Ubuntu Manpage: delta - syntax-highlighting pager for git, diff, and grep output

NAME

       delta - syntax-highlighting pager for git, diff, and grep output

DESCRIPTION

A viewer for git and diff output

Usage: delta [OPTIONS] [MINUS_FILE] [PLUS_FILE]

Arguments:

[MINUS_FILE]

First file to be compared when delta is being used in diff mode

`delta file_1 file_2` is equivalent to `diff -u file_1 file_2 | delta`.

[PLUS_FILE]

Second file to be compared when delta is being used in diff mode

Options:

--blame-code-style <STYLE>

Style string for the code section of a git blame line.

By default the code will be syntax-highlighted with the same background color as
the blame format section of the line (the background color is determined by
blame-palette). E.g. setting this option to 'syntax' will syntax-highlight the code
with no background color.

--blame-format <FMT>

Format string for git blame commit metadata.

Available placeholders are "{timestamp}", "{author}", and "{commit}".

[default: "{timestamp:<15} {author:<15.14} {commit:<8}"]

--blame-palette <COLORS>

Background colors used for git blame lines (space-separated string).

Lines added by the same commit are painted with the same color; colors are recycled
as needed.

--blame-separator-format <FMT>

Separator between the blame format and the code section of a git blame line.

Contains the line number by default. Possible values are "none" to disable line
numbers or a format string. This may contain one "{n:}" placeholder and will
display the line number on every line. A type may be added after all other format
specifiers and can be separated by '_': If type is set to 'block' (e.g.
"{n:^4_block}") the line number will only be shown when a new blame block starts;
or if it is set to 'every-N' the line will be show with every block and every N-th
(modulo) line.

[default: ???{n:^4}???]

--blame-separator-style <STYLE>

Style string for the blame-separator-format

--blame-timestamp-format <FMT>

Format of `git blame` timestamp in raw git output received by delta

[default: "%Y-%m-%d %H:%M:%S %z"]

--blame-timestamp-output-format <FMT>

Format string for git blame timestamp output.

This string is used for formatting the timestamps in git blame output. It must
follow the `strftime` format syntax specification. If it is not present, the
timestamps will be formatted in a human-friendly but possibly less accurate form.

See: (https://docs.rs/chrono/latest/chrono/format/strftime/index.html)

--color-only

Do not alter the input structurally in any way.

But color and highlight hunk lines according to your delta configuration. This is
mainly intended for other tools that use delta.

--config <PATH>

Load the config file at PATH instead of ~/.gitconfig

[default: ]

--commit-decoration-style <STYLE>

Style string for the commit hash decoration.

See STYLES section. The style string should contain one of the special attributes
'box', 'ul' (underline), 'ol' (overline), or the combination 'ul ol'.

[default: ]

--commit-regex <REGEX>

Regular expression used to identify the commit line when parsing git output

[default: "^commit "]

--commit-style <STYLE>

Style string for the commit hash line.

See STYLES section. The style 'omit' can be used to remove the commit hash line
from the output.

[default: raw]

--dark

Use default colors appropriate for a dark terminal background.

For more control, see the style options and --syntax-theme.

--default-language <LANG>

Default language used for syntax highlighting.

Used when the language cannot be inferred from a filename. It will typically make
sense to set this in per-repository git config (.git/config)

--diff-highlight

Emulate diff-highlight.

(https://github.com/git/git/tree/master/contrib/diff-highlight)

--diff-so-fancy

Emulate diff-so-fancy.

(https://github.com/so-fancy/diff-so-fancy)

--diff-stat-align-width <N>

Width allocated for file paths in a diff stat section.

If a relativized file path exceeds this width then the diff stat will be
misaligned.

[default: 48]

--features <FEATURES>

Names of delta features to activate (space-separated).

A feature is a named collection of delta options in ~/.gitconfig. See FEATURES
section. The environment variable DELTA_FEATURES can be set to a space-separated
list of feature names. If this is preceded with a + character, the features from
the environment variable will be added to those specified in git config. E.g.
DELTA_FEATURES=+side-by-side can be used to activate side-by-side temporarily (use
DELTA_FEATURES=+ to go back to just the features from git config).

--file-added-label <STRING>

Text to display before an added file path.

Used in the default value of navigate-regex.

[default: added:]

--file-copied-label <STRING>

Text to display before a copied file path

[default: copied:]

--file-decoration-style <STYLE>

Style string for the file decoration.

See STYLES section. The style string should contain one of the special attributes
'box', 'ul' (underline), 'ol' (overline), or the combination 'ul ol'.

[default: "blue ul"]

--file-modified-label <STRING>

Text to display before a modified file path.

Used in the default value of navigate-regex.

[default: ]

--file-removed-label <STRING>

Text to display before a removed file path.

Used in the default value of navigate-regex.

[default: removed:]

--file-renamed-label <STRING>

Text to display before a renamed file path.

Used in the default value of navigate-regex.

[default: renamed:]

--file-style <STYLE>

Style string for the file section.

See STYLES section. The style 'omit' can be used to remove the file section from
the output.

[default: blue]

--file-transformation <SED_CMD>

Sed-style command transforming file paths for display

--grep-context-line-style <STYLE>

Style string for non-matching lines of grep output.

See STYLES section. Defaults to zero-style.

--grep-file-style <STYLE>

Style string for file paths in grep output.

See STYLES section.

[default: magenta]

--grep-header-decoration-style <STYLE>

Style string for the header decoration in grep output.

Default is "none" when grep-ouput-type-is "ripgrep", otherwise defaults to value of
header-decoration-style. See hunk-header-decoration-style.

--grep-header-file-style <STYLE>

Style string for the file path part of the header in grep output.

See hunk_header_file_style.

--grep-line-number-style <STYLE>

Style string for line numbers in grep output.

See STYLES section.

[default: green]

--grep-output-type <OUTPUT_TYPE>

Grep output format. Possible values: "ripgrep" - file name printed once, followed
by matching lines within that file, each preceded by a line number. "classic" -
file name:line number, followed by matching line. Default is "ripgrep" if `rg
--json` format is detected, otherwise "classic"

--grep-match-line-style <STYLE>

Style string for matching lines of grep output.

See STYLES section. Defaults to plus-style.

--grep-match-word-style <STYLE>

Style string for the matching substrings within a matching line of grep output.

See STYLES section. Defaults to plus-style.

--grep-separator-symbol <STRING>

Separator symbol printed after the file path and line number in grep output.

Defaults to ":" for both match and context lines, since many terminal emulators
recognize constructs like "/path/to/file:7:". However, standard grep output uses
"-" for context lines: set this option to "keep" to keep the original separator
symbols.

[default: :]

--hunk-header-decoration-style <STYLE>

Style string for the hunk-header decoration.

See STYLES section. The style string should contain one of the special attributes
'box', 'ul' (underline), 'ol' (overline), or the combination 'ul ol'.

[default: "blue box"]

--hunk-header-file-style <STYLE>

Style string for the file path part of the hunk-header.

See STYLES section. The file path will only be displayed if hunk-header-style
contains the 'file' special attribute.

[default: blue]

--hunk-header-line-number-style <STYLE>

Style string for the line number part of the hunk-header.

See STYLES section. The line number will only be displayed if hunk-header-style
contains the 'line-number' special attribute.

[default: blue]

--hunk-header-style <STYLE>

Style string for the hunk-header.

See STYLES section. Special attributes 'file' and 'line-number' can be used to
include the file path, and number of first hunk line, in the hunk header. The style
'omit' can be used to remove the hunk header section from the output.

[default: "line-number syntax"]

--hunk-label <STRING>

Text to display before a hunk header.

Used in the default value of navigate-regex.

[default: ]

--hyperlinks

Render commit hashes, file names, and line numbers as hyperlinks.

Following the hyperlink spec for terminal emulators:
https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda. By default,
file names and line numbers link to the local file using a file URL, whereas commit
hashes link to the commit in GitHub, if the remote repository is hosted by GitHub.
See --hyperlinks-file-link-format for full control over the file URLs emitted.
Hyperlinks are supported by several common terminal emulators. To make them work,
you must use less version >= 581 with the -R flag (or use -r with older less
versions, but this will break e.g. --navigate). If you use tmux, then you will also
need a patched fork of tmux (see https://github.com/dandavison/tmux).

--hyperlinks-commit-link-format <FMT>

Format string for commit hyperlinks (requires --hyperlinks).

The placeholder "{commit}" will be replaced by the commit hash. For example:
--hyperlinks-commit-link-format='https://mygitrepo/{commit}/'

--hyperlinks-file-link-format <FMT>

Format string for file hyperlinks (requires --hyperlinks).

The placeholders "{path}" and "{line}" will be replaced by the absolute file path
and the line number, respectively. The default value of this option creates
hyperlinks using standard file URLs; your operating system should open these in the
application registered for that file type. However, these do not make use of the
line number. In order for the link to open the file at the correct line number, you
could use a custom URL format such as "file-line://{path}:{line}" and register an
application to handle the custom "file-line" URL scheme by opening the file in your
editor/IDE at the indicated line number. See
https://github.com/dandavison/open-in-editor for an example.

[default: file://{path}]

--inline-hint-style <STYLE>

Style string for short inline hint text.

This styles certain content added by delta to the original diff such as special
characters to highlight tabs, and the symbols used to indicate wrapped lines. See
STYLES section.

[default: blue]

--inspect-raw-lines <true|false>

Kill-switch for --color-moved support.

Whether to examine ANSI color escape sequences in raw lines received from Git and
handle lines colored in certain ways specially. This is on by default: it is how
Delta supports Git's --color-moved feature. Set this to "false" to disable this
behavior.

[default: true]

--keep-plus-minus-markers

Prefix added/removed lines with a +/- character, as git does.

By default, delta does not emit any prefix, so code can be copied directly from
delta's output.

--light

Use default colors appropriate for a light terminal background.

For more control, see the style options and --syntax-theme.

--line-buffer-size <N>

Size of internal line buffer.

Delta compares the added and removed versions of nearby lines in order to detect
and highlight changes at the level of individual words/tokens. Therefore, nearby
lines must be buffered internally before they are painted and emitted. Increasing
this value might improve highlighting of some large diff hunks. However, setting
this to a high value will adversely affect delta's performance when entire files
are added/removed.

[default: 32]

--line-fill-method <STRING>

Line-fill method in side-by-side mode.

How to extend the background color to the end of the line in side-by-side mode. Can
be ansi (default) or spaces (default if output is not to a terminal). Has no effect
if --width=variable is given.

-n, --line-numbers

Display line numbers next to the diff.

See LINE NUMBERS section.

--line-numbers-left-format <FMT>

Format string for the left column of line numbers.

A typical value would be "{nm:^4}???" which means to display the line numbers of
the minus file (old version), center-aligned, padded to a width of 4 characters,
followed by a dividing character. See the LINE NUMBERS section.

[default: {nm:^4}???]

--line-numbers-left-style <STYLE>

Style string for the left column of line numbers.

See STYLES and LINE NUMBERS sections.

[default: auto]

--line-numbers-minus-style <STYLE>

Style string for line numbers in the old (minus) version of the file.

See STYLES and LINE NUMBERS sections.

[default: auto]

--line-numbers-plus-style <STYLE>

Style string for line numbers in the new (plus) version of the file.

See STYLES and LINE NUMBERS sections.

[default: auto]

--line-numbers-right-format <FMT>

Format string for the right column of line numbers.

A typical value would be "{np:^4}??? " which means to display the line numbers of
the plus file (new version), center-aligned, padded to a width of 4 characters,
followed by a dividing character, and a space. See the LINE NUMBERS section.

[default: {np:^4}???]

--line-numbers-right-style <STYLE>

Style string for the right column of line numbers.

See STYLES and LINE NUMBERS sections.

[default: auto]

--line-numbers-zero-style <STYLE>

Style string for line numbers in unchanged (zero) lines.

See STYLES and LINE NUMBERS sections.

[default: auto]

--list-languages

List supported languages and associated file extensions

--list-syntax-themes

List available syntax-highlighting color themes

--map-styles <STYLES_MAP>

Map styles encountered in raw input to desired output styles.

An example is --map-styles='bold purple => red "#eeeeee", bold cyan => syntax
"#eeeeee"'

--max-line-distance <DIST>

Maximum line pair distance parameter in within-line diff algorithm.

This parameter is the maximum distance (0.0 - 1.0) between two lines for them to be
inferred to be homologous. Homologous line pairs are highlighted according to the
deletion and insertion operations transforming one into the other.

[default: 0.6]

--max-line-length <N>

Truncate lines longer than this.

To prevent any truncation, set to zero. Note that delta will be slow on very long
lines (e.g. minified .js) if truncation is disabled. When wrapping lines it is
automatically set to fit at least all visible characters.

[default: 512]

--merge-conflict-begin-symbol <STRING>

String marking the beginning of a merge conflict region.

The string will be repeated until it reaches the required length.

[default: ???]

--merge-conflict-end-symbol <STRING>

String marking the end of a merge conflict region.

The string will be repeated until it reaches the required length.

[default: ???]

--merge-conflict-ours-diff-header-decoration-style <STYLE>

Style string for the decoration of the header above the 'ours' merge conflict diff.

This styles the decoration of the header above the diff between the ancestral
commit and the 'ours' branch. See STYLES section. The style string should contain
one of the special attributes 'box', 'ul' (underline), 'ol' (overline), or the
combination 'ul ol'.

[default: box]

--merge-conflict-ours-diff-header-style <STYLE>

Style string for the header above the 'ours' branch merge conflict diff.

See STYLES section.

[default: normal]

--merge-conflict-theirs-diff-header-decoration-style <STYLE>

Style string for the decoration of the header above the 'theirs' merge conflict
diff.

This styles the decoration of the header above the diff between the ancestral commit and
'their' branch.
See STYLES section. The style string should contain one of the special attributes
'box', 'ul' (underline), 'ol' (overline), or the combination 'ul ol'.

[default: box]

--merge-conflict-theirs-diff-header-style <STYLE>

Style string for the header above the 'theirs' branch merge conflict diff.

This styles the header above the diff between the ancestral commit and 'their'
branch. See STYLES section.

[default: normal]

--minus-empty-line-marker-style <STYLE>

Style string for removed empty line marker.

Used only if --minus-style has no background color.

[default: "normal auto"]

--minus-emph-style <STYLE>

Style string for emphasized sections of removed lines.

See STYLES section.

[default: "normal auto"]

--minus-non-emph-style <STYLE>

Style string for non-emphasized sections of removed lines that have an emphasized
section.

See STYLES section.

[default: minus-style]

--minus-style <STYLE>

Style string for removed lines.

See STYLES section.

[default: "normal auto"]

--navigate

Activate diff navigation.

Use n to jump forwards and N to jump backwards. To change the file labels used see
--file-modified-label, --file-removed-label, --file-added-label,
--file-renamed-label.

--navigate-regex <REGEX>

Regular expression defining navigation stop points

--no-gitconfig

Do not read any settings from git config.

See GIT CONFIG section.

--pager <CMD>

Which pager to use.

The default pager is `less`. You can also change pager by setting the environment
variables DELTA_PAGER, BAT_PAGER, or PAGER (and that is their order of priority).
This option overrides all environment variables above.

--paging <auto|always|never>

Whether to use a pager when displaying output.

Options are: auto, always, and never.

