Documentation / git-replace.txton commit graph: add commit graph design document (ae30d7b)
   1git-replace(1)
   2==============
   3
   4NAME
   5----
   6git-replace - Create, list, delete refs to replace objects
   7
   8SYNOPSIS
   9--------
  10[verse]
  11'git replace' [-f] <object> <replacement>
  12'git replace' [-f] --edit <object>
  13'git replace' [-f] --graft <commit> [<parent>...]
  14'git replace' -d <object>...
  15'git replace' [--format=<format>] [-l [<pattern>]]
  16
  17DESCRIPTION
  18-----------
  19Adds a 'replace' reference in `refs/replace/` namespace.
  20
  21The name of the 'replace' reference is the SHA-1 of the object that is
  22replaced. The content of the 'replace' reference is the SHA-1 of the
  23replacement object.
  24
  25The replaced object and the replacement object must be of the same type.
  26This restriction can be bypassed using `-f`.
  27
  28Unless `-f` is given, the 'replace' reference must not yet exist.
  29
  30There is no other restriction on the replaced and replacement objects.
  31Merge commits can be replaced by non-merge commits and vice versa.
  32
  33Replacement references will be used by default by all Git commands
  34except those doing reachability traversal (prune, pack transfer and
  35fsck).
  36
  37It is possible to disable use of replacement references for any
  38command using the `--no-replace-objects` option just after 'git'.
  39
  40For example if commit 'foo' has been replaced by commit 'bar':
  41
  42------------------------------------------------
  43$ git --no-replace-objects cat-file commit foo
  44------------------------------------------------
  45
  46shows information about commit 'foo', while:
  47
  48------------------------------------------------
  49$ git cat-file commit foo
  50------------------------------------------------
  51
  52shows information about commit 'bar'.
  53
  54The `GIT_NO_REPLACE_OBJECTS` environment variable can be set to
  55achieve the same effect as the `--no-replace-objects` option.
  56
  57OPTIONS
  58-------
  59-f::
  60--force::
  61        If an existing replace ref for the same object exists, it will
  62        be overwritten (instead of failing).
  63
  64-d::
  65--delete::
  66        Delete existing replace refs for the given objects.
  67
  68--edit <object>::
  69        Edit an object's content interactively. The existing content
  70        for <object> is pretty-printed into a temporary file, an
  71        editor is launched on the file, and the result is parsed to
  72        create a new object of the same type as <object>. A
  73        replacement ref is then created to replace <object> with the
  74        newly created object. See linkgit:git-var[1] for details about
  75        how the editor will be chosen.
  76
  77--raw::
  78        When editing, provide the raw object contents rather than
  79        pretty-printed ones. Currently this only affects trees, which
  80        will be shown in their binary form. This is harder to work with,
  81        but can help when repairing a tree that is so corrupted it
  82        cannot be pretty-printed. Note that you may need to configure
  83        your editor to cleanly read and write binary data.
  84
  85--graft <commit> [<parent>...]::
  86        Create a graft commit. A new commit is created with the same
  87        content as <commit> except that its parents will be
  88        [<parent>...] instead of <commit>'s parents. A replacement ref
  89        is then created to replace <commit> with the newly created
  90        commit. See contrib/convert-grafts-to-replace-refs.sh for an
  91        example script based on this option that can convert grafts to
  92        replace refs.
  93
  94-l <pattern>::
  95--list <pattern>::
  96        List replace refs for objects that match the given pattern (or
  97        all if no pattern is given).
  98        Typing "git replace" without arguments, also lists all replace
  99        refs.
 100
 101--format=<format>::
 102        When listing, use the specified <format>, which can be one of
 103        'short', 'medium' and 'long'. When omitted, the format
 104        defaults to 'short'.
 105
 106FORMATS
 107-------
 108
 109The following format are available:
 110
 111* 'short':
 112        <replaced sha1>
 113* 'medium':
 114        <replaced sha1> -> <replacement sha1>
 115* 'long':
 116        <replaced sha1> (<replaced type>) -> <replacement sha1> (<replacement type>)
 117
 118CREATING REPLACEMENT OBJECTS
 119----------------------------
 120
 121linkgit:git-filter-branch[1], linkgit:git-hash-object[1] and
 122linkgit:git-rebase[1], among other git commands, can be used to create
 123replacement objects from existing objects. The `--edit` option can
 124also be used with 'git replace' to create a replacement object by
 125editing an existing object.
 126
 127If you want to replace many blobs, trees or commits that are part of a
 128string of commits, you may just want to create a replacement string of
 129commits and then only replace the commit at the tip of the target
 130string of commits with the commit at the tip of the replacement string
 131of commits.
 132
 133BUGS
 134----
 135Comparing blobs or trees that have been replaced with those that
 136replace them will not work properly. And using `git reset --hard` to
 137go back to a replaced commit will move the branch to the replacement
 138commit instead of the replaced commit.
 139
 140There may be other problems when using 'git rev-list' related to
 141pending objects.
 142
 143SEE ALSO
 144--------
 145linkgit:git-hash-object[1]
 146linkgit:git-filter-branch[1]
 147linkgit:git-rebase[1]
 148linkgit:git-tag[1]
 149linkgit:git-branch[1]
 150linkgit:git-commit[1]
 151linkgit:git-var[1]
 152linkgit:git[1]
 153
 154GIT
 155---
 156Part of the linkgit:git[1] suite