--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lisp/modes/tex-mode.el	Mon Aug 13 08:45:50 2007 +0200
@@ -0,0 +1,864 @@
+;;; tex-mode.el --- TeX, LaTeX, and SliTeX mode commands.
+
+;; Copyright (C) 1985-1992 Free Software Foundation, Inc.
+;; Contributions over the years by William F. Schelter, Dick King,
+;; Stephen Gildea, Michael Prange, and Edward M. Reingold.
+
+;; Latest revision (1992) by Edward M. Reingold <reingold@cs.uiuc.edu>.
+
+;; This file is part of XEmacs.
+
+;; XEmacs is free software; you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; XEmacs is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;; General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with XEmacs; see the file COPYING.  If not, write to the Free
+;; Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+(require 'comint)
+
+(defvar tex-shell-file-name nil
+  "*If non-nil, is file name to use for the subshell in which TeX is run.")
+
+(defvar tex-directory "."
+  "*Directory in which temporary files are left.
+You can make this /tmp if your TEXINPUTS has no relative directories in it
+and you don't try to apply \\[tex-region] or \\[tex-buffer] when there are
+\\input commands with relative directories.")
+
+(defvar tex-offer-save t
+  "*If non-nil, ask about saving modified buffers before \\[tex-file] is run.")
+
+(defvar tex-run-command "tex"
+  "*Command used to run TeX subjob.
+If this string contains an asterisk (*), it will be replaced by the
+filename; if not, the name of the file, preceded by blank, will be added to
+this string.")
+
+(defvar latex-run-command "latex"
+  "*Command used to run LaTeX subjob.
+If this string contains an asterisk (*), it will be replaced by the
+filename; if not, the name of the file, preceded by blank, will be added to
+this string.")
+
+(defvar standard-latex-block-names
+      '("abstract"         "array"            "center"       "description"
+        "displaymath"      "document"         "enumerate"    "eqnarray"
+        "eqnarray*"        "equation"         "figure"       "figure*"
+        "flushleft"        "flushright"       "itemize"      "letter"
+        "list"             "minipage"         "picture"      "quotation"
+        "quote"            "slide"            "sloppypar"     "tabbing"
+        "table"            "table*"           "tabular"       "tabular*"
+        "thebibliography"  "theindex*"        "titlepage"     "trivlist"
+        "verbatim"         "verbatim*"        "verse")
+  "Standard LaTeX block names.")
+
+(defvar latex-block-names nil
+  "*User defined LaTeX block names.
+Combined with `standard-latex-block-names' for minibuffer completion.")
+
+(defvar slitex-run-command "slitex"
+  "*Command used to run SliTeX subjob.
+If this string contains an asterisk (*), it will be replaced by the
+filename; if not, the name of the file, preceded by blank, will be added to
+this string.")
+
+(defvar tex-bibtex-command "bibtex"
+  "*Command used by `tex-bibtex-file' to gather bibliographic data.
+If this string contains an asterisk (*), it will be replaced by the
+filename; if not, the name of the file, preceded by blank, will be added to
+this string.")
+
+(defvar tex-dvi-print-command "lpr -d"
+  "*Command used by \\[tex-print] to print a .dvi file.
+If this string contains an asterisk (*), it will be replaced by the
+filename; if not, the name of the file, preceded by blank, will be added to
+this string.")
+
+(defvar tex-alt-dvi-print-command "lpr -d"
+  "*Command used by \\[tex-print] with a prefix arg to print a .dvi file.
+If this string contains an asterisk (*), it will be replaced by the
+filename; if not, the name of the file, preceded by blank, will be added to
+this string.
+
+If two printers are not enough of a choice, you can define the value
+of tex-alt-dvi-print-command to be an expression that asks what you want;
+for example,
+
+    (setq tex-alt-dvi-print-command
+         '(format \"lpr -P%s\" (read-string \"Use printer: \")))
+
+would tell \\[tex-print] with a prefix argument to ask you which printer to
+use.")
+
+(defvar tex-dvi-view-command nil
+  "*Command used by \\[tex-view] to display a .dvi file.
+If this string contains an asterisk (*), it will be replaced by the
+filename; if not, the name of the file, preceded by blank, will be added to
+this string.
+
+This can be set conditionally so that the previewer used is suitable for the
+window system being used.  For example,
+
+    (setq tex-dvi-view-command
+          (if (eq window-system 'x) \"xdvi\" \"dvi2tty * | cat -s\"))
+
+would tell \\[tex-view] use xdvi under X windows and to use dvi2tty
+otherwise.")
+
+(defvar tex-show-queue-command "lpq"
+  "*Command used by \\[tex-show-print-queue] to show the print queue.
