lisp/time-stamp.el

   1 ;;; time-stamp.el --- Maintain last change time stamps in files edited by Emacs
   2
   3 ;; Copyright 1989, 1993, 1994, 1995, 1997 Free Software Foundation, Inc.
   4
   5 ;; Maintainer's Time-stamp: <1999-06-26 15:12:53 gildea>
   6 ;; Maintainer: Stephen Gildea <gildea@alum.mit.edu>
   7 ;; Keywords: tools
   8
   9 ;; This file is free software; you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation; either version 2, or (at your option)
  12 ;; any later version.
  13
  14 ;; This file is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  22 ;; Boston, MA 02111-1307, USA.
  23
  24 ;;; Commentary:
  25
  26 ;; A template in a file can be updated with a new time stamp when
  27 ;; you save the file.  For example:
  28 ;;     static char *ts = "sdmain.c Time-stamp: <1996-08-13 10:20:51 gildea>";
  29 ;; See the top of `time-stamp.el' for another example.
  30
  31 ;; To use time-stamping, add this line to your .emacs file:
  32 ;;     (add-hook 'write-file-hooks 'time-stamp)
  33 ;; Now any time-stamp templates in your files will be updated automatically.
  34
  35 ;; See the documentation for the functions `time-stamp'
  36 ;; and `time-stamp-toggle-active' for details.
  37
  38 ;;; Code:
  39
  40 (defgroup time-stamp nil
  41   "Maintain last change time stamps in files edited by Emacs."
  42   :group 'data
  43   :group 'extensions)
  44
  45 (defcustom time-stamp-format "%:y-%02m-%02d %02H:%02M:%02S %u"
  46   "*Format of the string inserted by \\[time-stamp].
  47 The value may be a string or a list.  Lists are supported only for
  48 backward compatibility; see variable `time-stamp-old-format-warn'.
  49
  50 A string is used verbatim except for character sequences beginning with %:
  51
  52 %:a  weekday name: `Monday'.            %#A gives uppercase: `MONDAY'
  53 %3a  abbreviated weekday: `Mon'.        %3A gives uppercase: `MON'
  54 %:b  month name: `January'.             %#B gives uppercase: `JANUARY'
  55 %3b  abbreviated month: `Jan'.          %3B gives uppercase: `JAN'
  56 %02d day of month
  57 %02H 24-hour clock hour
  58 %02I 12-hour clock hour
  59 %02m month number
  60 %02M minute
  61 %#p  `am' or `pm'.                      %P  gives uppercase: `AM' or `PM'
  62 %02S seconds
  63 %w   day number of week, Sunday is 0
  64 %02y 2-digit year: `97'                 %:y 4-digit year: `1997'
  65 %z   time zone name: `est'.             %Z  gives uppercase: `EST'
  66
  67 Non-date items:
  68 %%   a literal percent character: `%'
  69 %f   file name without directory        %F  gives absolute pathname
  70 %s   system name
  71 %u   user's login name                  %U  user's full name
  72 %h   mail host name
  73
  74 Decimal digits between the % and the type character specify the
  75 field width.  Strings are truncated on the right; years on the left.
  76 A leading zero in the field width zero-fills a number.
  77
  78 For example, to get the format used by the `date' command,
  79 use \"%3a %3b %2d %02H:%02M:%02S %Z %:y\".
  80
  81 In the future these formats will be aligned more with `format-time-string'.
  82 Because of this transition, the default padding for numeric formats will
  83 change in a future version.  Therefore either a padding width should be
  84 specified, or the : modifier should be used to explicitly request the
  85 historical default."
  86   :type 'string
  87   :group 'time-stamp)
  88
  89 (defcustom time-stamp-active t
  90   "*Non-nil to enable time-stamping of buffers by \\[time-stamp].
  91 Can be toggled by \\[time-stamp-toggle-active].
  92 See also the variable `time-stamp-warn-inactive'."
  93   :type 'boolean
  94   :group 'time-stamp)
  95
  96 (defcustom time-stamp-warn-inactive t
  97   "Non-nil to have \\[time-stamp] warn if a buffer did not get time-stamped.
