06Using syntax highlighting
Black and white text is boring. With colors your file comes to life. This not only looks nice, it also speeds up your work. Change the colors used for the different sorts of text. Print your text, with the colors you see on the screen.
- Switching it on
- No or wrong colors?
- Different colors
- With colors or without colors
- Printing with colors
- Further reading
Table of contents
06.1Switching it on
It all starts with one simple command:
:syntax enable
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 enable
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 enable
endif
If you want syntax highlighting only in the GUI version, put the ":syntax enable" command in your gvimrc file.
06.2No 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
or (depending on your shell):
TERM=xterm-color; export TERM
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 to tell what language a file uses. Try this command:
:set filetype
If the result is
filetype=
then the problem is indeed that Vim doesn't know what type of file this is. You can set the type manually::set filetype=fortran
To see which types are available, look in the directory
$VIMRUNTIME/syntax
. For the GUI you can use the Syntax menu. Setting the filetype 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 (put it near the start or end of the file):# vim: syntax=make
You might know how to detect the file type yourself. Often the file name extension (after the dot) can be used. See new‑filetype for how to tell Vim to detect that file type.
There is no highlighting for your file type.
You could try using a similar file type by manually setting it as mentioned above. If that isn't good enough, 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 enable
command, otherwise the colors will already have been set. You could do:syntax reset
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. Some syntax files have a way to make it look further back, see the help for the specific syntax file. For example, tex.vim for the TeX syntax.
06.3Different colors
If you don't like the default colors, you can select another color scheme. In the GUI use the Edit/Color
Scheme menu. You can also type the command:
:colorscheme evening
evening
is the name of the color scheme. There are several others you might want to try out. Look in the directory $VIMRUNTIME/colors
.
When you found the color scheme that you like, add the :colorscheme
command to your vimrc file.
You could also write your own color scheme. This is how you do it:
Select a color scheme that comes close. Copy this file to your own Vim directory. For Unix, this should work:
!mkdir ~/.vim/colors !cp $VIMRUNTIME/colors/morning.vim ~/.vim/colors/mine.vim
This is done from Vim, because it knows the value of
$VIMRUNTIME
.Edit the color scheme file. These entries are useful:
term
attributes in a B&W terminal cterm
attributes in a color terminal ctermfg
foreground color in a color terminal ctermbg
background color in a color terminal gui
attributes in the GUI guifg
foreground color in the GUI guibg
background color in the GUI For example, to make comments green:
:highlight Comment ctermfg=green guifg=green
Attributes you can use for
cterm
andgui
arebold
andunderline
. If you want both, usebold,underline
. For details see the :highlight command.Tell Vim to always use your color scheme. Put this line in your vimrc:
colorscheme mine
If you want to see what the most often used color combinations look like, use this command:
:runtime syntax/colortest.vim
You will see text in various color combinations. You can check which ones are readable and look nice.
06.4With 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 highlighting for a moment:
:syntax clear
When editing another file (or the same one) the colors will come back.
If you want to stop highlighting completely use:
:syntax off
This will completely disable syntax highlighting and remove it immediately for all buffers. See :syntax‑off for more details.
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
06.5Printing with colors
In the MS-Windows version you can print the current file with this command:
:hardcopy
You will get the usual printer dialog, where you can select the printer and a few settings. If you have a color printer, the paper output should look the same as what you see inside Vim. But when you use a dark background the colors will be adjusted to look good on white paper.
There are several options that change the way Vim prints:
'printdevice' 'printheader' 'printfont' 'printoptions'
To print only a range of lines, use Visual mode to select the lines and then type the command:
v100j:hardcopy
v
starts Visual mode. 100j
moves a hundred lines down, they will be highlighted. Then :hardcopy
will print those lines. You can use other commands to move in Visual mode, of course.
This also works on Unix, if you have a PostScript printer. Otherwise, you will have to do a bit more work. You need to convert the text to HTML first, and then print it from a web browser.
Convert the current file to HTML with this command:
:TOhtml
In case that doesn't work:
:source $VIMRUNTIME/syntax/2html.vim
You will see it crunching away, this can take quite a while for a large file. Some time later another window shows the HTML code. Now write this somewhere (doesn't matter where, you throw it away later):
:write main.c.html
Open this file in your favorite browser and print it from there. If all goes well, the output should look exactly as it does in Vim. See 2html.vim for details. Don't forget to delete the HTML file when you are done with it.
Instead of printing, you could also put the HTML file on a web server, and let others look at the colored text.
06.6Further reading
“Your own syntax highlighted” Your own syntax highlighted. syntax All the details.