+Should show the queue(s) that \\[tex-print] puts jobs on.")
+
+(defvar tex-default-mode 'plain-tex-mode
+  "*Mode to enter for a new file that might be either TeX or LaTeX.
+This variable is used when it can't be determined whether the file
+is plain TeX or LaTeX or what because the file contains no commands.
+Normally set to either 'plain-tex-mode or 'latex-mode.")
+
+(defvar tex-open-quote "``"
+  "*String inserted by typing \\[tex-insert-quote] to open a quotation.")
+
+(defvar tex-close-quote "''"
+  "*String inserted by typing \\[tex-insert-quote] to close a quotation.")
+
+(defvar tex-last-temp-file nil
+  "Latest temporary file generated by \\[tex-region] and \\[tex-buffer].
+Deleted when the \\[tex-region] or \\[tex-buffer] is next run, or when the
+tex-shell goes away.")
+
+(defvar tex-command nil
+  "Command to run TeX.
+The name of the file, preceded by a blank, will be added to this string.")
+
+(defvar tex-trailer nil
+  "String appended after the end of a region sent to TeX by \\[tex-region].")
+
+(defvar tex-start-of-header nil
+  "String used by \\[tex-region] to delimit the start of the file's header.")
+
+(defvar tex-end-of-header nil
+  "String used by \\[tex-region] to delimit the end of the file's header.")
+
+(defvar tex-shell-cd-command "cd"
+  "Command to give to shell running TeX to change directory.
+The value of tex-directory will be appended to this, separated by a space.")
+
+(defvar tex-zap-file nil
+  "Temporary file name used for text being sent as input to TeX.
+Should be a simple file name with no extension or directory specification.")
+
+(defvar tex-last-buffer-texed nil
+  "Buffer which was last TeXed.")
+
+(defvar tex-print-file nil
+  "File name that \\[tex-print] prints.
+Set by \\[tex-region], \\[tex-buffer], and \\[tex-file].")
+
+(defvar tex-mode-syntax-table nil
+  "Syntax table used while in TeX mode.")
+
+(defun tex-define-common-keys (keymap)
+  "Define the keys that we want defined both in TeX mode and in the tex-shell."
+  (define-key keymap "\C-c\C-k" 'tex-kill-job)
+  (define-key keymap "\C-c\C-l" 'tex-recenter-output-buffer)
+  (define-key keymap "\C-c\C-q" 'tex-show-print-queue)
+  (define-key keymap "\C-c\C-p" 'tex-print)
+  (define-key keymap "\C-c\C-v" 'tex-view)
+  )
+
+(defvar tex-mode-map nil "Keymap for TeX mode.")
+
+(if tex-mode-map 
+    nil
+  (setq tex-mode-map (make-sparse-keymap))
+  (tex-define-common-keys tex-mode-map)
+  (define-key tex-mode-map "\"" 'tex-insert-quote)
+  (define-key tex-mode-map "\n" 'tex-terminate-paragraph)
+  (define-key tex-mode-map "\C-c}" 'up-list)
+  (define-key tex-mode-map "\C-c{" 'tex-insert-braces)
+  (define-key tex-mode-map "\C-c\C-r" 'tex-region)
+  (define-key tex-mode-map "\C-c\C-b" 'tex-buffer)
+  (define-key tex-mode-map "\C-c\C-f" 'tex-file)
+  (define-key tex-mode-map "\C-c\C-i" 'tex-bibtex-file)
+  (define-key tex-mode-map "\C-c\C-o" 'tex-latex-block)
+  (define-key tex-mode-map "\C-c\C-e" 'tex-close-latex-block))
+
+(defvar tex-shell-map nil
+  "Keymap for the tex-shell.  A comint-mode-map with a few additions.")
+
+;;; This would be a lot simpler if we just used a regexp search,
+;;; but then it would be too slow.
+;;;###autoload
+(defun tex-mode ()
+  "Major mode for editing files of input for TeX, LaTeX, or SliTeX.
+Tries to determine (by looking at the beginning of the file) whether
+this file is for plain TeX, LaTeX, or SliTeX and calls plain-tex-mode,
+latex-mode, or slitex-mode, respectively.  If it cannot be determined,
+such as if there are no commands in the file, the value of tex-default-mode
+is used."
