Feature-rich terminal pager ov

• 1. Feature

• 2. Install

• 3. Basic usage
• 4. Usage

• 5. How to reduce memory usage

• 6. Command option
• 7. Key bindings

• 8. Customize

• 9. VS
• 10. Work together
• 11. Contributing

1. Feature

• Quickly opens files larger than memory.
• Supports fixed header lines and columns.
• Optimized for tabular text with column mode and customizable column colors.
• Fully customizable shortcut keys and styles.
• Follow mode for real-time updates (like tail -f / tail -F).
• Exec mode to display command output dynamically.
• Watch mode to monitor file changes periodically.
• Advanced search: incremental, regex, and filter functions.
• Multi-color highlighting for multiple words.
• Supports Unicode and East Asian Width characters.
• Handles compressed files (gzip, bzip2, zstd, lz4, xz).

1.1. Not supported

• Does not support syntax highlighting for file types (source code, markdown, etc.)

2. Install

2.1. deb package

You can download the package from releases.

curl -L -O https://github.com/noborus/ov/releases/download/vx.x.x/ov_x.x.x-1_amd64.deb
sudo dpkg -i ov_x.x.x-1_amd64.deb

2.2. rpm package

You can download the package from releases.

sudo rpm -ivh https://github.com/noborus/ov/releases/download/vx.x.x/ov_x.x.x-1_amd64.rpm

2.3. MacPorts (macOS)

sudo port install ov

2.4. Homebrew(macOS or Linux)

brew install ov

2.5. winget(windows)

winget install -e --id noborus.ov

2.6. pkg (FreeBSD)

pkg install ov

2.7. Arch Linux

You can install ov using an AUR helper.

Choose an AUR package:

• https://aur.archlinux.org/packages/ov (build and install from latest stable source)
• https://aur.archlinux.org/packages/ov-bin (install pre-compiled binary)
• https://aur.archlinux.org/packages/ov-git (build and install from latest git commit)

2.8. nix (nixOS, Linux, or macOS)

ov is available as a nix package. You can install it with

nix profile install nixpkgs#ov

if you use flakes, or using nix-env otherwise:

nix-env -iA nixpkgs.ov

2.9. conda-forge (Linux, windows, or macOS)

ov is available as a conda-forge package. You can install it with

conda install ov -c conda-forge

pixi global install ov

2.10. Binary

You can download the binary from releases.

curl -L -O https://github.com/noborus/ov/releases/download/vx.x.x/ov_x.x.x_linux_amd64.zip
unzip ov_x.x.x_linux_amd64.zip
sudo install ov /usr/local/bin

2.11. go install

It will be installed in $GOPATH/bin by the following command.

go install github.com/noborus/ov@latest

Or to install the latest commit from master:

go install github.com/noborus/ov@master

2.12. Build from source

First of all, clone this repo with either git clone or gh repo clone, then cd to the directory, for example:

git clone https://github.com/noborus/ov.git
cd ov

Next, to install to $GOPATH/bin, run the make install command.

make install

Or, install it in a PATH location for other users to use (For example, in /usr/local/bin).

make
sudo install ov /usr/local/bin

2.13. Completion

You can generate completion scripts for bash, zsh, fish, and powershell.

2.13.1. bash

ov --completion bash > /etc/bash_completion.d/ov

2.13.2. zsh

ov --completion zsh > /usr/share/zsh/site-functions/_ov

For zinit users.

zinit load 'https://github.com/noborus/ov/blob/master/ov.plugin.zsh'

2.13.3. fish

ov --completion fish > ~/.config/fish/completions/ov.fish

2.13.4. powershell

ov --completion powershell | Out-String | Invoke-Expression

3. Basic usage

ov supports open file name or standard input.

ov filename

cat filename|ov

You can also explicitly specify standard input as -.

cat filename | ov -

Used by other commands by setting the environment variable PAGER.

export PAGER=ov

4. Usage

See the ov site for more use cases and examples.

[!NOTE]

(default key key) indicates the key that can be specified even after starting the same function as the command line option.

4.1. Config

You can set style and key bindings in the configuration file.

ov will look for a configuration file in the following paths in descending order:

$XDG_CONFIG_HOME/ov/config.yaml
$HOME/.config/ov/config.yaml
$HOME/.ov.yaml

On Windows:

%USERPROFILE%/.config/ov/config.yaml
%USERPROFILE%/.ov.yaml

Create a config.yaml file in one of the above directories. If the file is in the user home directory, it should be named .ov.yaml.

v0.53.0 and later

You can generate a default configuration with:

ov --generate-config > ~/.config/ov/config.yaml

On Windows (PowerShell):

ov --generate-config > $env:USERPROFILE/.config/ov/config.yaml

[!NOTE]

If you like less key bindings, generate it with --generate-config=less.

ov --generate-config=less > ~/.config/ov/config.yaml

4.2. Header

The --header (-H) (default key H) option fixedly displays the specified number of lines.

ov --header 1 README.md

Related styling: Header and HeaderBorder.

4.2.1. Skip

When used with the --skip-lines (default key Ctrl+s) option, it hides the number of lines specified by skip and then displays the header.

ov --skip-lines 1 --header 1 README.md

4.3. Vertical header

The --vertical-header (-y) (default key y) option fixedly displays the specified number of characters.

ov --vertical-header=4 README.md

If you want to specify by column instead of character, see Header Column.

Related styling: VerticalHeader and VerticalHeaderBorder.

4.4. Column mode

Specify the delimiter with --column-delimiter(default key is d) and set it to --column-mode(default key is c) to highlight the column.

ov --column-delimiter "," --column-mode test.csv

Regular expressions can be used for the --column-delimiter. Enclose in '/' when using regular expressions.

[!TIP]

Use regex delimiters like /\s+/ for variable whitespace or /[,;]/ for multiple delimiter characters.

ps aux | ov -H1 --column-delimiter "/\s+/" --column-rainbow --column-mode

Related styling: ColumnHighlight,ColumnRainbow.

4.5. Header column

The --header-column (-Y) (default key is Y) option fixedly displays the specified number of columns when column-mode is enabled.

ov --column-mode --column-delimiter="," --header-column=2 test.csv

When in column-mode, pressing F will switch to fixed display for the selected columns up to that point.

Related styling: VerticalHeader and VerticalHeaderBorder.

4.6. Column rainbow mode

You can also color each column individually in column mode. Specify --column-rainbow(default key is Ctrl+r) in addition to the --column-mode option.

Color customization is possible. Please specify 7 or more colors in config.yaml.

Style:
  ColumnRainbow:
    - Foreground: "white"
    - Foreground: "aqua"
    - Foreground: "lightsalmon"
    - Foreground: "lime"
    - Foreground: "blue"
    - Foreground: "yellowgreen"
    - Foreground: "red"

Style specifications other than Foreground can also be specified.

Style:
  ColumnRainbow:
    - Foreground: "white"
      Background: "red"
    - Foreground: "aqua"
      Underline: true
    - Foreground: "#ff7f00"
      Background: "blue"
      Bold: true
    - Foreground: "lime"
      Italic: true
    - Foreground: "blue"
      Dim: true
    - Foreground: "yellowgreen"
    - Foreground: "red"

Related styling: ColumnRainbow.

4.7. Column width

The --column-width option is designed for command output with irregular spaces, such as ps aux, df, etc. (default key Alt+o). It automatically detects and separates columns without needing a specific delimiter.

ps aux|ov -H1 --column-width --column-rainbow

!ps-ov.png

This column-width feature is implemented using guesswidth.

4.8. Wrap

Supports switching between wrapping and not wrapping lines.

The option is --wrap=char, specify --wrap=none (default key w, W) if you do not want to wrap.

4.8.1. word wrap mode

Added in v0.52.0

Word wrap has been added and the method of specification has changed.

• -w or -w=char(default): Wrap lines at screen width, breaking anywhere.
• -w=word: Wrap lines at screen width, breaking at word boundaries.
• -w=none: Disable line wrapping.

Added in v0.55.0

--break-indent applies only in -w=word mode. Wrapped-line indentation can be set with --break-indent or the default key Ctrl+Alt+n. Use 0 for no indentation, a positive number for a fixed width, L to match the source line's leading whitespace, or L+N/L-N to adjust that indentation. +N and -N are shorthand for the relative forms.

