tests/utils/tap-driver.sh

   1 #! /bin/sh
   2 # Copyright (C) 2011-2013 Free Software Foundation, Inc.
   3 #
   4 # This program is free software; you can redistribute it and/or modify
   5 # it under the terms of the GNU General Public License as published by
   6 # the Free Software Foundation; either version 2, or (at your option)
   7 # any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 # As a special exception to the GNU General Public License, if you
  18 # distribute this file as part of a program that contains a
  19 # configuration script generated by Autoconf, you may include it under
  20 # the same distribution terms that you use for the rest of that program.
  21
  22 # This file is maintained in Automake, please report
  23 # bugs to <bug-automake@gnu.org> or send patches to
  24 # <automake-patches@gnu.org>.
  25
  26 scriptversion=2013-12-23.17; # UTC
  27
  28 # Make unconditional expansion of undefined variables an error.  This
  29 # helps a lot in preventing typo-related bugs.
  30 set -u
  31
  32 me=tap-driver.sh
  33
  34 fatal ()
  35 {
  36   echo "$me: fatal: $*" >&2
  37   exit 1
  38 }
  39
  40 usage_error ()
  41 {
  42   echo "$me: $*" >&2
  43   print_usage >&2
  44   exit 2
  45 }
  46
  47 print_usage ()
  48 {
  49   cat <<END
  50 Usage:
  51   tap-driver.sh --test-name=NAME --log-file=PATH --trs-file=PATH
  52                 [--expect-failure={yes|no}] [--color-tests={yes|no}]
  53                 [--enable-hard-errors={yes|no}] [--ignore-exit]
  54                 [--diagnostic-string=STRING] [--merge|--no-merge]
  55                 [--comments|--no-comments] [--post-script] [--] TEST-COMMAND
  56 The '--test-name', '-log-file' and '--trs-file' options are mandatory.
  57 END
  58 }
  59
  60 # TODO: better error handling in option parsing (in particular, ensure
  61 # TODO: $log_file, $trs_file and $test_name are defined).
  62 test_name= # Used for reporting.
  63 log_file=  # Where to save the result and output of the test script.
  64 trs_file=  # Where to save the metadata of the test run.
  65 post_script= # Script to be run after the test.
  66 expect_failure=0
  67 color_tests=0
  68 merge=0
  69 ignore_exit=0
  70 comments=0
  71 diag_string='#'
  72 while test $# -gt 0; do
  73   case $1 in
  74   --help) print_usage; exit $?;;
  75   --version) echo "$me $scriptversion"; exit $?;;
  76   --test-name) test_name=$2; shift;;
  77   --log-file) log_file=$2; shift;;
  78   --trs-file) trs_file=$2; shift;;
  79   --color-tests) color_tests=$2; shift;;
  80   --expect-failure) expect_failure=$2; shift;;
  81   --enable-hard-errors) shift;; # No-op.
  82   --merge) merge=1;;
  83   --no-merge) merge=0;;
  84   --ignore-exit) ignore_exit=1;;
  85   --comments) comments=1;;
  86   --no-comments) comments=0;;
  87   --diagnostic-string) diag_string=$2; shift;;
  88   --post-script) post_script=$2; shift;;
  89   --) shift; break;;
  90   -*) usage_error "invalid option: '$1'";;
  91   esac
  92   shift
  93 done
  94
  95 test $# -gt 0 || usage_error "missing test command"
  96
  97 case $expect_failure in
  98   yes) expect_failure=1;;
  99     *) expect_failure=0;;
 100 esac
 101
 102 if test $color_tests = yes; then
 103   init_colors='
 104     color_map["red"]="\e[0;31m" # Red.
 105     color_map["grn"]="\e[0;32m" # Green.
 106     color_map["lgn"]="\e[1;32m" # Light green.
 107     color_map["blu"]="\e[1;34m" # Blue.
 108     color_map["mgn"]="\e[0;35m" # Magenta.
 109     color_map["std"]="\e[m"     # No color.