+  (interactive)
+  (let (mode slash comment)
+    (save-excursion
+      (goto-char (point-min))
+      (while (and (setq slash (search-forward "\\" nil t))
+		  (setq comment (let ((search-end (point)))
+				  (save-excursion
+				    (beginning-of-line)
+				    (search-forward "%" search-end t))))))
+      (if (and slash (not comment))
+	  (setq mode (if (looking-at "documentstyle")
+                         (if (looking-at "documentstyle{slides}")
+                             'slitex-mode
+                           'latex-mode)
+		       'plain-tex-mode))))
+    (if mode (funcall mode)
+      (funcall tex-default-mode))))
+;;;###autoload
+(fset 'TeX-mode 'tex-mode)
+;;;###autoload
+(fset 'LaTeX-mode 'latex-mode)
+
+;;;###autoload
+(defun plain-tex-mode ()
+  "Major mode for editing files of input for plain TeX.
+Makes $ and } display the characters they match.
+Makes \" insert `` when it seems to be the beginning of a quotation,
+and '' when it appears to be the end; it inserts \" only after a \\.
+
+Use \\[tex-region] to run TeX on the current region, plus a \"header\"
+copied from the top of the file (containing macro definitions, etc.),
+running TeX under a special subshell.  \\[tex-buffer] does the whole buffer.
+\\[tex-file] saves the buffer and then processes the file.
+\\[tex-print] prints the .dvi file made by any of these.
+\\[tex-view] previews the .dvi file made by any of these.
+\\[tex-bibtex-file] runs bibtex on the file of the current buffer.
+
+Use \\[validate-tex-buffer] to check buffer for paragraphs containing
+mismatched $'s or braces.
+
+Special commands:
+\\{tex-mode-map}
+
+Mode variables:
+tex-run-command
+	Command string used by \\[tex-region] or \\[tex-buffer].
+tex-directory
+	Directory in which to create temporary files for TeX jobs
+	run by \\[tex-region] or \\[tex-buffer].
+tex-dvi-print-command
+	Command string used by \\[tex-print] to print a .dvi file.
+tex-alt-dvi-print-command
+	Alternative command string used by \\[tex-print] (when given a prefix
+	argument) to print a .dvi file.
+tex-dvi-view-command
+	Command string used by \\[tex-view] to preview a .dvi file.
+tex-show-queue-command
+	Command string used by \\[tex-show-print-queue] to show the print
+	queue that \\[tex-print] put your job on.
+
+Entering Plain-tex mode calls the value of text-mode-hook, then the value of
+tex-mode-hook, and then the value of plain-tex-mode-hook.  When the special
+subshell is initiated, the value of tex-shell-hook is called."
+  (interactive)
+  (tex-common-initialization)
+  (setq mode-name "TeX")
+  (setq major-mode 'plain-tex-mode)
+  (setq tex-command tex-run-command)
+  (setq tex-start-of-header "%**start of header")
+  (setq tex-end-of-header "%**end of header")
+  (setq tex-trailer "\\bye\n")
+  (run-hooks 'text-mode-hook 'tex-mode-hook 'plain-tex-mode-hook))
+;;;###autoload
+(fset 'plain-TeX-mode 'plain-tex-mode)
+
+;;;###autoload
+(defun latex-mode ()
+  "Major mode for editing files of input for LaTeX.
+Makes $ and } display the characters they match.
+Makes \" insert `` when it seems to be the beginning of a quotation,
+and '' when it appears to be the end; it inserts \" only after a \\.
+
+Use \\[tex-region] to run LaTeX on the current region, plus the preamble
+copied from the top of the file (containing \\documentstyle, etc.),
+running LaTeX under a special subshell.  \\[tex-buffer] does the whole buffer.
+\\[tex-file] saves the buffer and then processes the file.
+\\[tex-print] prints the .dvi file made by any of these.
+\\[tex-view] previews the .dvi file made by any of these.
+\\[tex-bibtex-file] runs bibtex on the file of the current buffer.
+
+Use \\[validate-tex-buffer] to check buffer for paragraphs containing
+mismatched $'s or braces.
+
+Special commands:
+\\{tex-mode-map}
+
+Mode variables:
+latex-run-command
+	Command string used by \\[tex-region] or \\[tex-buffer].
+tex-directory
+	Directory in which to create temporary files for LaTeX jobs
+	run by \\[tex-region] or \\[tex-buffer].
+tex-dvi-print-command
+	Command string used by \\[tex-print] to print a .dvi file.
+tex-alt-dvi-print-command
+	Alternative command string used by \\[tex-print] (when given a prefix
+	argument) to print a .dvi file.
+tex-dvi-view-command
+	Command string used by \\[tex-view] to preview a .dvi file.
+tex-show-queue-command
+	Command string used by \\[tex-show-print-queue] to show the print
+	queue that \\[tex-print] put your job on.