4.8.2. Display markers

Added in v0.55.0

Display markers can be enabled with --sign-mode or the default key Ctrl+Alt+m. The default value is 0 (no markers). Add the bit values to enable markers. When wrapping is enabled, 1 displays a break marker (↳) at the start of a wrapped line and 2 displays a continue marker (↵) where a line continues. When wrapping is disabled, 4 displays a truncation marker (…) when a line is cut off.

| Value | Markers enabled | Display example | |-------|-----------------|-----------------| | 0 | None | long line | | 1 | ↳ | ↳ wrapped continuation | | 2 | ↵ | line continues ↵ | | 3 | ↳ and ↵ | line continues ↵
↳ wrapped continuation | | 4 | … | truncated line… | | 5 | ↳ and … | ↳ wrapped continuation or truncated line… | | 6 | ↵ and … | line continues ↵ or truncated line… | | 7 | ↳, ↵, and … | All applicable markers above |

The ↳ and ↵ markers are shown when line wrapping is enabled; … is shown when wrapping is disabled and a line is truncated. Marker characters and styles can be customized with BreakSign, ContinueSign, TruncSign and their corresponding Style entries under General in the config file.

4.9. Alternate-Rows

Alternate row styles with the --alternate-rows(-C) (default key C) option The style can be set with Style customization.

ov --alternate-rows test.csv

Related styling: Alternate.

4.10. Sidebar

Added in v0.51.0

!sidebar.png

ov now supports a sidebar feature, allowing you to display additional information alongside the main content.

The sidebar can show:

• Help (default key Alt + h)
• Mark list (default key Alt + m)
• Document list (default key Alt + l)
• Section list (default key Alt + u)
• Style list (default key Alt + y) (Added in v0.54.0)

Sidebar scrolling is independent of the main content. Default keys are:

• up(default key shift+up)
• down(default key shift+down)
• left(default key shift+left)
• right(default key shift+right)

ov --sidebar-mode=sections --section-delimiter "^#" README.md

You can specify the initial sidebar mode via CLI with --sidebar-mode=string or by setting it in the config file. You can set the sidebar width using SidebarWidth. This can be specified as a percentage (e.g., 20%) or as a fixed width in columns (e.g., 30).

Example:

SidebarMode: "marks"  # Open sidebar with this content. Options: "help", "marks", "documents", "sections", "styles", "none".
SidebarWidth: 30      # Width of the sidebar. Can be specified in percentage or fixed width (e.g., "30" for 30 columns).

4.11. Section

You can specify a section delimiter using --section-delimiter (default key Alt+d).

This allows you to move between sections (default keys space and ^).

The specified line will also be treated as a section header and will remain fixed at the specified position until the next section appears at the specified position.

The start of the section can be adjusted with --section-start(default key Ctrl+F3, Alt+s).

!section.png

The --section-delimiter is written in a regular expression (for example: "^#"). (Line breaks are not included in matching lines).

For example, if you specify "^diff" for a diff that contains multiple files, you can move the diff for each file.

The number of lines in section-header can be changed. You can specify the number of lines using the --section-header-num option or key input(default key F7).

The specified section can be viewed in the section list in the Sidebar(default key Alt+u).

4.11.1. section example

This is an example of using the git pager.

[pager]
  diff = "ov -F --section-delimiter '^diff'"
  log = "ov -F --section-delimiter '^commit' --section-header-num 3"

Related styling: SectionLine.

4.11.2. hide other sections

If you specify --hide-other-section(default key Alt+-), only the current section is displayed.

ov --section-delimiter "^#" --hide-other-section README.md

This is just hidden, so it will be displayed when you move to the next section.

4.12. Multiple files

ov can also open multiple files.

ov file1 file2

You can include standard input in the file list by specifying -.

command | ov - file1 file2

Multiple files are each opened as a document and can be navigated using the Next Document ] key (default), Previous Document key (default).

Specified multiple files can also be displayed in the document list in the [Sidebar(default key alt + l).

Related Styling: Customizing the bottom status line.

4.13. Follow mode

--follow-mode(-f)(default key Ctrl+f) prints appended data and moves to the bottom line (like tail -f).

ov --follow-mode /var/log/syslog

(while :; do echo random-$RANDOM; sleep 0.1; done;)|./ov  --follow-mode

4.13.1. Follow name

[!TIP]

Use --follow-name instead of --follow-mode when files might be rotated (like log files). This ensures you continue following the new file even if the original is moved or deleted.