 110     color_for_result["ERROR"] = "mgn"
 111     color_for_result["PASS"]  = "grn"
 112     color_for_result["XPASS"] = "red"
 113     color_for_result["FAIL"]  = "red"
 114     color_for_result["XFAIL"] = "lgn"
 115     color_for_result["SKIP"]  = "blu"'
 116 else
 117   init_colors=''
 118 fi
 119
 120 TIME_SCRIPT="$(realpath -e -- "$(dirname "$0")")/tap/clock"
 121
 122 # :; is there to work around a bug in bash 3.2 (and earlier) which
 123 # does not always set '$?' properly on redirection failure.
 124 # See the Autoconf manual for more details.
 125 :;{
 126   (
 127     # Ignore common signals (in this subshell only!), to avoid potential
 128     # problems with Korn shells.  Some Korn shells are known to propagate
 129     # to themselves signals that have killed a child process they were
 130     # waiting for; this is done at least for SIGINT (and usually only for
 131     # it, in truth).  Without the `trap' below, such a behaviour could
 132     # cause a premature exit in the current subshell, e.g., in case the
 133     # test command it runs gets terminated by a SIGINT.  Thus, the awk
 134     # script we are piping into would never seen the exit status it
 135     # expects on its last input line (which is displayed below by the
 136     # last `echo $?' statement), and would thus die reporting an internal
 137     # error.
 138     # For more information, see the Autoconf manual and the threads:
 139     # <http://lists.gnu.org/archive/html/bug-autoconf/2011-09/msg00004.html>
 140     # <http://mail.opensolaris.org/pipermail/ksh93-integration-discuss/2009-February/004121.html>
 141     trap : 1 3 2 13 15
 142     if test $merge -gt 0; then
 143       exec 2>&1
 144     else
 145       exec 2>&3
 146     fi
 147     # Since stderr and stdout may go to the same file and the script
 148     # may run in situations with different types of buffering, enforce
 149     # line buffering for both FDs. This helps to prevent interleave between
 150     # the outputs in the resulting file for half written lines, eg.
 151     #   ok 93 - Tes# PERROR - xxxx
 152     #   t some function
 153     if [ "${LTTNG_TESTS_TAP_AUTOTIME:-}" != 0 ]; then
 154       stdbuf -eL -oL -- "$@"
 155     else
 156       "$@"
 157     fi
 158     echo $?
 159   ) | LC_ALL=C ${AM_TAP_AWK-awk} \
 160         -v me="$me" \
 161         -v test_script_name="$test_name" \
 162         -v log_file="$log_file" \
 163         -v trs_file="$trs_file" \
 164         -v expect_failure="$expect_failure" \
 165         -v merge="$merge" \
 166         -v ignore_exit="$ignore_exit" \
 167         -v comments="$comments" \
 168         -v diag_string="$diag_string" \
 169         -v time_script="${TIME_SCRIPT}" \
 170 '
 171 # TODO: the usages of "cat >&3" below could be optimized when using
 172 #       GNU awk, and/on on systems that supports /dev/fd/.
 173
 174 # Implementation note: in what follows, `result_obj` will be an
 175 # associative array that (partly) simulates a TAP result object
 176 # from the `TAP::Parser` perl module.
 177
 178 ## ----------- ##
 179 ##  FUNCTIONS  ##
 180 ## ----------- ##
 181
 182 function fatal(msg)
 183 {
 184   print me ": " msg | "cat >&2"
 185   exit 1
 186 }
 187
 188 function abort(where)
 189 {
 190   fatal("internal error " where)
 191 }
 192
 193 # Convert a boolean to a "yes"/"no" string.
 194 function yn(bool)
 195 {
 196   return bool ? "yes" : "no";
 197 }
 198
 199 function add_test_result(result)
 200 {
 201   if (!test_results_index)
 202     test_results_index = 0
 203   test_results_list[test_results_index] = result
 204   test_results_index += 1
 205   test_results_seen[result] = 1;
 206 }
 207
 208 # Whether the test script should be re-run by "make recheck".
 209 function must_recheck()
 210 {
 211   for (k in test_results_seen)
 212     if (k != "XFAIL" && k != "PASS" && k != "SKIP")
 213       return 1
 214   return 0
 215 }
 216
 217 # Whether the content of the log file associated to this test should
 218 # be copied into the "global" test-suite.log.
