taskd/mail.sh

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