Import GNU Enscript version 1.6.4

[enscript.git] / docs / enscript.texi

\input texinfo   @c -*-texinfo-*-
@c %**start of header
@setfilename enscript.info
@settitle enscript
@setchapternewpage on
@c %**end of header

@include version.texi

@dircategory Utilities
@direntry
* Enscript: (enscript).             GNU Enscript
@end direntry

@c Combine function and variable indexes to the Concept index.
@synindex fn cp
@synindex vr cp

@ifinfo
This file documents GNU enscript @value{VERSION}

Copyright (C) 1995-1999 Markku Rossi.

Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.

@ignore
Permission is granted to process this file through TeX and print the
results, provided the printed document carries copying permission
notice identical to this one except for the removal of this paragraph


@end ignore
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the entire
resulting derived work is distributed under the terms of a permission
notice identical to this one.

Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions,
except that this permission notice may be stated in a translation approved
by the Foundation.
@end ifinfo


@titlepage
@title GNU enscript
@subtitle For version @value{VERSION}, @value{UPDATED}
@author Markku Rossi

@page
@vskip 0pt plus 1filll
Copyright @copyright{} 1995-1998 Markku Rossi.
@sp 2
This is the first edition of the GNU enscript documentation,@*
and is consistent with GNU enscript @value{VERSION}.@*

Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.

Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the entire
resulting derived work is distributed under the terms of a permission
notice identical to this one.

Permission is granted to copy and distribute translations of this manual
into another language, under the above conditions for modified versions,
except that this permission notice may be stated in a translation
approved by the Free Software Foundation.
@end titlepage

@ifinfo
@node Top, Introduction, (dir), (dir)
@comment  node-name,  next,  previous,  up
@top GNU enscript

This file documents the GNU enscript program.  This edition documents
version @value{VERSION}.

@menu
* Introduction::
* Invoking Enscript::
* Basic Printing::
* Advanced Usage::
* Configuration Files::
* Customization::
* The states Program::
* Writing New Highlighting Definitions::
* Index::
@end menu

@end ifinfo

@c ----------------------------------------------------------------------
@node Introduction, Invoking Enscript, Top, Top
@chapter Introduction

@itemize @bullet
@item overall
@item design
@end itemize

@c ----------------------------------------------------------------------
@node Invoking Enscript, Basic Printing, Introduction, Top
@chapter Invoking Enscript

@c ----------------------------------------------------------------------
@node Basic Printing, Advanced Usage, Invoking Enscript, Top
@chapter Basic Printing

@menu
* Input Encodings::
* Selecting Fonts::
* Page Headers::
* Page Handling::
* Highlighting::
@end menu

@node Input Encodings, Selecting Fonts, Basic Printing, Basic Printing
@section Input Encodings

@node Selecting Fonts, Page Headers, Input Encodings, Basic Printing
@section Selecting Fonts

@node Page Headers, Page Handling, Selecting Fonts, Basic Printing
@section Page Headers

@node Page Handling, Highlighting, Page Headers, Basic Printing
@section Page Handling

@menu
* Page Orientation::
* N-up Printing::
* Fitting Text to Page::
@end menu

@node Page Orientation, N-up Printing, Page Handling, Page Handling
@subsection Page Orientation

@node N-up Printing, Fitting Text to Page, Page Orientation, Page Handling
@subsection N-up Printing

@node Fitting Text to Page,  , N-up Printing, Page Handling
@subsection Fitting Text to Page

@node Highlighting,  , Page Handling, Basic Printing
@section Highlighting

@menu
* Different Output Languages::
@end menu

@node Different Output Languages,  , Highlighting, Highlighting
@subsection Different Output Languages

@c ----------------------------------------------------------------------
@node Advanced Usage, Configuration Files, Basic Printing, Top
@chapter Advanced Usage

@menu
* Selecting Pages::
* Escape Sequences::
* Input Filters::
* Slice Printing::
* PostScript Printer Controlling::
* Pass-Through Mode::
@end menu

@node Selecting Pages, Escape Sequences, Advanced Usage, Advanced Usage
@section Selecting Pages

@node Escape Sequences, Input Filters, Selecting Pages, Advanced Usage
@section Escape Sequences

@node Input Filters, Slice Printing, Escape Sequences, Advanced Usage
@section Input Filters

@node Slice Printing, PostScript Printer Controlling, Input Filters, Advanced Usage
@section Slice Printing

@node PostScript Printer Controlling, Pass-Through Mode, Slice Printing, Advanced Usage
@section PostScript Printer Controlling

@node Pass-Through Mode,  , PostScript Printer Controlling, Advanced Usage
@section Pass-Through Mode

@c ----------------------------------------------------------------------
@node Configuration Files, Customization, Advanced Usage, Top
@chapter Configuration Files

@c ----------------------------------------------------------------------
@node Customization, The states Program, Configuration Files, Top
@chapter Customization

@menu
* Output Media::
* User-Defined Fancy Headers::
@end menu

@node Output Media, User-Defined Fancy Headers, Customization, Customization
@section Output Media

@node User-Defined Fancy Headers,  , Output Media, Customization
@section User-Defined Fancy Headers


