contrib/hooks/post-receive-email

   1 #!/bin/sh
   2 #
   3 # Copyright (c) 2007 Andy Parkins
   4 #
   5 # An example hook script to mail out commit update information.  This hook
   6 # sends emails listing new revisions to the repository introduced by the
   7 # change being reported.  The rule is that (for branch updates) each commit
   8 # will appear on one email and one email only.
   9 #
  10 # This hook is stored in the contrib/hooks directory.  Your distribution
  11 # will have put this somewhere standard.  You should make this script
  12 # executable then link to it in the repository you would like to use it in.
  13 # For example, on debian the hook is stored in
  14 # /usr/share/doc/git-core/contrib/hooks/post-receive-email:
  15 #
  16 #  chmod a+x post-receive-email
  17 #  cd /path/to/your/repository.git
  18 #  ln -sf /usr/share/doc/git-core/contrib/hooks/post-receive-email hooks/post-receive
  19 #
  20 # This hook script assumes it is enabled on the central repository of a
  21 # project, with all users pushing only to it and not between each other.  It
  22 # will still work if you don't operate in that style, but it would become
  23 # possible for the email to be from someone other than the person doing the
  24 # push.
  25 #
  26 # To help with debugging and use on pre-v1.5.1 git servers, this script will
  27 # also obey the interface of hooks/update, taking its arguments on the
  28 # command line.  Unfortunately, hooks/update is called once for each ref.
  29 # To avoid firing one email per ref, this script just prints its output to
  30 # the screen when used in this mode.  The output can then be redirected if
  31 # wanted.
  32 #
  33 # Config
  34 # ------
  35 # hooks.mailinglist
  36 #   This is the list that all pushes will go to; leave it blank to not send
  37 #   emails for every ref update.
  38 # hooks.announcelist
  39 #   This is the list that all pushes of annotated tags will go to.  Leave it
  40 #   blank to default to the mailinglist field.  The announce emails lists
  41 #   the short log summary of the changes since the last annotated tag.
  42 # hooks.envelopesender
  43 #   If set then the -f option is passed to sendmail to allow the envelope
  44 #   sender address to be set
  45 # hooks.emailprefix
  46 #   All emails have their subjects prefixed with this prefix, or "[SCM]"
  47 #   if emailprefix is unset, to aid filtering
  48 # hooks.showrev
  49 #   The shell command used to format each revision in the email, with
  50 #   "%s" replaced with the commit id.  Defaults to "git rev-list -1
  51 #   --pretty %s", displaying the commit id, author, date and log
  52 #   message.  To list full patches separated by a blank line, you
  53 #   could set this to "git show -C %s; echo".
  54 #   To list a gitweb/cgit URL *and* a full patch for each change set, use this:
  55 #     "t=%s; printf 'http://.../?id=%%s' \$t; echo;echo; git show -C \$t; echo"
  56 #   Be careful if "..." contains things that will be expanded by shell "eval"
  57 #   or printf.
  58 # hooks.emailmaxlines
  59 #   The maximum number of lines that should be included in the generated
  60 #   email body. If not specified, there is no limit.
  61 #   Lines beyond the limit are suppressed and counted, and a final
  62 #   line is added indicating the number of suppressed lines.
  63 #
  64 # Notes
  65 # -----
  66 # All emails include the headers "X-Git-Refname", "X-Git-Oldrev",
  67 # "X-Git-Newrev", and "X-Git-Reftype" to enable fine tuned filtering and
  68 # give information for debugging.
  69 #
  70
  71 # ---------------------------- Functions
  72
  73 #
  74 # Function to prepare for email generation. This decides what type
  75 # of update this is and whether an email should even be generated.
