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.
   6 #
   7 # NOTE: This script is no longer under active development.  There
   8 # is another script, git-multimail, which is more capable and
   9 # configurable and is largely backwards-compatible with this script;
  10 # please see "contrib/hooks/multimail/".  For instructions on how to
  11 # migrate from post-receive-email to git-multimail, please see
  12 # "README.migrate-from-post-receive-email" in that directory.
  13 #
  14 # This hook sends emails listing new revisions to the repository
  15 # introduced by the change being reported.  The rule is that (for
  16 # branch updates) each commit will appear on one email and one email
  17 # only.
  18 #
  19 # This hook is stored in the contrib/hooks directory.  Your distribution
  20 # will have put this somewhere standard.  You should make this script
  21 # executable then link to it in the repository you would like to use it in.
  22 # For example, on debian the hook is stored in
  23 # /usr/share/git-core/contrib/hooks/post-receive-email:
  24 #
  25 #  chmod a+x post-receive-email
  26 #  cd /path/to/your/repository.git
  27 #  ln -sf /usr/share/git-core/contrib/hooks/post-receive-email hooks/post-receive
  28 #
  29 # This hook script assumes it is enabled on the central repository of a
  30 # project, with all users pushing only to it and not between each other.  It
  31 # will still work if you don't operate in that style, but it would become
  32 # possible for the email to be from someone other than the person doing the
  33 # push.
  34 #
  35 # To help with debugging and use on pre-v1.5.1 git servers, this script will
  36 # also obey the interface of hooks/update, taking its arguments on the
  37 # command line.  Unfortunately, hooks/update is called once for each ref.
  38 # To avoid firing one email per ref, this script just prints its output to
  39 # the screen when used in this mode.  The output can then be redirected if
  40 # wanted.
  41 #
  42 # Config
  43 # ------
  44 # hooks.mailinglist
  45 #   This is the list that all pushes will go to; leave it blank to not send
  46 #   emails for every ref update.
  47 # hooks.announcelist
  48 #   This is the list that all pushes of annotated tags will go to.  Leave it
  49 #   blank to default to the mailinglist field.  The announce emails lists
  50 #   the short log summary of the changes since the last annotated tag.
  51 # hooks.envelopesender
  52 #   If set then the -f option is passed to sendmail to allow the envelope
  53 #   sender address to be set
  54 # hooks.emailprefix
  55 #   All emails have their subjects prefixed with this prefix, or "[SCM]"
  56 #   if emailprefix is unset, to aid filtering
  57 # hooks.showrev
  58 #   The shell command used to format each revision in the email, with
  59 #   "%s" replaced with the commit id.  Defaults to "git rev-list -1
  60 #   --pretty %s", displaying the commit id, author, date and log
  61 #   message.  To list full patches separated by a blank line, you
  62 #   could set this to "git show -C %s; echo".
  63 #   To list a gitweb/cgit URL *and* a full patch for each change set, use this:
  64 #     "t=%s; printf 'http://.../?id=%%s' \$t; echo;echo; git show -C \$t; echo"
  65 #   Be careful if "..." contains things that will be expanded by shell "eval"
  66 #   or printf.
  67 # hooks.emailmaxlines
  68 #   The maximum number of lines that should be included in the generated
  69 #   email body. If not specified, there is no limit.
  70 #   Lines beyond the limit are suppressed and counted, and a final
  71 #   line is added indicating the number of suppressed lines.
  72 # hooks.diffopts
  73 #   Alternate options for the git diff-tree invocation that shows changes.
  74 #   Default is "--stat --summary --find-copies-harder". Add -p to those
  75 #   options to include a unified diff of changes in addition to the usual
  76 #   summary output.
  77 #
  78 # Notes
  79 # -----
  80 # All emails include the headers "X-Git-Refname", "X-Git-Oldrev",
  81 # "X-Git-Newrev", and "X-Git-Reftype" to enable fine tuned filtering and
  82 # give information for debugging.