@c ----------------------------------------------------------------------
@node The states Program, Writing New Highlighting Definitions, Customization, Top
@chapter The @samp{states} Program

@c ----------------------------------------------------------------------
@node Writing New Highlighting Definitions, Index, The states Program, Top
@chapter Writing New Highlighting Definitions

The highlighting works in three separate phases.  First, the
@dfn{highlighing rules} process the input stream and parse it into
logical components.  The components are called @dfn{faces}.  A face
presents one logical component of the input language, for example, a
keyword, a comment, etc..  The enscript's highlighting model defines the
following faces:

@table @b
@item bold
@itemx italic
@itemx bold_italic
Hard-coded faces for the bold, italic, and bold-italice text types.
These faces define the exact presentation of the face font, so the style
files have very little power in customizing their outlook.  These faces
should be avoided as much as possible.

@item comment
A comment, normally in a programming language.

@item function_name
A function name.  The function names are normally recognized from
function definitions, not from an use of the function.

@item variable_name
A variable name.  The variable names are normally recognized from
function, type, and variable definitions.

@item keyword
A reserved keyword.  Normally, all occurrences of the keywords are
recognized.

@item reference
A reference to another location in a file or to another file or
resource.  For example, in the C-language, the goto targets are
references.

@item string
A string literal.

@item builtin
A builtin function or property.  Normally, all occurrences of the
builtins are recognized.

@item type
A type specifier.  The types are normally recognized from function,
type, and variable definitions.

@end table

As the second step, the @dfn{output style} specifies how the faces are
presented in the generated output.  Each face has the following
properties:

@table @b
@item fontname
The PostScript font name of the the font that is used for the face.
This property is used only for the PostScript outputs.

@item boldp
A boolean flag which tells whether the face should be printed in bold
font.  This property is used for all output languages except for the
PostScript which uses the fontname property.

@item italicp
A boolean flag which tells whether the face shuold be printed with
italic font.  This property is used for all output languages except for
the PostScript which uses the fontname property.

@item fg_color
The foreground color of the face.

@item bg_color
The background color of the face.  This property is not implemented on
all output languages.
@end table

Finally, the @dfn{output language} describes how the faces and other
text are presented in the output language.  The output language defines
a set of functions which are called to generate the output.

@menu
* Highlighting Rules::
* Styles::
* Output Languages::
@end menu

@node Highlighting Rules, Styles, Writing New Highlighting Definitions, Writing New Highlighting Definitions
@section Highlighting Rules


@node Styles, Output Languages, Highlighting Rules, Writing New Highlighting Definitions
@section Styles

@node Output Languages,  , Styles, Writing New Highlighting Definitions
@section Output Languages

@deffn Function map_color (r, g, b)
@end deffn

@deffn Function language_print (string)
@end deffn

@deffn Function language_symbol (symbol)
@end deffn

@deffn Function header ()
@end deffn

@deffn Function trailer ()
@end deffn

@deffn Function face_on (face)
@end deffn

@deffn Function face_off (face)
@end deffn

@defvr Variable LANGUAGE_SPECIALS
@end defvr

The following example creates a new output language @code{simple_html}
that creates simple HTML outputs.  The output language is defined in a
file called @file{lang_simple_html.st}.  The file must define a state
called @code{lang_simple_html}.  The file can be located in any
directory that is in the load path of the states program.

The output language definitions are defined in the @code{BEGIN} block of
the @code{lang_simple_html} state.  Please, note that the @code{BEGIN}
block is ended with a @code{return}-statement.  This statement will
return the control to the calling state that is the start state of the
enscript highlight program.  If the @code{return}-statement was omitted,
the states would start processing the input with the
@code{lang_simple_html} state which is obviously a wrong choice.

@example
state lang_simple_html
@{
  BEGIN @{
    sub map_color (r, g, b)
    @{
      return sprintf ("#%02X%02X%02X", r, g, b);
    @}

    sub language_print (str)
    @{
      str = regsuball (str, /\&/, "&");
      str = regsuball (str, /</, "&lt;");
      str = regsuball (str, />/, "&gt;");
      str = regsuball (str, /\"/, "&quot;");
      print (str);
    @}

    sub language_symbol (symbol)
    @{
      return false;
    @}

    sub header ()
    @{
      print ("<html>\n<head>\n<title>Simple HTML Output</title>\n");
      print ("</head>\n<body>\n");
    @}

    sub trailer ()
    @{
      print ("</body>\n</html>\n");
    @}

    sub fase_on (face)
    @{
      if (face(boldp])
        print ("<B>");
      if (face(italicp])
        print ("<I>");
      if (face[fg_color])
        print ("<FONT COLOR=\", face[fg_color], "\">");
    @}

    sub face_off (face)
    @{
      if (face[fg_color])
        print ("</FONT>");
      if (face[italicp])
        print ("</I>");
      if (face[boldp])
        print ("</B>");
    @}

    LANGUAGE_SPECIALS = /[<>\&\"]/;

    return;
  @}
@}
@end example

@c ----------------------------------------------------------------------
@page
@node Index,  , Writing New Highlighting Definitions, Top
@unnumbered Index

@printindex cp

@contents
@bye