7. Starting Processors, Viewers and Other Programs

The most powerful features of AUCTeX may be those allowing you to run (La)TeX/ConTeXt and other external commands like BibTeX and makeindex from within Emacs, viewing and printing the results, and moreover allowing you to debug your documents.

7.1 Executing Commands

Formatting the document with TeX, LaTeX or ConTeXt, viewing with a previewer, printing the document, running BibTeX, making an index, or checking the document with lacheck or chktex all require running an external command.

There are two ways to run an external command, you can either run it on all of the current documents with TeX-command-master, or on the current region with TeX-command-region. A special case of running TeX on a region is TeX-command-buffer which differs from TeX-command-master if the current buffer is not its own master file.

Command: TeX-command-master

(C-c C-c) Query the user for a command, and run it on the master file associated with the current buffer. The name of the master file is controlled by the variable TeX-master. The available commands are controlled by the variable TeX-command-list.

See section 2. Installing AUCTeX, for a discussion about TeX-command-list and 8. Multifile Documents for a discussion about TeX-master.

Command: TeX-command-region

(C-c C-r) Query the user for a command, and run it on the "region file". Some commands (typically those invoking TeX or LaTeX) will write the current region into the region file, after extracting the header and tailer from the master file. If mark is inactive (which can happen with transient-mark-mode), use the old region. The name of the region file is controlled by the variable TeX-region. The name of the master file is controlled by the variable TeX-master. The header is all text up to the line matching the regular expression TeX-header-end. The trailer is all text from the line matching the regular expression TeX-trailer-start. The available commands are controlled by the variable TeX-command-list.

Command: TeX-pin-region

(C-c C-t C-r) If you don't have a mode like transient-mark-mode active, where marks get disabled automatically, the region would need to get properly set before each call to TeX-command-region. If you fix the current region with C-c C-t C-r, then it will get used for more commands even though mark and point may change. An explicitly activated mark, however, will always define a new region when calling TeX-command-region.

Command: TeX-command-buffer

(C-c C-b) Query the user for a command, and run it on the "region file". Some commands (typically those invoking TeX or LaTeX) will write the current buffer into the region file, after extracting the header and tailer from the master file. See above for details.

AUCTeX will allow one process for each document, plus one process for the region file to be active at the same time. Thus, if you are editing n different documents, you can have n plus one processes running at the same time. If the last process you started was on the region, the commands described in 7.3 Catching the errors and 7.5 Controlling the output will work on that process, otherwise they will work on the process associated with the current document.

User Option: TeX-region

The name of the file for temporarily storing the text when formatting the current region.

User Option: TeX-header-end

A regular expression matching the end of the header. By default, this is `\begin{document}' in LaTeX mode and `%**end of header' in TeX mode.

User Option: TeX-trailer-start

A regular expression matching the start of the trailer. By default, this is `\end{document}' in LaTeX mode and `\bye' in TeX mode.

AUCTeX will try to guess what command you want to invoke, but by default it will assume that you want to run TeX in TeX mode and LaTeX in LaTeX mode. You can overwrite this by setting the variable TeX-command-default.

User Option: TeX-command-default

The default command to run in this buffer. Must be an entry in TeX-command-list.

If you want to overwrite the values of TeX-header-end, TeX-trailer-start, or TeX-command-default, you can do that for all files by setting them in either TeX-mode-hook, plain-TeX-mode-hook, or LaTeX-mode-hook. To overwrite them for a single file, define them as file variables (see section `File Variables' in The Emacs Editor). You do this by putting special formatted text near the end of the file.

%%% Local Variables:
%%% TeX-header-end: "% End-Of-Header"
%%% TeX-trailer-start: "% Start-Of-Trailer"
%%% TeX-command-default: "SliTeX"
%%% End:

AUCTeX will try to save any buffers related to the document, and check if the document needs to be reformatted. If the variable TeX-save-query is non-nil, AUCTeX will query before saving each file. By default AUCTeX will check emacs buffers associated with files in the current directory, in one of the TeX-macro-private directories, and in the TeX-macro-global directories. You can change this by setting the variable TeX-check-path.

User Option: TeX-check-path

Directory path to search for dependencies.

If nil, just check the current file. Used when checking if any files have changed.

Command: TeX-PDF-mode

(C-c C-t C-p) This command toggles the PDF mode of AUCTeX, a buffer-local minor mode. You can customize TeX-PDF-mode to give it a different default. The default is used when AUCTeX does not have additional clue about what a document might want. This option usually results in calling either PDFTeX or ordinary TeX.

User Option: TeX-DVI-via-PDFTeX

If this is set, DVI will also be produced by calling PDFTeX, setting \pdfoutput=0. This makes it possible to use packages like `pdfcprot' even when producing DVI files. Some modern TeX distributions, e.g. teTeX 3.0, do this anyway, so that you need not enable it within AUCTeX.

Command: TeX-interactive-mode

(C-c C-t C-i) This command toggles the interactive mode of AUCTeX, a global minor mode. You can customize TeX-interactive-mode to give it a different default. In interactive mode, TeX will pause with an error prompt when errors are encountered and wait for the user to type something.

Command: TeX-source-specials-mode

(C-c C-t C-s) toggles Source Special support. Source Specials will move the DVI viewer to the location corresponding to point (forward search), and it will use `emacsclient' or `gnuclient' to have the previewer move Emacs to a location corresponding to a control-click in the previewer window. See section 7.2 Viewing the formatted output.

You can permanently activate TeX-source-specials-mode with

(TeX-source-specials-mode 1)

or by customizing the variable TeX-source-specials-mode. There is a bunch of customization options, use customize-group on the group `TeX-source-specials' to find out more.