  98 A warning is printed if `time-stamp-active' disables time stamping and the
  99 buffer contains a template that would otherwise have been updated."
 100   :type 'boolean
 101   :group 'time-stamp)
 102
 103 (defcustom time-stamp-old-format-warn 'ask
 104   "Action to take if `time-stamp-format' is an old-style list.
 105 If `error', the format is not used.  If `ask', the user is queried about
 106 using the time-stamp-format.  If `warn', a warning is displayed.
 107 If nil, no notification is given."
 108   :type '(choice (const :tag "No notification" nil)
 109                  (const :tag "Don't use the format" error)
 110                  (const ask) (const warn))
 111   :group 'time-stamp)
 112
 113 (defcustom time-stamp-time-zone nil
 114   "If non-nil, a string naming the timezone to be used by \\[time-stamp].
 115 Format is the same as that used by the environment variable TZ on your system."
 116   :type '(choice (const nil) string)
 117   :group 'time-stamp)
 118
 119
 120 ;;; Do not change time-stamp-line-limit, time-stamp-start,
 121 ;;; time-stamp-end, time-stamp-pattern, time-stamp-inserts-lines,
 122 ;;; or time-stamp-count in your .emacs or you will be incompatible
 123 ;;; with other people's files!  If you must change them, do so only
 124 ;;; in the local variables section of the file itself.
 125
 126
 127 (defvar time-stamp-line-limit 8     ;Do not change!
 128   "Lines of a file searched; positive counts from start, negative from end.
 129 The patterns `time-stamp-start' and `time-stamp-end' must be found in
 130 the first (last) `time-stamp-line-limit' lines of the file for the
 131 file to be time-stamped by \\[time-stamp].  A value of 0 searches the
 132 entire buffer (use with care).
 133
 134 Do not change `time-stamp-line-limit', `time-stamp-start', or
 135 `time-stamp-end' for yourself or you will be incompatible
 136 with other people's files!  If you must change them for some application,
 137 do so in the local variables section of the time-stamped file itself.")
 138
 139
 140 (defvar time-stamp-start "Time-stamp:[ \t]+\\\\?[\"<]+"    ;Do not change!
 141   "Regexp after which the time stamp is written by \\[time-stamp].
 142 See also the variables `time-stamp-end' and `time-stamp-line-limit'.
 143
 144 Do not change `time-stamp-line-limit', `time-stamp-start', or
 145 `time-stamp-end' for yourself or you will be incompatible
 146 with other people's files!  If you must change them for some application,
 147 do so in the local variables section of the time-stamped file itself.")
 148
 149
 150 (defvar time-stamp-end "\\\\?[\">]"    ;Do not change!
 151   "Regexp marking the text after the time stamp.
 152 \\[time-stamp] deletes the text between the first match of `time-stamp-start'
 153 and the following match of `time-stamp-end', then writes the
 154 time stamp specified by `time-stamp-format' between them.
 155
 156 The end text normally starts on the same line as the start text ends,
 157 but if there are any newlines in `time-stamp-format', the same number
 158 of newlines must separate the start and end.  \\[time-stamp] tries
 159 to not change the number of lines in the buffer.  `time-stamp-inserts-lines'
 160 controls this behavior.
 161
 162 Do not change `time-stamp-line-limit', `time-stamp-start', `time-stamp-end',
 163 or `time-stamp-inserts-lines' for yourself or you will be incompatible
 164 with other people's files!  If you must change them for some application,
 165 do so in the local variables section of the time-stamped file itself.")
 166
 167
 168 (defvar time-stamp-inserts-lines nil    ;Do not change!
 169   "Whether time-stamp can change the number of lines in a file.
 170 If nil, \\[time-stamp] skips as many lines as there are newlines in
 171 `time-stamp-format' before looking for the `time-stamp-end' pattern,
 172 thus it tries not to change the number of lines in the buffer.
 173 If non-nil, \\[time-stamp] starts looking for the end pattern
 174 immediately after the start pattern.  This behavior can cause
 175 unexpected changes in the buffer if used carelessly, but it is useful
 176 for generating repeated time stamps.
 177
 178 Do not change `time-stamp-end' or `time-stamp-inserts-lines' for
 179 yourself or you will be incompatible with other people's files!
