VIM: simple steps to create syntax highlight file - for logfiles

Question

I have some (log4j generated) logfiles to go through; I know their format pretty well (I mean I have already got off-the-peg regexes etc I can use). I want to automatically highlight them in VIM when I load them up (*.log). A logfile entry looks something like this: ``` YYYY-MM-DD HH:MM:ss,SSS [...] #LOG-LEVEL# [...] Message ``` Where #LOG-LEVEL# is one of the standard 'ERROR', 'INFO', 'DEBUG', 'FATAL'....and the 'YYYY-MM...' represents the date/time to millisecond resolution. To get me started , what are the steps needed to get the date-string highlighted in (say) yellow-background with blue text - and also when the text reads ' ERROR ' this should have a red-background with white text. I have tried going through some tutorials on this, but can't find one which is simple enough to understand, so I'm after some real basic steps here ! Cheers EDIT: Here's the summary of what I did, based on the instructions below: Created the syntax file 'log.vim' in .vim\syntax (see below for example…

Accepted Answer

There are three ways of defining syntax items (see `:help :syn-define`):

- Keywords: these are for items that are simple strings of keyword characters. This is the fastest matcher.

- Matches: these are regular expressions for matching.

- Regions: these are for long regions that are likely to contain other items.

There are various arguments that make things more complicated (to do with matches within regions etc), see `:help :syn-arguments` for a discussion of this.

There is a priority that comes into effect (see `:help :syn-priority`).

Colouring is controlled by the highlight command and is separate to the syntax commands.

A simple way to get started would be to use a match to detect the date and a keyword to detect error. Then use highlight to make the colours come to life:

```
" This creates a keyword ERROR and puts it in the highlight group called logError
:syn keyword logError ERROR
" This creates a match on the date and puts in the highlight group called logDate.  The
" nextgroup and skipwhite makes vim look for logTime after the match
:syn match logDate /^\d\{4}-\d\{2}-\d\{2}/ nextgroup=logTime skipwhite

" This creates a match on the time (but only if it follows the date)
:syn match logTime /\d\{2}:\d\{2}:\d\{2},\d\{3}/

" Now make them appear:
" Link just links logError to the colouring for error
hi link logError Error
" Def means default colour - colourschemes can override
hi def logDate guibg=yellow guifg=blue
hi def logTime guibg=green guifg=white
```

Bung all of that in ~/.vim/syntax/log.vim and make sure the file type is set properly (see `:help filetype.txt`) - it should then load automatically.

Hopefully that should give you something to get going with. Have a (very gradual) read of the various sections of `:help syntax.txt` and `:help usr_44.txt` for further info.

VIM: simple steps to create syntax highlight file - for logfiles

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