It has to be stressed very strongly however, that Source Specials can cause differences in page breaks, in spacing, can seriously interfere with various packages and should thus never be used for the final version of a document. In particular, fine-tuning the page breaks should be done with Source Specials switched off.

Command: TeX-Omega-mode

(C-c C-t C-o) This command toggles the use of the Omega @tex () mode of AUCTeX, a buffer-local minor mode. If it is switched on, omega will be used instead of tex, and lambda instead of latex.

7.2 Viewing the formatted output

AUCTeX allows you to start external programs for previewing your document. These are normally invoked by pressing C-c C-c once the document is formatted or via the respective entry in the Command menu.

AUCTeX will try to guess which type of viewer (DVI, PostScript or PDF) has to be used and what options are to be passed over to it. This decision is based on the output files present in the working directory as well as the class and style options used in the document. For example, if there is a DVI file in your working directory, a DVI viewer will be invoked. In case of a PDF file it will be a PDF viewer. If you specified a special paper format like `a5paper' or use the `landscape' option, this will be passed to the viewer by the appropriate options. Especially some DVI viewers depend on this kind of information in order to display your document correctly. In case you are using `pstricks' or `psfrag' in your document, a DVI viewer cannot display the contents correctly and a PostScript viewer will be invoked instead.

The information about which file types and style options are associated with which viewers and options for them is stored in the variables TeX-output-view-style and TeX-view-style.

Command: TeX-view

The command TeX-view, bound to C-c C-v, starts a viewer without confirmation. The viewer is started either on a region or the master file, depending on the last command issued. This is especially useful for jumping to the location corresponding to point in the DVI viewer when using TeX-source-specials-mode.

User Option: TeX-output-view-style

List of output file extensions, style options and view options.

User Option: TeX-view-style

List of style options and view options. This is the predecessor of TeX-output-view-style which does not allow the specification of output file extensions. It is used as a fallback in case none of the alternatives specified in TeX-output-view-style match. In case none of the entries in TeX-view-style match either, no suggestion for a viewer will be made.

7.2.1 Forward and inverse search

You can make use of forward and inverse searching if this is supported by your DVI viewer and you enabled TeX-source-specials-mode as described in 7.1 Executing Commands. AUCTeX will automatically pass the necessary command line options to the viewer in order to display the page containing the content you are currently editing (forward search). Upon opening the viewer you will be asked if you want to start a server process (Gnuserv or Emacs server) which is necessary for inverse search. This happens only if there is no server running already. You can customize the variable TeX-source-specials-view-start-server to inhibit the question and always or never start the server respectively. Once the server and the viewer are running you can use a mouse click in the viewer to jump to the corresponding part of your document in Emacs (inverse search). Refer to the documentation of your viewer to find out what you have to do exactly. In xdvi you usually have to use C-down-mouse-1.

User Option: TeX-source-specials-view-start-server

If TeX-source-specials-mode is active and a DVI viewer is invoked, the default behavior is to ask if a server process should be started. Set this variable to t if the question should be inhibited and the server should be started always. Set it to nil if the server should never be started. Inverse search will not be available in the latter case.

7.3 Catching the errors

Once you've formatted your document you may `debug' it, i.e. browse through the errors (La)TeX reported.

Command: TeX-next-error

(C-c `) Go to the next error reported by TeX. The view will be split in two, with the cursor placed as close as possible to the error in the top view. In the bottom view, the error message will be displayed along with some explanatory text.

Normally AUCTeX will only report real errors, but you may as well ask it to report `bad boxes' as well.

Command: TeX-toggle-debug-bad-boxes

(C-c C-w) Toggle whether AUCTeX should stop at bad boxes (i.e. over/under full boxes) as well as at normal errors.

As default, AUCTeX will display that special `*help*' buffer containing the error reported by TeX along with the documentation. There is however an `expert' option, which allows you to display the real TeX output.

User Option: TeX-display-help

When non-nil AUCTeX will automatically display a help text whenever an error is encountered using TeX-next-error (C-c `).

7.4 Checking for problems

Running TeX or LaTeX will only find regular errors in the document, not examples of bad style. Furthermore, description of the errors may often be confusing. The utility lacheck can be used to find style errors, such as forgetting to escape the space after an abbreviation or using `...' instead of `\ldots' and many other problems like that. You start lacheck with C-c C-c Check RET. The result will be a list of errors in the `*compilation*' buffer. You can go through the errors with C-x ` (next-error, see section `Compilation' in The Emacs Editor), which will move point to the location of the next error.

Another newer program which can be used to find errors is chktex. It is much more configurable than lacheck, but doesn't find all the problems lacheck does, at least in its default configuration. You must install the programs before using them, and for chktex you must also modify TeX-command-list. You can get lacheck from `<URL:ftp://ftp.ctan.org/tex-archive/support/lacheck/>' or alternatively chktex from `<URL:ftp://ftp.ctan.org/tex-archive/support/chktex/>'. Search for `chktex' in `tex.el' to see how to switch between them.

7.5 Controlling the output

A number of commands are available for controlling the output of an application running under AUCTeX

Command: TeX-kill-job

(C-c C-k) Kill currently running external application. This may be either of TeX, LaTeX, previewer, BibTeX, etc.

Command: TeX-recenter-output-buffer

(C-c C-l) Recenter the output buffer so that the bottom line is visible.

Command: TeX-home-buffer

(C-c ^) Go to the `master' file in the document associated with the current buffer, or if already there, to the file where the current process was started.

This document was generated by XEmacs shared group account on December, 19 2009 using texi2html 1.65.