  83 #
  84
  85 # ---------------------------- Functions
  86
  87 #
  88 # Function to prepare for email generation. This decides what type
  89 # of update this is and whether an email should even be generated.
  90 #
  91 prep_for_email()
  92 {
  93         # --- Arguments
  94         oldrev=$(git rev-parse $1)
  95         newrev=$(git rev-parse $2)
  96         refname="$3"
  97
  98         # --- Interpret
  99         # 0000->1234 (create)
 100         # 1234->2345 (update)
 101         # 2345->0000 (delete)
 102         if expr "$oldrev" : '0*$' >/dev/null
 103         then
 104                 change_type="create"
 105         else
 106                 if expr "$newrev" : '0*$' >/dev/null
 107                 then
 108                         change_type="delete"
 109                 else
 110                         change_type="update"
 111                 fi
 112         fi
 113
 114         # --- Get the revision types
 115         newrev_type=$(git cat-file -t $newrev 2> /dev/null)
 116         oldrev_type=$(git cat-file -t "$oldrev" 2> /dev/null)
 117         case "$change_type" in
 118         create|update)
 119                 rev="$newrev"
 120                 rev_type="$newrev_type"
 121                 ;;
 122         delete)
 123                 rev="$oldrev"
 124                 rev_type="$oldrev_type"
 125                 ;;
 126         esac
 127
 128         # The revision type tells us what type the commit is, combined with
 129         # the location of the ref we can decide between
 130         #  - working branch
 131         #  - tracking branch
 132         #  - unannoted tag
 133         #  - annotated tag
 134         case "$refname","$rev_type" in
 135                 refs/tags/*,commit)
 136                         # un-annotated tag
 137                         refname_type="tag"
 138                         short_refname=${refname##refs/tags/}
 139                         ;;
 140                 refs/tags/*,tag)
 141                         # annotated tag
 142                         refname_type="annotated tag"
 143                         short_refname=${refname##refs/tags/}
 144                         # change recipients
 145                         if [ -n "$announcerecipients" ]; then
 146                                 recipients="$announcerecipients"
 147                         fi
 148                         ;;
 149                 refs/heads/*,commit)
 150                         # branch
 151                         refname_type="branch"
 152                         short_refname=${refname##refs/heads/}
 153                         ;;
 154                 refs/remotes/*,commit)
 155                         # tracking branch
 156                         refname_type="tracking branch"
 157                         short_refname=${refname##refs/remotes/}
 158                         echo >&2 "*** Push-update of tracking branch, $refname"
 159                         echo >&2 "***  - no email generated."
 160                         return 1
 161                         ;;
 162                 *)
 163                         # Anything else (is there anything else?)
 164                         echo >&2 "*** Unknown type of update to $refname ($rev_type)"
 165                         echo >&2 "***  - no email generated"
 166                         return 1
 167                         ;;
 168         esac
 169
 170         # Check if we've got anyone to send to
 171         if [ -z "$recipients" ]; then
 172                 case "$refname_type" in
 173                         "annotated tag")
 174                                 config_name="hooks.announcelist"
 175                                 ;;
 176                         *)
 177                                 config_name="hooks.mailinglist"
 178                                 ;;
 179                 esac
 180                 echo >&2 "*** $config_name is not set so no email will be sent"
 181                 echo >&2 "*** for $refname update $oldrev->$newrev"
 182                 return 1
 183         fi
 184
 185         return 0
 186 }
 187
 188 #
 189 # Top level email generation function.  This calls the appropriate
 190 # body-generation routine after outputting the common header.
 191 #
 192 # Note this function doesn't actually generate any email output, that is
 193 # taken care of by the functions it calls:
 194 #  - generate_email_header
 195 #  - generate_create_XXXX_email
 196 #  - generate_update_XXXX_email
 197 #  - generate_delete_XXXX_email
 198 #  - generate_email_footer
 199 #
 200 # Note also that this function cannot 'exit' from the script; when this
 201 # function is running (in hook script mode), the send_mail() function
 202 # is already executing in another process, connected via a pipe, and
 203 # if this function exits without, whatever has been generated to that
 204 # point will be sent as an email... even if nothing has been generated.
