TAIL TALES

A TUI log parser written in Rust

Objetives

To easy inspect existing logs or streaming logs, with some filters, marking of messages and easy finding information in the logs.

Use

• Can set default command or file to open: tt
• Can read exisitng files, checks for changes: tt /var/log/messages
• Can be used as pipe destination: journalctl -f | tt
• Can execute commands and show stdout / stderr: tt !journalctl -f -- AS bash does not like use of ! in commands there is an alternative format: tt -- journalctl -f. Another option is tt \!journalctl -f.

Commands

All keybindings are transalted to internal commands. It's possible to execute commands directly entering command mode (: by default).

Keybindings

Settings

It comes with some sensible default settings from the settings.yaml file. It can overwriten, by section at ~/.config/tailtales/settings.yaml or the appropiate XDG config directory. See the file for further information.

Rules

The settings file have several default rules, and more may be added (send your pull request with new file formats!).

It has a basic pattern on the file name to discover which rules to use and acording to the matrched rule it can set:

• Data extractors: as logfmt, patterns and regex. These extracted data allows easy filtering and search.
• Columns: From the extracted data, it can show some data into the columns.For example to easily format timestamp or processing time.
• Filters: Acording filters from the filtering language, allows to color the lines, or add a gutter (symbol at the left of the table).

Filter Language

Its possible to search and filter based on both the line and the structured parsed contents.

• Just text will look for text
• The proper way is "text", but if just a simple text is given its understood as text (converts the variable name to a string)
• ~ regex or better ~ "regex" can also be used to search / filter by regex
• Basic operations as >, <, >=, <=, ==, != between variablers (record fields) and strings or numbers

More will be added.

Example expressions

• INFO
• "^INFO -- The closing " is assumed
• timestamp <= "2025-01-01" -- The comparison is string based, so timestamps better in ISO format
• line_number > 1000 && line_number < 2000 -- TODO, no priority, no parenteheiss, will not work

Features

• TUI
• Read a log file and be able to navigate using arrows and simple search commands
• Read stdout/stderr from executed commands
• Filter messages with some simple expressions
• Parse the lines and provide a formated simple dictionary (key:value). Can see the log lines and the formatted data. Firswt version bassed on patterns.
• Logfmt format parsing
• Pattern format parsing
• Regex format parsing
• Filtering language
• Filtering and marking based on these filters
• Streaming input. Changes in the file, or pipe in, or executed command are seen inmediately.
• As it may have many many lines, be able to scroll efficiently
• Never blocking