Avarel/bvr

Chew through logs with a pager written in Rust.

bvr

Powerful pager written in rust, purpose-built for chewing through logs.

BVR (pronounced "beaver") is still under heavy development.

Motivation

I needed a pager that could handle large log files and be fast and responsive. I especially hated grepping a file, piping it to less, exiting and then grepping with a different regex. I wanted to compare log files side by side. I also needed a plethora of other features that I couldn't find in any other pager.

Goals

• Fast and responsive
• Intuitive and easy to use
  • Intuitive keybindings
  • Mouse support
• Targeted use: scrolling through log files
  • Multiplexing
• Built from the ground up to be modular
• Simple and easy to understand codebase

Non-Goals

• Syntax highlighting
• Editing files

Features

In-Progress or Planned

Feature	Description	Progress
Custom Keybindings	Customize the keybindings of the program.	After MVP
Word-Wrapping	Wrap long lines.	After MVP

Basic Support

Feature	Description	Progress
Filter Presets	Add preset filters upon startup.	In Development
Filter Linking	Synchronize filters across the opened files.	In Development
Filter Editing	Edit filters.	Basic
Piping Files	View piped outputs of other programs, ie. cat file | bvr	Basic
Status Bar	View current state of the pager.	Basic
Commands	Use modal commands to interact with the pager.	Basic
Horizontal Scrolling	Pan the view horizontally.	Basic
Export Output	Export data of active filters to a file.	Done
Mouse Support	Use mouse to interact with the TUI.	Done
Filter (Regex)	Select and disable additive search filters.	Done
Filter Intersection	Compose filters by their intersection instead of their union.	Done
Filter Match Jumping	Jump to the next or previous line that matches a filter.	Done
Multiplexing	View multiple files through tabs or windows.	Done
Follow Output	Constantly scroll down as new data is loaded.	Done

Built-in Keybindings

• Custom keybindings will be added in the future.

Normal Mode

This is the default mode. You can scroll through files.

Keybinding	Description
Up and Down	Pan the view.
n p	Pan to next/previous active match.
Home/g	Pan the view to end of the file.
End/G	Pan the view to the end of the file (follow output).
PageUp and PageDown/Space	Pan the view by a page.
Shift + Up and Down	Pan the view by a half-page.

Command Mode

In this mode, you can enter commands to interact with the pager.

Command	Description
:quit :q	Quit.
:open <file> :o	Open a file in a new tab/view.
:close :c	Close the current tab/view.
:mux :m	Toggle the multiplexer mode between windows or tabs.
:mux tabs :mux split :m t :m s	Set the multiplexer to the respective mode.
:pb pbcopy	Copy the output of the active filters to the clipboard.
:filter persist	Persist the filters on shutdown and launch.
:filter link	Synchronize filters across opened files.
:filter regex <regex> :f r <regex>	Create a new filter searching for the regex.
:filter lit <lit> :f l <regex>	Create a new filter searching for the literal.
:filter clear :f c	Clear all filters.
:filter union :f |	Use union strategy for filter composites (default).
:filter intersect :f &	Use intersection strategy for filter composites.
:<number>	Go to the specific line number (or nearest if not available).

Note: find is an alias for filter.

Visual Mode

In this mode, you can select lines to bookmark.

Keybinding	Description
Up and Down	Move the select cursor.
n p	Select next/previous active match.
Shift + Up and Down, n and p	Expand the select cursor into a selection range.
Space and Enter	Toggle bookmark at current line.

Filter Mode

In this mode, you can toggle filters from bookmarks or searches to omit or include certain lines in the viewer.

Keybinding	Description
Esc and Tab	Exit selection mode (enter viewer mode).
:	Enter command mode.
i	Enter selection mode.
Up and Down	Change which filter is selected.
Space and Enter	Toggle selected filter.
^R	Escape the provided filter (search in literal mode).

Mode-Independent

Keybinding	Description
Esc	Exit selection mode (enter normal mode).
Ctr; + C	Exit the program.
:	Enter command mode.
/	Create a new filter.
v	Enter visual mode.
f	Enter filter mode.
Tab and BackTab	Switch selected view (forward and backward).
1 .. 9	Switch selected view to the nth buffer.