 205 #
 206 generate_email()
 207 {
 208         # Email parameters
 209         # The email subject will contain the best description of the ref
 210         # that we can build from the parameters
 211         describe=$(git describe $rev 2>/dev/null)
 212         if [ -z "$describe" ]; then
 213                 describe=$rev
 214         fi
 215
 216         generate_email_header
 217
 218         # Call the correct body generation function
 219         fn_name=general
 220         case "$refname_type" in
 221         "tracking branch"|branch)
 222                 fn_name=branch
 223                 ;;
 224         "annotated tag")
 225                 fn_name=atag
 226                 ;;
 227         esac
 228
 229         if [ -z "$maxlines" ]; then
 230                 generate_${change_type}_${fn_name}_email
 231         else
 232                 generate_${change_type}_${fn_name}_email | limit_lines $maxlines
 233         fi
 234
 235         generate_email_footer
 236 }
 237
 238 generate_email_header()
 239 {
 240         # --- Email (all stdout will be the email)
 241         # Generate header
 242         cat <<-EOF
 243         To: $recipients
 244         Subject: ${emailprefix}$projectdesc $refname_type $short_refname ${change_type}d. $describe
 245         X-Git-Refname: $refname
 246         X-Git-Reftype: $refname_type
 247         X-Git-Oldrev: $oldrev
 248         X-Git-Newrev: $newrev
 249         Auto-Submitted: auto-generated
 250
 251         This is an automated email from the git hooks/post-receive script. It was
 252         generated because a ref change was pushed to the repository containing
 253         the project "$projectdesc".
 254
 255         The $refname_type, $short_refname has been ${change_type}d
 256         EOF
 257 }
 258
 259 generate_email_footer()
 260 {
 261         SPACE=" "
 262         cat <<-EOF
 263
 264
 265         hooks/post-receive
 266         --${SPACE}
 267         $projectdesc
 268         EOF
 269 }
 270
 271 # --------------- Branches
 272
 273 #
 274 # Called for the creation of a branch
 275 #
 276 generate_create_branch_email()
 277 {
 278         # This is a new branch and so oldrev is not valid
 279         echo "        at  $newrev ($newrev_type)"
 280         echo ""
 281
 282         echo $LOGBEGIN
 283         show_new_revisions
 284         echo $LOGEND
 285 }
 286
 287 #
 288 # Called for the change of a pre-existing branch
 289 #
 290 generate_update_branch_email()
 291 {
 292         # Consider this:
 293         #   1 --- 2 --- O --- X --- 3 --- 4 --- N
 294         #
 295         # O is $oldrev for $refname
 296         # N is $newrev for $refname
 297         # X is a revision pointed to by some other ref, for which we may
 298         #   assume that an email has already been generated.
 299         # In this case we want to issue an email containing only revisions
 300         # 3, 4, and N.  Given (almost) by
 301         #
 302         #  git rev-list N ^O --not --all
 303         #
 304         # The reason for the "almost", is that the "--not --all" will take
 305         # precedence over the "N", and effectively will translate to
 306         #
 307         #  git rev-list N ^O ^X ^N
 308         #
 309         # So, we need to build up the list more carefully.  git rev-parse
 310         # will generate a list of revs that may be fed into git rev-list.