 219 function copy_in_global_log()
 220 {
 221   for (k in test_results_seen)
 222     if (k != "PASS")
 223       return 1
 224   return 0
 225 }
 226
 227 function gettime_ns(    r)
 228 {
 229    r = ""
 230    if (time_script | getline r) {
 231      r = r
 232    }
 233    close(time_script)
 234    return sprintf("%f", r)
 235 }
 236
 237 function get_global_test_result()
 238 {
 239     if ("ERROR" in test_results_seen)
 240       return "ERROR"
 241     if ("FAIL" in test_results_seen || "XPASS" in test_results_seen)
 242       return "FAIL"
 243     all_skipped = 1
 244     for (k in test_results_seen)
 245       if (k != "SKIP")
 246         all_skipped = 0
 247     if (all_skipped)
 248       return "SKIP"
 249     return "PASS";
 250 }
 251
 252 function stringify_result_obj(result_obj)
 253 {
 254   if (result_obj["is_unplanned"] || result_obj["number"] != testno)
 255     return "ERROR"
 256
 257   if (plan_seen == LATE_PLAN)
 258     return "ERROR"
 259
 260   if (result_obj["directive"] == "TODO")
 261     return result_obj["is_ok"] ? "XPASS" : "XFAIL"
 262
 263   if (result_obj["directive"] == "SKIP")
 264     return result_obj["is_ok"] ? "SKIP" : COOKED_FAIL;
 265
 266   if (length(result_obj["directive"]))
 267       abort("in function stringify_result_obj()")
 268
 269   return result_obj["is_ok"] ? COOKED_PASS : COOKED_FAIL
 270 }
 271
 272 function decorate_result(result)
 273 {
 274   color_name = color_for_result[result]
 275   if (color_name)
 276     return color_map[color_name] "" result "" color_map["std"]
 277   # If we are not using colorized output, or if we do not know how
 278   # to colorize the given result, we should return it unchanged.
 279   return result
 280 }
 281
 282 function report(result, details)
 283 {
 284   if (result ~ /^(X?(PASS|FAIL)|SKIP|ERROR)/)
 285     {
 286       msg = ": " test_script_name
 287       add_test_result(result)
 288     }
 289   else if (result == "#")
 290     {
 291       msg = " " test_script_name ":"
 292     }
 293   else
 294     {
 295       abort("in function report()")
 296     }
 297   if (length(details))
 298     msg = msg " " details
 299   # Output on console might be colorized.
 300   print decorate_result(result) msg
 301   # Flush stdout after each test result, this is useful when stdout
 302   # is buffered, for example in a CI system.
 303   fflush()
 304   # Log the result in the log file too, to help debugging (this is
 305   # especially true when said result is a TAP error or "Bail out!").
 306   print result msg | "cat >&3";
 307 }
 308
 309 function testsuite_error(error_message)
 310 {
 311   report("ERROR", "- " error_message)
 312 }
 313
 314 function handle_tap_result()
 315 {
 316   details = result_obj["number"];
 317   if (length(result_obj["description"]))
 318     details = details " " result_obj["description"]
 319
 320   if (plan_seen == LATE_PLAN)
 321     {
 322       details = details " # AFTER LATE PLAN";
 323     }
 324   else if (result_obj["is_unplanned"])
 325     {
 326        details = details " # UNPLANNED";
 327     }
 328   else if (result_obj["number"] != testno)
 329     {
 330        details = sprintf("%s # OUT-OF-ORDER (expecting %d)",
 331                          details, testno);
 332     }
 333   else if (result_obj["directive"])
 334     {
 335       details = details " # " result_obj["directive"];
 336       if (length(result_obj["explanation"]))
 337         details = details " " result_obj["explanation"]
 338     }
 339
 340   report(stringify_result_obj(result_obj), details)
 341 }
 342
 343 # `skip_reason` should be empty whenever planned > 0.
 344 function handle_tap_plan(planned, skip_reason)
 345 {
 346   planned += 0 # Avoid getting confused if, say, `planned` is "00"
 347   if (length(skip_reason) && planned > 0)
 348     abort("in function handle_tap_plan()")
 349   if (plan_seen)
 350     {
 351       # Error, only one plan per stream is acceptable.
 352       testsuite_error("multiple test plans")
 353       return;
 354     }
 355   planned_tests = planned
 356   # The TAP plan can come before or after *all* the TAP results; we speak
 357   # respectively of an "early" or a "late" plan.  If we see the plan line
 358   # after at least one TAP result has been seen, assume we have a late
 359   # plan; in this case, any further test result seen after the plan will
 360   # be flagged as an error.