You can specify the file name to follow with --follow-name(like tail -F). Monitor file names instead of file descriptors.

ov --follow-name /var/log/nginx/access.log

4.13.2. Follow all mode

--follow-all(-A)(default key Ctrl+a) is the same as follow mode, it switches to the last updated file if there are multiple files.

ov --follow-all /var/log/nginx/access.log /var/log/nginx/error.log

4.13.3. Follow section mode

Use the --follow-section(default key F2) option to follow by section. Follow mode is line-by-line, while follow section mode is section-by-section. Follow section mode displays the bottom section. The following example is displayed from the header (#) at the bottom.

ov --section-delimiter "^#" --follow-section README.md

[!NOTE]

Watch mode is a mode in which --follow-section and --section-delimiter "^\f" are automatically set.

4.13.4. Sticky follow

Follow mode uses Sticky follow by default. In Sticky follow mode, when you move up from the bottom, follow mode temporarily pauses. Follow mode resumes automatically when you return to the bottom of the file.

This behavior allows you to:

• Scroll up to examine previous content without losing your position
• Automatically resume following new content when you return to the bottom
• Maintain context while monitoring live files

When follow mode is paused, you'll see visual indicators to help you understand the current state:

• || appears at the beginning of the status line to indicate that follow mode is paused
• The line where follow mode was paused is highlighted with the PauseLine style

General:
  DisableStickyFollow: true

Related styling: PauseLine.

4.14. Exec mode

Exec mode captures the output of a command and displays it in ov. It works similarly to watch, but with advanced paging features.

Use the --exec (-e) option to run the command and display stdout/stderr separately.

[!TIP]

When using --exec, you must insert -- to separate ov's options from the command you want to run.

Everything after -- is interpreted as the command and its arguments.

ov --exec -- ls -l

Shows the stderr screen as soon as an error occurs, when used with --follow-all.

ov --follow-all --exec -- make

In exec mode (other than Windows) the output is opened by opening a pty. Therefore, the command is likely to be printed in color.

ov --exec -- eza -l

It is useful to use the --notify-eof option together with exec mode to get notified when the command finishes. This is especially helpful for long-running commands like make.

ov --notify-eof --exec -- make

4.15. Search

Search by forward search / key(default) or the backward search ? key(default). Search can be toggled between incremental search, regular expression search, and case sensitivity. Displayed when the following are enabled in the search input prompt:

| Function | display | (Default)key | command option | config file | |---------------------------|---------|--------------|------------------------|--------------------| | Incremental search | (I) | Alt+i | --incsearch | Incsearch | | Regular expression search | (R) | Alt+r | --regexp-search | RegexpSearch | | Case-sensitive | (Aa) | Alt+c | -i, --case-sensitive | CaseSensitive | | Smart case-sensitive | (S) | Alt+s | --smart-case-sensitive | SmartCaseSensitive |

Specify true/false in config file.

``config.yaml CaseSensitive: false RegexpSearch: false Incsearch: true SmartCaseSensitive: true

Related styling: SearchHighlight

 4.15.1. <a name='pattern'></a>Pattern
The pattern option allows you to specify a search at startup.

####  4.15.2. <a name='filter'></a>Filter

Filter input is possible using the & key(default).
The filter input creates a new document only for the lines that match the filter.

Move next document ] and previous document  key(default) allow you to move between the filter document and the original document.

The K(shift+k) key (default) closes all documents created by the filter.

You can also specify a filter using the command line option --filter.

The filter is a regular expression.

You can also filter for lines that do not match the specified pattern.

If you press ! on & while inputting a filter, non-matching lines will be targeted.

The command line option for this can be specified with --non-match-filter.

If you specify both a filter option and the [Quit if one screen option,
the command will display the results of the filter and then quit if the results fit on one screen.

###  4.16. <a name='caption'></a>Caption

You can specify a caption instead of the file name in status line to display it.

It can also be specified as an environment variable.

###  4.17. <a name='mark'></a>Mark

Mark the display position with the m key(default).
The mark is decorated with MarkLine and MarkStyleWidth.

Marks can be erased individually with the M key(default).
It is also possible to delete all marks with the ctrl + delete key(default).

The specified marks can be displayed in the mark list in the Sidebar(default key alt + m).

Related styling: MarkLine.

 4.17.1. <a name='mark-by-pattern'></a>mark by pattern
You can use mark by pattern to mark all lines that match the search(default key *).
This will enter pattern input mode and, when you press Enter, mark all lines
that match the pattern.

Use --mark-by-pattern to mark matching lines when ov starts.

 4.17.2. <a name='specifying-a-mark'></a>Specifying a mark
Use the >next and <previous (default) key to move to the marked position.
You can also enter mark specify mode with , (default) and select a mark by
number. There are two input styles: enter the number directly, or enter a
relative offset like +N/-N from the current mark. When you press ,, the
mark list sidebar opens automatically along with number input mode.