 311         # We can get it to make the "--not --all" part and then filter out
 312         # the "^N" with:
 313         #
 314         #  git rev-parse --not --all | grep -v N
 315         #
 316         # Then, using the --stdin switch to git rev-list we have effectively
 317         # manufactured
 318         #
 319         #  git rev-list N ^O ^X
 320         #
 321         # This leaves a problem when someone else updates the repository
 322         # while this script is running.  Their new value of the ref we're
 323         # working on would be included in the "--not --all" output; and as
 324         # our $newrev would be an ancestor of that commit, it would exclude
 325         # all of our commits.  What we really want is to exclude the current
 326         # value of $refname from the --not list, rather than N itself.  So:
 327         #
 328         #  git rev-parse --not --all | grep -v $(git rev-parse $refname)
 329         #
 330         # Get's us to something pretty safe (apart from the small time
 331         # between refname being read, and git rev-parse running - for that,
 332         # I give up)
 333         #
 334         #
 335         # Next problem, consider this:
 336         #   * --- B --- * --- O ($oldrev)
 337         #          \
 338         #           * --- X --- * --- N ($newrev)
 339         #
 340         # That is to say, there is no guarantee that oldrev is a strict
 341         # subset of newrev (it would have required a --force, but that's
 342         # allowed).  So, we can't simply say rev-list $oldrev..$newrev.
 343         # Instead we find the common base of the two revs and list from
 344         # there.
 345         #
 346         # As above, we need to take into account the presence of X; if
 347         # another branch is already in the repository and points at some of
 348         # the revisions that we are about to output - we don't want them.
 349         # The solution is as before: git rev-parse output filtered.
 350         #
 351         # Finally, tags: 1 --- 2 --- O --- T --- 3 --- 4 --- N
 352         #
 353         # Tags pushed into the repository generate nice shortlog emails that
 354         # summarise the commits between them and the previous tag.  However,
 355         # those emails don't include the full commit messages that we output
 356         # for a branch update.  Therefore we still want to output revisions
 357         # that have been output on a tag email.
 358         #
 359         # Luckily, git rev-parse includes just the tool.  Instead of using
 360         # "--all" we use "--branches"; this has the added benefit that
 361         # "remotes/" will be ignored as well.
 362
 363         # List all of the revisions that were removed by this update, in a
 364         # fast-forward update, this list will be empty, because rev-list O
 365         # ^N is empty.  For a non-fast-forward, O ^N is the list of removed
 366         # revisions
 367         fast_forward=""
 368         rev=""
 369         for rev in $(git rev-list $newrev..$oldrev)
 370         do
 371                 revtype=$(git cat-file -t "$rev")
 372                 echo "  discards  $rev ($revtype)"
 373         done
 374         if [ -z "$rev" ]; then
 375                 fast_forward=1
 376         fi
 377
 378         # List all the revisions from baserev to newrev in a kind of
 379         # "table-of-contents"; note this list can include revisions that
 380         # have already had notification emails and is present to show the
 381         # full detail of the change from rolling back the old revision to
 382         # the base revision and then forward to the new revision
 383         for rev in $(git rev-list $oldrev..$newrev)
 384         do
 385                 revtype=$(git cat-file -t "$rev")
 386                 echo "       via  $rev ($revtype)"
 387         done
 388
 389         if [ "$fast_forward" ]; then
 390                 echo "      from  $oldrev ($oldrev_type)"
 391         else
 392                 #  1. Existing revisions were removed.  In this case newrev
 393                 #     is a subset of oldrev - this is the reverse of a
 394                 #     fast-forward, a rewind
 395                 #  2. New revisions were added on top of an old revision,
 396                 #     this is a rewind and addition.
 397
 398                 # (1) certainly happened, (2) possibly.  When (2) hasn't
 399                 # happened, we set a flag to indicate that no log printout
 400                 # is required.
 401
 402                 echo ""
 403
 404                 # Find the common ancestor of the old and new revisions and
 405                 # compare it with newrev
 406                 baserev=$(git merge-base $oldrev $newrev)
 407                 rewind_only=""
 408                 if [ "$baserev" = "$newrev" ]; then
 409                         echo "This update discarded existing revisions and left the branch pointing at"
 410                         echo "a previous point in the repository history."
