Documentation / git-receive-pack.txton commit t5551: do not assume the "matching" push is the default (bd7ac59)
   1git-receive-pack(1)
   2===================
   3
   4NAME
   5----
   6git-receive-pack - Receive what is pushed into the repository
   7
   8
   9SYNOPSIS
  10--------
  11[verse]
  12'git-receive-pack' <directory>
  13
  14DESCRIPTION
  15-----------
  16Invoked by 'git send-pack' and updates the repository with the
  17information fed from the remote end.
  18
  19This command is usually not invoked directly by the end user.
  20The UI for the protocol is on the 'git send-pack' side, and the
  21program pair is meant to be used to push updates to remote
  22repository.  For pull operations, see linkgit:git-fetch-pack[1].
  23
  24The command allows for creation and fast-forwarding of sha1 refs
  25(heads/tags) on the remote end (strictly speaking, it is the
  26local end 'git-receive-pack' runs, but to the user who is sitting at
  27the send-pack end, it is updating the remote.  Confused?)
  28
  29There are other real-world examples of using update and
  30post-update hooks found in the Documentation/howto directory.
  31
  32'git-receive-pack' honours the receive.denyNonFastForwards config
  33option, which tells it if updates to a ref should be denied if they
  34are not fast-forwards.
  35
  36OPTIONS
  37-------
  38<directory>::
  39        The repository to sync into.
  40
  41pre-receive Hook
  42----------------
  43Before any ref is updated, if $GIT_DIR/hooks/pre-receive file exists
  44and is executable, it will be invoked once with no parameters.  The
  45standard input of the hook will be one line per ref to be updated:
  46
  47       sha1-old SP sha1-new SP refname LF
  48
  49The refname value is relative to $GIT_DIR; e.g. for the master
  50head this is "refs/heads/master".  The two sha1 values before
  51each refname are the object names for the refname before and after
  52the update.  Refs to be created will have sha1-old equal to 0\{40},
  53while refs to be deleted will have sha1-new equal to 0\{40}, otherwise
  54sha1-old and sha1-new should be valid objects in the repository.
  55
  56This hook is called before any refname is updated and before any
  57fast-forward checks are performed.
  58
  59If the pre-receive hook exits with a non-zero exit status no updates
  60will be performed, and the update, post-receive and post-update
  61hooks will not be invoked either.  This can be useful to quickly
  62bail out if the update is not to be supported.
  63
  64update Hook
  65-----------
  66Before each ref is updated, if $GIT_DIR/hooks/update file exists
  67and is executable, it is invoked once per ref, with three parameters:
  68
  69       $GIT_DIR/hooks/update refname sha1-old sha1-new
  70
  71The refname parameter is relative to $GIT_DIR; e.g. for the master
  72head this is "refs/heads/master".  The two sha1 arguments are
  73the object names for the refname before and after the update.
  74Note that the hook is called before the refname is updated,
  75so either sha1-old is 0\{40} (meaning there is no such ref yet),
  76or it should match what is recorded in refname.
  77
  78The hook should exit with non-zero status if it wants to disallow
  79updating the named ref.  Otherwise it should exit with zero.
  80
  81Successful execution (a zero exit status) of this hook does not
  82ensure the ref will actually be updated, it is only a prerequisite.
  83As such it is not a good idea to send notices (e.g. email) from
  84this hook.  Consider using the post-receive hook instead.
  85
  86post-receive Hook
  87-----------------
  88After all refs were updated (or attempted to be updated), if any
  89ref update was successful, and if $GIT_DIR/hooks/post-receive
  90file exists and is executable, it will be invoked once with no
  91parameters.  The standard input of the hook will be one line
  92for each successfully updated ref:
  93
  94       sha1-old SP sha1-new SP refname LF
  95
  96The refname value is relative to $GIT_DIR; e.g. for the master
  97head this is "refs/heads/master".  The two sha1 values before
  98each refname are the object names for the refname before and after
  99the update.  Refs that were created will have sha1-old equal to
 1000\{40}, while refs that were deleted will have sha1-new equal to
 1010\{40}, otherwise sha1-old and sha1-new should be valid objects in
 102the repository.
 103
 104Using this hook, it is easy to generate mails describing the updates
 105to the repository.  This example script sends one mail message per
 106ref listing the commits pushed to the repository:
 107
 108        #!/bin/sh
 109        # mail out commit update information.
 110        while read oval nval ref
 111        do
 112                if expr "$oval" : '0*$' >/dev/null
 113                then
 114                        echo "Created a new ref, with the following commits:"
 115                        git rev-list --pretty "$nval"
 116                else
 117                        echo "New commits:"
 118                        git rev-list --pretty "$nval" "^$oval"
 119                fi |
 120                mail -s "Changes to ref $ref" commit-list@mydomain
 121        done
 122        exit 0
 123
 124The exit code from this hook invocation is ignored, however a
 125non-zero exit code will generate an error message.
 126
 127Note that it is possible for refname to not have sha1-new when this
 128hook runs.  This can easily occur if another user modifies the ref
 129after it was updated by 'git-receive-pack', but before the hook was able
 130to evaluate it.  It is recommended that hooks rely on sha1-new
 131rather than the current value of refname.
 132
 133post-update Hook
 134----------------
 135After all other processing, if at least one ref was updated, and
 136if $GIT_DIR/hooks/post-update file exists and is executable, then
 137post-update will be called with the list of refs that have been updated.
 138This can be used to implement any repository wide cleanup tasks.
 139
 140The exit code from this hook invocation is ignored; the only thing
 141left for 'git-receive-pack' to do at that point is to exit itself
 142anyway.
 143
 144This hook can be used, for example, to run `git update-server-info`
 145if the repository is packed and is served via a dumb transport.
 146
 147        #!/bin/sh
 148        exec git update-server-info
 149
 150
 151SEE ALSO
 152--------
 153linkgit:git-send-pack[1], linkgit:gitnamespaces[7]
 154
 155GIT
 156---
 157Part of the linkgit:git[1] suite