 4.18. <a name='watch'></a>Watch
ov has a watch mode that reads the file every N seconds and adds it to the end.
When you reach EOF, add '\f' instead.
Use the --watch(-T) option.
Go further to the last section.
The default is 'section-delimiter', so the last loaded content is displayed.

for example.

###  4.19. <a name='mouse-support'></a>Mouse support

The ov supports mouse input for text selection, scrolling, and other interactions.
This can be disabled with the option --disable-mouse (default keys for toggling mouse support are Ctrl+Alt+r).

If mouse support is enabled, tabs and line breaks will be interpreted correctly when copying.
If your terminal supports OSC52, it is recommended to use OSC52 for clipboard operations(default).
Set ClipboardMethod to OSC52 in the configuration file (config.yaml):

> [!TIP]
> Use OSC52 method if you're working over SSH or in terminal multiplexers like tmux/screen where traditional clipboard tools might not work.

This method is useful in environments where OSC52 is supported by the terminal.

If your terminal does not support OSC52, or if you do not want to use OSC52,
set ClipboardMethod to system to use atotto/clipboard
for clipboard operations.

In Linux/Unix environments, this requires the xclip or xsel command.

Selecting the range with the mouse and then left-clicking will copy it to the clipboard.

Pasting in ov is done with the middle button.
In other applications, it is pasted from the clipboard (often by pressing the right-click).

 4.19.1. <a name='text-selection'></a>Text selection
The mouse supports intelligent text selection for improved productivity:
Single click: Place cursor and start text selection by dragging
Double click: Select the word under the cursor
Triple click: Select the entire line under the cursor
These selection methods work seamlessly with the clipboard functionality. After making a selection with double or triple click, the selected text is automatically copied to the clipboard.
 4.19.2. <a name='wheel-scroll'></a>Wheel scroll
When mouse support is enabled, you can use the mouse wheel for navigation:
Vertical scrolling: Use the mouse wheel to scroll up and down
Horizontal scrolling: Use Shift + wheel to scroll left and right

 4.19.3. <a name='scroll-amount-configuration'></a>Scroll amount configuration
You can customize the scroll amounts using command-line options or configuration file settings:
 4.19.4. <a name='anchor-and-extend-selection'></a>Anchor and extend selection
Added in v0.50.0
You can now use "Anchor and Extend Selection" with the mouse:
Set Anchor: Left-click to set an anchor point.
Extend Selection: After setting an anchor, use Alt+Click or right-click to extend the selection from the anchor to the clicked position and copy the selected range.

Clear Anchor: If no selection is created, double-click will clear the anchor.
Anchor Highlight: When there is no selection, the anchor point is visually highlighted (reverse style).

This feature enables flexible, editor-like selection and copy operations using the mouse.
Vertical Scroll Amount:
Command-line: Not directly configurable (uses system default)
Config file: Set VScrollLines in the General section

Horizontal Scroll Amount:
Command-line: --hscroll-width (e.g., --hscroll-width "20%" or --hscroll-width "10")
Config file: Set HScrollWidth in the General section

###  4.20. <a name='multi-color-highlight'></a>Multi color highlight

This feature styles multiple words individually.
.key(default) enters multi-word input mode.
Enter multiple words (regular expressions) separated by spaces.

For example, error info warn debug will color errors red, info cyan, warn yellow, and debug magenta.

It can also be specified with the command line option --multi-color(-M)(default key .).
For command line options, pass them separated by ,(comma).

For example:

!multi-color.png

Color customization is possible. Please specify 7 or more colors in config.yaml.

Related styling: MultiColorHighlight.

 4.21. <a name='plain'></a>Plain
Disables the decoration of the text, such as color and style, and displays it in plain text.
Use Plain when you want to remove all decorations at once. If you only want to disable specific styles, use Suppress styles instead.
The option is --plain (or -p) (default key Ctrl+e).

 4.22. <a name='converter'></a>Converter
Converter selects the engine to convert and display the text.
Usually, the escape sequence is interpreted and displayed by es (default).
raw displays as it is without interpreting the escape sequence.

You can specify the --converter option with [es|raw|align],
and you can also specify the --raw, --align(Align) option as a shortcut option.

> [!NOTE]
> raw also displays the character string of the escape sequence,
> but be aware that Plain hides the decoration after interpreting the escape sequence.