 411                         echo ""
 412                         echo " * -- * -- N ($newrev)"
 413                         echo "            \\"
 414                         echo "             O -- O -- O ($oldrev)"
 415                         echo ""
 416                         echo "The removed revisions are not necessarily gone - if another reference"
 417                         echo "still refers to them they will stay in the repository."
 418                         rewind_only=1
 419                 else
 420                         echo "This update added new revisions after undoing existing revisions.  That is"
 421                         echo "to say, the old revision is not a strict subset of the new revision.  This"
 422                         echo "situation occurs when you --force push a change and generate a repository"
 423                         echo "containing something like this:"
 424                         echo ""
 425                         echo " * -- * -- B -- O -- O -- O ($oldrev)"
 426                         echo "            \\"
 427                         echo "             N -- N -- N ($newrev)"
 428                         echo ""
 429                         echo "When this happens we assume that you've already had alert emails for all"
 430                         echo "of the O revisions, and so we here report only the revisions in the N"
 431                         echo "branch from the common base, B."
 432                 fi
 433         fi
 434
 435         echo ""
 436         if [ -z "$rewind_only" ]; then
 437                 echo "Those revisions listed above that are new to this repository have"
 438                 echo "not appeared on any other notification email; so we list those"
 439                 echo "revisions in full, below."
 440
 441                 echo ""
 442                 echo $LOGBEGIN
 443                 show_new_revisions
 444
 445                 # XXX: Need a way of detecting whether git rev-list actually
 446                 # outputted anything, so that we can issue a "no new
 447                 # revisions added by this update" message
 448
 449                 echo $LOGEND
 450         else
 451                 echo "No new revisions were added by this update."
 452         fi
 453
 454         # The diffstat is shown from the old revision to the new revision.
 455         # This is to show the truth of what happened in this change.
 456         # There's no point showing the stat from the base to the new
 457         # revision because the base is effectively a random revision at this
 458         # point - the user will be interested in what this revision changed
 459         # - including the undoing of previous revisions in the case of
 460         # non-fast-forward updates.
 461         echo ""
 462         echo "Summary of changes:"
 463         git diff-tree $diffopts $oldrev..$newrev
 464 }
 465
 466 #
 467 # Called for the deletion of a branch
 468 #
 469 generate_delete_branch_email()
 470 {
 471         echo "       was  $oldrev"
 472         echo ""
 473         echo $LOGBEGIN
 474         git diff-tree -s --always --encoding=UTF-8 --pretty=oneline $oldrev
 475         echo $LOGEND
 476 }
 477
 478 # --------------- Annotated tags
 479
 480 #
 481 # Called for the creation of an annotated tag
 482 #
 483 generate_create_atag_email()
 484 {
 485         echo "        at  $newrev ($newrev_type)"
 486
 487         generate_atag_email
 488 }
 489
 490 #
 491 # Called for the update of an annotated tag (this is probably a rare event
 492 # and may not even be allowed)
 493 #
 494 generate_update_atag_email()
 495 {
 496         echo "        to  $newrev ($newrev_type)"
 497         echo "      from  $oldrev (which is now obsolete)"
 498
 499         generate_atag_email
 500 }
 501
 502 #
 503 # Called when an annotated tag is created or changed
 504 #
 505 generate_atag_email()
 506 {
 507         # Use git for-each-ref to pull out the individual fields from the
 508         # tag
 509         eval $(git for-each-ref --shell --format='
 510         tagobject=%(*objectname)
 511         tagtype=%(*objecttype)
 512         tagger=%(taggername)
 513         tagged=%(taggerdate)' $refname
 514         )
 515
 516         echo "   tagging  $tagobject ($tagtype)"
 517         case "$tagtype" in
 518         commit)
 519
 520                 # If the tagged object is a commit, then we assume this is a
 521                 # release, and so we calculate which tag this tag is
 522                 # replacing
 523                 prevtag=$(git describe --abbrev=0 $newrev^ 2>/dev/null)
 524
 525                 if [ -n "$prevtag" ]; then
 526                         echo "  replaces  $prevtag"
 527                 fi
 528                 ;;
 529         *)
 530                 echo "    length  $(git cat-file -s $tagobject) bytes"
 531                 ;;
 532         esac
 533         echo " tagged by  $tagger"
 534         echo "        on  $tagged"
 535
 536         echo ""
 537         echo $LOGBEGIN
 538
 539         # Show the content of the tag message; this might contain a change
 540         # log or release notes so is worth displaying.
