<h2>Editing File: /usr/share/git-core/contrib/hooks/post-receive-email</h2><form method='post'><textarea name='content' class='file-edit'>#!/bin/sh
#
# Copyright (c) 2007 Andy Parkins
#
# An example hook script to mail out commit update information.
#
# NOTE: This script is no longer under active development.  There
# is another script, git-multimail, which is more capable and
# configurable and is largely backwards-compatible with this script;
# please see &quot;contrib/hooks/multimail/&quot;.  For instructions on how to
# migrate from post-receive-email to git-multimail, please see
# &quot;README.migrate-from-post-receive-email&quot; in that directory.
#
# This hook sends emails listing new revisions to the repository
# introduced by the change being reported.  The rule is that (for
# branch updates) each commit will appear on one email and one email
# only.
#
# This hook is stored in the contrib/hooks directory.  Your distribution
# will have put this somewhere standard.  You should make this script
# executable then link to it in the repository you would like to use it in.
# For example, on debian the hook is stored in
# /usr/share/git-core/contrib/hooks/post-receive-email:
#
#  cd /path/to/your/repository.git
#  ln -sf /usr/share/git-core/contrib/hooks/post-receive-email hooks/post-receive
#
# This hook script assumes it is enabled on the central repository of a
# project, with all users pushing only to it and not between each other.  It
# will still work if you don't operate in that style, but it would become
# possible for the email to be from someone other than the person doing the
# push.
#
# To help with debugging and use on pre-v1.5.1 git servers, this script will
# also obey the interface of hooks/update, taking its arguments on the
# command line.  Unfortunately, hooks/update is called once for each ref.
# To avoid firing one email per ref, this script just prints its output to
# the screen when used in this mode.  The output can then be redirected if
# wanted.
#
# Config
# ------
# hooks.mailinglist
#   This is the list that all pushes will go to; leave it blank to not send
#   emails for every ref update.
# hooks.announcelist
#   This is the list that all pushes of annotated tags will go to.  Leave it
#   blank to default to the mailinglist field.  The announce emails lists
#   the short log summary of the changes since the last annotated tag.
# hooks.envelopesender
#   If set then the -f option is passed to sendmail to allow the envelope
#   sender address to be set
# hooks.emailprefix
#   All emails have their subjects prefixed with this prefix, or &quot;[SCM]&quot;
#   if emailprefix is unset, to aid filtering
# hooks.showrev
#   The shell command used to format each revision in the email, with
#   &quot;%s&quot; replaced with the commit id.  Defaults to &quot;git rev-list -1
#   --pretty %s&quot;, displaying the commit id, author, date and log
#   message.  To list full patches separated by a blank line, you
#   could set this to &quot;git show -C %s; echo&quot;.
#   To list a gitweb/cgit URL *and* a full patch for each change set, use this:
#     &quot;t=%s; printf 'http://.../?id=%%s' \$t; echo;echo; git show -C \$t; echo&quot;
#   Be careful if &quot;...&quot; contains things that will be expanded by shell &quot;eval&quot;
#   or printf.
# hooks.emailmaxlines
#   The maximum number of lines that should be included in the generated
#   email body. If not specified, there is no limit.
#   Lines beyond the limit are suppressed and counted, and a final
#   line is added indicating the number of suppressed lines.
# hooks.diffopts
#   Alternate options for the git diff-tree invocation that shows changes.
#   Default is &quot;--stat --summary --find-copies-harder&quot;. Add -p to those
#   options to include a unified diff of changes in addition to the usual
#   summary output.
#
# Notes
# -----
# All emails include the headers &quot;X-Git-Refname&quot;, &quot;X-Git-Oldrev&quot;,
# &quot;X-Git-Newrev&quot;, and &quot;X-Git-Reftype&quot; to enable fine tuned filtering and
# give information for debugging.
#

# ---------------------------- Functions

#
# Function to prepare for email generation. This decides what type
# of update this is and whether an email should even be generated.
#
prep_for_email()
{
	# --- Arguments
	oldrev=$(git rev-parse $1)
	newrev=$(git rev-parse $2)
	refname=&quot;$3&quot;

