A log file highlighter

Features

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Table of Contents

Overview

tailspin works by reading through a log file line by line, running a series of regexes against each line. The regexes recognize patterns like dates, numbers, severity keywords and more.

tailspin does not make any assumptions on the format or position of the items it wants to highlight. For this reason, it requires no configuration or setup and will work predictably regardless of the format the log file is in.

Installing

The binary name for tailspin is spin.

```console

Cargo

cargo install tailspin

Debian

apt install tailspin

AUR

paru -S tailspin

Nix

nix-shell -p tailspin ```

Highlight Groups

Dates

Keywords

URLs

Numbers

IP Addresses

Quotes

Unix file paths

UUIDs

Key-value pairs

Unix processes

Customizing Highlight Groups

Overview

tailspin uses a single config.toml file to configure all highlight groups. When customizing highlights, it is advised to start with the --create-default-config flag to place a config.toml with default options in ~/.config/tailspin.

To disable a highlight group, either comment it out or delete it.

Highlights have the following shape:

toml style = { fg = "color", bg = "color", italic = false, bold = false, underline = false }

Adding Keywords

To add custom keywords, either include them in the list of keywords or add new entries:

```toml [[groups.keywords]] words = ['MyCustomKeyword'] style = { fg = "green" }

[[groups.keywords]] words = ['null', 'true', 'false'] style = { fg = "red", italic = true } ```

Working with stdin and stdout

By default, tailspin will open a file in the pager less. However, if you pipe something into tailspin, it will print the highlighted output directly to stdout. This is similar to running spin [file] --print.

To let tailspin highlight the logs of different commands, you can pipe the output of those commands into tailspin like so:

console journalctl -f | spin cat /var/log/syslog | spin kubectl logs -f pod_name | spin

Using the pager less

Overview

tailspin uses less as its pager to view the highlighted log files. You can get more info on less via the man command (man less) or by hitting the h button to access the help screen.

Navigating

Navigating within less uses a set of keybindings that may be familiar to users of vim or other vi-like editors. Here's a brief overview of the most useful navigation commands:

Follow mode

When you run tailspin with the -f or --follow flag, it will scroll to the bottom and print new lines to the screen as they're added to the file.

To stop following the file, interrupt with Ctrl + C. This will stop the tailing, but keep the file open, allowing you to review the existing content.

To resume following the file from within less, press Shift + f.

Search

Use / followed by your search query. For example, /ERROR finds the first occurrence of ERROR.

After the search, n finds the next instance, and N finds the previous instance.

Filtering

less allows filtering lines by a keyword, using & followed by the pattern. For instance, &ERROR shows only lines with ERROR.

To only show lines containing either ERROR or WARN, use a regular expression: &\(ERROR\|WARN\).

To clear the filter, use & with no pattern.

Settings

console -f, --follow Follow the contents of the file -t, --tail Start at the end of the file -p, --print Print the output to stdout -c, --config-path PATH Path to a custom configuration file -t, --follow-command 'CMD' Follows the output of the provided command --create-default-config Generate a new configuration file --show-default-config Print the default configuration