+
+Entering Latex mode calls the value of text-mode-hook, then the value of
+tex-mode-hook, and then the value of latex-mode-hook.  When the special
+subshell is initiated, the value of tex-shell-hook is called."
+  (interactive)
+  (tex-common-initialization)
+  (setq mode-name "LaTeX")
+  (setq major-mode 'latex-mode)
+  (setq tex-command latex-run-command)
+  (setq tex-start-of-header "\\documentstyle")
+  (setq tex-end-of-header "\\begin{document}")
+  (setq tex-trailer "\\end{document}\n")
+  (run-hooks 'text-mode-hook 'tex-mode-hook 'latex-mode-hook))
+
+(defun slitex-mode ()
+  "Major mode for editing files of input for SliTeX.
+Makes $ and } display the characters they match.
+Makes \" insert `` when it seems to be the beginning of a quotation,
+and '' when it appears to be the end; it inserts \" only after a \\.
+
+Use \\[tex-region] to run SliTeX on the current region, plus the preamble
+copied from the top of the file (containing \\documentstyle, etc.),
+running SliTeX under a special subshell.  \\[tex-buffer] does the whole buffer.
+\\[tex-file] saves the buffer and then processes the file.
+\\[tex-print] prints the .dvi file made by any of these.
+\\[tex-view] previews the .dvi file made by any of these.
+\\[tex-bibtex-file] runs bibtex on the file of the current buffer.
+
+Use \\[validate-tex-buffer] to check buffer for paragraphs containing
+mismatched $'s or braces.
+
+Special commands:
+\\{tex-mode-map}
+
+Mode variables:
+slitex-run-command
+	Command string used by \\[tex-region] or \\[tex-buffer].
+tex-directory
+	Directory in which to create temporary files for SliTeX jobs
+	run by \\[tex-region] or \\[tex-buffer].
+tex-dvi-print-command
+	Command string used by \\[tex-print] to print a .dvi file.
+tex-alt-dvi-print-command
+	Alternative command string used by \\[tex-print] (when given a prefix
+	argument) to print a .dvi file.
+tex-dvi-view-command
+	Command string used by \\[tex-view] to preview a .dvi file.
+tex-show-queue-command
+	Command string used by \\[tex-show-print-queue] to show the print
+	queue that \\[tex-print] put your job on.
+
+Entering SliTeX mode calls the value of text-mode-hook, then the value of
+tex-mode-hook, then the value of latex-mode-hook, and then the value of
+slitex-mode-hook.  When the special subshell is initiated, the value of
+tex-shell-hook is called."
+  (interactive)
+  (tex-common-initialization)
+  (setq mode-name "SliTeX")
+  (setq major-mode 'slitex-mode)
+  (setq tex-command slitex-run-command)
+  (setq tex-start-of-header "\\documentstyle{slides}")
+  (setq tex-end-of-header "\\begin{document}")
+  (setq tex-trailer "\\end{document}\n")
+  (run-hooks
+   'text-mode-hook 'tex-mode-hook 'latex-mode-hook 'slitex-mode-hook))
+
+(defun tex-common-initialization ()
+  (kill-all-local-variables)
+  (use-local-map tex-mode-map)
+  (setq local-abbrev-table text-mode-abbrev-table)
+  (if (null tex-mode-syntax-table)
+      (let ((char 0))
+	(setq tex-mode-syntax-table (make-syntax-table))
+	(set-syntax-table tex-mode-syntax-table)
+	(while (< char ? )
+	  (modify-syntax-entry char ".")
+	  (setq char (1+ char)))
+	(modify-syntax-entry ?\C-@ "w")
+	(modify-syntax-entry ?\t " ")
+	(modify-syntax-entry ?\n ">")
+	(modify-syntax-entry ?\f ">")
+	(modify-syntax-entry ?$ "$$")
+	(modify-syntax-entry ?% "<")
+	(modify-syntax-entry ?\\ "/")
+	(modify-syntax-entry ?\" ".")
+	(modify-syntax-entry ?& ".")
+	(modify-syntax-entry ?_ ".")