  76 #
  77 prep_for_email()
  78 {
  79         # --- Arguments
  80         oldrev=$(git rev-parse $1)
  81         newrev=$(git rev-parse $2)
  82         refname="$3"
  83         maxlines=$4
  84
  85         # --- Interpret
  86         # 0000->1234 (create)
  87         # 1234->2345 (update)
  88         # 2345->0000 (delete)
  89         if expr "$oldrev" : '0*$' >/dev/null
  90         then
  91                 change_type="create"
  92         else
  93                 if expr "$newrev" : '0*$' >/dev/null
  94                 then
  95                         change_type="delete"
  96                 else
  97                         change_type="update"
  98                 fi
  99         fi
 100
 101         # --- Get the revision types
 102         newrev_type=$(git cat-file -t $newrev 2> /dev/null)
 103         oldrev_type=$(git cat-file -t "$oldrev" 2> /dev/null)
 104         case "$change_type" in
 105         create|update)
 106                 rev="$newrev"
 107                 rev_type="$newrev_type"
 108                 ;;
 109         delete)
 110                 rev="$oldrev"
 111                 rev_type="$oldrev_type"
 112                 ;;
 113         esac
 114
 115         # The revision type tells us what type the commit is, combined with
 116         # the location of the ref we can decide between
 117         #  - working branch
 118         #  - tracking branch
 119         #  - unannoted tag
 120         #  - annotated tag
 121         case "$refname","$rev_type" in
 122                 refs/tags/*,commit)
 123                         # un-annotated tag
 124                         refname_type="tag"
 125                         short_refname=${refname##refs/tags/}
 126                         ;;
 127                 refs/tags/*,tag)
 128                         # annotated tag
 129                         refname_type="annotated tag"
 130                         short_refname=${refname##refs/tags/}
 131                         # change recipients
 132                         if [ -n "$announcerecipients" ]; then
 133                                 recipients="$announcerecipients"
 134                         fi
 135                         ;;
 136                 refs/heads/*,commit)
 137                         # branch
 138                         refname_type="branch"
 139                         short_refname=${refname##refs/heads/}
 140                         ;;
 141                 refs/remotes/*,commit)
 142                         # tracking branch
 143                         refname_type="tracking branch"
 144                         short_refname=${refname##refs/remotes/}
 145                         echo >&2 "*** Push-update of tracking branch, $refname"
 146                         echo >&2 "***  - no email generated."
 147                         exit 0
 148                         ;;
 149                 *)
 150                         # Anything else (is there anything else?)
 151                         echo >&2 "*** Unknown type of update to $refname ($rev_type)"
 152                         echo >&2 "***  - no email generated"
 153                         return 0
 154                         ;;
 155         esac
 156
 157         # Check if we've got anyone to send to
 158         if [ -z "$recipients" ]; then
 159                 case "$refname_type" in
 160                         "annotated tag")
 161                                 config_name="hooks.announcelist"
 162                                 ;;
 163                         *)
 164                                 config_name="hooks.mailinglist"
 165                                 ;;
 166                 esac
 167                 echo >&2 "*** $config_name is not set so no email will be sent"
 168                 echo >&2 "*** for $refname update $oldrev->$newrev"
 169                 return 0
 170         fi
 171
 172         return 1
 173 }
 174
 175 #
 176 # Top level email generation function.  This calls the appropriate
 177 # body-generation routine after outputting the common header.
 178 #
 179 # Note this function doesn't actually generate any email output, that is
 180 # taken care of by the functions it calls:
 181 #  - generate_email_header
 182 #  - generate_create_XXXX_email
 183 #  - generate_update_XXXX_email
 184 #  - generate_delete_XXXX_email
 185 #  - generate_email_footer
 186 #
 187 # Note also that this function cannot 'exit' from the script; when this
 188 # function is running (in hook script mode), the send_mail() function
 189 # is already executing in another process, connected via a pipe, and
 190 # if this function exits without, whatever has been generated to that
 191 # point will be sent as an email... even if nothing has been generated.
 192 #
 193 generate_email()
 194 {
 195         # Email parameters
 196         # The email subject will contain the best description of the ref
 197         # that we can build from the parameters
 198         describe=$(git describe $rev 2>/dev/null)
 199         if [ -z "$describe" ]; then
 200                 describe=$rev
 201         fi
 202
 203         generate_email_header
 204
 205         # Call the correct body generation function
 206         fn_name=general
 207         case "$refname_type" in
 208         "tracking branch"|branch)
 209                 fn_name=branch
 210                 ;;
 211         "annotated tag")
 212                 fn_name=atag
 213                 ;;
 214         esac
 215
 216         if [ -z "$maxlines" ]; then
 217                 generate_${change_type}_${fn_name}_email
 218         else
 219                 generate_${change_type}_${fn_name}_email | limit_lines $maxlines
 220         fi
 221
 222         generate_email_footer
 223 }
 224
 225 generate_email_header()
 226 {
 227         # --- Email (all stdout will be the email)
 228         # Generate header
 229         cat <<-EOF
 230         To: $recipients
 231         Subject: ${emailprefix}$projectdesc $refname_type $short_refname ${change_type}d. $describe
 232         X-Git-Refname: $refname
 233         X-Git-Reftype: $refname_type
 234         X-Git-Oldrev: $oldrev
 235         X-Git-Newrev: $newrev
 236
 237         This is an automated email from the git hooks/post-receive script. It was
 238         generated because a ref change was pushed to the repository containing
 239         the project "$projectdesc".
