Function: sort-regexp-fields

sort-regexp-fields is an autoloaded, interactive and byte-compiled function defined in sort.el.gz.

Signature

(sort-regexp-fields REVERSE RECORD-REGEXP KEY-REGEXP BEG END)

Documentation

Sort the text in the region lexicographically.

If called interactively, prompt for two regular expressions, RECORD-REGEXP and KEY-REGEXP.

RECORD-REGEXP specifies the textual units to be sorted.
  For example, to sort lines, RECORD-REGEXP would be "^.*$".

KEY-REGEXP specifies the part of each record (i.e. each match for
  RECORD-REGEXP) to be used for sorting.
  If it is "\\\\digit", use the digit'th "\\\\(...\\\\)"
  match field specified by RECORD-REGEXP.
  If it is "\\\\&", use the whole record.
  Otherwise, KEY-REGEXP should be a regular expression with which
  to search within the record. If a match for KEY-REGEXP is not
  found within a record, that record is ignored.

With a negative prefix arg, sort in reverse order.

The variable sort-fold-case determines whether alphabetic case affects the sort order.

For example: to sort lines in the region by the first word on each line
 starting with the letter "f",
 RECORD-REGEXP would be "^.*$" and KEY would be "\\\\=\\<f\\\\w*\\\\>"

Key Bindings

Source Code

;; Defined in /usr/src/emacs/lisp/sort.el.gz
;;;###autoload
(defun sort-regexp-fields (reverse record-regexp key-regexp beg end)
  "Sort the text in the region lexicographically.
If called interactively, prompt for two regular expressions,
RECORD-REGEXP and KEY-REGEXP.

RECORD-REGEXP specifies the textual units to be sorted.
  For example, to sort lines, RECORD-REGEXP would be \"^.*$\".

KEY-REGEXP specifies the part of each record (i.e. each match for
  RECORD-REGEXP) to be used for sorting.
  If it is \"\\\\digit\", use the digit'th \"\\\\(...\\\\)\"
  match field specified by RECORD-REGEXP.
  If it is \"\\\\&\", use the whole record.
  Otherwise, KEY-REGEXP should be a regular expression with which
  to search within the record.  If a match for KEY-REGEXP is not
  found within a record, that record is ignored.

With a negative prefix arg, sort in reverse order.

The variable `sort-fold-case' determines whether alphabetic case affects
the sort order.

For example: to sort lines in the region by the first word on each line
 starting with the letter \"f\",
 RECORD-REGEXP would be \"^.*$\" and KEY would be \"\\\\=\\<f\\\\w*\\\\>\""
  ;; using negative prefix arg to mean "reverse" is now inconsistent with
  ;; other sort-.*fields functions but then again this was before, since it
  ;; didn't use the magnitude of the arg to specify anything.
  (interactive "P\nsRegexp specifying records to sort: \n\
sRegexp specifying key within record: \nr")
  (cond ((or (equal key-regexp "") (equal key-regexp "\\&"))
	 (setq key-regexp 0))
	((string-match "\\`\\\\[1-9]\\'" key-regexp)
	 (setq key-regexp (- (aref key-regexp 1) ?0))))
  (save-excursion
    (save-restriction
      (narrow-to-region beg end)
      (goto-char (point-min))
      (let (sort-regexp-record-end
	    (sort-regexp-fields-regexp record-regexp))
	(re-search-forward sort-regexp-fields-regexp nil t)
	(setq sort-regexp-record-end (point))
	(goto-char (match-beginning 0))
	(sort-subr reverse
		   'sort-regexp-fields-next-record
                   (lambda ()
                     (goto-char sort-regexp-record-end))
                   (lambda ()
                     (let ((n 0))
                       (cond ((numberp key-regexp)
                              (setq n key-regexp))
                             ((re-search-forward
                               key-regexp sort-regexp-record-end t)
                              (setq n 0))
                             (t (throw 'key nil)))
                       (condition-case ()
                           (cons (match-beginning n)
                                 (match-end n))
                         ;; if there was no such register
                         (error (throw 'key nil))))))))))