NAME

sdif - side-by-side diff viewer for ANSI terminal

VERSION

Version 4.26

SYNOPSIS

  sdif file_1 file_2

  diff ... | sdif

OPTIONS:

  -i, --ignore-case
  -b, --ignore-space-change
  -w, --ignore-all-space
  -B, --ignore-blank-lines

  --[no]number, -n	print line number
  --digit=#		set the line number digits (default 4)
  --truncate, -t	truncate long line
  --[no]onword	fold line on word boundaries
  --context, -c, -C#	context diff
  --unified, -u, -U#	unified diff

  --width=#, -W#	specify width of output (default 80)
  --margin=#		specify margin column number (default 0)
  --runin=#		specify run-in column number (default --margin)
  --runout=#		specify run-out column number (default --margin)
  --mark=position	mark position (right, left, center, side) or no
  --column=order	set column order (default ONM)
  --view, -v		viewer mode
  --parallel[=#], -V	treat unknown text as common part (default 2)
  --ambiguous=s	ambiguous character width (detect, wide, narrow)
  --[no]command	print diff control command (default on)
  --[no]prefix	process git --graph output (default on)
  --prefix-pattern    prefix pattern

  --color=when	'always' (default), 'never' or 'auto'
  --nocolor		--color=never
  --colormap, --cm	specify color map
  --colortable	show color table
  --[no]256		on/off ANSI 256 color mode (default on)

  --man		display manual page
  --diff=s		set diff command
  --diffopts=s	set diff command options

  --[no]lenience	supress unexpected input warning (default on)
  --visible xx=1	set visible chars
  --tabhead=char	set tabhead char
  --tabspace=char	set tabspace char
  --tabstyle=style	set tabstyle (dot, symbol, shade, bar, dash...)
  --tabstop=#		set tabstop width (default 8)

  --[no]cdif		use ``cdif'' as word context diff backend
  --unit=s		pass through to cdif (word, char, mecab)
  --cdifopts=s	set cdif command options

DESCRIPTION

sdif is inspired by the System V sdiff(1) command. The basic feature of sdif is making a side-by-side listing of two different files. All contents of two files are listed on left and right sides. Center column is used to indicate how different those lines are. No mark means no difference. Added, deleted and modified lines are marked with minus - and plus + character, and wrapped line is marked with period ..

1 deleted  -
2 same          1 same
3 changed  -+   2 modified
  wrapped  ..     folded
4 same          3 same
            +   4 added

It also reads and formats the output from diff command from standard input. Besides normal diff output, context diff -c and unified diff -u output will be handled properly. Combined diff format is also supported, but currently limited up to three files.

If you want to just show multiple files side-by-side in parallel, and do not concern about the difference of them, use App::ansicolumn command.

STARTUP and MODULE

sdif utilizes Perl Getopt::EX module, and reads ~/.sdifrc file if available when starting up. You can define original and default option there. To show the line number always, define like this:

option default -n

Modules under App::sdif can be loaded by -M option without prefix. Next command load App::sdif::colors module.

$ sdif -Mcolors

You can also define options in module file. Read `perldoc Getopt::EX::Module` for detail.

COLOR

Each lines are displayed in different colors by default. Use --no-color option to disable it. Each text segment has own labels, and color for them can be specified by --colormap option. Read `perldoc Getopt::EX::Colormap` for detail.

Standard module -Mcolors is loaded by default, and define several color maps for light and dark screen. If you want to use CMY colors in dark screen, place next line in your ~/.sdifrc.

option default --dark-cmy

Option --autocolor is defined in default module to call Getopt::EX::termcolor module. It sets --light or --dark option according to the brightness of the terminal screen. You can set preferred color in your ~/.sdifrc like:

option --light --cmy
option --dark  --dark-cmy

Automatic setting is done by Getopt::EX::termcolor module and it works with macOS Terminal.app and iTerm.app, and other XTerm compatible terminals. This module accept environment variable TERM_BGCOLOR as a terminal background color in a form of #FFFFFF.

Option --autocolor is set by default, so override it to do nothing to disable.

option --autocolor --nop

WORD DIFFERENCE

While sdif doesn't care about the contents of each modified lines, it can read the output from cdif command which show the word context differences of each lines. Use cdif command with option --sdif to set the appropriate options for sdif. Set --no-cc, --no-mc options at least when invoking cdif manually. Option --no-tc is preferable because text color can be handled by sdif.

