*usr_07.txt*	For Vim version 6.0j.  Last change: 2000 Jul 09

		     VIM USER MANUAL - by Bram Moolenaar
		
			  Using syntax highlighting


|07.1|  Switching it on
|07.2|  No or wrong colors?
|07.3|  Different colors
|07.4|  With colors or without colors
|07.5|  Printing with colors

     Next chapter: |usr_08.txt|  Editing more than one file
 Previous chapter: |usr_06.txt|  Set your settings
Table of contents: |usr_toc.txt|

==============================================================================
*07.1*  Switching it on

It all starts with one simple command: >
	:syntax on

That should work in most situations to get color in your files.  Vim will
automagically detect the type of file and load the right syntax highlighting.
Suddenly comments are blue, keywords brown and strings red.  This makes it
easy to overview the file.  After a while you will find that black&white text
slows you down!

If you always want to use syntax highlighting, put the "syntax on" command in
your |vimrc| file.

If you want syntax highlighting only when the terminal supports colors, you
can put this in your |vimrc| file: >
	if &t_Co > 1
	   syntax on
	endif

If you want syntax highlighting only in the GUI version, put the ":syntax on"
command in your |gvimrc| file.

==============================================================================
*07.2*  No or wrong colors?

There can be a number of reasons why you don't see colors:

- Your terminal does not support colors.
	Vim will use bold, italic and underlined text, but this doesn't look
	very nice.  You probably will want to try to get a terminal with
	colors.  For Unix, I recommend the xterm from the XFree86 project:
	|xfree-xterm|.

- Your terminal does support colors, but Vim doesn't know this.
	Make sure your $TERM setting is correct.  For example, when using an
	xterm that supports colors: >
		setenv TERM xterm-color
<	The terminal name must match the terminal you are using.  If it
	still doesn't work, have a look at |xterm-color|, which shows a few
	ways to make Vim display colors (not only for an xterm).

- The file type is not recognized.
	Vim doesn't know all file types, and sometimes it's near to impossible
	what language a file uses.  Then you can set the type manually: >
		:set syntax=fortran
<	To see which types are available, look in the directory
	$VIMRUNTIME/syntax.
	This can also be done with a |modeline|, so that the file will be
	highlighted each time you edit it.  For example, this line can be used
	in a Makefile: >
		# vim: syntax=make
<	If you are clever, you might be able to detect the file type yourself.
	See |new-filetype| for how to tell Vim to detect that file type.

- There is no highlighing for your file type.
	You could try using a similar file type by manually setting it as
	mentioned above.  If that isn't good enouh, you can write your own
	syntax file, see |mysyntaxfile|.
	

Or the colors could be wrong:

- The colored text is very hard to read.
	Vim guesses the background color that you are using.  If it is black
	(or another dark color) it will use light colors for text.  If it is
	white (or another light color) it will use dark colors for text.  If
	Vim guessed wrong the text will be hard to read.  To solve this, set
	the 'background' option.  For a dark background: >
		:set background=dark
<	And for a light background: >
		:set background=light
<	Make sure you put this _before_ the ":syntax on" command, otherwise
	the colors will already have been set.  You could do ":syntax on"
	after setting 'background' to make Vim set the default colors again.

- The colors are wrong when scrolling bottom to top.
	Vim doesn't read the whole file to parse the text.  It starts parsing
	wherever you are viewing the file.  That saves a lot of time, but
	sometimes the colors are wrong.  A simple fix is hitting CTRL-L.  Or
	scroll back a bit and then forward again.
	For a real fix, see ":syn-sync".

==============================================================================
*07.3*  Different colors				*:syn-default-override*

You can change the colors used for each item with the ":highlight" command.
for example, to make comments green: >
	:highlight Comment ctermfg=green guifg=green
See |:highlight| about how to specify highlighting attributes.

You can make your own preferred set of colors this way.  If you want to use
this always, put the ":highlight" commands in your "vimrc" file.  Make sure
they are _after_ the ":syntax on" command, because that will set the default
colors.

==============================================================================
*07.4*  With colors or without colors

Displaying text in color takes a lot of effort.  If you find the displaying
too slow, you might want to disable syntax highlighthig for a moment: >
	:syntax clear
When editing another file (or the same one) the colors will come back.
							*:syn-off*
If you want to stop highlighting completely use: >
	:syntax off
This will completely disable syntax highlighting and remove it immediately for
all buffers.

							*:syn-manual*
If you want syntax highlighting only for specific files, use this: >
	:syntax manual
This will enable the syntax highlighting, but not switch it on automatically
when starting to edit a buffer.  To switch highlighting on for the current
buffer, set the 'syntax' option: >
	:set syntax=ON
<
==============================================================================
*07.5*  Printing with colors				*syntax-printing*

If you want to print your colored text, you will have to convert it to HTML
first, and then print it from a web browser such as Netscape.  See |2html.vim|
for details.

To do this manually, edit the file you want to print: >
	:e main.c
The source the 2html.vim script: >
	:source $VIMRUNTIME/syntax/2html.vim
You will see it crunching away, and some time later another window shows the
HTML code.  Now write this somewhere: >
	:w main.c.html
Open this file in your favorite browser and print it from there.

Instead of printing, you could also put the HTML file on a web server, and let
others look at the colored text.

==============================================================================
 vim:tw=78:
