README

*** Since Github is now part of Mordor Corp, the highlight Git repo        ***
*** moved to https://gitlab.com/saalen/highlight                           ***

-------------------------------------------------------------------------------
---  HIGHLIGHT MANUAL -------  Version 3.43   ------------------ April 2018 ---
-------------------------------------------------------------------------------

OSI Certified Open Source Software

Deutsche Anleitung: README_DE

CONTENT
-------------------------------------------------------------------------------

1. OVERVIEW
   1.1 INTENDED PURPOSE
   1.2 FEATURE LIST
   1.3 SUPPORTED PROGRAMMING AND MARKUP LANGUAGES

2. USAGE AND OPTIONS
   2.1 QUICK INTRODUCTION
   2.2 CLI OPTIONS
   2.3 GUI OPTIONS
   2.4 INPUT AND OUTPUT
   2.5 GNU SOURCE-HIGHLIGHT COMPATIBILITY
   2.6 ADVANCED OPTIONS
   2.7 ENVIRONMENT VARIABLES

3. CONFIGURATION
   3.1 FILE FORMAT
   3.2 LANGUAGE DEFINITIONS 
   3.3 REGULAR EXPRESSIONS
   3.4 THEME DEFINITIONS
   3.5 KEYWORD GROUPS
   3.6 PLUG-INS
   3.7 FILE MAPPING
   3.8 CONFIG FILE SEARCH

4. EMBEDDING HIGHLIGHT
   4.1 SAMPLE SCRIPTS
   4.2 PANDOC
   4.3 SWIG
   4.4 TCL
   4.5 THIRD PARTY SCRIPTS AND PLUG-INS

5. BUILDING AND INSTALLING
   5.1 PRECOMPILED PACKAGES
   5.2 BUILDING DEPENDENCIES

6. DEVELOPER CONTACT


1. OVERVIEW
-------------------------------------------------------------------------------

Highlight converts sourcecode to HTML, XHTML, RTF, ODT, LaTeX, TeX, SVG, BBCode, 
Pango markup and terminal escape sequences with coloured syntax highlighting.
Language definitions and colour themes are customizable.


1.1 INTENDED PURPOSE
-------------------------------------------------------------------------------

Highlight was designed to offer a flexible but easy to use syntax highlighter
for several output formats. No syntax or colouring information is hardcoded,
instead all relevant data is stored in configuration scripts. These Lua scripts
may be altered and enhanced with plug-in scripts.


1.2 FEATURE LIST
-------------------------------------------------------------------------------

* highlighting of keywords, types, strings, numbers, escape sequences, comments,
  operators and preprocessor directives
* coloured output in HTML, XHTML 1.1, RTF, TeX, LaTeX, SVG, BBCode, Pango Markup 
  and terminal escape sequences
* supports referenced stylesheet files for HTML, LaTeX, TeX or SVG output
* configuration files are Lua scripts
* supports plug-in scripts to tweak language definitions and themes
* syntax elements are defined as regular expressions or plain string lists
* customizable keyword groups
* recognition of nested languages within a file
* reformatting and indentation of C, C++, C# and Java source code
* wrapping of long lines
* configurable output of line numbers


1.3 SUPPORTED PROGRAMMING AND MARKUP LANGUAGES
-------------------------------------------------------------------------------

Please see README_LANGLIST for the current set of supported languages.
You may also run "highlight --list-scripts=langs" to get a list and associated
file extensions.


2. USAGE AND OPTIONS
-------------------------------------------------------------------------------

2.1 QUICK INTRODUCTION
-------------------------------------------------------------------------------

The following examples show how to produce a highlighted C++ file, using 
main.cpp as input file:

- Generate HTML:
  highlight -i main.cpp -o main.cpp.html
  highlight < main.cpp > main.cpp.html --syntax cpp

  You will find the HTML file and highlight.css in the working directory.
  If you use IO redirection (2nd example), you must define the programming
  language with --syntax.

- Generate HTML with embedded CSS definitions and line numbers:
  highlight -i main.cpp -o main.cpp.html --include-style --line-numbers

- Generate HTML with inline CSS definitions:
  highlight -i main.cpp -o main.cpp.html --inline-css

- Generate LaTeX using "horstmann" source formatting style and "neon" colour
  theme: 
  highlight -O latex -i main.cpp -o main.cpp.tex --reformat horstmann --style neon

  The following output formats may be defined with --out-format:
  
  html:      HTML5 (default)
  xhtml:     XHTML 1.1
  tex:       Plain TeX
  latex:     LaTeX
  rtf:       RTF
  odt:       OpenDocument Text (Flat XML)
  svg:       SVG
  bbcode:    BBCode
  pango:     Pango markup
  ansi:      Terminal 16 color escape codes
  xterm256:  Terminal 256 color escape codes
  truecolor: Terminal 16m color escape codes

- Customize font settings:
  highlight --syntax ada --font-size 12 --font "'Courier New',monospace"
  highlight --syntax ada --out-format=latex --font-size tiny --font sffamily

- Define an output directory:
  highlight -d some/target/dir/ *.cpp *.h

See "highlight --help" or "man highlight" for more details.


2.2 CLI OPTIONS
-------------------------------------------------------------------------------

The command line version of highlight offers the following options:

USAGE: highlight [OPTIONS]... [FILES]...

General options:

 -B, --batch-recursive=<wc>     convert all matching files, searches subdirs
                                  (Example: -B '*.cpp')
 -D, --data-dir=<directory>     set path to data directory
     --config-file=<file>       set path to a lang or theme file
 -d, --outdir=<directory>       name of output directory
 -h, --help                     print this help
 -i, --input=<file>             name of single input file
 -o, --output=<file>            name of single output file
 -P, --progress                 print progress bar in batch mode
 -q, --quiet                    supress progress info in batch mode
 -S, --syntax=<type>            specify type of source code
 -v, --verbose                  print debug info
     --force                    generate output if input syntax is unknown
     --list-scripts=<type>      list installed scripts
                                  <type> = [langs, themes, plugins]
     --plug-in=<script>         execute Lua plug-in script; repeat option to
                                  execute multiple plug-ins
     --plug-in-param=<value>    set plug-in input parameter
     --print-config             print path configuration
     --print-style              print stylesheet only (see --style-outfile)
     --skip=<list>              ignore listed unknown file types
                                  (Example: --skip='bak;c~;h~')
     --start-nested=<lang>      define nested language which starts input
                                  without opening delimiter
     --stdout                   output to stdout (batch mode, --print-style)
     --validate-input           test if input is text, remove Unicode BOM
     --version                  print version and copyright information


Output formatting options:

 -O, --out-format=<format>      output file in given format
                                  <format>=[html, xhtml, latex, tex, odt, rtf,
                                  ansi, xterm256, truecolor, bbcode, pango, svg]
 -c, --style-outfile=<file>     name of style file or print to stdout, if
                                  'stdout' is given as file argument
 -e, --style-infile=<file>      to be included in style-outfile (deprecated)
                                  use a plug-in file instead
 -f, --fragment                 omit document header and footer
 -F, --reformat=<style>         reformats and indents output in given style
                                  <style> = [allman, banner, gnu,
                                  horstmann, java, kr, linux, mozilla, otbs, vtk,
                                  stroustrup, whitesmith, google, pico, lisp]
 -I, --include-style            include style definition in output file
 -J, --line-length=<num>        line length before wrapping (see -V, -W)
 -j, --line-number-length=<num> line number width incl. left padding (default: 5)
 -k, --font=<font>              set font (specific to output format)
 -K, --font-size=<num?>         set font size (specific to output format)
 -l, --line-numbers             print line numbers in output file
 -m, --line-number-start=<cnt>  start line numbering with cnt (assumes -l)
 -s, --style=<style>            set colour style (theme)
 -t, --replace-tabs=<num>       replace tabs by <num> spaces
 -T, --doc-title=<title>        document title
 -u, --encoding=<enc>           set output encoding which matches input file
                                  encoding; omit encoding info if set to NONE
 -V, --wrap-simple              wrap lines after 80 (default) characters w/o
                                  indenting function parameters and statements
 -W, --wrap                     wrap lines after 80 (default) characters
     --wrap-no-numbers          omit line numbers of wrapped lines
                                  (assumes -l)
 -z, --zeroes                   pad line numbers with 0's
     --delim-cr                 set CR as end-of-line delimiter (MacOS 9)
     --keep-injections          output plug-in injections in spite of -f
     --kw-case=<case>           change case of case insensitive keywords
                                  <case> =  [upper, lower, capitalize]
     --no-trailing-nl           omit trailing newline
     --no-version-info          omit version info comment


(X)HTML output options:

 -a, --anchors                  attach anchor to line numbers
 -y, --anchor-prefix=<str>      set anchor name prefix
 -N, --anchor-filename          use input file name as anchor prefix
 -C, --print-index              print index with hyperlinks to output files
 -n, --ordered-list             print lines as ordered list items
     --class-name=<name>        set CSS class name prefix;
                                  omit class name if set to NONE
     --inline-css               output CSS within each tag (verbose output)
     --enclose-pre              enclose fragmented output with pre tag 
                                  (assumes -f)


LaTeX output options:

 -b, --babel                    disable Babel package shorthands
 -r, --replace-quotes           replace double quotes by \dq{}
     --beamer                   adapt output for the Beamer package
     --pretty-symbols           improve appearance of brackets and other symbols


RTF output options:

     --page-color               include page color attributes
 -x, --page-size=<ps>           set page size 
                                  <ps> = [a3, a4, a5, b4, b5, b6, letter]
     --char-styles              include character stylesheets


SVG output options:

     --height                   set image height (units allowed)
     --width                    set image width (see --height)


GNU source-highlight compatibility options:

     --doc                      create stand alone document
     --no-doc                   cancel the --doc option
     --css=filename             the external style sheet filename
     --src-lang=STRING          source language
 -t, --tab=INT                  specify tab length
 -n, --line-number[=0]          number all output lines, optional padding
     --line-number-ref[=p]      number all output lines and generate an anchor,
                                  made of the specified prefix p + the line
                                  number  (default='line')
     --output-dir=path          output directory
     --failsafe                 if no language definition is found for the
                                  input, it is simply copied to the output
                                  
2.3 GUI OPTIONS
-------------------------------------------------------------------------------

The Graphical User Interface offers a subset of the CLI's features. It includes
a dynamic preview of the output file's apperarance. Please see screenshots and
screencasts on the project website.
Invoke highlight-gui with the --portable option to let it save its settings
in the binary's current directory (instead of using the registry).


2.4 INPUT AND OUTPUT
-------------------------------------------------------------------------------

If no input or output file name is defined by --input and --output options,
highlight will use stdin and stdout for file processing.

If no input filename is defined by --input or given at the prompt, highlight is
not able to determine the language type by means of the file extension (except
some scripting languages which are figured out by the shebang in the first input
line). In this case you have to pass highlight the given langage with --syntax
(this should be the file suffix of the source file in most cases).
Example: If you want to convert a Python file, highlight needs to load the
py.lang language definition. The correct argument of --syntax would be "py".

highlight test.py
highlight < test.py --syntax py       # --syntax option necessary
cat test.py | highlight --syntax py

If there exist multiple suffixes (like C, cc, cpp, h for C++ - files),
they are mapped to a language definition in $CONF_DIR/filetypes.conf.

Highlight enters the batch processing mode if multiple input files are defined
or if --batch-recursive is set.
In batch mode, highlight will save the generated files using the original
filename, appending the extension of the chosen output type.
If files in the input directories happen to share the same name, the output
files will be prefixed with their source path name.
The --out-dir option is recommended in batch mode. Use --quiet to improve
performance (recommended for usage in shell scripts).

HTML, TeX, LaTeX and SVG output
-------------------------------

The HTML, TeX, LaTeX and SVG output formats allow to reference a stylesheet
file which contains the formatting information.

In HTML and SVG output, this file contains CSS definitions and is saved as
'highlight.css'. In LaTeX and TeX, it contains macro definitions, and is saved
as 'highlight.sty'.

Name and path of the stylesheet may be modified with --style-outfile.
If the --outdir option is given, all generated output, including stylesheets,
are stored in this directory.

Use --include-style to embed the style information in the output documents
without referencing a stylesheet.

Referenced stylesheets have the advantage to share all formatting information
in a single file, which affects all referencing documents.

With --style-infile you define a file to be included in the final formatting
information of the document. This way you enhance or redefine the default
highlight style definitions without editing generated code.
Note: Using a plug-in script is the preferred way to enhance styling.

Terminal output:
----------------

Since there are limited colours defined for ANSI terminal output, there exists
only one hard coded colour theme with --out-format=ansi. You should therefore
use --out-format=xterm256 to enable output in 256 colours. The 256 colour mode
is supported by recent releases of xterm, rxvt and Putty (among others).
Recent terminal emulators also support 16m colors, this mode is enabled with
--out-format=truecolors.

highlight --out-format=ansi <inputfile> | less -R
highlight --out-format=xterm256 <inputfile> | less -R

Text processing:
----------------

If the language definition is specified as "txt", no highlighting takes place.

highlight -S txt --out-format=latex README > README.tex


Examples
--------

highlight --out-format=xhtml  --batch-recursive '*.cpp' --outdir ~/html_code/
This command converts all *.cpp files in the current directory and its sub-
directories to xhtml files, and stores the output in /home/you/html_code.

highlight -out-format=latex  * --outdir /home/you/latex_code/
This command onverts all files to LaTeX, stored in /home/you/latex_code/.

highlight --stdout -s seashell --print-style
This command prints only the CSS information to stdout (theme: Seashell).


2.5 GNU SOURCE-HIGHLIGHT COMPATIBILITY
-------------------------------------------------------------------------------

The command line interface is extensively harmonised with source-highlight
(http://www.gnu.org/software/src-highlite/).

The following highlight options have the same meaning as in source-highlight:
 --input, --output, --help, --version, --out-format, --title, --data-dir,
 --verbose, --quiet

These options were added to enhance compatibility:
 --css, --doc, --failsafe, --line-number, --line-number-ref, --no-doc, --tab,
 --output-dir, --src-lang

These switches provide a common highlighter interface for scripts, plugins etc.


2.6 ADVANCED OPTIONS
-------------------------------------------------------------------------------

Prevent parsing of binary input files
-------------------------------------

If highlight could be invoked with all kinds of input, you can disable parsing
of binary files using --validate-input. This flag causes highlight to match the
input file header with a list of magic numbers. If a binary file type is
detected, highlight quits with an error message. This switch also removes an
UTF-8 BOM in the output.

Highlight nested code without starting delimiter
------------------------------------------------

If a file starts with an embedded code section which misses an appropriate opening
delimiter, the --start-nested option will switch to the nested language mode.
This can be useful with LuaTeX files:
highlight luatex.tex --latex --start-nested=inc_luatex

inc_luatex is a Lua language definition with TeX line comments.
Note that the nested code section has to end with the ending delimiter defined
in the host language definition.

Test new configuration scripts
------------------------------

The option --config-file helps to test new config files before installing them.
The given file must be a lang or theme file.

highlight --config-file xxx.lang --config-file yyy.theme -I

Debug language definitions
--------------------------

Use --verbose to display the Lua and syntax data.

Remove an UTF8 BOM:
-------------------

Use --validate-input to get rid of UTF8 byte order marks.

Force output to stdout
----------------------

Use --stdout to write output files in batch mode to stdout.

Portable GUI (Windows build)
----------------------------

Invoke highlight-gui.exe with the --portable switch to save its configuration
in text files instead of the registry.


2.7 ENVIRONMENT VARIABLES
-------------------------------------------------------------------------------

The command line version recognizes these variables:

HIGHLIGHT_DATADIR: sets the path to highlight's configuration scripts
HIGHLIGHT_OPTIONS: may contain command line options, but no input file paths.


3. CONFIGURATION
-------------------------------------------------------------------------------

3.1 FILE FORMAT
-------------------------------------------------------------------------------

Configuration files are Lua scripts. 
Please refer to http://www.lua.org/manual/5.1/manual.html for more details
about the Lua syntax.

These constructs are sufficient to edit the scripts:

Variable assigment:
name = value
(variables have no type, only values have)

Strings:
string1="string literal with escape: \n"
string2=[[raw string without escape sequence]]

If raw string content starts with "[" or ends with "]", pad the paranthesis
with space to avoid a syntax error. Highlight will strip the string.
If the string is a regular expression containing a set with a character class
like [[:space:]], use string delimiters with a "filler": [=[ regex string ]=]

Comments:
-- line comment
--[[ block comment ]]

Arrays:
array = { first=1, second="2", 3, { 4,5 } }
Arrays may contain variables and can be nested.


3.2 LANGUAGE DEFINITIONS
-------------------------------------------------------------------------------

A language definition describes all elements of a programming language which
will be highlighted by different colours and font types.
Save the new file in langDefs/, using the following name convention:
<usual extension of sourcecode files>.lang

Examples: PHP -> php.lang, Java -> java.lang
If there exist multiple suffixes, list them in filetypes.conf.


Syntax elements:

Keywords = { Id, List|Regex, Group? }

  Id:    Integer, keyword group id (values 1-4, can be reused for several keyword
          groups)
  List:  List, list of keywords
  Regex: String, regular expression
  Group: Integer, capturing group id of regular expression, defines part of regex
         which should be returned as keyword (optional; if not set, the match
         with the highest group number is returned (counts from left to right))


Comments = { {Block, Nested?, Delimiter={Open, Close?} }

  Block:     Boolean, true if comment is a block comment
  Nested:    Boolean, true if block comments can be nested (optional)
  Delimiter: List, contains open delimiter regex (line comment) or open and close
             delimiter regexes (block comment)


Strings = { Delimiter|DelimiterPairs={Open, Close, Raw?}, Escape?, Interpolation?,
            RawPrefix?, AssertEqualLength? }

  Delimiter:         String, regular expression which describes string delimiters
  DelimiterPairs:    List, includes open and close delimiter expressions if not
                     equal, includes optional Raw flag as boolean which marks
                     delimiter pair to contain a raw string
  Escape:            String, regex of escape sequences (optional)
  Interpolation:     String, regex of interpolation sequences (optional)
  RawPrefix:         String, defines raw string indicator (optional)
  AssertEqualLength: Boolean, set true if delimiters must have the same length


PreProcessor = { Prefix, Continuation? }

  Prefix:        String, regular expression which describes open delimiter
  Continuation:  String, contains line continuation character (optional).


NestedSections = {Lang, Delimiter= {} }

  Lang:      String, name of nested language
  Delimiter: List, contains open and close delimiters of the code section
  

Description:       String, Defines syntax description

Digits:            String, Regular expression which defines digits (optional)

Identifiers:       String, Regular expression which defines identifiers
                   (optional)

Operators:         String, Regular expression which defines operators

EnableIndentation: Boolean, set true if syntax may be reformatted and indented

IgnoreCase:        Boolean, set true if keyword case should be ignored


Global variables:

The following variables are available within a language definition:

HL_LANG_DIR: path of language definition directory (use with Lua dofile function)

Identifiers: Default regex for identifiers
Digits:      Default regex for numbers

The following integer variables represent the internal highlighting states:

HL_STANDARD
HL_STRING
HL_NUMBER
HL_LINE_COMMENT
HL_BLOCK_COMMENT
HL_ESC_SEQ
HL_PREPROC
HL_PREPROC_STRING
HL_OPERATOR
HL_INTERPOLATION
HL_LINENUMBER
HL_KEYWORD
HL_STRING_END
HL_LINE_COMMENT_END
HL_BLOCK_COMMENT_END
HL_ESC_SEQ_END
HL_PREPROC_END
HL_OPERATOR_END
HL_INTERPOLATION_END
HL_KEYWORD_END
HL_EMBEDDED_CODE_BEGIN
HL_EMBEDDED_CODE_END
HL_IDENTIFIER_BEGIN
HL_IDENTIFIER_END
HL_UNKNOWN
HL_REJECT

The function OnStateChange:

This function is a hook which is called if an internal state changes (e.g. from
HL_STANDARD to HL_KEYWORD if a keyword is found). It can be used to alter
the new state or to manipulate syntax elements like keyword lists.

OnStateChange(oldState, newState, token, kwGroupID)

  Hook Event: Highlighting parser state change
  Parameters: oldState:  old state
              newState:  intended new state
              token:     the current token which triggered the new state
              kwGroupID: if newState is HL_KEYWORD, the parameter
                         contains the keyword group ID
  Returns:    Correct state to continue OR HL_REJECT

Return HL_REJECT if the recognized token and state should be discarded; the 
first character of token will be outputted and highlighted as "oldState".

The highlighting is not working as expected? See src/include/codegenerator.hpp
for details about the parser.

Examples:

function OnStateChange(oldState, newState, token)
   if token=="]]" and oldState==HL_STRING and newState==HL_BLOCK_COMMENT_END then
      return HL_STRING_END
   end
   return newState
end

This function resolves a Lua parsing issue with the "]]" close delimiter which
ends both comments and strings.


function OnStateChange(oldState, newState, token)
   if token=="'" and oldState==HL_NUMBER and newState==HL_STRING then
      return HL_NUMBER
   end   
   return newState
end

This hook enables correct parsing of C++14 number separator syntax.

See README_PLUGINS for other available functions.


Example:
--------

Description="C and C++"

Keywords={
  {  Id=1,
   List={"goto", "break", "return", "continue", "asm", "case", "default",
         -- [..]
        }
  },
  -- [..]
}

Strings = {
  Delimiter=[["|']],
  RawPrefix="R",
}

Comments = {
   { Block=true,
     Nested=false,
     Delimiter = { [[\/\*]], [[\*\/]] }  },
   { Block=false,
     Delimiter = { [[//]] } }
}

IgnoreCase=false

PreProcessor = {
  Prefix=[[#]],
  Continuation="\\",
}

Operators=[[\(|\)|\[|\]|\{|\}|\,|\;|\.|\:|\&|\<|\>|\!|\=|\/|\*|\%|\+|\-|\~]]

EnableIndentation=true


3.3 REGULAR EXPRESSIONS
-------------------------------------------------------------------------------

Please see README_REGEX for the supported regex constructs.


3.4 THEME DEFINITIONS
-------------------------------------------------------------------------------

Colour themes contain the formatting information of the language elements which
are described in language definitions.

The files have to be stored as *.theme in themes/.
Apply a theme with the --style option.


Format attributes:

Attributes = {Colour, Bold?, Italic?, Underline? }

Colour:    String, defines colour in HTML hex notation ("#rrggbb")
Bold:      Boolean, true if font should be bold (optional)
Italic:    Boolean, true if font should be italic (optional)
Underline: Boolean, true if font should be underlined (optional)


Theme elements:

Description:   String, Defines theme description

Default        = Attributes (Colour of unspecified text)

Canvas         = Attributes (Background colour )

Number         = Attributes (Formatting of numbers)

Escape         = Attributes (Formatting of escape sequences)

String         = Attributes (Formatting of strings)

Interpolation  = Attributes (Formatting of interpolation sequences)

PreProcessor   = Attributes (Formatting of preprocessor directives)

StringPreProc  = Attributes (Formatting of strings within
                            preprocessor directives)

BlockComment   = Attributes (Formatting of block comments)

LineComment    = Attributes (Formatting of line comments)

LineNum        = Attributes (Formatting of line numbers)

Operator       = Attributes (Formatting of operators)

Keywords= {
  Attributes1,
  Attributes2,
  Attributes3,
  Attributes4,
}

AttributesN: Formatting of keyword group N. There should be at least four items
             to match the number of keyword groups defined in the language
             definitions

Example:

Default        = { Colour="#000000" }
Canvas         = { Colour="#ffffff" }
Number         = { Colour="#000000" }
Escape         = { Colour="#bd8d8b" }
String         = { Colour="#bd8d8b" }
StringPreProc  = { Colour="#bd8d8b" }
BlockComment   = { Colour="#ac2020", Italic=true }
PreProcessor   = { Colour="#000000" }
LineNum        = { Colour="#555555" }
Operator       = { Colour="#000000" }
LineComment = BlockComment

Keywords = {
  { Colour= "#9c20ee", Bold=true },
  { Colour= "#208920" },
  { Colour= "#0000ff" },
  { Colour= "#000000" },
}


3.5 KEYWORD GROUPS
-------------------------------------------------------------------------------

You may define custom keyword groups and corresponding highlighting styles.
This is useful if you want to highlight functions of a third party library,
macros, constants etc.

You define a new group in two steps:

 1. Define a new group in your language definition:

    Keywords = {
      -- add your keyword description:
      {Id=5, List = {"ERROR", "DEBUG", "WARN"} }
    }

 2. Add a corresponding highlighting style in your colour theme:

    Keywords= {
      --add your keyword style as 5th item in the list:
      { Colour= "#ff0000", Bold=true },
    }

It is recommended to define keyword groups in user-defined plugin scripts to
avoid editing of original highlight files.
See the cpp_qt.lua sample plug-in script and README_PLUGINS for details.


3.6 PLUG-INS
-------------------------------------------------------------------------------

The --plug-in option receives the path of a Lua script which overrides or
enhances the settings of theme and language definition files. Plug-ins make
it possible to apply costum settings without the need to edit installed
configuration files.
You can apply multiple plugins by using the --plug-in option more than once.

See README_PLUGINS for a detailed description and examples of packaged plugins.


3.7 FILE MAPPING
-------------------------------------------------------------------------------

The script filetypes.conf assigns file extensions and shebang descriptions to
language definitions.
A configuration is mandatory only if multiple file extensions are linked to
one syntax or if a extension is ambiguous. Otherwise the syntax definition whose
name corresponds to the input file extension will be applied.

Format:

FileMapping={
  {  Lang, Filenames|Extensions|Shebang },
}

Lang:       String, name of language definition
Filenames:  list of strings, contains filenames referring to "Lang"
Extensions: list of strings, contains file extensions referring to "Lang"
Shebang:    String, Regular expression which matches the first line of the input
            file

Behaviour upon ambiguous file extensions:
- CLI: the first association listed here will be used
- GUI: a syntax selection prompt will be shown

Edit the file gui_files/ext/fileopenfilter.conf to add new syntax types to
the GUI's file open filter.


3.8 CONFIG FILE SEARCH
-------------------------------------------------------------------------------

Configuration scripts are searched in the following directories:

1. ~/.highlight/
2. value of the environment variable HIGHLIGHT_DATADIR
3. user defined directory set with --data-dir (deprecated option)
4. /usr/share/highlight/
5. /etc/highlight/ (location of filetypes.conf)
6. current working directory (fallback)

These subdirectories are expected to contain the corresponding scripts:
-langDefs: *.lang
-themes: *.theme
-plugins: *.lua

A custom filetypes.conf may be placed directly in ~/.highlight/.
This search order enables you to enhance the installed scripts without the need
to copy preinstalled files somewhere else.


4. EMBEDDING HIGHLIGHT
-------------------------------------------------------------------------------

4.1 SAMPLE SCRIPTS
-------------------------------------------------------------------------------

See the extras/ subdirectory in the highlight package for some scripts in PHP,
Perl and Python  which invoke highlight and retrieve its output as string.
These scripts may be used as reference to develop plug-ins for other apps.

4.2 PANDOC
-------------------------------------------------------------------------------

PP macros file and tutorial are located in extras/pandoc.
See README.html for usage instruction and example files as reference.

4.3 SWIG
-------------------------------------------------------------------------------

A SWIG interface file is located in extras/swig.
See README_SWIG for installation instructions and the example scripts in Perl,
PHP and Python as programming reference.

4.4 TCL
-------------------------------------------------------------------------------

A TCL extension is located in extras/tcl.
See README_TCL for installation instructions.


4.5 THIRD PARTY SCRIPTS AND PLUG-INS
-------------------------------------------------------------------------------

See the extras/web_plugins subdirectory in the highlight package for
some plugins which integrate highlight in Wiki and Blogging software:

-DokuWiki
-MovableType
-Wordpress
-Serendipity

Other uses of highlight can be found on andre-smon.de
This site shows several use cases of highlight in projects like Webgit, 
Evolution, Inkscape, Ranger and more.


5. BUILDING AND INSTALLING
-------------------------------------------------------------------------------

5.1 PRECOMPILED PACKAGES
-------------------------------------------------------------------------------

The file INSTALL describes the installation from source and includes links to 
precompiled packages.


5.2 BUILDING DEPENDENCIES
-------------------------------------------------------------------------------

Highlight is known to compile with gcc and clang.
It depends on Boost headers and Lua 5.x/LuaJit developer packages.
The optional GUI depends on Qt5 developer packages.
Please see the makefile for further options.


6. DEVELOPER CONTACT
-------------------------------------------------------------------------------

Andre Simon
andre.simon1@gmx.de
http://www.andre-simon.de/

Github project with Git repository, bug tracker:
https://github.com/andre-simon/highlight

sf.net project with SVN repository, download mirror, bug tracker, help forum:
http://sourceforge.net/projects/syntaxhighlight/