[default: auto]

--parse-ansi

Display ANSI color escape sequences in human-readable form.

Example usage: git show --color=always | delta --parse-ansi This can be used to
help identify input style strings to use with map-styles.

--plus-emph-style <STYLE>

Style string for emphasized sections of added lines.

See STYLES section.

[default: "syntax auto"]

--plus-empty-line-marker-style <STYLE>

Style string for added empty line marker.

Used only if --plus-style has no background color.

[default: "normal auto"]

--plus-non-emph-style <STYLE>

Style string for non-emphasized sections of added lines that have an emphasized
section.

See STYLES section.

[default: plus-style]

--plus-style <STYLE>

Style string for added lines.

See STYLES section.

[default: "syntax auto"]

--raw

Do not alter the input in any way.

This is mainly intended for testing delta.

--relative-paths

Output all file paths relative to the current directory.

This means that they will resolve correctly when clicked on or used in shell
commands.

--right-arrow <STRING>

Text to display with a changed file path.

For example, a unified diff heading, a rename, or a chmod.

[default: "???
"]

--show-colors

Show available named colors.

In addition to named colors, arbitrary colors can be specified using RGB hex codes.
See COLORS section.

--show-config

Display the active values for all Delta options.

Style string options are displayed with foreground and background colors. This can
be used to experiment with colors by combining this option with other options such
as --minus-style, --zero-style, --plus-style, --light, --dark, etc.

--show-syntax-themes

Show example diff for available syntax-highlighting themes.

If diff output is supplied on standard input then this will be used for the demo.
For example: `git show | delta --show-syntax-themes`.

--show-themes

Show example diff for available delta themes.

A delta theme is a delta named feature (see --features) that sets either `light` or
`dark`. See https://github.com/dandavison/delta#custom-color-themes. If diff output
is supplied on standard input then this will be used for the demo. For example:
`git show | delta --show-themes`. By default shows dark or light themes only,
according to whether delta is in dark or light mode (as set by the user or inferred
from BAT_THEME). To control the themes shown, use --dark or --light, or both, on
the command line together with this option.

-s, --side-by-side

Display diffs in side-by-side layout

--syntax-theme <SYNTAX_THEME>

The syntax-highlighting theme to use.

Use --show-syntax-themes to demo available themes. Defaults to the value of the
BAT_THEME environment variable, if that contains a valid theme name.
--syntax-theme=none disables all syntax highlighting.

--tabs <N>

The number of spaces to replace tab characters with.

Use --tabs=0 to pass tab characters through directly, but note that in that case
delta will calculate line widths assuming tabs occupy one character's width on the
screen: if your terminal renders tabs as more than one character wide then delta's
output will look incorrect.

[default: 8]

--true-color <auto|always|never>

Whether to emit 24-bit ("true color") RGB color codes.

Options are auto, always, and never. "auto" means that delta will emit 24-bit color
codes if the environment variable COLORTERM has the value "truecolor" or "24bit".
If your terminal application (the application you use to enter commands at a shell
prompt) supports 24 bit colors, then it probably already sets this environment
variable, in which case you don't need to do anything.

[default: auto]

--whitespace-error-style <STYLE>

Style string for whitespace errors.

Defaults to color.diff.whitespace if that is set in git config, or else 'magenta
reverse'.

[default: "auto auto"]

-w, --width <N>

The width of underline/overline decorations.

Examples: "72" (exactly 72 characters), "-2" (auto-detected terminal width minus
2). An expression such as "74-2" is also valid (equivalent to 72 but may be useful
if the caller has a variable holding the value "74"). Use --width=variable to
extend decorations and background colors to the end of the text only. Otherwise
background colors extend to the full terminal width.

--word-diff-regex <REGEX>

Regular expression defining a 'word' in within-line diff algorithm.

The regular expression used to decide what a word is for the within-line highlight
algorithm. For less fine-grained matching than the default try
--word-diff-regex="\S+" --max-line-distance=1.0 (this is more similar to `git
--word-diff`).