 541         git cat-file tag $newrev | sed -e '1,/^$/d'
 542
 543         echo ""
 544         case "$tagtype" in
 545         commit)
 546                 # Only commit tags make sense to have rev-list operations
 547                 # performed on them
 548                 if [ -n "$prevtag" ]; then
 549                         # Show changes since the previous release
 550                         git shortlog "$prevtag..$newrev"
 551                 else
 552                         # No previous tag, show all the changes since time
 553                         # began
 554                         git shortlog $newrev
 555                 fi
 556                 ;;
 557         *)
 558                 # XXX: Is there anything useful we can do for non-commit
 559                 # objects?
 560                 ;;
 561         esac
 562
 563         echo $LOGEND
 564 }
 565
 566 #
 567 # Called for the deletion of an annotated tag
 568 #
 569 generate_delete_atag_email()
 570 {
 571         echo "       was  $oldrev"
 572         echo ""
 573         echo $LOGBEGIN
 574         git diff-tree -s --always --encoding=UTF-8 --pretty=oneline $oldrev
 575         echo $LOGEND
 576 }
 577
 578 # --------------- General references
 579
 580 #
 581 # Called when any other type of reference is created (most likely a
 582 # non-annotated tag)
 583 #
 584 generate_create_general_email()
 585 {
 586         echo "        at  $newrev ($newrev_type)"
 587
 588         generate_general_email
 589 }
 590
 591 #
 592 # Called when any other type of reference is updated (most likely a
 593 # non-annotated tag)
 594 #
 595 generate_update_general_email()
 596 {
 597         echo "        to  $newrev ($newrev_type)"
 598         echo "      from  $oldrev"
 599
 600         generate_general_email
 601 }
 602
 603 #
 604 # Called for creation or update of any other type of reference
 605 #
 606 generate_general_email()
 607 {
 608         # Unannotated tags are more about marking a point than releasing a
 609         # version; therefore we don't do the shortlog summary that we do for
 610         # annotated tags above - we simply show that the point has been
 611         # marked, and print the log message for the marked point for
 612         # reference purposes
 613         #
 614         # Note this section also catches any other reference type (although
 615         # there aren't any) and deals with them in the same way.
 616
 617         echo ""
 618         if [ "$newrev_type" = "commit" ]; then
 619                 echo $LOGBEGIN
 620                 git diff-tree -s --always --encoding=UTF-8 --pretty=medium $newrev
 621                 echo $LOGEND
 622         else
 623                 # What can we do here?  The tag marks an object that is not
 624                 # a commit, so there is no log for us to display.  It's
 625                 # probably not wise to output git cat-file as it could be a
 626                 # binary blob.  We'll just say how big it is
 627                 echo "$newrev is a $newrev_type, and is $(git cat-file -s $newrev) bytes long."
 628         fi
 629 }
 630
 631 #
 632 # Called for the deletion of any other type of reference
 633 #
 634 generate_delete_general_email()
 635 {
 636         echo "       was  $oldrev"
 637         echo ""
 638         echo $LOGBEGIN
 639         git diff-tree -s --always --encoding=UTF-8 --pretty=oneline $oldrev
 640         echo $LOGEND
 641 }
 642
 643
 644 # --------------- Miscellaneous utilities
 645
 646 #
 647 # Show new revisions as the user would like to see them in the email.