 4.23. <a name='align'></a>Align
The --align option adjusts column widths to improve readability for irregularly formatted tabular data, such as CSV files with misaligned columns.

Example:

After applying --align:

!ov-align
Align can also shrink column.
 4.23.1. <a name='shrink'></a>Shrink
Align allows columns to be shrunk and stretched by toggling with the (default key s).

!ov-column-shrink
To change the character displayed when columns are shrunk, set ShrinkChar in the configuration file:

####  4.23.2. <a name='right-align'></a>Right align

Columns displayed by alignment are left-justified. Columns can be right-aligned (default key Alt+a).
 4.24. <a name='jump-target'></a>Jump target
You can specify the lines to be displayed in the search results.
This function is similar to --jump-target of less.
Positive numbers are displayed downwards by the number of lines from the top(1).
Negative numbers are displayed up by the number of lines from the bottom(-1).
. (dot) can be used to specify a percentage. .5 is the middle of the screen(.5).
You can also specify a percentage, such as (50%).

This option can be specified with --jump-target(or -j) (default key j).

If section is specified as the --jump-target, the display will start from the beginning of the section as much as possible
and the jump-target will be changed.

Related styling: JumpTargetLine.

 4.25. <a name='view-mode'></a>View mode
You can also use a combination of modes using the --view-mode(default key p) option.
In that case, you can set it in advance and specify the combined mode at once.

For example, if you write the following settings in ov.yaml,
 the csv mode will be set with --view-mode csv.

####  4.25.1. <a name='view-mode-sidebar'></a>View mode sidebar

Added in v0.52.0
When you press p to enter view mode selection, a sidebar automatically opens and displays the list of available view modes with their index numbers. You can select a mode either by name or by its number.

!view mode sidebar
 4.25.2. <a name='list-view-modes'></a>List view modes
The --list-view-modes option outputs a list of available view modes defined in the configuration file.

Example output:

This is useful for checking predefined view modes and their configurations.

 4.26. <a name='output-on-exit'></a>Output on exit
--exit-write, -X(default key Q) option prints the current screen on exit.
This looks like the display remains on the console after the ov is over.

By default, it outputs the amount of the displayed screen with all decorations, such as search highlights, as it appears on the screen.

If you want to revert to the previous behavior (outputting the original text without decorations), set IsWriteOriginal: true in the configuration file.

You can change how much is written using --exit-write-before and --exit-write-after(default key Ctrl+q).
--exit-write-before

--exit-write-before specifies the number of lines before the current position(top of screen).
--exit-write-before 3 will output from 3 lines before.

--exit-write-after specifies the number of lines after the current position (top of screen).

--exit-write-before 3 --exit-write-after 3 outputs 6 lines.

 4.27. <a name='quit-if-one-screen'></a>Quit if one screen
The --quit-if-one-screen, -F option allows the program to exit immediately if the content fits within one screen.
This can be useful when you only want to view small files or when you want to quickly check the content without scrolling.

If you want to enable this option by default, set QuitSmall to true in the configuration file.

###  4.28. <a name='suspend'></a>Suspend

You can suspend ov with Ctrl+z(default key).
Normally, you can resume from suspend by typing fg.

On Windows or if the environment variable OV_SUBSHELL is set, exit instead of fg.
The process actually starts a subshell without suspending.

###  4.29. <a name='edit'></a>Edit

You can edit the currently displayed file with your preferred editor by pressing the default key Alt+v.

If the file is not a regular file (for example, when viewing input from a pipe or standard input), a temporary file is created and passed to the editor for editing. This ensures that you can still edit the content even if the original input is not seekable.
The editor command is determined by the OVEDIT or EDITOR environment variable, or by the Editor setting in the configuration file.

You can use %f and %d as arguments in the editor command:

%f will be replaced with the current file name.

%d will be replaced with the current line number.

For example:

This will open the current file in vim at the specified line number.
 4.30. <a name='save'></a>Save
If the file input is via a pipe, you can save it by pressing the save buffer (default S) key.

This will put you in input mode, so enter the file name.
Only the buffer currently in memory is saved.

If the file name already exists, select Overwrite, Append, or Cancel.

###  4.31. <a name='ruler'></a>Ruler

The --ruler option displays a ruler at the top of the screen to help you see the column positions. (default key Alt+Shift+F9)

--ruler or --ruler=1: Displays a relative ruler that moves with horizontal scrolling.