[default: \w+]

--wrap-left-symbol <STRING>

End-of-line wrapped content symbol (left-aligned).

Symbol added to the end of a line indicating that the content has been wrapped onto
the next line and continues left-aligned.

[default: ???]

--wrap-max-lines <N>

How often a line should be wrapped if it does not fit.

Zero means to never wrap. Any content which does not fit after wrapping will be
truncated. A value of "unlimited" means a line will be wrapped as many times as
required.

[default: 2]

--wrap-right-percent <PERCENT>

Threshold for right-aligning wrapped content.

If the length of the remaining wrapped content, as a percentage of width, is less
than this quantity it will be right-aligned. Otherwise it will be left-aligned.

[default: 37.0]

--wrap-right-prefix-symbol <STRING>

Pre-wrapped content symbol (right-aligned).

Symbol displayed before right-aligned wrapped content.

[default: ???]

--wrap-right-symbol <STRING>

End-of-line wrapped content symbol (right-aligned).

Symbol added to the end of a line indicating that the content has been wrapped onto
the next line and continues right-aligned.

[default: ???]

--zero-style <STYLE>

Style string for unchanged lines.

See STYLES section.

[default: "syntax normal"]

--24-bit-color <auto|always|never>

Deprecated: use --true-color

-h, --help

Print help (see a summary with '-h')

-V, --version

Print version

GIT CONFIG ----------

By default, delta takes settings from a section named "delta" in git config files, if one
is present. The git config file to use for delta options will usually be ~/.gitconfig, but
delta follows the rules given in https://git-scm.com/docs/git-config#FILES. Most delta
options can be given in a git config file, using the usual option names but without the
initial '--'. An example is

[delta]

line-numbers = true zero-style = dim syntax

FEATURES -------- A feature is a named collection of delta options in git config. An
example is:

[delta "my-delta-feature"]

syntax-theme = Dracula plus-style = bold syntax "#002800"

To activate those options, you would use:

delta --features my-delta-feature

A feature name may not contain whitespace. You can activate multiple features:

[delta]

features = my-highlight-styles-colors-feature my-line-number-styles-feature

If more than one feature sets the same option, the last one wins.

If an option is present in the [delta] section, then features are not considered at all.

If you want an option to be fully overridable by a feature and also have a non default
value when no features are used, then you need to define a "default" feature and include
it in the main delta configuration.

For instance:

[delta] feature = default-feature

[delta "default-feature"] width = 123

At this point, you can override features set in the command line or in the environment
variables and the "last one wins" rules will apply as expected.

STYLES ------

All options that have a name like --*-style work the same way. It is very similar to how
colors/styles are specified in a gitconfig file:
https://git-scm.com/docs/git-config#Documentation/git-config.txt-color

Here is an example:

--minus-style 'red bold ul "#ffeeee"'

That means: For removed lines, set the foreground (text) color to 'red', make it bold and
underlined, and set the background color to '#ffeeee'.

See the COLORS section below for how to specify a color. In addition to real colors, there
are 4 special color names: 'auto', 'normal', 'raw', and 'syntax'.

Here is an example of using special color names together with a single attribute:

--minus-style 'syntax bold auto'

That means: For removed lines, syntax-highlight the text, and make it bold, and do
whatever delta normally does for the background.

The available attributes are: 'blink', 'bold', 'dim', 'hidden', 'italic', 'reverse',
'strike', and 'ul' (or 'underline').

The attribute 'omit' is supported by commit-style, file-style, and hunk-header-style,
meaning to remove the element entirely from the output.

A complete description of the style string syntax follows:

- If the input that delta is receiving already has colors, and you want delta to output
those colors unchanged, then use the special style string 'raw'. Otherwise, delta will
strip any colors from its input.

- A style string consists of 0, 1, or 2 colors, together with an arbitrary number of style
attributes, all separated by spaces.

- The first color is the foreground (text) color. The second color is the background
color. Attributes can go in any position.

