Documentation / git-fetch.txton commit Merge branch 'ab/perf-installed-fix' (82dca95)
   1git-fetch(1)
   2============
   3
   4NAME
   5----
   6git-fetch - Download objects and refs from another repository
   7
   8
   9SYNOPSIS
  10--------
  11[verse]
  12'git fetch' [<options>] [<repository> [<refspec>...]]
  13'git fetch' [<options>] <group>
  14'git fetch' --multiple [<options>] [(<repository> | <group>)...]
  15'git fetch' --all [<options>]
  16
  17
  18DESCRIPTION
  19-----------
  20Fetch branches and/or tags (collectively, "refs") from one or more
  21other repositories, along with the objects necessary to complete their
  22histories.  Remote-tracking branches are updated (see the description
  23of <refspec> below for ways to control this behavior).
  24
  25By default, any tag that points into the histories being fetched is
  26also fetched; the effect is to fetch tags that
  27point at branches that you are interested in.  This default behavior
  28can be changed by using the --tags or --no-tags options or by
  29configuring remote.<name>.tagOpt.  By using a refspec that fetches tags
  30explicitly, you can fetch tags that do not point into branches you
  31are interested in as well.
  32
  33'git fetch' can fetch from either a single named repository or URL,
  34or from several repositories at once if <group> is given and
  35there is a remotes.<group> entry in the configuration file.
  36(See linkgit:git-config[1]).
  37
  38When no remote is specified, by default the `origin` remote will be used,
  39unless there's an upstream branch configured for the current branch.
  40
  41The names of refs that are fetched, together with the object names
  42they point at, are written to `.git/FETCH_HEAD`.  This information
  43may be used by scripts or other git commands, such as linkgit:git-pull[1].
  44
  45OPTIONS
  46-------
  47include::fetch-options.txt[]
  48
  49include::pull-fetch-param.txt[]
  50
  51include::urls-remotes.txt[]
  52
  53
  54CONFIGURED REMOTE-TRACKING BRANCHES[[CRTB]]
  55-------------------------------------------
  56
  57You often interact with the same remote repository by
  58regularly and repeatedly fetching from it.  In order to keep track
  59of the progress of such a remote repository, `git fetch` allows you
  60to configure `remote.<repository>.fetch` configuration variables.
  61
  62Typically such a variable may look like this:
  63
  64------------------------------------------------
  65[remote "origin"]
  66        fetch = +refs/heads/*:refs/remotes/origin/*
  67------------------------------------------------
  68
  69This configuration is used in two ways:
  70
  71* When `git fetch` is run without specifying what branches
  72  and/or tags to fetch on the command line, e.g. `git fetch origin`
  73  or `git fetch`, `remote.<repository>.fetch` values are used as
  74  the refspecs--they specify which refs to fetch and which local refs
  75  to update.  The example above will fetch
  76  all branches that exist in the `origin` (i.e. any ref that matches
  77  the left-hand side of the value, `refs/heads/*`) and update the
  78  corresponding remote-tracking branches in the `refs/remotes/origin/*`
  79  hierarchy.
  80
  81* When `git fetch` is run with explicit branches and/or tags
  82  to fetch on the command line, e.g. `git fetch origin master`, the
  83  <refspec>s given on the command line determine what are to be
  84  fetched (e.g. `master` in the example,
  85  which is a short-hand for `master:`, which in turn means
  86  "fetch the 'master' branch but I do not explicitly say what
  87  remote-tracking branch to update with it from the command line"),
  88  and the example command will
  89  fetch _only_ the 'master' branch.  The `remote.<repository>.fetch`
  90  values determine which
  91  remote-tracking branch, if any, is updated.  When used in this
  92  way, the `remote.<repository>.fetch` values do not have any
  93  effect in deciding _what_ gets fetched (i.e. the values are not
  94  used as refspecs when the command-line lists refspecs); they are
  95  only used to decide _where_ the refs that are fetched are stored
  96  by acting as a mapping.
