dalog is a terminal-based log viewing application built with Python and Textual. It provides advanced features for viewing, searching, and analyzing log files with a modern, keyboard-driven interface optimized for developer workflows.
- Live Search: Real-time filtering
- Exclusion System: Filter out unwanted log entries with persistent patterns and regex
- Smart Styling: Pattern-based syntax highlighting with regex support
- Live Reload: Automatically update when log files change (like
tail -f) - Visual Mode: Vi-style visual line selection with clipboard support
- HTML Rendering: Render HTML tags in logs (configurable tags)
- ** Vim Keybindings**: Full vim-style navigation with customizable keybindings
- ** Configurable**: Extensive configuration options via TOML files
- CLI Exclusions: Filter logs directly from command line with
--excludeparameter - Theme Support: Choose from built-in Textual themes via CLI
pip install dalog# Clone the repository
git clone https://github.com/mwmdev/dalog.git
cd dalog
# Install in development mode
pip install -e .
# Or with development dependencies
pip install -e ".[dev]"# View a single log file
dalog application.log
# Start with search pre-filled
dalog --search ERROR application.log
# Exclude unwanted log levels
dalog --exclude "WARNING" application.log
# Load only last 1000 lines
dalog --tail 1000 large-application.log
# Use custom configuration
dalog --config ~/.config/dalog/custom.toml app.log
# Use a specific Textual theme
dalog --theme gruvbox error.loglog_file- The path to the log file you want to view- Must be an existing, readable file
- Example:
dalog application.logordalog /var/log/app.log
-
--config/-c- Specify a custom configuration file- Type: Path to existing TOML configuration file
- Example:
dalog --config ~/.config/dalog/custom.toml app.log - If not specified, dalog searches for config files in the standard locations
-
--search/-s- Start dalog with a search term already applied- Type: String (search term or regex pattern)
- Example:
dalog --search "ERROR" app.log - Example:
dalog -s "user_id=\\d+" app.log(regex pattern)
-
--tail/-t- Load only the last N lines from the file- Type: Integer (number of lines)
- Useful for large log files to improve startup performance
- Example:
dalog --tail 1000 large-app.log - Example:
dalog -t 500 app.log
-
--theme- Set the visual theme for the application- Type: String (theme name)
- Available themes include:
textual-dark,textual-light,nord,gruvbox,catppuccin-mocha,dracula,tokyo-night,monokai,flexoki,catppuccin-latte,solarized-light - Example:
dalog --theme gruvbox app.log - Example:
dalog --theme nord error.log
-
--exclude/-e- Exclude lines matching the specified pattern- Type: String (pattern or regex)
- Can be used multiple times to exclude multiple patterns
- Patterns are case-sensitive and support regex
- Applied in addition to config file exclusions
- Example:
dalog --exclude "DEBUG" app.log - Example:
dalog -e "WARNING" -e "INFO" app.log - Example:
dalog --exclude "ERROR.*timeout" app.log(regex)
-
--version/-V- Display the version number and exit- Example:
dalog --version - Example:
dalog -V
- Example:
| Key | Action |
|---|---|
/ |
Open search |
ESC |
Close search/cancel/exit visual mode |
j/k |
Navigate down/up |
h/l |
Navigate left/right |
g/G |
Go to top/bottom |
Ctrl+u/Ctrl+d |
Page up/down |
V |
Enter visual line mode (vi-style selection) |
v |
Start selection at cursor (in visual mode) |
y |
Yank/copy selected lines to clipboard (in visual mode) |
r |
Reload file |
L |
Toggle live reload |
w |
Toggle text wrapping |
e |
Manage exclusions |
q |
Quit |
DaLog supports vi-style visual line selection:
- Press
V(or enter a line number and pressV) to enter visual line mode - Use
j/kto navigate to the desired starting line (cursor shown with underline) - Press
vto start selection from the current cursor position - Use
j/kto extend the selection up/down - Press
yto yank (copy) selected lines to clipboard - Press
ESCto exit visual mode without copying
DaLog looks for configuration files in the following order:
- Command-line specified:
--config path/to/config.toml $XDG_CONFIG_HOME/dalog/config.toml~/.config/dalog/config.toml~/.dalog.toml./config.toml(current directory)
[app]
default_tail_lines = 1000
live_reload = true
case_sensitive_search = false
vim_mode = true
[keybindings]
search = "/"
reload = "r"
toggle_live_reload = "L"
toggle_wrap = "w"
quit = "q"
show_exclusions = "e"
scroll_down = "j"
scroll_up = "k"
scroll_left = "h"
scroll_right = "l"
scroll_home = "g"
scroll_end = "G"
[display]
show_line_numbers = true
wrap_lines = false
max_line_length = 1000
visual_mode_bg = "white" # Background color for visual mode selection
[styling.patterns]
error = { pattern = "(?i)error", background = "red", color = "white" }
warning = { pattern = "(?i)warning", background = "yellow", color = "black", bold = true }
info = { pattern = "(?i)info", color = "blue" }
[styling.timestamps]
iso_datetime = { pattern = "\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}", color = "cyan" }
[html]
# Configure which HTML tags to render in logs
enabled_tags = ["b", "i", "em", "strong", "span", "code", "pre"]
strip_unknown_tags = true
[exclusions]
patterns = ["DEBUG:", "TRACE:"]
regex = true
case_sensitive = falseDaLog supports powerful regex-based styling patterns:
[styling.custom]
# Highlight IP addresses
ip_address = { pattern = "\\b(?:[0-9]{1,3}\\.){3}[0-9]{1,3}\\b", color = "magenta" }
# Highlight URLs
url = { pattern = "https?://[\\w\\.-]+", color = "blue", underline = true }
# Highlight email addresses
email = { pattern = "\\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Z|a-z]{2,}\\b", color = "cyan" }
# Custom application-specific patterns
user_id = { pattern = "user_id=\\d+", color = "green", bold = true }# Clone the repository
git clone https://github.com/mwmdev/dalog.git
cd dalog
# Install development dependencies
pip install -e ".[dev]"
# Run tests
pytest
# Run linting
black src/
mypy src/
pylint src/dalog/
├── src/dalog/ # Main package
│ ├── app.py # Textual application
│ ├── cli.py # Click CLI interface
│ ├── config/ # Configuration management
│ ├── core/ # Core functionality
│ ├── widgets/ # Custom Textual widgets
│ └── styles/ # CSS styles
├── tests/ # Test suite
├── docs/ # Documentation
└── pyproject.toml # Project configuration
Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.
- Fork the repository
- Create your feature branch (
git checkout -b feature/amazing-feature) - Commit your changes (
git commit -m 'Add some amazing feature') - Push to the branch (
git push origin feature/amazing-feature) - Open a Pull Request
This project is licensed under the MIT License - see the LICENSE file for details.
- Built with Textual - an amazing TUI framework
- Inspired by traditional Unix tools like
tail,less, andgrep - Thanks to all contributors and users