 240
 241         The $refname_type, $short_refname has been ${change_type}d
 242         EOF
 243 }
 244
 245 generate_email_footer()
 246 {
 247         SPACE=" "
 248         cat <<-EOF
 249
 250
 251         hooks/post-receive
 252         --${SPACE}
 253         $projectdesc
 254         EOF
 255 }
 256
 257 # --------------- Branches
 258
 259 #
 260 # Called for the creation of a branch
 261 #
 262 generate_create_branch_email()
 263 {
 264         # This is a new branch and so oldrev is not valid
 265         echo "        at  $newrev ($newrev_type)"
 266         echo ""
 267
 268         echo $LOGBEGIN
 269         show_new_revisions
 270         echo $LOGEND
 271 }
 272
 273 #
 274 # Called for the change of a pre-existing branch
 275 #
 276 generate_update_branch_email()
 277 {
 278         # Consider this:
 279         #   1 --- 2 --- O --- X --- 3 --- 4 --- N
 280         #
 281         # O is $oldrev for $refname
 282         # N is $newrev for $refname
 283         # X is a revision pointed to by some other ref, for which we may
 284         #   assume that an email has already been generated.
 285         # In this case we want to issue an email containing only revisions
 286         # 3, 4, and N.  Given (almost) by
 287         #
 288         #  git rev-list N ^O --not --all
 289         #
 290         # The reason for the "almost", is that the "--not --all" will take
 291         # precedence over the "N", and effectively will translate to
 292         #
 293         #  git rev-list N ^O ^X ^N
 294         #
 295         # So, we need to build up the list more carefully.  git rev-parse
 296         # will generate a list of revs that may be fed into git rev-list.
 297         # We can get it to make the "--not --all" part and then filter out
 298         # the "^N" with:
 299         #
 300         #  git rev-parse --not --all | grep -v N
 301         #
 302         # Then, using the --stdin switch to git rev-list we have effectively
 303         # manufactured
 304         #
 305         #  git rev-list N ^O ^X
 306         #
 307         # This leaves a problem when someone else updates the repository
 308         # while this script is running.  Their new value of the ref we're
 309         # working on would be included in the "--not --all" output; and as
 310         # our $newrev would be an ancestor of that commit, it would exclude
 311         # all of our commits.  What we really want is to exclude the current
 312         # value of $refname from the --not list, rather than N itself.  So:
 313         #
 314         #  git rev-parse --not --all | grep -v $(git rev-parse $refname)
 315         #
 316         # Get's us to something pretty safe (apart from the small time
 317         # between refname being read, and git rev-parse running - for that,
 318         # I give up)
 319         #
 320         #
 321         # Next problem, consider this:
 322         #   * --- B --- * --- O ($oldrev)
 323         #          \
 324         #           * --- X --- * --- N ($newrev)
 325         #
 326         # That is to say, there is no guarantee that oldrev is a strict
 327         # subset of newrev (it would have required a --force, but that's
 328         # allowed).  So, we can't simply say rev-list $oldrev..$newrev.
 329         # Instead we find the common base of the two revs and list from
 330         # there.
 331         #
 332         # As above, we need to take into account the presence of X; if
 333         # another branch is already in the repository and points at some of
 334         # the revisions that we are about to output - we don't want them.
 335         # The solution is as before: git rev-parse output filtered.
 336         #
 337         # Finally, tags: 1 --- 2 --- O --- T --- 3 --- 4 --- N
 338         #
 339         # Tags pushed into the repository generate nice shortlog emails that
 340         # summarise the commits between them and the previous tag.  However,
 341         # those emails don't include the full commit messages that we output
 342         # for a branch update.  Therefore we still want to output revisions
 343         # that have been output on a tag email.
 344         #
 345         # Luckily, git rev-parse includes just the tool.  Instead of using
 346         # "--all" we use "--branches"; this has the added benefit that
 347         # "remotes/" will be ignored as well.