+	(modify-syntax-entry ?@ "_")
+	(modify-syntax-entry ?~ " ")
+	(modify-syntax-entry ?' "w"))
+    (set-syntax-table tex-mode-syntax-table))
+  (make-local-variable 'paragraph-start)
+  (setq paragraph-start "^[ \t]*$\\|^[\f\\\\%]")
+  (make-local-variable 'paragraph-separate)
+  (setq paragraph-separate paragraph-start)
+  (make-local-variable 'comment-start)
+  (setq comment-start "%")
+  (make-local-variable 'comment-start-skip)
+  (setq comment-start-skip "\\(\\(^\\|[^\\]\\)\\(\\\\\\\\\\)*\\)\\(%+ *\\)")
+  (make-local-variable 'comment-indent-function)
+  (setq comment-indent-function 'tex-comment-indent)
+  (make-local-variable 'compare-windows-whitespace)
+  (setq compare-windows-whitespace 'tex-categorize-whitespace)
+  (make-local-variable 'tex-command)
+  (make-local-variable 'tex-start-of-header)
+  (make-local-variable 'tex-end-of-header)
+  (make-local-variable 'tex-trailer))
+
+(defun tex-comment-indent ()
+  (if (looking-at "%%%")
+      (current-column)
+    (skip-chars-backward " \t")
+    (max (if (bolp) 0 (1+ (current-column)))
+	 comment-column)))
+
+(defun tex-categorize-whitespace (backward-limit)
+  ;; compare-windows-whitespace is set to this.
+  ;; This is basically a finite-state machine.
+  ;; Returns a symbol telling how TeX would treat
+  ;; the whitespace we are looking at: null, space, or par.
+  (let ((category 'null)
+	(not-finished t))
+    (skip-chars-backward " \t\n\f" backward-limit)
+    (while not-finished
+      (cond ((looking-at "[ \t]+")
+	     (goto-char (match-end 0))
+	     (if (eql category 'null)
+		 (setq category 'space)))
+	    ((looking-at "\n")
+	     (cond ((eql category 'newline)
+		    (setq category 'par)
+		    (setq not-finished nil))
+		   (t
+		    (setq category 'newline) ;a strictly internal state
+		    (goto-char (match-end 0)))))
+	    ((looking-at "\f+")
+	     (setq category 'par)
+	     (setq not-finished nil))
+	    (t
+	     (setq not-finished nil))))
+    (skip-chars-forward " \t\n\f")
+    (if (eql category 'newline)
+	'space				;TeX doesn't distinguish
+      category)))
+
+(defun tex-insert-quote (arg)
+  "Insert the appropriate quote marks for TeX.
+Inserts the value of tex-open-quote (normally ``) or tex-close-quote
+(normally '') depending on the context.  With prefix argument, always
+inserts \" characters."
+  (interactive "*P")
+  (if arg
+      (self-insert-command (prefix-numeric-value arg))
+    (insert
+     (cond ((or (bobp)
+		(save-excursion
+		  (forward-char -1)
+		  (looking-at "\\s(\\|\\s \\|\\s>")))
+	    tex-open-quote)
+	   ((= (preceding-char) ?\\)
+	    ?\")
+	   (t
+	    tex-close-quote)))))
+
+(defun validate-tex-buffer ()
+  "Check current buffer for paragraphs containing mismatched $'s.
+As each such paragraph is found, a mark is pushed at its beginning,
+and the location is displayed for a few seconds."
+  (interactive)
+  (let ((opoint (point)))
+    (goto-char (point-max))
+    ;; Does not use save-excursion
+    ;; because we do not want to save the mark.
+    (unwind-protect
+	(while (and (not (input-pending-p)) (not (bobp)))
+	  (let ((end (point)))
+	    (search-backward "\n\n" nil 'move)
+	    (or (tex-validate-region (point) end)
+		(progn
+		  (push-mark (point))
+		  (message "Mismatch found in pararaph starting here")
+		  (sit-for 4)))))
+      (goto-char opoint))))
+
+(defun tex-validate-region (start end)
+  "Check for mismatched braces or $'s in region.
+Returns t if no mismatches.  Returns nil and moves point to suspect
+area if a mismatch is found."
+  (interactive "r")
+  (let ((failure-point nil) (max-possible-sexps (- end start)))
+    (save-excursion
+      (condition-case ()
+	  (save-restriction
+	    (narrow-to-region start end)
+	    (goto-char start)
+	    (while (< 0 (setq max-possible-sexps (1- max-possible-sexps)))
+	      (forward-sexp 1)))
+	(error
+	  (setq failure-point (point)))))
+    (if failure-point
+	(progn
+	  (goto-char failure-point)
+	  nil)
+      t)))
+
+(defun tex-terminate-paragraph (inhibit-validation)
+  "Insert two newlines, breaking a paragraph for TeX.
+Check for mismatched braces/$'s in paragraph being terminated.
+A prefix arg inhibits the checking."
+  (interactive "*P")
+  (or inhibit-validation
+      (save-excursion
+	(tex-validate-region
+	  (save-excursion
+	    (search-backward "\n\n" nil 'move)
+	    (point))
+	  (point)))
+      (message "Paragraph being closed appears to contain a mismatch"))
+  (insert "\n\n"))
+
+(defun tex-insert-braces ()
+  "Make a pair of braces and be poised to type inside of them."