--ruler=2: Displays an absolute ruler that does not move with horizontal scrolling.

--ruler=0: Disables the ruler (default).

!ov-ruler.png
Related styling: Ruler .

 4.32. <a name='redirect-output'></a>Redirect output
By default, ov does not show the screen when output is redirected.
To force display, use the --force-screen option:

###  4.33. <a name='suppress-styles'></a>Suppress styles

Added in v0.54.0
Syntax highlighting and other styles (including those represented by escape sequences) can be enabled or disabled individually.
This is especially useful when ov is used as a pager from syntax-highlighting tools such as bat.
Unlike Plain, this feature does not remove all decoration at once; it lets you selectively suppress only the styles you do not want.

After startup, press o (default key) to enter Toggle styles: input mode.
In this mode, the sidebar shows a numbered list of available styles (indices start at 0).
Specify styles by the numbers shown in the sidebar labels.

Use commas to select multiple items: 1,3,5

Use hyphens for ranges: 4-9

You can combine both forms: 1,3-5,9

Special commands are also available in Toggle styles: input:
o: disable all styles

a: enable all styles

i: invert all styles

You can combine special commands and numeric selections in one input.
For example:
o1-3 disables all styles, then enables styles 1 through 3

i2 inverts all styles, then toggles style 2 again

!ov-styles.png
 5. <a name='how-to-reduce-memory-usage'></a>How to reduce memory usage
Since v0.30.0 it no longer loads everything into memory.
The first chunk from the beginning to the 10,000th line is loaded into memory
and never freed.
Therefore, files with less than 10,000 lines do not change behavior.
The --memory-limit option can be used to limit the chunks loaded into memory.
Memory limits vary by file type.

Also, go may use a lot of memory until the memory is freed by GC.
Also consider setting the environment variable GOMEMLIMIT.

###  5.1. <a name='regular-file-(seekable)'></a>Regular file (seekable)

!regular file memory
Normally large (10,000+ lines) files are loaded in chunks when needed. It also frees chunks that are no longer needed.
If --memory-limit is not specified, it will be limited to 100.

Specify MemoryLimit in the configuration file.

You can also use the --memory-limit-file option and the MemoryLimitFile setting for those who think regular files are good memory saving.

 5.2. <a name='other-files,-pipes(non-seekable)'></a>Other files, pipes(Non-seekable)
!non-regular file memory
Non-seekable files and pipes cannot be read again, so they must exist in memory.
If you specify the upper limit of chunks with --memory-limit or MemoryLimit,
it will read up to the upper limit first, but after that,
when the displayed position advances, the old chunks will be released.
Unlimited if --memory-limit is not specified.

It is recommended to put a limit in the config file as you may receive output larger than memory.

6. Command option

| Short | Long | Purpose | |-------|--------------------------------------------|-----------------------------------------------------------------------------------------------------------------------| | -l, | --align | align the output columns for better readability | | -C, | --alternate-rows | highlight even and odd rows in alternating colors | | | --break-indent string | indent width for wrapped lines (default "0") | | | --caption string | override the status line file name with a custom label | | -i, | --case-sensitive | case-sensitive in search | | -d, | --column-delimiter character | column delimiter character (default ",") | | -c, | --column-mode | split content into columns at the delimiter | | | --column-rainbow | colorize each column with a distinct color | | | --column-width | column mode using fixed-width fields instead of a delimiter | | | --completion string | generate completion script [bash\|zsh\|fish\|powershell] | | | --config file | config file (default is $XDG_CONFIG_HOME/ov/config.yaml) | | | --converter string | content processing mode [es\|raw\|align\|wordwrap] (default "es") | | | --debug | debug mode | | | --disable-column-cycle | keep column cursor from wrapping to the first column | | | --disable-mouse | disable mouse support | | -e, | --exec | run command and display its output; use '--' to separate ov flags from command arguments (e.g., 'ov --exec -- ls -l') | | -X, | --exit-write | output the current screen when exiting | | -a, | --exit-write-after int | extra lines below the current view to output on exit | | -b, | --exit-write-before int | extra lines above the current view to output on exit | | | --filter string | show only lines matching this pattern | | -A, | --follow-all | follow multiple files and show the most recently updated one | | -f, | --follow-mode | monitor file and display new content as it is written | | | --follow-name | follow by file name mode; survives log rotation | | | --follow-section | follow mode: jump to the most recently updated section

... (README truncated for length)