A simple and lightweight Neovim plugin that brings syntax highlighting to generic log files and provides straightforward configuration to manage filetype detection rules and custom keyword highlighting for your logs.

Use your favorite plugin manager to install the plugin.

{
    'fei6409/log-highlight.nvim',
    opts = {},
},

Plug 'fei6409/log-highlight.nvim'

Don't forget to add syntax on in your .vimrc, init.vim, or init.lua to enable syntax highlighting.

This plugin uses Neovim's built-in filetype detection mechanism.

By default, the log filetype is only applied to files with .log extension (e.g., sys.log) after setup.

To further configure filetype detection rules and other options:

require('log-highlight').setup {
    ---@type string|string[]: File extensions. Default: 'log'
    extension = 'log',

    ---@type string|string[]: File names or full file paths. Default: {}
    filename = {
        'syslog',
    },

    ---@type string|string[]: File name/path glob patterns. Default: {}
    pattern = {
        -- Use `%` to escape special characters and match them literally.
        '%/var%/log%/.*',
        'console%-ramoops.*',
        'log.*%.txt',
        'logcat.*',
    },

    ---@type table<string, string|string[]>: Custom keywords to highlight.
    ---This allows you to define custom keywords to be highlighted based on
    ---the group.
    ---
    ---The following highlight groups are supported:
    ---    'error', 'warning', 'info', 'debug' and 'pass'.
    ---
    ---The value for each group can be a string or a list of strings.
    ---All groups are empty by default. Keywords are case-sensitive.
    keyword = {
        error = 'ERROR_MSG',
        warning = { 'WARN_X', 'WARN_Y' },
        info = { 'INFORMATION' },
        debug = {},
        pass = {},
    },
}

By default, the log filetype is applied to files matching *.log or *_log.

You can customize filetype rules by adding autocommands to .vimrc like this:

autocmd BufNewFile,BufRead /var/log/* set filetype=log

• v1.2.1: Fix bug that may write the syntax file in directory with no permission
• v1.2.0: Allow keyword customization in selected range
• v1.1.0: Add more pattern highlighting to log levels, date & time, hex numbers, MAC addresses, and Windows and POSIX paths
• v1.0.1: Add support for spdlog-style and lowercase log levels
• v1.0.0: Perform minor cleanup and mark official release
• v0.0.2: Add more support for HDL
• v0.0.1: Initial release

Bug reports, feature requests, and pull requests are welcome. When opening an issue or PR, please consider attaching a snippet of the relevant log pattern.

If you are submitting a pull request, please also consider adding new log samples to the samples/ directory:

• For atomic patterns or small snippets, add them to patterns.log.
• For longer, real-world log examples, create a new file.

This helps verify that new changes do not break existing syntax highlighting.

• vim-log-highlighting by MTDL9
• Built-in messages.vim

This project is licensed under the MIT License.