+  (interactive "*")
+  (insert ?\{)
+  (save-excursion
+    (insert ?})))
+
+;;; Like tex-insert-braces, but for LaTeX.
+(defun tex-latex-block (name)
+  "Creates a matching pair of lines \\begin{NAME} and \\end{NAME} at point.
+Puts point on a blank line between them."
+  (interactive
+   (prog2
+      (barf-if-buffer-read-only)
+      (list
+       (completing-read "LaTeX block name: "
+			(mapcar 'list
+                                (append standard-latex-block-names
+                                        latex-block-names))))))
+  (let ((col (current-column)))
+    (insert (format "\\begin{%s}\n" name))
+    (indent-to col)
+    (save-excursion
+      (insert ?\n)
+      (indent-to col)
+      (insert (format "\\end{%s}" name))
+      (if (eobp) (insert ?\n)))))
+
+(defun tex-last-unended-begin ()
+  "Leave point at the beginning of the last \\begin{...} that is unended."
+  (while (and (re-search-backward "\\(\\\\begin\\s *{\\)\\|\\(\\\\end\\s *{\\)")
+              (looking-at "\\\\end{"))
+    (tex-last-unended-begin)))
+
+(defun tex-close-latex-block ()
+  "Creates an \\end{...} to match the last unclosed \\begin{...}."
+  (interactive "*")
+  (let ((new-line-needed (bolp))
+	text indentation)
+    (save-excursion
+      (condition-case nil
+          (tex-last-unended-begin)
+        (error (error "Couldn't find unended \\begin")))
+      (setq indentation (current-column))
+      (re-search-forward "\\\\begin\\(\\s *{[^}\n]*}\\)")
+      (setq text (buffer-substring (match-beginning 1) (match-end 1))))
+    (indent-to indentation)
+    (insert "\\end" text)
+    (if new-line-needed (insert ?\n))))
+
+;;; Invoking TeX in an inferior shell.
+
+;;; Why use a shell instead of running TeX directly?  Because if TeX
+;;; gets stuck, the user can switch to the shell window and type at it.
+
+;;; The utility functions:
+
+(defun tex-start-shell ()
+  (save-excursion
+    (set-buffer
+     (make-comint
+      "tex-shell"
+      (or tex-shell-file-name (getenv "ESHELL") (getenv "SHELL") "/bin/sh")
+      nil "-v"))
+    (let ((proc (get-process "tex-shell")))
+      (set-process-sentinel proc 'tex-shell-sentinel)
+      (process-kill-without-query proc)
+      (setq tex-shell-map (copy-keymap comint-mode-map))
+      (tex-define-common-keys tex-shell-map)
+      (use-local-map tex-shell-map)
+      (run-hooks 'tex-shell-hook)
+      (while (zerop (buffer-size))
+          (sleep-for 1)))))
+
+(defun tex-shell-sentinel (proc msg)
+  (cond ((null (buffer-name (process-buffer proc)))
+	 ;; buffer killed
+	 (set-process-buffer proc nil)
+         (tex-delete-last-temp-files))
+	((memq (process-status proc) '(signal exit))
+         (tex-delete-last-temp-files))))
+
+(defun tex-set-buffer-directory (buffer directory)
+  "Set BUFFER's default directory to be DIRECTORY."
+  (setq directory (file-name-as-directory (expand-file-name directory)))
+  (if (not (file-directory-p directory))
+      (error "%s is not a directory" directory)
+    (save-excursion
+      (set-buffer buffer)
+      (setq default-directory directory))))
+
+(defun tex-send-command (command &optional file background)
+  "Send COMMAND to tex-shell, substituting optional FILE for *; in background
+if optional BACKGROUND is t.   If COMMAND has no *, FILE will be appended,
+preceded by a blank, to COMMAND.  If FILE is nil, no substitution will be made
+in COMMAND.  COMMAND can be any expression that evaluates to a command string."
+  (save-excursion
+    (let* ((cmd (eval command))
+           (star (string-match "\\*" cmd)))
+      (comint-proc-query (get-process "tex-shell")
+                         (concat (substring cmd 0 star)
+                                 (if file (concat " " file) "")
+                                 (if star (substring cmd (1+ star) nil) "")
+                                 (if background "&\n" "\n"))))))
+
+(defun tex-delete-last-temp-files ()
+  "Delete any junk files from last temp file."