 348
 349         # List all of the revisions that were removed by this update, in a
 350         # fast-forward update, this list will be empty, because rev-list O
 351         # ^N is empty.  For a non-fast-forward, O ^N is the list of removed
 352         # revisions
 353         fast_forward=""
 354         rev=""
 355         for rev in $(git rev-list $newrev..$oldrev)
 356         do
 357                 revtype=$(git cat-file -t "$rev")
 358                 echo "  discards  $rev ($revtype)"
 359         done
 360         if [ -z "$rev" ]; then
 361                 fast_forward=1
 362         fi
 363
 364         # List all the revisions from baserev to newrev in a kind of
 365         # "table-of-contents"; note this list can include revisions that
 366         # have already had notification emails and is present to show the
 367         # full detail of the change from rolling back the old revision to
 368         # the base revision and then forward to the new revision
 369         for rev in $(git rev-list $oldrev..$newrev)
 370         do
 371                 revtype=$(git cat-file -t "$rev")
 372                 echo "       via  $rev ($revtype)"
 373         done
 374
 375         if [ "$fast_forward" ]; then
 376                 echo "      from  $oldrev ($oldrev_type)"
 377         else
 378                 #  1. Existing revisions were removed.  In this case newrev
 379                 #     is a subset of oldrev - this is the reverse of a
 380                 #     fast-forward, a rewind
 381                 #  2. New revisions were added on top of an old revision,
 382                 #     this is a rewind and addition.
 383
 384                 # (1) certainly happened, (2) possibly.  When (2) hasn't
 385                 # happened, we set a flag to indicate that no log printout
 386                 # is required.
 387
 388                 echo ""
 389
 390                 # Find the common ancestor of the old and new revisions and
 391                 # compare it with newrev
 392                 baserev=$(git merge-base $oldrev $newrev)
 393                 rewind_only=""
 394                 if [ "$baserev" = "$newrev" ]; then
 395                         echo "This update discarded existing revisions and left the branch pointing at"
 396                         echo "a previous point in the repository history."
 397                         echo ""
 398                         echo " * -- * -- N ($newrev)"
 399                         echo "            \\"
 400                         echo "             O -- O -- O ($oldrev)"
 401                         echo ""
 402                         echo "The removed revisions are not necessarilly gone - if another reference"
 403                         echo "still refers to them they will stay in the repository."
 404                         rewind_only=1
 405                 else
 406                         echo "This update added new revisions after undoing existing revisions.  That is"
 407                         echo "to say, the old revision is not a strict subset of the new revision.  This"
 408                         echo "situation occurs when you --force push a change and generate a repository"
 409                         echo "containing something like this:"
 410                         echo ""
 411                         echo " * -- * -- B -- O -- O -- O ($oldrev)"
 412                         echo "            \\"
 413                         echo "             N -- N -- N ($newrev)"
 414                         echo ""
 415                         echo "When this happens we assume that you've already had alert emails for all"
 416                         echo "of the O revisions, and so we here report only the revisions in the N"
 417                         echo "branch from the common base, B."
 418                 fi
 419         fi
 420
 421         echo ""
 422         if [ -z "$rewind_only" ]; then
 423                 echo "Those revisions listed above that are new to this repository have"
 424                 echo "not appeared on any other notification email; so we list those"
 425                 echo "revisions in full, below."
 426
 427                 echo ""
 428                 echo $LOGBEGIN
 429                 show_new_revisions
 430
 431                 # XXX: Need a way of detecting whether git rev-list actually
 432                 # outputted anything, so that we can issue a "no new
 433                 # revisions added by this update" message
 434
 435                 echo $LOGEND
 436         else
 437                 echo "No new revisions were added by this update."
 438         fi
 439
 440         # The diffstat is shown from the old revision to the new revision.
 441         # This is to show the truth of what happened in this change.
 442         # There's no point showing the stat from the base to the new
 443         # revision because the base is effectively a random revision at this
 444         # point - the user will be interested in what this revision changed
 445         # - including the undoing of previous revisions in the case of
 446         # non-fast-forward updates.