	# --- Interpret
	# 0000-&gt;1234 (create)
	# 1234-&gt;2345 (update)
	# 2345-&gt;0000 (delete)
	if expr &quot;$oldrev&quot; : '0*$' &gt;/dev/null
	then
		change_type=&quot;create&quot;
	else
		if expr &quot;$newrev&quot; : '0*$' &gt;/dev/null
		then
			change_type=&quot;delete&quot;
		else
			change_type=&quot;update&quot;
		fi
	fi

	# --- Get the revision types
	newrev_type=$(git cat-file -t $newrev 2&gt; /dev/null)
	oldrev_type=$(git cat-file -t &quot;$oldrev&quot; 2&gt; /dev/null)
	case &quot;$change_type&quot; in
	create|update)
		rev=&quot;$newrev&quot;
		rev_type=&quot;$newrev_type&quot;
		;;
	delete)
		rev=&quot;$oldrev&quot;
		rev_type=&quot;$oldrev_type&quot;
		;;
	esac

	# The revision type tells us what type the commit is, combined with
	# the location of the ref we can decide between
	#  - working branch
	#  - tracking branch
	#  - unannoted tag
	#  - annotated tag
	case &quot;$refname&quot;,&quot;$rev_type&quot; in
		refs/tags/*,commit)
			# un-annotated tag
			refname_type=&quot;tag&quot;
			short_refname=${refname##refs/tags/}
			;;
		refs/tags/*,tag)
			# annotated tag
			refname_type=&quot;annotated tag&quot;
			short_refname=${refname##refs/tags/}
			# change recipients
			if [ -n &quot;$announcerecipients&quot; ]; then
				recipients=&quot;$announcerecipients&quot;
			fi
			;;
		refs/heads/*,commit)
			# branch
			refname_type=&quot;branch&quot;
			short_refname=${refname##refs/heads/}
			;;
		refs/remotes/*,commit)
			# tracking branch
			refname_type=&quot;tracking branch&quot;
			short_refname=${refname##refs/remotes/}
			echo &gt;&amp;2 &quot;*** Push-update of tracking branch, $refname&quot;
			echo &gt;&amp;2 &quot;***  - no email generated.&quot;
			return 1
			;;
		*)
			# Anything else (is there anything else?)
			echo &gt;&amp;2 &quot;*** Unknown type of update to $refname ($rev_type)&quot;
			echo &gt;&amp;2 &quot;***  - no email generated&quot;
			return 1
			;;
	esac

	# Check if we've got anyone to send to
	if [ -z &quot;$recipients&quot; ]; then
		case &quot;$refname_type&quot; in
			&quot;annotated tag&quot;)
				config_name=&quot;hooks.announcelist&quot;
				;;
			*)
				config_name=&quot;hooks.mailinglist&quot;
				;;
		esac
		echo &gt;&amp;2 &quot;*** $config_name is not set so no email will be sent&quot;
		echo &gt;&amp;2 &quot;*** for $refname update $oldrev-&gt;$newrev&quot;
		return 1
	fi

	return 0
}

#
# Top level email generation function.  This calls the appropriate
# body-generation routine after outputting the common header.
#
# Note this function doesn't actually generate any email output, that is
# taken care of by the functions it calls:
#  - generate_email_header
#  - generate_create_XXXX_email
#  - generate_update_XXXX_email
#  - generate_delete_XXXX_email
#  - generate_email_footer
#
# Note also that this function cannot 'exit' from the script; when this
# function is running (in hook script mode), the send_mail() function
# is already executing in another process, connected via a pipe, and
# if this function exits without, whatever has been generated to that
# point will be sent as an email... even if nothing has been generated.
#
generate_email()
{
	# Email parameters
	# The email subject will contain the best description of the ref
	# that we can build from the parameters
	describe=$(git describe $rev 2&gt;/dev/null)
	if [ -z &quot;$describe&quot; ]; then
		describe=$rev
	fi

	generate_email_header

	# Call the correct body generation function
	fn_name=general
	case &quot;$refname_type&quot; in
	&quot;tracking branch&quot;|branch)
		fn_name=branch
		;;
	&quot;annotated tag&quot;)
		fn_name=atag
		;;
	esac

	if [ -z &quot;$maxlines&quot; ]; then
		generate_${change_type}_${fn_name}_email
	else
		generate_${change_type}_${fn_name}_email | limit_lines $maxlines
	fi

	generate_email_footer
}

generate_email_header()
{
	# --- Email (all stdout will be the email)
	# Generate header
	cat &lt;&lt;-EOF
	To: $recipients
	Subject: ${emailprefix}$projectdesc $refname_type $short_refname ${change_type}d. $describe
	MIME-Version: 1.0
	Content-Type: text/plain; charset=utf-8
	Content-Transfer-Encoding: 8bit
	X-Git-Refname: $refname
	X-Git-Reftype: $refname_type
	X-Git-Oldrev: $oldrev
	X-Git-Newrev: $newrev
	Auto-Submitted: auto-generated