+  (if tex-last-temp-file
+      (let* ((dir (file-name-directory tex-last-temp-file))
+             (list (file-name-all-completions
+                    (file-name-nondirectory tex-last-temp-file) dir)))
+        (while list
+          (delete-file (concat dir (car list)))
+          (setq list (cdr list))))))
+
+(add-hook 'kill-emacs-hook 'tex-delete-last-temp-files)
+
+;;; The commands:
+
+(defun tex-region (beg end)
+  "Run TeX on the current region, via a temporary file.
+The file's name comes from the variable `tex-zap-file' and the
+variable `tex-directory' says where to put it.
+
+If the buffer has a header, the header is given to TeX before the
+region itself.  The buffer's header is all lines between the strings
+defined by `tex-start-of-header' and `tex-end-of-header' inclusive.
+The header must start in the first 100 lines of the buffer.
+
+The value of `tex-trailer' is given to TeX as input after the region.
+
+The value of `tex-command' specifies the command to use to run TeX."
+  (interactive "r")
+  (if (tex-shell-running)
+      (tex-kill-job)
+    (tex-start-shell))
+  (or tex-zap-file
+      (setq tex-zap-file (tex-generate-zap-file-name)))
+  (let* ((temp-buffer (get-buffer-create " TeX-Output-Buffer"))
+         ; Temp file will be written and TeX will be run in zap-directory.
+         ; If the TEXINPUTS file has relative directories or if the region has
+         ; \input of files, this must be the same directory as the file for
+         ; TeX to access the correct inputs.  That's why it's safest if
+         ; tex-directory is ".".
+         (zap-directory
+          (file-name-as-directory (expand-file-name tex-directory)))
+         (tex-out-file (concat zap-directory tex-zap-file)))
+    (tex-delete-last-temp-files)
+    ;; Write the new temp file.
+    (save-excursion
+      (save-restriction
+	(widen)
+	(goto-char (point-min))
+	(forward-line 100)
+	(let ((search-end (point))
+	      (hbeg (point-min)) (hend (point-min))
+	      (default-directory zap-directory))
+	  (goto-char (point-min))
+	  ;; Initialize the temp file with either the header or nothing
+	  (if (search-forward tex-start-of-header search-end t)
+	      (progn
+		(beginning-of-line)
+		(setq hbeg (point))	;mark beginning of header
+		(if (search-forward tex-end-of-header nil t)
+		    (progn (forward-line 1)
+			   (setq hend (point)))	;mark end of header
+		  (setq hbeg (point-min))))) ;no header
+	  (write-region (min hbeg beg) hend
+                        (concat tex-out-file ".tex") nil nil)
+	  (write-region (max beg hend) end (concat tex-out-file ".tex") t nil))
+	(let ((local-tex-trailer tex-trailer))
+	  (set-buffer temp-buffer)
+	  (erase-buffer)
+	  ;; make sure trailer isn't hidden by a comment
+	  (insert ?\n)
+	  (if local-tex-trailer (insert local-tex-trailer))
+	  (tex-set-buffer-directory temp-buffer zap-directory)
+	  (write-region (point-min) (point-max)
+                        (concat tex-out-file ".tex") t nil))))
+    ;; Record the file name to be deleted afterward.
+    (setq tex-last-temp-file tex-out-file)
+    (tex-send-command tex-shell-cd-command zap-directory)
+    (tex-send-command tex-command tex-out-file)
+    (setq tex-print-file tex-out-file)
+    (setq tex-last-buffer-texed (current-buffer))))
+
+(defun tex-buffer ()
+  "Run TeX on current buffer.  See \\[tex-region] for more information.
+Does not save the buffer, so it's useful for trying experimental versions.
+See \\[tex-file] for an alternative."
+  (interactive)
+  (tex-region (point-min) (point-max)))
+
+(defun tex-file ()
+  "Prompt to save all buffers and run TeX (or LaTeX) on current buffer's file.
+This function is more useful than \\[tex-buffer] when you need the
+`.aux' file of LaTeX to have the correct name."
+  (interactive)
+  (let ((tex-out-file
+         (if (buffer-file-name)
+             (file-name-nondirectory (buffer-file-name))
+           (error "Buffer does not seem to be associated with any file")))
+	(file-dir (file-name-directory (buffer-file-name))))
+    (save-some-buffers)
+    (if (tex-shell-running)
+        (tex-kill-job)
+      (tex-start-shell))
+    (tex-send-command tex-shell-cd-command file-dir)
+    (tex-send-command tex-command tex-out-file))
+  (setq tex-last-buffer-texed (current-buffer))
+  (setq tex-print-file (buffer-file-name)))
+
+(defun tex-generate-zap-file-name ()
+  "Generate a unique name suitable for use as a file name."
+  ;; Include the shell process number and host name
+  ;; in case there are multiple shells (for same or different user).