 447         echo ""
 448         echo "Summary of changes:"
 449         git diff-tree --stat --summary --find-copies-harder $oldrev..$newrev
 450 }
 451
 452 #
 453 # Called for the deletion of a branch
 454 #
 455 generate_delete_branch_email()
 456 {
 457         echo "       was  $oldrev"
 458         echo ""
 459         echo $LOGEND
 460         git show -s --pretty=oneline $oldrev
 461         echo $LOGEND
 462 }
 463
 464 # --------------- Annotated tags
 465
 466 #
 467 # Called for the creation of an annotated tag
 468 #
 469 generate_create_atag_email()
 470 {
 471         echo "        at  $newrev ($newrev_type)"
 472
 473         generate_atag_email
 474 }
 475
 476 #
 477 # Called for the update of an annotated tag (this is probably a rare event
 478 # and may not even be allowed)
 479 #
 480 generate_update_atag_email()
 481 {
 482         echo "        to  $newrev ($newrev_type)"
 483         echo "      from  $oldrev (which is now obsolete)"
 484
 485         generate_atag_email
 486 }
 487
 488 #
 489 # Called when an annotated tag is created or changed
 490 #
 491 generate_atag_email()
 492 {
 493         # Use git for-each-ref to pull out the individual fields from the
 494         # tag
 495         eval $(git for-each-ref --shell --format='
 496         tagobject=%(*objectname)
 497         tagtype=%(*objecttype)
 498         tagger=%(taggername)
 499         tagged=%(taggerdate)' $refname
 500         )
 501
 502         echo "   tagging  $tagobject ($tagtype)"
 503         case "$tagtype" in
 504         commit)
 505
 506                 # If the tagged object is a commit, then we assume this is a
 507                 # release, and so we calculate which tag this tag is
 508                 # replacing
 509                 prevtag=$(git describe --abbrev=0 $newrev^ 2>/dev/null)
 510
 511                 if [ -n "$prevtag" ]; then
 512                         echo "  replaces  $prevtag"
 513                 fi
 514                 ;;
 515         *)
 516                 echo "    length  $(git cat-file -s $tagobject) bytes"
 517                 ;;
 518         esac
 519         echo " tagged by  $tagger"
 520         echo "        on  $tagged"
 521
 522         echo ""
 523         echo $LOGBEGIN
 524
 525         # Show the content of the tag message; this might contain a change
 526         # log or release notes so is worth displaying.
 527         git cat-file tag $newrev | sed -e '1,/^$/d'
 528
 529         echo ""
 530         case "$tagtype" in
 531         commit)
 532                 # Only commit tags make sense to have rev-list operations
 533                 # performed on them
 534                 if [ -n "$prevtag" ]; then
 535                         # Show changes since the previous release
 536                         git rev-list --pretty=short "$prevtag..$newrev" | git shortlog
 537                 else
 538                         # No previous tag, show all the changes since time
 539                         # began
 540                         git rev-list --pretty=short $newrev | git shortlog
 541                 fi
 542                 ;;
 543         *)
 544                 # XXX: Is there anything useful we can do for non-commit
 545                 # objects?
 546                 ;;
 547         esac
 548
 549         echo $LOGEND
 550 }
 551
 552 #
 553 # Called for the deletion of an annotated tag
 554 #
 555 generate_delete_atag_email()
 556 {
 557         echo "       was  $oldrev"
 558         echo ""
 559         echo $LOGEND
 560         git show -s --pretty=oneline $oldrev
 561         echo $LOGEND
 562 }
 563
 564 # --------------- General references
 565
 566 #
 567 # Called when any other type of reference is created (most likely a
 568 # non-annotated tag)
 569 #
 570 generate_create_general_email()
 571 {
 572         echo "        at  $newrev ($newrev_type)"
 573
 574         generate_general_email
 575 }
 576
 577 #
 578 # Called when any other type of reference is updated (most likely a
 579 # non-annotated tag)
 580 #
 581 generate_update_general_email()
 582 {
 583         echo "        to  $newrev ($newrev_type)"
 584         echo "      from  $oldrev"
 585
 586         generate_general_email
 587 }
 588
 589 #
 590 # Called for creation or update of any other type of reference
 591 #
 592 generate_general_email()
 593 {
 594         # Unannotated tags are more about marking a point than releasing a
 595         # version; therefore we don't do the shortlog summary that we do for
 596         # annotated tags above - we simply show that the point has been
 597         # marked, and print the log message for the marked point for
 598         # reference purposes
 599         #
 600         # Note this section also catches any other reference type (although
 601         # there aren't any) and deals with them in the same way.
 602
 603         echo ""
 604         if [ "$newrev_type" = "commit" ]; then
 605                 echo $LOGBEGIN
 606                 git show --no-color --root -s --pretty=medium $newrev
 607                 echo $LOGEND
 608         else
 609                 # What can we do here?  The tag marks an object that is not
 610                 # a commit, so there is no log for us to display.  It's
 611                 # probably not wise to output git cat-file as it could be a
 612                 # binary blob.  We'll just say how big it is
 613                 echo "$newrev is a $newrev_type, and is $(git cat-file -s $newrev) bytes long."