 180 If you must change them for some application, do so in the local
 181 variables section of the time-stamped file itself.")
 182
 183
 184 (defvar time-stamp-count 1              ;Do not change!
 185   "How many time stamp templates \\[time-stamp] will look for in a buffer.
 186 The same time-stamp will be written in each case.
 187
 188 Do not change `time-stamp-count' for yourself or you will be
 189 incompatible with other people's files!  If you must change it for
 190 some application, do so in the local variables section of the
 191 time-stamped file itself.")
 192
 193
 194 (defvar time-stamp-pattern "%%"         ;Do not change!
 195   "Convenience variable setting all `time-stamp' location and format values.
 196 This string has four parts, each of which is optional.
 197 These four parts set `time-stamp-line-limit', `time-stamp-start',
 198 `time-stamp-format', and `time-stamp-end'.  See the documentation
 199 for each of these variables for details.
 200
 201 The first part is a number followed by a slash; the number sets the number
 202 of lines at the beginning (negative counts from end) of the file searched
 203 for the time-stamp.  The number and the slash may be omitted to use the
 204 normal value.
 205
 206 The second part is a regexp identifying the pattern preceding the time stamp.
 207 This part may be omitted to use the normal pattern.
 208
 209 The third part specifies the format of the time-stamp inserted.  See
 210 the documentation for `time-stamp-format' for details.  Specify this
 211 part as \"%%\" to use the normal format.
 212
 213 The fourth part is a regexp identifying the pattern following the time stamp.
 214 This part may be omitted to use the normal pattern.
 215
 216 As an example, the default behavior can be specified something like this:
 217 \"8/Time-stamp: [\\\"<]%:y-%02m-%02d %02H:%02M:%02S %u[\\\">]\"
 218
 219 Do not change `time-stamp-pattern' for yourself or you will be incompatible
 220 with other people's files!  Set it only in the local variables section
 221 of the time-stamped file itself.")
 222
 223
 224
 225 ;;;###autoload
 226 (defun time-stamp ()
 227   "Update the time stamp string(s) in the buffer.
 228 A template in a file can be automatically updated with a new time stamp
 229 every time you save the file.  Add this line to your .emacs file:
 230     (add-hook 'write-file-hooks 'time-stamp)
 231 Normally the template must appear in the first 8 lines of a file and
 232 look like one of the following:
 233       Time-stamp: <>
 234       Time-stamp: \" \"
 235 The time stamp is written between the brackets or quotes:
 236       Time-stamp: <1998-02-18 10:20:51 gildea>
 237 The time stamp is updated only if the variable `time-stamp-active' is non-nil.
 238 The format of the time stamp is set by the variable `time-stamp-format'.
 239 The variables `time-stamp-line-limit', `time-stamp-start', `time-stamp-end',
 240 `time-stamp-count', and `time-stamp-inserts-lines' control finding the
 241 template."
 242   (interactive)
 243   (let ((line-limit time-stamp-line-limit)
 244         (ts-start time-stamp-start)
 245         (ts-format time-stamp-format)
 246         (ts-end time-stamp-end)
 247         (ts-count time-stamp-count)
 248         (format-lines 0)
 249         (end-lines 1)
 250         (start nil)
 251         search-limit)
 252     (if (stringp time-stamp-pattern)
 253         (progn
 254           (string-match "\\`\\(\\(-?[0-9]+\\)/\\)?\\([^%]+\\)?\\(\\(.\\|\n\\)*%[-.,:@+_ #^()0-9]*[A-Za-z%]\\)?\\([^%]+\\)?\\'" time-stamp-pattern)
 255           (and (match-beginning 2)
 256                (setq line-limit
 257                      (string-to-int (match-string 2 time-stamp-pattern))))
 258           (and (match-beginning 3)
 259                (setq ts-start (match-string 3 time-stamp-pattern)))
 260           (and (match-beginning 4)
 261                (not (string-equal (match-string 4 time-stamp-pattern) "%%"))
 262                (setq ts-format (match-string 4 time-stamp-pattern)))
 263           (and (match-beginning 6)
 264                (setq ts-end (match-string 6 time-stamp-pattern)))))
 265     (cond ((not (integerp line-limit))
 266            (setq line-limit 8)
 267            (message "time-stamp-line-limit is not an integer")
 268            (sit-for 1)))
 269     (cond ((not (integerp ts-count))
 270            (setq ts-count 1)
 271            (message "time-stamp-count is not an integer")
 272            (sit-for 1))
 273           ((< ts-count 1)
 274            ;; We need to call time-stamp-once at least once
 275            ;; to output any warnings about time-stamp not being active.
