# bvr

![BVR CLI](assets/simple.png)

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  |
| ------------------ | ----------------------------------------- | --------- |
| Command Completion | Use tabs to complete commands.            | Planned   |
| Filter Presets     | Add preset filters upon startup.          | After MVP |
| Custom Keybindings | Customize the keybindings of the program. | After MVP |
| Word-Wrapping      | Wrap long lines.                          | After MVP |

### Basic Support
| Feature              | Description                                                   | Progress |
| -------------------- | ------------------------------------------------------------- | -------- |
| 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` <br> `:q`                           | Quit.                                                         |
| `:open <file>` <br> `:o`                    | Open a file in a new tab/view.                                |
| `:close` <br> `:c`                          | Close the current tab/view.                                   |
| `:mux` <br>  `:m`                           | Toggle the multiplexer mode between windows or tabs.          |
| `:mux tabs` `:mux split` <br> `:m t` `:m s` | Set the multiplexer to the respective mode.                   |
| `:pb` `pbcopy`                              | Copy the output of the active filters to the clipboard.       |
| `:filter regex <regex>` <br> `:f r <regex>` | Create a new filter searching for the regex.                  |
| `:filter lit <lit>` <br> `:f l <regex>`     | Create a new filter searching for the literal.                |
| `:filter clear` <br> `:f c`                 | Clear all filters.                                            |
| `:filter union` <br> `:f \|`                | Use union strategy for filter composites (default).           |
| `:filter intersect` <br> `: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.                  |

### Mode-Independent
| Keybinding      | Description                                  |
| --------------- | -------------------------------------------- |
| `Esc`           | Exit selection mode (enter normal mode).     |
| `Ctr;` + `C`    | Exit the program.                            |
| `:`             | Enter command mode.                          |
| `/`             | Create a new filter.                         |
| `?`             | Create a new filter (literal).               |
| `v`             | Enter visual mode.                           |
| `Tab`           | Enter filter mode.                           |
| `` ` `` and `~` | Switch selected view (forward and backward). |
| `1` .. `9`      | Switch selected view to the `n`th buffer.    |