  97
  98The latter use of the `remote.<repository>.fetch` values can be
  99overridden by giving the `--refmap=<refspec>` parameter(s) on the
 100command line.
 101
 102PRUNING
 103-------
 104
 105Git has a default disposition of keeping data unless it's explicitly
 106thrown away; this extends to holding onto local references to branches
 107on remotes that have themselves deleted those branches.
 108
 109If left to accumulate, these stale references might make performance
 110worse on big and busy repos that have a lot of branch churn, and
 111e.g. make the output of commands like `git branch -a --contains
 112<commit>` needlessly verbose, as well as impacting anything else
 113that'll work with the complete set of known references.
 114
 115These remote-tracking references can be deleted as a one-off with
 116either of:
 117
 118------------------------------------------------
 119# While fetching
 120$ git fetch --prune <name>
 121
 122# Only prune, don't fetch
 123$ git remote prune <name>
 124------------------------------------------------
 125
 126To prune references as part of your normal workflow without needing to
 127remember to run that, set `fetch.prune` globally, or
 128`remote.<name>.prune` per-remote in the config. See
 129linkgit:git-config[1].
 130
 131Here's where things get tricky and more specific. The pruning feature
 132doesn't actually care about branches, instead it'll prune local <->
 133remote-references as a function of the refspec of the remote (see
 134`<refspec>` and <<CRTB,CONFIGURED REMOTE-TRACKING BRANCHES>> above).
 135
 136Therefore if the refspec for the remote includes
 137e.g. `refs/tags/*:refs/tags/*`, or you manually run e.g. `git fetch
 138--prune <name> "refs/tags/*:refs/tags/*"` it won't be stale remote
 139tracking branches that are deleted, but any local tag that doesn't
 140exist on the remote.
 141
 142This might not be what you expect, i.e. you want to prune remote
 143`<name>`, but also explicitly fetch tags from it, so when you fetch
 144from it you delete all your local tags, most of which may not have
 145come from the `<name>` remote in the first place.
 146
 147So be careful when using this with a refspec like
 148`refs/tags/*:refs/tags/*`, or any other refspec which might map
 149references from multiple remotes to the same local namespace.
 150
 151Since keeping up-to-date with both branches and tags on the remote is
 152a common use-case the `--prune-tags` option can be supplied along with
 153`--prune` to prune local tags that don't exist on the remote, and
 154force-update those tags that differ. Tag pruning can also be enabled
 155with `fetch.pruneTags` or `remote.<name>.pruneTags` in the config. See
 156linkgit:git-config[1].
 157
 158The `--prune-tags` option is equivalent to having
 159`refs/tags/*:refs/tags/*` declared in the refspecs of the remote. This
 160can lead to some seemingly strange interactions:
 161
 162------------------------------------------------
 163# These both fetch tags
 164$ git fetch --no-tags origin 'refs/tags/*:refs/tags/*'
 165$ git fetch --no-tags --prune-tags origin
 166------------------------------------------------
 167
 168The reason it doesn't error out when provided without `--prune` or its
 169config versions is for flexibility of the configured versions, and to
 170maintain a 1=1 mapping between what the command line flags do, and
 171what the configuration versions do.
 172
 173It's reasonable to e.g. configure `fetch.pruneTags=true` in
 174`~/.gitconfig` to have tags pruned whenever `git fetch --prune` is
 175run, without making every invocation of `git fetch` without `--prune`
 176an error.
 177
 178Pruning tags with `--prune-tags` also works when fetching a URL
 179instead of a named remote. These will all prune tags not found on
 180origin:
 181
 182------------------------------------------------
 183$ git fetch origin --prune --prune-tags
 184$ git fetch origin --prune 'refs/tags/*:refs/tags/*'
 185$ git fetch <url of origin> --prune --prune-tags
 186$ git fetch <url of origin> --prune 'refs/tags/*:refs/tags/*'
 187------------------------------------------------
 188
 189OUTPUT
 190------
 191
 192The output of "git fetch" depends on the transport method used; this
 193section describes the output when fetching over the Git protocol
 194(either locally or via ssh) and Smart HTTP protocol.