 361   plan_seen = (testno >= 1 ? LATE_PLAN : EARLY_PLAN)
 362   # If testno > 0, we have an error ("too many tests run") that will be
 363   # automatically dealt with later, so do not worry about it here.  If
 364   # $plan_seen is true, we have an error due to a repeated plan, and that
 365   # has already been dealt with above.  Otherwise, we have a valid "plan
 366   # with SKIP" specification, and should report it as a particular kind
 367   # of SKIP result.
 368   if (planned == 0 && testno == 0)
 369     {
 370       if (length(skip_reason))
 371         skip_reason = "- "  skip_reason;
 372       report("SKIP", skip_reason);
 373     }
 374 }
 375
 376 function extract_tap_comment(line)
 377 {
 378   if (index(line, diag_string) == 1)
 379     {
 380       # Strip leading `diag_string` from `line`.
 381       line = substr(line, length(diag_string) + 1)
 382       # And strip any leading and trailing whitespace left.
 383       sub("^[ \t]*", "", line)
 384       sub("[ \t]*$", "", line)
 385       # Return what is left (if any).
 386       return line;
 387     }
 388   return "";
 389 }
 390
 391 # When this function is called, we know that line is a TAP result line,
 392 # so that it matches the (perl) RE "^(not )?ok\b".
 393 function setup_result_obj(line)
 394 {
 395   # Get the result, and remove it from the line.
 396   result_obj["is_ok"] = (substr(line, 1, 2) == "ok" ? 1 : 0)
 397   sub("^(not )?ok[ \t]*", "", line)
 398
 399   # If the result has an explicit number, get it and strip it; otherwise,
 400   # automatically assing the next progresive number to it.
 401   if (line ~ /^[0-9]+$/ || line ~ /^[0-9]+[^a-zA-Z0-9_]/)
 402     {
 403       match(line, "^[0-9]+")
 404       # The final `+ 0` is to normalize numbers with leading zeros.
 405       result_obj["number"] = substr(line, 1, RLENGTH) + 0
 406       line = substr(line, RLENGTH + 1)
 407     }
 408   else
 409     {
 410       result_obj["number"] = testno
 411     }
 412
 413   if (plan_seen == LATE_PLAN)
 414     # No further test results are acceptable after a "late" TAP plan
 415     # has been seen.
 416     result_obj["is_unplanned"] = 1
 417   else if (plan_seen && testno > planned_tests)
 418     result_obj["is_unplanned"] = 1
 419   else
 420     result_obj["is_unplanned"] = 0
 421
 422   # Strip trailing and leading whitespace.
 423   sub("^[ \t]*", "", line)
 424   sub("[ \t]*$", "", line)
 425
 426   # This will have to be corrected if we have a "TODO"/"SKIP" directive.
 427   result_obj["description"] = line
 428   result_obj["directive"] = ""
 429   result_obj["explanation"] = ""
 430
 431   if (index(line, "#") == 0)
 432     return # No possible directive, nothing more to do.
 433
 434   # Directives are case-insensitive.
 435   rx = "[ \t]*#[ \t]*([tT][oO][dD][oO]|[sS][kK][iI][pP])[ \t]*"
 436
 437   # See whether we have the directive, and if yes, where.
 438   pos = match(line, rx "$")
 439   if (!pos)
 440     pos = match(line, rx "[^a-zA-Z0-9_]")
 441
 442   # If there was no TAP directive, we have nothing more to do.
 443   if (!pos)
 444     return
 445
 446   # Let`s now see if the TAP directive has been escaped.  For example:
 447   #  escaped:     ok \# SKIP
 448   #  not escaped: ok \\# SKIP
 449   #  escaped:     ok \\\\\# SKIP
 450   #  not escaped: ok \ # SKIP
 451   if (substr(line, pos, 1) == "#")
 452     {
 453       bslash_count = 0
 454       for (i = pos; i > 1 && substr(line, i - 1, 1) == "\\"; i--)
 455         bslash_count += 1
 456       if (bslash_count % 2)
 457         return # Directive was escaped.
 458     }
 459
 460   # Strip the directive and its explanation (if any) from the test
 461   # description.