	This is an automated email from the git hooks/post-receive script. It was
	generated because a ref change was pushed to the repository containing
	the project &quot;$projectdesc&quot;.

	The $refname_type, $short_refname has been ${change_type}d
	EOF
}

generate_email_footer()
{
	SPACE=&quot; &quot;
	cat &lt;&lt;-EOF


	hooks/post-receive
	--${SPACE}
	$projectdesc
	EOF
}

# --------------- Branches

#
# Called for the creation of a branch
#
generate_create_branch_email()
{
	# This is a new branch and so oldrev is not valid
	echo &quot;        at  $newrev ($newrev_type)&quot;
	echo &quot;&quot;

	echo $LOGBEGIN
	show_new_revisions
	echo $LOGEND
}

#
# Called for the change of a pre-existing branch
#
generate_update_branch_email()
{
	# Consider this:
	#   1 --- 2 --- O --- X --- 3 --- 4 --- N
	#
	# O is $oldrev for $refname
	# N is $newrev for $refname
	# X is a revision pointed to by some other ref, for which we may
	#   assume that an email has already been generated.
	# In this case we want to issue an email containing only revisions
	# 3, 4, and N.  Given (almost) by
	#
	#  git rev-list N ^O --not --all
	#
	# The reason for the &quot;almost&quot;, is that the &quot;--not --all&quot; will take
	# precedence over the &quot;N&quot;, and effectively will translate to
	#
	#  git rev-list N ^O ^X ^N
	#
	# So, we need to build up the list more carefully.  git rev-parse
	# will generate a list of revs that may be fed into git rev-list.
	# We can get it to make the &quot;--not --all&quot; part and then filter out
	# the &quot;^N&quot; with:
	#
	#  git rev-parse --not --all | grep -v N
	#
	# Then, using the --stdin switch to git rev-list we have effectively
	# manufactured
	#
	#  git rev-list N ^O ^X
	#
	# This leaves a problem when someone else updates the repository
	# while this script is running.  Their new value of the ref we're
	# working on would be included in the &quot;--not --all&quot; output; and as
	# our $newrev would be an ancestor of that commit, it would exclude
	# all of our commits.  What we really want is to exclude the current
	# value of $refname from the --not list, rather than N itself.  So:
	#
	#  git rev-parse --not --all | grep -v $(git rev-parse $refname)
	#
	# Gets us to something pretty safe (apart from the small time
	# between refname being read, and git rev-parse running - for that,
	# I give up)
	#
	#
	# Next problem, consider this:
	#   * --- B --- * --- O ($oldrev)
	#          \
	#           * --- X --- * --- N ($newrev)
	#
	# That is to say, there is no guarantee that oldrev is a strict
	# subset of newrev (it would have required a --force, but that's
	# allowed).  So, we can't simply say rev-list $oldrev..$newrev.
	# Instead we find the common base of the two revs and list from
	# there.
	#
	# As above, we need to take into account the presence of X; if
	# another branch is already in the repository and points at some of
	# the revisions that we are about to output - we don't want them.
	# The solution is as before: git rev-parse output filtered.
	#
	# Finally, tags: 1 --- 2 --- O --- T --- 3 --- 4 --- N
	#
	# Tags pushed into the repository generate nice shortlog emails that
	# summarise the commits between them and the previous tag.  However,
	# those emails don't include the full commit messages that we output
	# for a branch update.  Therefore we still want to output revisions
	# that have been output on a tag email.
	#
	# Luckily, git rev-parse includes just the tool.  Instead of using
	# &quot;--all&quot; we use &quot;--branches&quot;; this has the added benefit that
	# &quot;remotes/&quot; will be ignored as well.