- This means that in order to specify a background color you must also specify a
foreground (text) color.

- If you want delta to choose one of the colors automatically, then use the special color
'auto'. This can be used for both foreground and background.

- If you want the foreground/background color to be your terminal's foreground/background
color, then use the special color 'normal'.

- If you want the foreground text to be syntax-highlighted according to its language, then
use the special foreground color 'syntax'. This can only be used for the foreground
(text).

- The minimal style specification is the empty string ''. This means: do not apply any
colors or styling to the element in question.

COLORS ------

There are four ways to specify a color (this section applies to foreground and background
colors within a style string):

1. CSS color name

Any of the 140 color names used in CSS:
https://www.w3schools.com/colors/colors_groups.asp

2. RGB hex code

An example of using an RGB hex code is: --file-style="#0e7c0e"

3. ANSI color name

There are 8 ANSI color names: black, red, green, yellow, blue, magenta, cyan,
white.

In addition, all of them have a bright form: brightblack, brightred, brightgreen,
brightyellow, brightblue, brightmagenta, brightcyan, brightwhite.

An example of using an ANSI color name is: --file-style="green"

Unlike RGB hex codes, ANSI color names are just names: you can choose the exact
color that each name corresponds to in the settings of your terminal application
(the application you use to enter commands at a shell prompt). This means that if
you use ANSI color names, and you change the color theme used by your terminal,
then delta's colors will respond automatically, without needing to change the delta
command line.

"purple" is accepted as a synonym for "magenta". Color names and codes are
case-insensitive.

4. ANSI color number

An example of using an ANSI color number is: --file-style=28

There are 256 ANSI color numbers: 0-255. The first 16 are the same as the colors
described in the "ANSI color name" section above. See
https://en.wikipedia.org/wiki/ANSI_escape_code#8-bit. Specifying colors like this
is useful if your terminal only supports 256 colors (i.e. doesn't support 24-bit
color).

LINE NUMBERS ------------

To display line numbers, use --line-numbers.

Line numbers are displayed in two columns. Here's what it looks like by default:

1 ??? 1 ??? unchanged line

2 ??? ??? removed line

??? 2 ??? added line

In that output, the line numbers for the old (minus) version of the file appear in the
left column, and the line numbers for the new (plus) version of the file appear in the
right column. In an unchanged (zero) line, both columns contain a line number.

The following options allow the line number display to be customized:

--line-numbers-left-format: Change the contents of the left column
--line-numbers-right-format: Change the contents of the right column
--line-numbers-left-style: Change the style applied to the left column
--line-numbers-right-style: Change the style applied to the right column
--line-numbers-minus-style: Change the style applied to line numbers in minus lines
--line-numbers-zero-style: Change the style applied to line numbers in unchanged lines
--line-numbers-plus-style: Change the style applied to line numbers in plus lines

Options --line-numbers-left-format and --line-numbers-right-format allow you to change the
contents of the line number columns. Their values are arbitrary format strings, which are
allowed to contain the placeholders {nm} for the line number associated with the old
version of the file and {np} for the line number associated with the new version of the
file. The placeholders support a subset of the string formatting syntax documented here:
https://doc.rust-lang.org/std/fmt/#formatting-parameters. Specifically, you can use the
alignment and width syntax.

For example, the default value of --line-numbers-left-format is '{nm:^4}???'. This means
that the left column should display the minus line number (nm), center-aligned, padded
with spaces to a width of 4 characters, followed by a unicode dividing-line character
(???).

Similarly, the default value of --line-numbers-right-format is '{np:^4}???'. This means
that the right column should display the plus line number (np), center-aligned, padded
with spaces to a width of 4 characters, followed by a unicode dividing-line character
(???).

Use '<' for left-align, '^' for center-align, and '>' for right-align.

If something isn't working correctly, or you have a feature request, please open an issue
at https://github.com/dandavison/delta/issues.

For a short help summary, please use delta -h.