 462   result_obj["description"] = substr(line, 1, pos - 1)
 463   # Now remove the test description from the line, that has been dealt
 464   # with already.
 465   line = substr(line, pos)
 466   # Strip the directive, and save its value (normalized to upper case).
 467   sub("^[ \t]*#[ \t]*", "", line)
 468   result_obj["directive"] = toupper(substr(line, 1, 4))
 469   line = substr(line, 5)
 470   # Now get the explanation for the directive (if any), with leading
 471   # and trailing whitespace removed.
 472   sub("^[ \t]*", "", line)
 473   sub("[ \t]*$", "", line)
 474   result_obj["explanation"] = line
 475 }
 476
 477 function get_test_exit_message(status)
 478 {
 479   if (status == 0)
 480     return ""
 481   if (status !~ /^[1-9][0-9]*$/)
 482     abort("getting exit status")
 483   if (status < 127)
 484     exit_details = ""
 485   else if (status == 127)
 486     exit_details = " (command not found?)"
 487   else if (status >= 128 && status <= 255)
 488     exit_details = sprintf(" (terminated by signal %d?)", status - 128)
 489   else if (status > 256 && status <= 384)
 490     # We used to report an "abnormal termination" here, but some Korn
 491     # shells, when a child process die due to signal number n, can leave
 492     # in $? an exit status of 256+n instead of the more standard 128+n.
 493     # Apparently, both behaviours are allowed by POSIX (2008), so be
 494     # prepared to handle them both.  See also Austing Group report ID
 495     # 0000051 <http://www.austingroupbugs.net/view.php?id=51>
 496     exit_details = sprintf(" (terminated by signal %d?)", status - 256)
 497   else
 498     # Never seen in practice.
 499     exit_details = " (abnormal termination)"
 500   return sprintf("exited with status %d%s", status, exit_details)
 501 }
 502
 503 function write_test_results()
 504 {
 505   print ":global-test-result: " get_global_test_result() > trs_file
 506   print ":recheck: "  yn(must_recheck()) > trs_file
 507   print ":copy-in-global-log: " yn(copy_in_global_log()) > trs_file
 508   print ":time-taken: " sprintf("%f", gettime_ns() - TIME_START) > trs_file
 509   for (i = 0; i < test_results_index; i += 1)
 510     print ":test-result: " test_results_list[i] > trs_file
 511   close(trs_file);
 512 }
 513
 514 BEGIN {
 515
 516 ## ------- ##
 517 ##  SETUP  ##
 518 ## ------- ##
 519
 520 '"$init_colors"'
 521
 522 # Properly initialized once the TAP plan is seen.
 523 planned_tests = 0
 524
 525 COOKED_PASS = expect_failure ? "XPASS": "PASS";
 526 COOKED_FAIL = expect_failure ? "XFAIL": "FAIL";
 527
 528 # Enumeration-like constants to remember which kind of plan (if any)
 529 # has been seen.  It is important that NO_PLAN evaluates "false" as
 530 # a boolean.
 531 NO_PLAN = 0
 532 EARLY_PLAN = 1
 533 LATE_PLAN = 2
 534
 535 testno = 0     # Number of test results seen so far.
 536 bailed_out = 0 # Whether a "Bail out!" directive has been seen.
 537
 538 # Whether the TAP plan has been seen or not, and if yes, which kind
 539 # it is ("early" is seen before any test result, "late" otherwise).
 540 plan_seen = NO_PLAN
 541
 542 TIME_START = gettime_ns();
 543 ## --------- ##
 544 ##  PARSING  ##
 545 ## --------- ##
 546
 547 is_first_read = 1
 548
 549 while (1)
 550   {
 551     # Involutions required so that we are able to read the exit status
 552     # from the last input line.
 553     st = getline
 554     if (st < 0) # I/O error.
 555       fatal("I/O error while reading from input stream")
 556     else if (st == 0) # End-of-input
 557       {
 558         if (is_first_read)
 559           abort("in input loop: only one input line")
 560         break
 561       }
 562     if (is_first_read)
 563       {
 564         is_first_read = 0
 565         nextline = $0
 566         continue
 567       }
 568     else
 569       {
 570         curline = nextline
 571         nextline = $0
 572         $0 = curline
 573       }
 574     # Copy any input line verbatim into the log file.