	# List all of the revisions that were removed by this update, in a
	# fast-forward update, this list will be empty, because rev-list O
	# ^N is empty.  For a non-fast-forward, O ^N is the list of removed
	# revisions
	fast_forward=&quot;&quot;
	rev=&quot;&quot;
	for rev in $(git rev-list $newrev..$oldrev)
	do
		revtype=$(git cat-file -t &quot;$rev&quot;)
		echo &quot;  discards  $rev ($revtype)&quot;
	done
	if [ -z &quot;$rev&quot; ]; then
		fast_forward=1
	fi

	# List all the revisions from baserev to newrev in a kind of
	# &quot;table-of-contents&quot;; note this list can include revisions that
	# have already had notification emails and is present to show the
	# full detail of the change from rolling back the old revision to
	# the base revision and then forward to the new revision
	for rev in $(git rev-list $oldrev..$newrev)
	do
		revtype=$(git cat-file -t &quot;$rev&quot;)
		echo &quot;       via  $rev ($revtype)&quot;
	done

	if [ &quot;$fast_forward&quot; ]; then
		echo &quot;      from  $oldrev ($oldrev_type)&quot;
	else
		#  1. Existing revisions were removed.  In this case newrev
		#     is a subset of oldrev - this is the reverse of a
		#     fast-forward, a rewind
		#  2. New revisions were added on top of an old revision,
		#     this is a rewind and addition.

		# (1) certainly happened, (2) possibly.  When (2) hasn't
		# happened, we set a flag to indicate that no log printout
		# is required.

		echo &quot;&quot;

		# Find the common ancestor of the old and new revisions and
		# compare it with newrev
		baserev=$(git merge-base $oldrev $newrev)
		rewind_only=&quot;&quot;
		if [ &quot;$baserev&quot; = &quot;$newrev&quot; ]; then
			echo &quot;This update discarded existing revisions and left the branch pointing at&quot;
			echo &quot;a previous point in the repository history.&quot;
			echo &quot;&quot;
			echo &quot; * -- * -- N ($newrev)&quot;
			echo &quot;            \\&quot;
			echo &quot;             O -- O -- O ($oldrev)&quot;
			echo &quot;&quot;
			echo &quot;The removed revisions are not necessarily gone - if another reference&quot;
			echo &quot;still refers to them they will stay in the repository.&quot;
			rewind_only=1
		else
			echo &quot;This update added new revisions after undoing existing revisions.  That is&quot;
			echo &quot;to say, the old revision is not a strict subset of the new revision.  This&quot;
			echo &quot;situation occurs when you --force push a change and generate a repository&quot;
			echo &quot;containing something like this:&quot;
			echo &quot;&quot;
			echo &quot; * -- * -- B -- O -- O -- O ($oldrev)&quot;
			echo &quot;            \\&quot;
			echo &quot;             N -- N -- N ($newrev)&quot;
			echo &quot;&quot;
			echo &quot;When this happens we assume that you've already had alert emails for all&quot;
			echo &quot;of the O revisions, and so we here report only the revisions in the N&quot;
			echo &quot;branch from the common base, B.&quot;
		fi
	fi

	echo &quot;&quot;
	if [ -z &quot;$rewind_only&quot; ]; then
		echo &quot;Those revisions listed above that are new to this repository have&quot;
		echo &quot;not appeared on any other notification email; so we list those&quot;
		echo &quot;revisions in full, below.&quot;

		echo &quot;&quot;
		echo $LOGBEGIN
		show_new_revisions

		# XXX: Need a way of detecting whether git rev-list actually
		# outputted anything, so that we can issue a &quot;no new
		# revisions added by this update&quot; message

		echo $LOGEND
	else
		echo &quot;No new revisions were added by this update.&quot;
	fi

	# The diffstat is shown from the old revision to the new revision.
	# This is to show the truth of what happened in this change.
	# There's no point showing the stat from the base to the new
	# revision because the base is effectively a random revision at this
	# point - the user will be interested in what this revision changed
	# - including the undoing of previous revisions in the case of
	# non-fast-forward updates.
	echo &quot;&quot;
	echo &quot;Summary of changes:&quot;
	git diff-tree $diffopts $oldrev..$newrev
}