 614         fi
 615 }
 616
 617 #
 618 # Called for the deletion of any other type of reference
 619 #
 620 generate_delete_general_email()
 621 {
 622         echo "       was  $oldrev"
 623         echo ""
 624         echo $LOGEND
 625         git show -s --pretty=oneline $oldrev
 626         echo $LOGEND
 627 }
 628
 629
 630 # --------------- Miscellaneous utilities
 631
 632 #
 633 # Show new revisions as the user would like to see them in the email.
 634 #
 635 show_new_revisions()
 636 {
 637         # This shows all log entries that are not already covered by
 638         # another ref - i.e. commits that are now accessible from this
 639         # ref that were previously not accessible
 640         # (see generate_update_branch_email for the explanation of this
 641         # command)
 642
 643         # Revision range passed to rev-list differs for new vs. updated
 644         # branches.
 645         if [ "$change_type" = create ]
 646         then
 647                 # Show all revisions exclusive to this (new) branch.
 648                 revspec=$newrev
 649         else
 650                 # Branch update; show revisions not part of $oldrev.
 651                 revspec=$oldrev..$newrev
 652         fi
 653
 654         other_branches=$(git for-each-ref --format='%(refname)' refs/heads/ |
 655             grep -F -v $refname)
 656         git rev-parse --not $other_branches |
 657         if [ -z "$custom_showrev" ]
 658         then
 659                 git rev-list --pretty --stdin $revspec
 660         else
 661                 git rev-list --stdin $revspec |
 662                 while read onerev
 663                 do
 664                         eval $(printf "$custom_showrev" $onerev)
 665                 done
 666         fi
 667 }
 668
 669
 670 limit_lines()
 671 {
 672         lines=0
 673         skipped=0
 674         while IFS="" read -r line; do
 675                 lines=$((lines + 1))
 676                 if [ $lines -gt $1 ]; then
 677                         skipped=$((skipped + 1))
 678                 else
 679                         printf "%s\n" "$line"
 680                 fi
 681         done
 682         if [ $skipped -ne 0 ]; then
 683                 echo "... $skipped lines suppressed ..."
 684         fi
 685 }
 686
 687
 688 send_mail()
 689 {
 690         if [ -n "$envelopesender" ]; then
 691                 /usr/sbin/sendmail -t -f "$envelopesender"
 692         else
 693                 /usr/sbin/sendmail -t
 694         fi
 695 }
 696
 697 # ---------------------------- main()
 698
 699 # --- Constants
 700 LOGBEGIN="- Log -----------------------------------------------------------------"
 701 LOGEND="-----------------------------------------------------------------------"
 702
 703 # --- Config
 704 # Set GIT_DIR either from the working directory, or from the environment
 705 # variable.
 706 GIT_DIR=$(git rev-parse --git-dir 2>/dev/null)
 707 if [ -z "$GIT_DIR" ]; then
 708         echo >&2 "fatal: post-receive: GIT_DIR not set"
 709         exit 1
 710 fi
 711
 712 projectdesc=$(sed -ne '1p' "$GIT_DIR/description")
 713 # Check if the description is unchanged from it's default, and shorten it to
 714 # a more manageable length if it is
 715 if expr "$projectdesc" : "Unnamed repository.*$" >/dev/null
 716 then
 717         projectdesc="UNNAMED PROJECT"
 718 fi
 719
 720 recipients=$(git config hooks.mailinglist)
 721 announcerecipients=$(git config hooks.announcelist)
 722 envelopesender=$(git config hooks.envelopesender)
 723 emailprefix=$(git config hooks.emailprefix || echo '[SCM] ')
 724 custom_showrev=$(git config hooks.showrev)
 725 maxlines=$(git config hooks.emailmaxlines)
 726
 727 # --- Main loop
 728 # Allow dual mode: run from the command line just like the update hook, or
 729 # if no arguments are given then run as a hook script
 730 if [ -n "$1" -a -n "$2" -a -n "$3" ]; then
 731         # Output to the terminal in command line mode - if someone wanted to
 732         # resend an email; they could redirect the output to sendmail
 733         # themselves
 734         prep_for_email $2 $3 $1 && PAGER= generate_email
 735 else
 736         while read oldrev newrev refname
 737         do
 738                 prep_for_email $oldrev $newrev $refname || continue
 739                 generate_email $maxlines | send_mail
 740         done
 741 fi