 195
 196The status of the fetch is output in tabular form, with each line
 197representing the status of a single ref. Each line is of the form:
 198
 199-------------------------------
 200 <flag> <summary> <from> -> <to> [<reason>]
 201-------------------------------
 202
 203The status of up-to-date refs is shown only if the --verbose option is
 204used.
 205
 206In compact output mode, specified with configuration variable
 207fetch.output, if either entire `<from>` or `<to>` is found in the
 208other string, it will be substituted with `*` in the other string. For
 209example, `master -> origin/master` becomes `master -> origin/*`.
 210
 211flag::
 212        A single character indicating the status of the ref:
 213(space);; for a successfully fetched fast-forward;
 214`+`;; for a successful forced update;
 215`-`;; for a successfully pruned ref;
 216`t`;; for a successful tag update;
 217`*`;; for a successfully fetched new ref;
 218`!`;; for a ref that was rejected or failed to update; and
 219`=`;; for a ref that was up to date and did not need fetching.
 220
 221summary::
 222        For a successfully fetched ref, the summary shows the old and new
 223        values of the ref in a form suitable for using as an argument to
 224        `git log` (this is `<old>..<new>` in most cases, and
 225        `<old>...<new>` for forced non-fast-forward updates).
 226
 227from::
 228        The name of the remote ref being fetched from, minus its
 229        `refs/<type>/` prefix. In the case of deletion, the name of
 230        the remote ref is "(none)".
 231
 232to::
 233        The name of the local ref being updated, minus its
 234        `refs/<type>/` prefix.
 235
 236reason::
 237        A human-readable explanation. In the case of successfully fetched
 238        refs, no explanation is needed. For a failed ref, the reason for
 239        failure is described.
 240
 241EXAMPLES
 242--------
 243
 244* Update the remote-tracking branches:
 245+
 246------------------------------------------------
 247$ git fetch origin
 248------------------------------------------------
 249+
 250The above command copies all branches from the remote refs/heads/
 251namespace and stores them to the local refs/remotes/origin/ namespace,
 252unless the branch.<name>.fetch option is used to specify a non-default
 253refspec.
 254
 255* Using refspecs explicitly:
 256+
 257------------------------------------------------
 258$ git fetch origin +pu:pu maint:tmp
 259------------------------------------------------
 260+
 261This updates (or creates, as necessary) branches `pu` and `tmp` in
 262the local repository by fetching from the branches (respectively)
 263`pu` and `maint` from the remote repository.
 264+
 265The `pu` branch will be updated even if it is does not fast-forward,
 266because it is prefixed with a plus sign; `tmp` will not be.
 267
 268* Peek at a remote's branch, without configuring the remote in your local
 269  repository:
 270+
 271------------------------------------------------
 272$ git fetch git://git.kernel.org/pub/scm/git/git.git maint
 273$ git log FETCH_HEAD
 274------------------------------------------------
 275+
 276The first command fetches the `maint` branch from the repository at
 277`git://git.kernel.org/pub/scm/git/git.git` and the second command uses
 278`FETCH_HEAD` to examine the branch with linkgit:git-log[1].  The fetched
 279objects will eventually be removed by git's built-in housekeeping (see
 280linkgit:git-gc[1]).
 281
 282include::transfer-data-leaks.txt[]
 283
 284BUGS
 285----
 286Using --recurse-submodules can only fetch new commits in already checked
 287out submodules right now. When e.g. upstream added a new submodule in the
 288just fetched commits of the superproject the submodule itself can not be
 289fetched, making it impossible to check out that submodule later without
 290having to do a fetch again. This is expected to be fixed in a future Git
 291version.
 292
 293SEE ALSO
 294--------
 295linkgit:git-pull[1]
 296
 297GIT
 298---
 299Part of the linkgit:git[1] suite