 276            (setq ts-count 1)))
 277     ;; Figure out what lines the end should be on.
 278     (let ((nl-start 0))
 279       (while (string-match "\n" ts-format nl-start)
 280         (setq format-lines (1+ format-lines) nl-start (match-end 0))))
 281     (let ((nl-start 0))
 282       (while (string-match "\n" ts-end nl-start)
 283         (setq end-lines (1+ end-lines) nl-start (match-end 0))))
 284     ;; Find overall what lines to look at
 285     (save-excursion
 286       (save-restriction
 287         (widen)
 288         (cond ((> line-limit 0)
 289                (goto-char (setq start (point-min)))
 290                (forward-line line-limit)
 291                (setq search-limit (point)))
 292               ((< line-limit 0)
 293                (goto-char (setq search-limit (point-max)))
 294                (forward-line line-limit)
 295                (setq start (point)))
 296               (t                        ;0 => no limit (use with care!)
 297                (setq start (point-min))
 298                (setq search-limit (point-max))))))
 299     (while (and start
 300                 (< start search-limit)
 301                 (> ts-count 0))
 302       (setq start (time-stamp-once start search-limit ts-start ts-end
 303                                    ts-format format-lines end-lines))
 304       (setq ts-count (1- ts-count))))
 305   ;; be sure to return nil so can be used on write-file-hooks
 306   nil)
 307
 308 (defun time-stamp-once (start search-limit ts-start ts-end
 309                         ts-format format-lines end-lines)
 310   "Update one time-stamp.  Internal routine called by \\[time-stamp].
 311 Returns the end point, which is where `time-stamp' begins the next search."
 312   (let ((case-fold-search nil)
 313         (end nil)
 314         end-search-start
 315         (end-length nil))
 316     (save-excursion
 317       (save-restriction
 318         (widen)
 319         ;; Find the location of the time stamp.
 320         (while (and (< (goto-char start) search-limit)
 321                     (not end)
 322                     (re-search-forward ts-start search-limit 'move))
 323           (setq start (point))
 324           (if (not time-stamp-inserts-lines)
 325               (forward-line format-lines))
 326           (setq end-search-start (max start (point)))
 327           (if (= (forward-line end-lines) 0)
 328               (progn
 329                (and (bolp) (backward-char))
 330                (let ((line-end (min (point) search-limit)))
 331                  (if (>= line-end end-search-start)
 332                      (progn
 333                       (goto-char end-search-start)
 334                       (if (re-search-forward ts-end line-end t)
 335                           (progn
 336                             (setq end (match-beginning 0))
 337                             (setq end-length (- (match-end 0) end))))))))))))
 338     (if end
 339         (progn
 340           ;; do all warnings outside save-excursion
 341           (cond
 342            ((not time-stamp-active)
 343             (if time-stamp-warn-inactive
 344                 ;; don't signal an error in a write-file-hook
 345                 (progn
 346                   (message "Warning: time-stamp-active is off; did not time-stamp buffer.")
 347                   (sit-for 1))))
 348            ((not (and (stringp ts-start)
 349                       (stringp ts-end)))
 350             (message "time-stamp-start or time-stamp-end is not a string")
 351             (sit-for 1))
 352            (t
 353             (let ((new-time-stamp (time-stamp-string ts-format)))
 354               (if (and (stringp new-time-stamp)
 355                        (not (string-equal (buffer-substring start end)
 356                                           new-time-stamp)))
 357                   (save-excursion
 358                     (save-restriction
 359                       (widen)
 360                       (delete-region start end)
 361                       (goto-char start)
 362                       (insert-and-inherit new-time-stamp)
 363                       (setq end (point))
 364                       ;; remove any tabs used to format time stamp
 365                       (if (search-backward "\t" start t)
 366                           (progn
 367                             (untabify start end)
 368                             (setq end (point))))))))))))
 369     ;; return the location after this time stamp, if there was one
 370     (and end end-length
 371          (+ end end-length))))
 372
 373
 374 ;;;###autoload
 375 (defun time-stamp-toggle-active (&optional arg)
 376   "Toggle `time-stamp-active', setting whether \\[time-stamp] updates a buffer.
 377 With arg, turn time stamping on if and only if arg is positive."
 378   (interactive "P")
 379   (setq time-stamp-active
 380         (if (null arg)
 381             (not time-stamp-active)
 382           (> (prefix-numeric-value arg) 0)))
 383   (message "time-stamp is now %s." (if time-stamp-active "active" "off")))
 384
 385
 386 (defun time-stamp-string (&optional ts-format)
 387   "Generate the new string to be inserted by \\[time-stamp].
 388 Optionally use FORMAT."
 389   (or ts-format
 390       (setq ts-format time-stamp-format))
 391   (if (stringp ts-format)
 392       (if (stringp time-stamp-time-zone)
 393           (let ((ts-real-time-zone (getenv "TZ")))
 394             (unwind-protect
 395                 (progn
 396                   (setenv "TZ" time-stamp-time-zone)
 397                   (format-time-string
 398                    (time-stamp-string-preprocess ts-format)))
 399               (setenv "TZ" ts-real-time-zone)))
 400         (format-time-string
 401          (time-stamp-string-preprocess ts-format)))
 402     ;; handle version 1 compatibility
 403     (cond ((or (eq time-stamp-old-format-warn 'error)
 404                (and (eq time-stamp-old-format-warn 'ask)
 405                     (not (y-or-n-p "Use non-string time-stamp-format? "))))
 406            (message "Warning: no time-stamp: time-stamp-format not a string")
 407            (sit-for 1)
 408            nil)
 409           (t
 410            (cond ((eq time-stamp-old-format-warn 'warn)
 411                   (message "Obsolescent time-stamp-format type; should be string")
 412                   (sit-for 1)))
 413            (time-stamp-fconcat ts-format " ")))))
 414
 415 (defconst time-stamp-no-file "(no file)"
 416   "String to use when the buffer is not associated with a file.")
 417
 418 ;;; time-stamp is transitioning to using the new, expanded capabilities
 419 ;;; of format-time-string.  During the process, this function implements
 420 ;;; intermediate, compatible formats and complains about old, soon to
 421 ;;; be unsupported, formats.  This function will get a lot (a LOT) shorter
 422 ;;; when the transition is complete and we can just pass most things
 423 ;;; straight through to format-time-string.
 424 ;;;      At all times, all the formats recommended in the doc string
 425 ;;; of time-stamp-format will work not only in the current version of
 426 ;;; Emacs, but in all versions that have been released within the past
 427 ;;; two years.
 428 ;;;      The : modifier is a temporary conversion feature used to resolve
 429 ;;; ambiguous formats--formats that are changing (over time) incompatibly.
 430 (defun time-stamp-string-preprocess (format &optional time)
 431   ;; Use a FORMAT to format date, time, file, and user information.
 432   ;; Optional second argument TIME is only for testing.
 433   ;; Implements non-time extensions to format-time-string
 434   ;; and all time-stamp-format compatibility.
 435   (let ((fmt-len (length format))
 436         (ind 0)
 437         cur-char
 438         (prev-char nil)
 439         (result "")
 440         field-width
 441         field-result
 442         alt-form change-case require-padding
 443         (paren-level 0))
 444     (while (< ind fmt-len)
 445       (setq cur-char (aref format ind))
 446       (setq
 447        result
 448        (concat result
 449       (cond
 450        ((eq cur-char ?%)
 451         ;; eat any additional args to allow for future expansion
 452         (setq alt-form nil change-case nil require-padding nil field-width "")
 453         (while (progn
 454                  (setq ind (1+ ind))
 455                  (setq cur-char (if (< ind fmt-len)
 456                                     (aref format ind)
 457                                   ?\0))
 458                  (or (eq ?. cur-char)
 459                      (eq ?, cur-char) (eq ?: cur-char) (eq ?@ cur-char)
 460                      (eq ?- cur-char) (eq ?+ cur-char) (eq ?_ cur-char)
 461                      (eq ?\  cur-char) (eq ?# cur-char) (eq ?^ cur-char)
 462                      (and (eq ?\( cur-char)
 463                           (not (eq prev-char ?\\))
 464                           (setq paren-level (1+ paren-level)))
 465                      (if (and (eq ?\) cur-char)
 466                               (not (eq prev-char ?\\))
 467                               (> paren-level 0))
 468                          (setq paren-level (1- paren-level))
 469                        (and (> paren-level 0)
 470                             (< ind fmt-len)))
 471                      (if (and (<= ?0 cur-char) (>= ?9 cur-char))
 472                          ;; get format width
 473                          (let ((field-index ind))
 474                            (while (progn
 475                                     (setq ind (1+ ind))
 476                                     (setq cur-char (if (< ind fmt-len)
 477                                                        (aref format ind)
 478                                                      ?\0))
 479                                     (and (<= ?0 cur-char) (>= ?9 cur-char))))
 480                            (setq field-width (substring format field-index ind))
 481                            (setq ind (1- ind))
 482                            t))))
 483           (setq prev-char cur-char)
 484           ;; some characters we actually use
 485           (cond ((eq cur-char ?:)
 486                  (setq alt-form t))
 487                 ((eq cur-char ?#)
 488                  (setq change-case t))))
 489         (setq field-result
 490         (cond
 491          ((eq cur-char ?%)
 492           "%%")
 493          ((eq cur-char ?a)              ;day of week
 494           (if change-case
 495               (format-time-string "%#A" time)
 496             (or alt-form (not (string-equal field-width ""))
 497                 (time-stamp-conv-warn "%a" "%:a"))
 498             (if (and alt-form (not (string-equal field-width "")))
 499                 ""                      ;discourage "%:3a"
 500               (format-time-string "%A" time))))
 501          ((eq cur-char ?A)
 502           (if alt-form
 503               (format-time-string "%A" time)
 504             (or change-case (not (string-equal field-width ""))
 505                 (time-stamp-conv-warn "%A" "%#A"))
 506             (format-time-string "%#A" time)))
 507          ((eq cur-char ?b)              ;month name
 508           (if change-case
 509               (format-time-string "%#B" time)
 510             (or alt-form (not (string-equal field-width ""))
 511                 (time-stamp-conv-warn "%b" "%:b"))
 512             (if (and alt-form (not (string-equal field-width "")))
 513                 ""                      ;discourage "%:3b"
 514             (format-time-string "%B" time))))
 515          ((eq cur-char ?B)
 516           (if alt-form
 517               (format-time-string "%B" time)
 518             (or change-case (not (string-equal field-width ""))
 519                 (time-stamp-conv-warn "%B" "%#B"))
 520             (format-time-string "%#B" time)))
 521          ((eq cur-char ?d)              ;day of month, 1-31
 522           (time-stamp-do-number cur-char alt-form field-width time))
 523          ((eq cur-char ?H)              ;hour, 0-23
 524           (time-stamp-do-number cur-char alt-form field-width time))
 525          ((eq cur-char ?I)              ;hour, 1-12
 526           (time-stamp-do-number cur-char alt-form field-width time))
 527          ((eq cur-char ?m)              ;month number, 1-12
 528           (time-stamp-do-number cur-char alt-form field-width time))
 529          ((eq cur-char ?M)              ;minute, 0-59
 530           (time-stamp-do-number cur-char alt-form field-width time))
 531          ((eq cur-char ?p)              ;am or pm
 532           (or change-case
 533               (time-stamp-conv-warn "%p" "%#p"))
 534           (format-time-string "%#p" time))
 535          ((eq cur-char ?P)              ;AM or PM
 536           (format-time-string "%p" time))
 537          ((eq cur-char ?S)              ;seconds, 00-60
 538           (time-stamp-do-number cur-char alt-form field-width time))
 539          ((eq cur-char ?w)              ;weekday number, Sunday is 0
 540           (format-time-string "%w" time))
 541          ((eq cur-char ?y)              ;year
 542           (or alt-form (not (string-equal field-width ""))
 543               (time-stamp-conv-warn "%y" "%:y"))
 544           (string-to-int (format-time-string "%Y" time)))
 545          ((eq cur-char ?Y)              ;4-digit year, new style
 546           (string-to-int (format-time-string "%Y" time)))
 547          ((eq cur-char ?z)              ;time zone lower case
 548           (if change-case
 549               ""                        ;discourage %z variations
 550             (format-time-string "%#Z" time)))
 551          ((eq cur-char ?Z)
 552           (if change-case
 553               (format-time-string "%#Z" time)
 554             (format-time-string "%Z" time)))
 555          ((eq cur-char ?f)              ;buffer-file-name, base name only
 556           (if buffer-file-name
 557               (file-name-nondirectory buffer-file-name)
 558             time-stamp-no-file))
 559          ((eq cur-char ?F)              ;buffer-file-name, full path
 560           (or buffer-file-name
 561               time-stamp-no-file))
 562          ((eq cur-char ?s)              ;system name
 563           (system-name))
 564          ((eq cur-char ?u)              ;user name
 565           (user-login-name))
 566          ((eq cur-char ?U)              ;user full name
 567           (user-full-name))
 568          ((eq cur-char ?l)              ;logname (undocumented user name alt)
 569           (user-login-name))
 570          ((eq cur-char ?L)              ;(undocumented alt user full name)
 571           (user-full-name))
 572          ((eq cur-char ?h)              ;mail host name
 573           (time-stamp-mail-host-name))
 574          ))
 575         (if (string-equal field-width "")
 576             (format "%s" field-result)
 577           (let ((padded-result
 578                  (format (format "%%%s%c"
 579                                  field-width
 580                                  (if (numberp field-result) ?d ?s))
 581                          (or field-result ""))))
 582             (let ((initial-length (length padded-result))
 583                   (desired-length (string-to-int field-width)))
 584               (if (> initial-length desired-length)
 585                   ;; truncate strings on right, years on left
 586                   (if (stringp field-result)
 587                       (substring padded-result 0 desired-length)
 588                     (if (eq cur-char ?y)
 589                         (substring padded-result (- desired-length))
 590                       padded-result))   ;non-year numbers don't truncate
 591                 padded-result)))))
 592        (t
 593         (char-to-string cur-char)))))
 594       (setq ind (1+ ind)))
 595     result))
 596
 597 (defun time-stamp-do-number (format-char alt-form field-width time)
 598   ;; Handle a compatible FORMAT-CHAR where only
 599   ;; the default width/padding will change.
 600   ;; ALT-FORM is whether `#' specified.  FIELD-WIDTH is the string
 601   ;; width specification or "".  TIME is the time to convert.
 602   (let ((format-string (concat "%" (char-to-string format-char))))
 603     (and (not alt-form) (string-equal field-width "")
 604          (time-stamp-conv-warn format-string
 605                                (format "%%:%c" format-char)))
 606     (if (and alt-form (not (string-equal field-width "")))
 607         ""                              ;discourage "%:2d" and the like
 608       (string-to-int (format-time-string format-string time)))))
 609
 610 (defvar time-stamp-conversion-warn t
 611   "Non-nil to warn about soon-to-be-unsupported forms in `time-stamp-format'.
 612 In would be a bad idea to disable these warnings!
 613 You really need to update your files instead.
 614
 615 The new formats will work with old versions of Emacs.
 616 New formats are being recommended now to allow `time-stamp-format'
 617 to change in the future to be compatible with `format-time-string'.
 618 The new forms being recommended now will continue to work then.")
 619
 620
 621 (defun time-stamp-conv-warn (old-form new-form)
 622   ;; Display a warning about a soon-to-be-obsolete format.
 623   (cond
 624    (time-stamp-conversion-warn
 625     (save-excursion
 626       (set-buffer (get-buffer-create "*Time-stamp-compatibility*"))
 627       (goto-char (point-max))
 628       (if (bobp)
 629           (progn
 630             (insert
 631              "The formats recognized in time-stamp-format will change in a future release\n"
 632              "to be compatible with the new, expanded format-time-string function.\n\n"
 633              "The following obsolescent time-stamp-format construct(s) were found:\n\n")))
 634       (insert "\"" old-form "\" -- use " new-form "\n"))
 635     (display-buffer "*Time-stamp-compatibility*"))))
 636
 637
 638
 639 (defun time-stamp-mail-host-name ()
 640   "Return the name of the host where the user receives mail.
 641 This is the value of `mail-host-address' if bound and a string,
 642 otherwise the value of the function `system-name'."
 643   (or (and (boundp 'mail-host-address)
 644            (stringp mail-host-address)
 645            mail-host-address)
 646       (system-name)))
 647
 648 ;;; the rest of this file is for version 1 compatibility
 649
 650 (defun time-stamp-fconcat (list sep)
 651   "Similar to (mapconcat 'funcall LIST SEP) but LIST allows literals.
 652 If an element of LIST is a symbol, it is funcalled to get the string to use;
 653 the separator SEP is used between two strings obtained by funcalling a
 654 symbol.  Otherwise the element itself is inserted; no separator is used
 655 around literals."
 656   (let ((return-string "")
 657         (insert-sep-p nil))
 658     (while list
 659       (cond ((symbolp (car list))
 660              (if insert-sep-p
 661                  (setq return-string (concat return-string sep)))
 662              (setq return-string (concat return-string (funcall (car list))))
 663              (setq insert-sep-p t))
 664             (t
 665              (setq return-string (concat return-string (car list)))
 666              (setq insert-sep-p nil)))
 667       (setq list (cdr list)))
 668     return-string))
 669
 670 ;;; Some functions used in time-stamp-format
 671
 672 ;;; Could generate most of a message-id with
 673 ;;; '(time-stamp-yymmdd "" time-stamp-hhmm "@" time-stamp-mail-host-name)
 674
 675 ;;; pretty form, suitable for a title page
 676
 677 (defun time-stamp-month-dd-yyyy ()
 678   "Return the current date as a string in \"Month DD, YYYY\" form."
 679   (format-time-string "%B %e, %Y"))
 680
 681 (defun time-stamp-dd/mm/yyyy ()
 682   "Return the current date as a string in \"DD/MM/YYYY\" form."
 683   (format-time-string "%d/%m/%Y"))
 684
 685 ;;; same as __DATE__ in ANSI C
 686
 687 (defun time-stamp-mon-dd-yyyy ()
 688   "Return the current date as a string in \"Mon DD YYYY\" form.
 689 The first character of DD is space if the value is less than 10."
 690   (format-time-string "%b %d %Y"))
 691
 692 ;;; RFC 822 date
 693
 694 (defun time-stamp-dd-mon-yy ()
 695   "Return the current date as a string in \"DD Mon YY\" form."
 696   (format-time-string "%d %b %y"))
 697
 698 ;;; RCS 3 date
 699
 700 (defun time-stamp-yy/mm/dd ()
 701   "Return the current date as a string in \"YY/MM/DD\" form."
 702   (format-time-string "%y/%m/%d"))
 703
 704 ;;; RCS 5 date
 705
 706 (defun time-stamp-yyyy/mm/dd ()
 707   "Return the current date as a string in \"YYYY/MM/DD\" form."
 708   (format-time-string "%Y/%m/%d"))
 709
 710 ;;; ISO 8601 date
 711
 712 (defun time-stamp-yyyy-mm-dd ()
 713   "Return the current date as a string in \"YYYY-MM-DD\" form."
 714   (format-time-string "%Y-%m-%d"))
 715
 716 (defun time-stamp-yymmdd ()
 717   "Return the current date as a string in \"YYMMDD\" form."
 718   (format-time-string "%y%m%d"))
 719
 720 (defun time-stamp-hh:mm:ss ()
 721   "Return the current time as a string in \"HH:MM:SS\" form."
 722   (format-time-string "%T"))
 723
 724 (defun time-stamp-hhmm ()
 725   "Return the current time as a string in \"HHMM\" form."
 726   (format-time-string "%H%M"))
 727
 728 (provide 'time-stamp)
 729
 730 ;;; time-stamp.el ends here