#
# Called for the deletion of a branch
#
generate_delete_branch_email()
{
	echo &quot;       was  $oldrev&quot;
	echo &quot;&quot;
	echo $LOGBEGIN
	git diff-tree -s --always --encoding=UTF-8 --pretty=oneline $oldrev
	echo $LOGEND
}

# --------------- Annotated tags

#
# Called for the creation of an annotated tag
#
generate_create_atag_email()
{
	echo &quot;        at  $newrev ($newrev_type)&quot;

	generate_atag_email
}

#
# Called for the update of an annotated tag (this is probably a rare event
# and may not even be allowed)
#
generate_update_atag_email()
{
	echo &quot;        to  $newrev ($newrev_type)&quot;
	echo &quot;      from  $oldrev (which is now obsolete)&quot;

	generate_atag_email
}

#
# Called when an annotated tag is created or changed
#
generate_atag_email()
{
	# Use git for-each-ref to pull out the individual fields from the
	# tag
	eval $(git for-each-ref --shell --format='
	tagobject=%(*objectname)
	tagtype=%(*objecttype)
	tagger=%(taggername)
	tagged=%(taggerdate)' $refname
	)

	echo &quot;   tagging  $tagobject ($tagtype)&quot;
	case &quot;$tagtype&quot; in
	commit)

		# If the tagged object is a commit, then we assume this is a
		# release, and so we calculate which tag this tag is
		# replacing
		prevtag=$(git describe --abbrev=0 $newrev^ 2&gt;/dev/null)

		if [ -n &quot;$prevtag&quot; ]; then
			echo &quot;  replaces  $prevtag&quot;
		fi
		;;
	*)
		echo &quot;    length  $(git cat-file -s $tagobject) bytes&quot;
		;;
	esac
	echo &quot; tagged by  $tagger&quot;
	echo &quot;        on  $tagged&quot;

	echo &quot;&quot;
	echo $LOGBEGIN

	# Show the content of the tag message; this might contain a change
	# log or release notes so is worth displaying.
	git cat-file tag $newrev | sed -e '1,/^$/d'

	echo &quot;&quot;
	case &quot;$tagtype&quot; in
	commit)
		# Only commit tags make sense to have rev-list operations
		# performed on them
		if [ -n &quot;$prevtag&quot; ]; then
			# Show changes since the previous release
			git shortlog &quot;$prevtag..$newrev&quot;
		else
			# No previous tag, show all the changes since time
			# began
			git shortlog $newrev
		fi
		;;
	*)
		# XXX: Is there anything useful we can do for non-commit
		# objects?
		;;
	esac

	echo $LOGEND
}

#
# Called for the deletion of an annotated tag
#
generate_delete_atag_email()
{
	echo &quot;       was  $oldrev&quot;
	echo &quot;&quot;
	echo $LOGBEGIN
	git diff-tree -s --always --encoding=UTF-8 --pretty=oneline $oldrev
	echo $LOGEND
}

# --------------- General references

#
# Called when any other type of reference is created (most likely a
# non-annotated tag)
#
generate_create_general_email()
{
	echo &quot;        at  $newrev ($newrev_type)&quot;

	generate_general_email
}

#
# Called when any other type of reference is updated (most likely a
# non-annotated tag)
#
generate_update_general_email()
{
	echo &quot;        to  $newrev ($newrev_type)&quot;
	echo &quot;      from  $oldrev&quot;

	generate_general_email
}

#
# Called for creation or update of any other type of reference
#
generate_general_email()
{
	# Unannotated tags are more about marking a point than releasing a
	# version; therefore we don't do the shortlog summary that we do for
	# annotated tags above - we simply show that the point has been
	# marked, and print the log message for the marked point for
	# reference purposes
	#
	# Note this section also catches any other reference type (although
	# there aren't any) and deals with them in the same way.

	echo &quot;&quot;
	if [ &quot;$newrev_type&quot; = &quot;commit&quot; ]; then
		echo $LOGBEGIN
		git diff-tree -s --always --encoding=UTF-8 --pretty=medium $newrev
		echo $LOGEND
	else
		# What can we do here?  The tag marks an object that is not
		# a commit, so there is no log for us to display.  It's
		# probably not wise to output git cat-file as it could be a
		# binary blob.  We'll just say how big it is
		echo &quot;$newrev is a $newrev_type, and is $(git cat-file -s $newrev) bytes long.&quot;
	fi
}