+  (format "#tz%d%s"
+          (process-id (get-buffer-process "*tex-shell*"))
+	  (tex-strip-dots (system-name))))
+
+(defun tex-strip-dots (s)
+  (setq s (copy-sequence s))
+  (while (string-match "\\." s)
+    (aset s (match-beginning 0) ?-))
+  s)
+
+;; This will perhaps be useful for modifying TEXINPUTS.
+;; Expand each file name, separated by colons, in the string S.
+(defun tex-expand-files (s)
+  (let (elts (start 0))
+    (while (string-match ":" s start)
+      (setq elts (cons (substring s start (match-beginning 0)) elts))
+      (setq start (match-end 0)))
+    (or (= start 0)
+	(setq elts (cons (substring s start) elts)))
+    (mapconcat 'expand-file-name (nreverse elts) ":")))
+
+(defun tex-shell-running ()
+  (and (get-process "tex-shell")
+       (eq (process-status (get-process "tex-shell")) 'run)))
+
+(defun tex-kill-job ()
+  "Kill the currently running TeX job."
+  (interactive)
+  (quit-process (get-process "tex-shell") t))
+
+(defun tex-recenter-output-buffer (linenum)
+  "Redisplay buffer of TeX job output so that most recent output can be seen.
+The last line of the buffer is displayed on
+line LINE of the window, or centered if LINE is nil."
+  (interactive "P")
+  (let ((tex-shell (get-buffer "*tex-shell*"))
+	(old-buffer (current-buffer)))
+    (if (null tex-shell)
+	(message "No TeX output buffer")
+      (pop-to-buffer tex-shell)
+      (bury-buffer tex-shell)
+      (goto-char (point-max))
+      (recenter (if linenum
+		    (prefix-numeric-value linenum)
+		  (/ (window-height) 2)))
+      (pop-to-buffer old-buffer))))
+
+(defun tex-print (&optional alt)
+  "Print the .dvi file made by \\[tex-region], \\[tex-buffer] or \\[tex-file].
+Runs the shell command defined by tex-dvi-print-command.  If prefix argument
+is provided, use the alternative command, tex-alt-dvi-print-command."
+  (interactive "P")
+  (let ((print-file-name-dvi (tex-append tex-print-file ".dvi"))
+	test-name)
+    (if (and (not (equal (current-buffer) tex-last-buffer-texed))
+	     (file-newer-than-file-p
+	      (setq test-name (tex-append (buffer-file-name) ".dvi"))
+	      print-file-name-dvi))
+	(setq print-file-name-dvi test-name))
+    (if (not (file-exists-p print-file-name-dvi))
+        (error "No appropriate `.dvi' file could be found")
+      (tex-send-command
+        (if alt tex-alt-dvi-print-command tex-dvi-print-command)
+        print-file-name-dvi t))))
+
+(defun tex-view ()
+  "Preview the last `.dvi' file made by running TeX under Emacs.
+This means, made using \\[tex-region], \\[tex-buffer] or \\[tex-file].
+The variable `tex-dvi-view-command' specifies the shell command for preview."
+  (interactive)
+  (let ((tex-dvi-print-command tex-dvi-view-command))
+    (tex-print)))
+
+(defun tex-append (file-name suffix)
+  "Append to FILENAME the suffix SUFFIX, using same algorithm TeX uses.
+Scans for the first (not last) period.
+No period is retained immediately before SUFFIX,
+so normally SUFFIX starts with one."
+  (if (stringp file-name)
+      (let ((file (file-name-nondirectory file-name)))
+	(concat (file-name-directory file-name)
+		(substring file 0
+			   (string-match "\\." file))
+		suffix))
+    " "))
+
+(defun tex-show-print-queue ()
+  "Show the print queue that \\[tex-print] put your job on.
+Runs the shell command defined by tex-show-queue-command."
+  (interactive)
+  (if (tex-shell-running)
+      (tex-kill-job)
+    (tex-start-shell))
+  (tex-send-command tex-show-queue-command))
+
+(defun tex-bibtex-file ()
+  "Run BibTeX on the current buffer's file."
+  (interactive)
+  (if (tex-shell-running)
+      (tex-kill-job)
+    (tex-start-shell))
+  (let ((tex-out-file
+         (tex-append (file-name-nondirectory (buffer-file-name)) ""))
+	(file-dir (file-name-directory (buffer-file-name))))
+    (tex-send-command tex-shell-cd-command file-dir)
+    (tex-send-command bibtex-command tex-out-file)))
+
+(run-hooks 'tex-mode-load-hook)
+
+(provide 'tex-mode)