 575     print | "cat >&3"
 576     # Parsing of TAP input should stop after a "Bail out!" directive.
 577     if (bailed_out)
 578       continue
 579
 580     # TAP test result.
 581     if ($0 ~ /^(not )?ok$/ || $0 ~ /^(not )?ok[^a-zA-Z0-9_]/)
 582       {
 583         testno += 1
 584         setup_result_obj($0)
 585         handle_tap_result()
 586       }
 587     # TAP plan (normal or "SKIP" without explanation).
 588     else if ($0 ~ /^1\.\.[0-9]+[ \t]*$/)
 589       {
 590         # The next two lines will put the number of planned tests in $0.
 591         sub("^1\\.\\.", "")
 592         sub("[^0-9]*$", "")
 593         handle_tap_plan($0, "")
 594         continue
 595       }
 596     # TAP "SKIP" plan, with an explanation.
 597     else if ($0 ~ /^1\.\.0+[ \t]*#/)
 598       {
 599         # The next lines will put the skip explanation in $0, stripping
 600         # any leading and trailing whitespace.  This is a little more
 601         # tricky in truth, since we want to also strip a potential leading
 602         # "SKIP" string from the message.
 603         sub("^[^#]*#[ \t]*(SKIP[: \t][ \t]*)?", "")
 604         sub("[ \t]*$", "");
 605         handle_tap_plan(0, $0)
 606       }
 607     # "Bail out!" magic.
 608     # Older versions of prove and TAP::Harness (e.g., 3.17) did not
 609     # recognize a "Bail out!" directive when preceded by leading
 610     # whitespace, but more modern versions (e.g., 3.23) do.  So we
 611     # emulate the latter, "more modern" behaviour.
 612     else if ($0 ~ /^[ \t]*Bail out!/)
 613       {
 614         bailed_out = 1
 615         # Get the bailout message (if any), with leading and trailing
 616         # whitespace stripped.  The message remains stored in `$0`.
 617         sub("^[ \t]*Bail out![ \t]*", "");
 618         sub("[ \t]*$", "");
 619         # Format the error message for the
 620         bailout_message = "Bail out!"
 621         if (length($0))
 622           bailout_message = bailout_message " " $0
 623         testsuite_error(bailout_message)
 624       }
 625     # Maybe we have too look for dianogtic comments too.
 626     else if (comments != 0)
 627       {
 628         comment = extract_tap_comment($0);
 629         if (length(comment))
 630           report("#", comment);
 631       }
 632   }
 633
 634 ## -------- ##
 635 ##  FINISH  ##
 636 ## -------- ##
 637
 638 # A "Bail out!" directive should cause us to ignore any following TAP
 639 # error, as well as a non-zero exit status from the TAP producer.
 640 if (!bailed_out)
 641   {
 642     if (!plan_seen)
 643       {
 644         testsuite_error("missing test plan")
 645       }
 646     else if (planned_tests != testno)
 647       {
 648         bad_amount = testno > planned_tests ? "many" : "few"
 649         testsuite_error(sprintf("too %s tests run (expected %d, got %d)",
 650                                 bad_amount, planned_tests, testno))
 651       }
 652     if (!ignore_exit)
 653       {
 654         # Fetch exit status from the last line.
 655         exit_message = get_test_exit_message(nextline)
 656         if (exit_message)
 657           testsuite_error(exit_message)
 658       }
 659   }
 660
 661 write_test_results()
 662
 663 exit 0
 664
 665 } # End of "BEGIN" block.
 666 '
 667
 668 # TODO: document that we consume the file descriptor 3 :-(
 669 } 3>"$log_file"
 670
 671 test $? -eq 0 || fatal "I/O or internal error"
 672
 673 if test ! -z $post_script ; then
 674   $post_script
 675   test $? -eq 0 || fatal "Post script returned an error. See $log_file"
 676 fi
 677
 678 # Local Variables:
 679 # mode: shell-script
 680 # sh-indentation: 2
 681 # eval: (add-hook 'write-file-hooks 'time-stamp)
 682 # time-stamp-start: "scriptversion="
 683 # time-stamp-format: "%:y-%02m-%02d.%02H"
 684 # time-stamp-time-zone: "UTC"
 685 # time-stamp-end: "; # UTC"
 686 # End: