+;;; time-stamp is transitioning to using the new, expanded capabilities
+;;; of format-time-string. During the process, this function implements
+;;; intermediate, compatible formats and complains about old, soon to
+;;; be unsupported, formats. This function will get a lot (a LOT) shorter
+;;; when the transition is complete and we can just pass most things
+;;; straight through to format-time-string.
+;;; At all times, all the formats recommended in the doc string
+;;; of time-stamp-format will work not only in the current version of
+;;; Emacs, but in all versions that have been released within the past
+;;; two years.
+;;; The : modifier is a temporary conversion feature used to resolve
+;;; ambiguous formats--formats that are changing (over time) incompatibly.
+(defun time-stamp-string-preprocess (format &optional time)
+ ;; Uses a FORMAT to format date, time, file, and user information.
+ ;; Optional second argument TIME is only for testing.
+ ;; Implements non-time extensions to format-time-string
+ ;; and all time-stamp-format compatibility.
+ (let ((fmt-len (length format))
+ (ind 0)
+ cur-char
+ (prev-char nil)
+ (result "")
+ field-width
+ field-result
+ alt-form change-case require-padding
+ (paren-level 0))
+ (while (< ind fmt-len)
+ (setq cur-char (aref format ind))
+ (setq
+ result
+ (concat result
+ (cond
+ ((eq cur-char ?%)
+ ;; eat any additional args to allow for future expansion
+ (setq alt-form nil change-case nil require-padding nil field-width "")
+ (while (progn
+ (setq ind (1+ ind))
+ (setq cur-char (if (< ind fmt-len)
+ (aref format ind)
+ ?\0))
+ (or (eq ?. cur-char)
+ (eq ?, cur-char) (eq ?: cur-char) (eq ?@ cur-char)
+ (eq ?- cur-char) (eq ?+ cur-char) (eq ?_ cur-char)
+ (eq ?\ cur-char) (eq ?# cur-char) (eq ?^ cur-char)
+ (and (eq ?\( cur-char)
+ (not (eq prev-char ?\\))
+ (setq paren-level (1+ paren-level)))
+ (if (and (eq ?\) cur-char)
+ (not (eq prev-char ?\\))
+ (> paren-level 0))
+ (setq paren-level (1- paren-level))
+ (and (> paren-level 0)
+ (< ind fmt-len)))
+ (if (and (<= ?0 cur-char) (>= ?9 cur-char))
+ ;; get format width
+ (let ((field-index ind))
+ (while (progn
+ (setq ind (1+ ind))
+ (setq cur-char (if (< ind fmt-len)
+ (aref format ind)
+ ?\0))
+ (and (<= ?0 cur-char) (>= ?9 cur-char))))
+ (setq field-width (substring format field-index ind))
+ (setq ind (1- ind))
+ t))))
+ (setq prev-char cur-char)
+ ;; some characters we actually use
+ (cond ((eq cur-char ?:)
+ (setq alt-form t))
+ ((eq cur-char ?#)
+ (setq change-case t))))
+ (setq field-result
+ (cond
+ ((eq cur-char ?%)
+ "%")
+ ((eq cur-char ?a) ;day of week
+ (if change-case
+ (format-time-string "%#A" time)
+ (or alt-form (not (string-equal field-width ""))
+ (time-stamp-conv-warn "%a" "%:a"))
+ (if (and alt-form (not (string-equal field-width "")))
+ "" ;discourage "%:3a"
+ (format-time-string "%A" time))))
+ ((eq cur-char ?A)
+ (if alt-form
+ (format-time-string "%A" time)
+ (or change-case (not (string-equal field-width ""))
+ (time-stamp-conv-warn "%A" "%#A"))
+ (format-time-string "%#A" time)))
+ ((eq cur-char ?b) ;month name
+ (if change-case
+ (format-time-string "%#B" time)
+ (or alt-form (not (string-equal field-width ""))
+ (time-stamp-conv-warn "%b" "%:b"))
+ (if (and alt-form (not (string-equal field-width "")))
+ "" ;discourage "%:3b"
+ (format-time-string "%B" time))))
+ ((eq cur-char ?B)
+ (if alt-form
+ (format-time-string "%B" time)
+ (or change-case (not (string-equal field-width ""))
+ (time-stamp-conv-warn "%B" "%#B"))
+ (format-time-string "%#B" time)))
+ ((eq cur-char ?d) ;day of month, 1-31
+ (time-stamp-do-number cur-char alt-form field-width time))
+ ((eq cur-char ?H) ;hour, 0-23
+ (time-stamp-do-number cur-char alt-form field-width time))
+ ((eq cur-char ?I) ;hour, 1-12
+ (time-stamp-do-number cur-char alt-form field-width time))
+ ((eq cur-char ?m) ;month number, 1-12
+ (time-stamp-do-number cur-char alt-form field-width time))
+ ((eq cur-char ?M) ;minute, 0-59
+ (time-stamp-do-number cur-char alt-form field-width time))
+ ((eq cur-char ?p) ;am or pm
+ (or change-case
+ (time-stamp-conv-warn "%p" "%#p"))
+ (format-time-string "%#p" time))
+ ((eq cur-char ?P) ;AM or PM
+ (format-time-string "%p" time))
+ ((eq cur-char ?S) ;seconds, 00-60
+ (time-stamp-do-number cur-char alt-form field-width time))
+ ((eq cur-char ?w) ;weekday number, Sunday is 0
+ (format-time-string "%w" time))
+ ((eq cur-char ?y) ;year
+ (or alt-form (not (string-equal field-width ""))
+ (time-stamp-conv-warn "%y" "%:y"))
+ (string-to-int (format-time-string "%Y" time)))
+ ((eq cur-char ?Y) ;4-digit year, new style
+ (string-to-int (format-time-string "%Y" time)))
+ ((eq cur-char ?z) ;time zone lower case
+ (if change-case
+ "" ;discourage %z variations
+ (format-time-string "%#Z" time)))
+ ((eq cur-char ?Z)
+ (if change-case
+ (format-time-string "%#Z" time)
+ (format-time-string "%Z" time)))
+ ((eq cur-char ?f) ;buffer-file-name, base name only
+ (if buffer-file-name
+ (file-name-nondirectory buffer-file-name)
+ time-stamp-no-file))
+ ((eq cur-char ?F) ;buffer-file-name, full path
+ (or buffer-file-name
+ time-stamp-no-file))
+ ((eq cur-char ?s) ;system name
+ (system-name))
+ ((eq cur-char ?u) ;user name
+ (user-login-name))
+ ((eq cur-char ?U) ;user full name
+ (user-full-name))
+ ((eq cur-char ?h) ;mail host name
+ (time-stamp-mail-host-name))
+ ))
+ (if (string-equal field-width "")
+ field-result
+ (let ((padded-result
+ (format (format "%%%s%c"
+ field-width
+ (if (numberp field-result) ?d ?s))
+ (or field-result ""))))
+ (let ((initial-length (length padded-result))
+ (desired-length (string-to-int field-width)))
+ (if (> initial-length desired-length)
+ ;; truncate strings on right, years on left
+ (if (stringp field-result)
+ (substring padded-result 0 desired-length)
+ (if (eq cur-char ?y)
+ (substring padded-result (- desired-length))
+ padded-result)) ;non-year numbers don't truncate
+ padded-result)))))
+ (t
+ (char-to-string cur-char)))))
+ (setq ind (1+ ind)))
+ result))
+
+(defun time-stamp-do-number (format-char alt-form field-width time)
+ ;; Handle a compatible FORMAT-CHAR where only
+ ;; the default width/padding will change.
+ ;; ALT-FORM is whether `#' specified. FIELD-WIDTH is the string
+ ;; width specification or "". TIME is the time to convert.
+ (let ((format-string (concat "%" (char-to-string format-char))))
+ (and (not alt-form) (string-equal field-width "")
+ (time-stamp-conv-warn format-string
+ (format "%%:%c" format-char)))
+ (if (and alt-form (not (string-equal field-width "")))
+ "" ;discourage "%:2d" and the like
+ (string-to-int (format-time-string format-string time)))))
+
+(defvar time-stamp-conversion-warn t
+ "Non-nil to warn about soon-to-be-unsupported forms in time-stamp-format.
+In would be a bad idea to disable these warnings!
+You really need to update your files instead.
+
+The new formats will work with old versions of Emacs.
+New formats are being recommended now to allow time-stamp-format
+to change in the future to be compatible with format-time-string.
+The new forms being recommended now will continue to work then.")
+
+
+(defun time-stamp-conv-warn (old-form new-form)
+ ;; Display a warning about a soon-to-be-obsolete format.
+ (cond
+ (time-stamp-conversion-warn
+ (save-excursion
+ (set-buffer (get-buffer-create "*Time-stamp-compatibility*"))
+ (goto-char (point-max))
+ (if (bobp)
+ (progn
+ (insert
+ "The formats recognized in time-stamp-format will change in a future release\n"
+ "to be compatible with the new, expanded format-time-string function.\n\n"
+ "The following obsolescent time-stamp-format construct(s) were found:\n\n")))
+ (insert "\"" old-form "\" -- use " new-form "\n"))
+ (display-buffer "*Time-stamp-compatibility*"))))
+
+
+
+(defun time-stamp-string (&optional ts-format)
+ "Generate the new string to be inserted by \\[time-stamp].
+Optionally use FORMAT."
+ (or ts-format
+ (setq ts-format time-stamp-format))
+ (if (stringp ts-format)
+ (if (stringp time-stamp-time-zone)
+ (let ((real-time-zone (getenv "TZ")))
+ (unwind-protect
+ (progn
+ (setenv "TZ" time-stamp-time-zone)
+ (format-time-string
+ (time-stamp-string-preprocess ts-format)))
+ (setenv "TZ" real-time-zone)))
+ (format-time-string
+ (time-stamp-string-preprocess ts-format)))