation --------------- -Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>. - GIT --- Part of the linkgit:git[1] suite |