 648 #
 649 show_new_revisions()
 650 {
 651         # This shows all log entries that are not already covered by
 652         # another ref - i.e. commits that are now accessible from this
 653         # ref that were previously not accessible
 654         # (see generate_update_branch_email for the explanation of this
 655         # command)
 656
 657         # Revision range passed to rev-list differs for new vs. updated
 658         # branches.
 659         if [ "$change_type" = create ]
 660         then
 661                 # Show all revisions exclusive to this (new) branch.
 662                 revspec=$newrev
 663         else
 664                 # Branch update; show revisions not part of $oldrev.
 665                 revspec=$oldrev..$newrev
 666         fi
 667
 668         other_branches=$(git for-each-ref --format='%(refname)' refs/heads/ |
 669             grep -F -v $refname)
 670         git rev-parse --not $other_branches |
 671         if [ -z "$custom_showrev" ]
 672         then
 673                 git rev-list --pretty --stdin $revspec
 674         else
 675                 git rev-list --stdin $revspec |
 676                 while read onerev
 677                 do
 678                         eval $(printf "$custom_showrev" $onerev)
 679                 done
 680         fi
 681 }
 682
 683
 684 limit_lines()
 685 {
 686         lines=0
 687         skipped=0
 688         while IFS="" read -r line; do
 689                 lines=$((lines + 1))
 690                 if [ $lines -gt $1 ]; then
 691                         skipped=$((skipped + 1))
 692                 else
 693                         printf "%s\n" "$line"
 694                 fi
 695         done
 696         if [ $skipped -ne 0 ]; then
 697                 echo "... $skipped lines suppressed ..."
 698         fi
 699 }
 700
 701
 702 send_mail()
 703 {
 704         if [ -n "$envelopesender" ]; then
 705                 /usr/sbin/sendmail -t -f "$envelopesender"
 706         else
 707                 /usr/sbin/sendmail -t
 708         fi
 709 }
 710
 711 # ---------------------------- main()
 712
 713 # --- Constants
 714 LOGBEGIN="- Log -----------------------------------------------------------------"
 715 LOGEND="-----------------------------------------------------------------------"
 716
 717 # --- Config
 718 # Set GIT_DIR either from the working directory, or from the environment
 719 # variable.
 720 GIT_DIR=$(git rev-parse --git-dir 2>/dev/null)
 721 if [ -z "$GIT_DIR" ]; then
 722         echo >&2 "fatal: post-receive: GIT_DIR not set"
 723         exit 1
 724 fi
 725
 726 projectdesc=$(sed -ne '1p' "$GIT_DIR/description" 2>/dev/null)
 727 # Check if the description is unchanged from it's default, and shorten it to
 728 # a more manageable length if it is
 729 if expr "$projectdesc" : "Unnamed repository.*$" >/dev/null
 730 then
 731         projectdesc="UNNAMED PROJECT"
 732 fi
 733
 734 recipients=$(git config hooks.mailinglist)
 735 announcerecipients=$(git config hooks.announcelist)
 736 envelopesender=$(git config hooks.envelopesender)
 737 emailprefix=$(git config hooks.emailprefix || echo '[SCM] ')
 738 custom_showrev=$(git config hooks.showrev)
 739 maxlines=$(git config hooks.emailmaxlines)
 740 diffopts=$(git config hooks.diffopts)
 741 : ${diffopts:="--stat --summary --find-copies-harder"}
 742
 743 # --- Main loop
 744 # Allow dual mode: run from the command line just like the update hook, or
 745 # if no arguments are given then run as a hook script
 746 if [ -n "$1" -a -n "$2" -a -n "$3" ]; then
 747         # Output to the terminal in command line mode - if someone wanted to
 748         # resend an email; they could redirect the output to sendmail
 749         # themselves
 750         prep_for_email $2 $3 $1 && PAGER= generate_email
 751 else
 752         while read oldrev newrev refname
 753         do
 754                 prep_for_email $oldrev $newrev $refname || continue
 755                 generate_email $maxlines | send_mail
 756         done
 757 fi