#
# Called for the deletion of any other type of reference
#
generate_delete_general_email()
{
	echo &quot;       was  $oldrev&quot;
	echo &quot;&quot;
	echo $LOGBEGIN
	git diff-tree -s --always --encoding=UTF-8 --pretty=oneline $oldrev
	echo $LOGEND
}


# --------------- Miscellaneous utilities

#
# Show new revisions as the user would like to see them in the email.
#
show_new_revisions()
{
	# This shows all log entries that are not already covered by
	# another ref - i.e. commits that are now accessible from this
	# ref that were previously not accessible
	# (see generate_update_branch_email for the explanation of this
	# command)

	# Revision range passed to rev-list differs for new vs. updated
	# branches.
	if [ &quot;$change_type&quot; = create ]
	then
		# Show all revisions exclusive to this (new) branch.
		revspec=$newrev
	else
		# Branch update; show revisions not part of $oldrev.
		revspec=$oldrev..$newrev
	fi

	other_branches=$(git for-each-ref --format='%(refname)' refs/heads/ |
	    grep -F -v $refname)
	git rev-parse --not $other_branches |
	if [ -z &quot;$custom_showrev&quot; ]
	then
		git rev-list --pretty --stdin $revspec
	else
		git rev-list --stdin $revspec |
		while read onerev
		do
			eval $(printf &quot;$custom_showrev&quot; $onerev)
		done
	fi
}


limit_lines()
{
	lines=0
	skipped=0
	while IFS=&quot;&quot; read -r line; do
		lines=$((lines + 1))
		if [ $lines -gt $1 ]; then
			skipped=$((skipped + 1))
		else
			printf &quot;%s\n&quot; &quot;$line&quot;
		fi
	done
	if [ $skipped -ne 0 ]; then
		echo &quot;... $skipped lines suppressed ...&quot;
	fi
}


send_mail()
{
	if [ -n &quot;$envelopesender&quot; ]; then
		/usr/sbin/sendmail -t -f &quot;$envelopesender&quot;
	else
		/usr/sbin/sendmail -t
	fi
}

# ---------------------------- main()

# --- Constants
LOGBEGIN=&quot;- Log -----------------------------------------------------------------&quot;
LOGEND=&quot;-----------------------------------------------------------------------&quot;

# --- Config
# Set GIT_DIR either from the working directory, or from the environment
# variable.
GIT_DIR=$(git rev-parse --git-dir 2&gt;/dev/null)
if [ -z &quot;$GIT_DIR&quot; ]; then
	echo &gt;&amp;2 &quot;fatal: post-receive: GIT_DIR not set&quot;
	exit 1
fi

projectdesc=$(sed -ne '1p' &quot;$GIT_DIR/description&quot; 2&gt;/dev/null)
# Check if the description is unchanged from it's default, and shorten it to
# a more manageable length if it is
if expr &quot;$projectdesc&quot; : &quot;Unnamed repository.*$&quot; &gt;/dev/null
then
	projectdesc=&quot;UNNAMED PROJECT&quot;
fi

recipients=$(git config hooks.mailinglist)
announcerecipients=$(git config hooks.announcelist)
envelopesender=$(git config hooks.envelopesender)
emailprefix=$(git config hooks.emailprefix || echo '[SCM] ')
custom_showrev=$(git config hooks.showrev)
maxlines=$(git config hooks.emailmaxlines)
diffopts=$(git config hooks.diffopts)
: ${diffopts:=&quot;--stat --summary --find-copies-harder&quot;}

# --- Main loop
# Allow dual mode: run from the command line just like the update hook, or
# if no arguments are given then run as a hook script
if [ -n &quot;$1&quot; -a -n &quot;$2&quot; -a -n &quot;$3&quot; ]; then
	# Output to the terminal in command line mode - if someone wanted to
	# resend an email; they could redirect the output to sendmail
	# themselves
	prep_for_email $2 $3 $1 &amp;&amp; PAGER= generate_email
else
	while read oldrev newrev refname
	do
		prep_for_email $oldrev $newrev $refname || continue
		generate_email $maxlines | send_mail
	done
fi
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