Documentation / git-receive-pack.txton commit glossary: update description of "tag" (487b044)
   1git-receive-pack(1)
   2===================
   3
   4NAME
   5----
   6git-receive-pack - Receive what is pushed into the repository
   7
   8
   9SYNOPSIS
  10--------
  11'git-receive-pack' <directory>
  12
  13DESCRIPTION
  14-----------
  15Invoked by 'git send-pack' and updates the repository with the
  16information fed from the remote end.
  17
  18This command is usually not invoked directly by the end user.
  19The UI for the protocol is on the 'git send-pack' side, and the
  20program pair is meant to be used to push updates to remote
  21repository.  For pull operations, see linkgit:git-fetch-pack[1].
  22
  23The command allows for creation and fast-forwarding of sha1 refs
  24(heads/tags) on the remote end (strictly speaking, it is the
  25local end 'git-receive-pack' runs, but to the user who is sitting at
  26the send-pack end, it is updating the remote.  Confused?)
  27
  28There are other real-world examples of using update and
  29post-update hooks found in the Documentation/howto directory.
  30
  31'git-receive-pack' honours the receive.denyNonFastForwards config
  32option, which tells it if updates to a ref should be denied if they
  33are not fast-forwards.
  34
  35OPTIONS
  36-------
  37<directory>::
  38        The repository to sync into.
  39
  40pre-receive Hook
  41----------------
  42Before any ref is updated, if $GIT_DIR/hooks/pre-receive file exists
  43and is executable, it will be invoked once with no parameters.  The
  44standard input of the hook will be one line per ref to be updated:
  45
  46       sha1-old SP sha1-new SP refname LF
  47
  48The refname value is relative to $GIT_DIR; e.g. for the master
  49head this is "refs/heads/master".  The two sha1 values before
  50each refname are the object names for the refname before and after
  51the update.  Refs to be created will have sha1-old equal to 0\{40},
  52while refs to be deleted will have sha1-new equal to 0\{40}, otherwise
  53sha1-old and sha1-new should be valid objects in the repository.
  54
  55This hook is called before any refname is updated and before any
  56fast-forward checks are performed.
  57
  58If the pre-receive hook exits with a non-zero exit status no updates
  59will be performed, and the update, post-receive and post-update
  60hooks will not be invoked either.  This can be useful to quickly
  61bail out if the update is not to be supported.
  62
  63update Hook
  64-----------
  65Before each ref is updated, if $GIT_DIR/hooks/update file exists
  66and is executable, it is invoked once per ref, with three parameters:
  67
  68       $GIT_DIR/hooks/update refname sha1-old sha1-new
  69
  70The refname parameter is relative to $GIT_DIR; e.g. for the master
  71head this is "refs/heads/master".  The two sha1 arguments are
  72the object names for the refname before and after the update.
  73Note that the hook is called before the refname is updated,
  74so either sha1-old is 0\{40} (meaning there is no such ref yet),
  75or it should match what is recorded in refname.
  76
  77The hook should exit with non-zero status if it wants to disallow
  78updating the named ref.  Otherwise it should exit with zero.
  79
  80Successful execution (a zero exit status) of this hook does not
  81ensure the ref will actually be updated, it is only a prerequisite.
  82As such it is not a good idea to send notices (e.g. email) from
  83this hook.  Consider using the post-receive hook instead.
  84
  85post-receive Hook
  86-----------------
  87After all refs were updated (or attempted to be updated), if any
  88ref update was successful, and if $GIT_DIR/hooks/post-receive
  89file exists and is executable, it will be invoked once with no
  90parameters.  The standard input of the hook will be one line
  91for each successfully updated ref:
  92
  93       sha1-old SP sha1-new SP refname LF
  94
  95The refname value is relative to $GIT_DIR; e.g. for the master
  96head this is "refs/heads/master".  The two sha1 values before
  97each refname are the object names for the refname before and after
  98the update.  Refs that were created will have sha1-old equal to
  990\{40}, while refs that were deleted will have sha1-new equal to
 1000\{40}, otherwise sha1-old and sha1-new should be valid objects in
 101the repository.
 102
 103Using this hook, it is easy to generate mails describing the updates
 104to the repository.  This example script sends one mail message per
 105ref listing the commits pushed to the repository:
 106
 107        #!/bin/sh
 108        # mail out commit update information.
 109        while read oval nval ref
 110        do
 111                if expr "$oval" : '0*$' >/dev/null
 112                then
 113                        echo "Created a new ref, with the following commits:"
 114                        git rev-list --pretty "$nval"
 115                else
 116                        echo "New commits:"
 117                        git rev-list --pretty "$nval" "^$oval"
 118                fi |
 119                mail -s "Changes to ref $ref" commit-list@mydomain
 120        done
 121        exit 0
 122
 123The exit code from this hook invocation is ignored, however a
 124non-zero exit code will generate an error message.
 125
 126Note that it is possible for refname to not have sha1-new when this
 127hook runs.  This can easily occur if another user modifies the ref
 128after it was updated by 'git-receive-pack', but before the hook was able
 129to evaluate it.  It is recommended that hooks rely on sha1-new
 130rather than the current value of refname.
 131
 132post-update Hook
 133----------------
 134After all other processing, if at least one ref was updated, and
 135if $GIT_DIR/hooks/post-update file exists and is executable, then
 136post-update will be called with the list of refs that have been updated.
 137This can be used to implement any repository wide cleanup tasks.
 138
 139The exit code from this hook invocation is ignored; the only thing
 140left for 'git-receive-pack' to do at that point is to exit itself
 141anyway.
 142
 143This hook can be used, for example, to run `git update-server-info`
 144if the repository is packed and is served via a dumb transport.
 145
 146        #!/bin/sh
 147        exec git update-server-info
 148
 149
 150SEE ALSO
 151--------
 152linkgit:git-send-pack[1]
 153
 154GIT
 155---
 156Part of the linkgit:git[1] suite