From version 4.1.0, option --cdif is set by default, so use --no-cdif option to disable it. Option --unit (default word) will be passed through to cdif. Other cdif options can be specified by --cdifopts.

EXIT STATUS

sdif always exit with status zero unless error occurred.

OPTIONS

--width=width, -W width

Use width as a width of output listing. Default width is 80. If the standard error is assigned to a terminal, the width is taken from it if possible.

--margin=column
--runin=column
--runout=column

Set the number of margin column. Margin columns are left blank at the end of each line. This option implicitly declare line break control, which allows to run-in and run-out prohibited characters at the head-and-end of line. Margin columns are used for run-in/run-out columns unless they are given explicitly. See `perldoc Text::ANSI::Fold` for detail.

-n, --[no-]number

Print line number on each lines. Default false.

--[no-]command

Print diff command control lines. Default true.

--digit=n

Line number is displayed in 4 digits by default. Use this option to change it.

-i, --ignore-case
-b, --ignore-space-change
-w, --ignore-all-space
-B, --ignore-blank-lines
-c, --context=n, -Cn
-u, --unified=n, -Un

Passed through to the back-end diff command. Sdif can interpret the output from normal, context (diff -c) and unified diff (diff -u).

-t, --[no-]truncate

Truncate lines if they are longer than printing width. Default false.

--[no-]onword

Fold long line at word boundaries. Default true.

--[no-]cdif[=command]

Use cdif command instead of normal diff command. Enabled by default and use --no-cdif option explicitly to disable it. This option accepts optional parameter as an actual cdif command.

--cdifopts=option

Specify options for back-end cdif command.

--unit=[word,letter,char,mecab]
--by=[word,letter,char,mecab]
--mecab

These options are simply sent to back-end cdif command. Choose value from word (default), letter, char or mecab. Option --by is an alias for --unit. Option --mecab is a shortcut for --unit=mecab. Consult cdif manual for detail.

Use --cdifopts to set other options.

--diff=command

Any command can be specified as a diff command to be used. Piping output to sdif is easier unless you want to get whole text.

--diffopts=option

Specify options for back-end diff command.

--mark=position

Specify the position for a mark. Choose from left, right, center, side or no. Default is center.

--column=order

Specify the order of each column by O (1: old), N (2: new) and M (3: merged). Default order is "ONM" or "123". If you want to show new file on left side and old file in right side, use like:

$ sdif --column NO

Next example show merged file on left-most column for diff3 data.

$ sdif --column MON

Next two commands produce same output.

$ git diff v1 v2 v3 | sdif --column 312

$ git diff v3 v1 v2 | sdif
--[no-]color

Use ANSI color escape sequence for output. Default is true.

--[no-]256

Use ANSI 256 color mode. Default is true.

--colortable

Show table of ANSI 216 colors.

-v, --view

Viewer mode. Display each files in straightforward order. Without this option, unchanged lines are placed at the same position.

-V, --parallel
-V3, --parallel=3

sdif processes only looks-like-diff-output data and print anything else as is to standard out. Option -V or --parralel makes unknown text as common to old and new data. This is useful to see file including conflict marker data compatible with git(1).

This option takes an optional number parameter and 2 is assumed when omitted. Other than 2, only 3 is an effective number.

--ambiguous=width_spec

This is an experimental option to specify how to treat Unicode ambiguous width characters. Default value is 'narrow'.

detect or auto

Detect from user's locate. Set 'wide' when used in CJK environment.

wide or full

Treat ambiguous characters as wide.

narrow or half

Treat ambiguous characters as narrow.

--[no-]prefix

Understand prefix for diff output including git --graph option. True by default.

--prefix-pattern=pattern

Specify prefix pattern in regex. Default pattern is:

(?:\| )*(?:  )?

This pattern matches git graph style and whitespace indented diff output.

--[no-]lenience

Suppress warning message for unexpected input from diff command. True by default.

--visible charname=[0,1]
--tabhead=char
--tabspace=char

Visualize characters. Currently only ht (horizontal tab) is supported. Each horizontal tab character is converted to tabhead and following tabspace characters. They can be specified by --tabhead and --tabspace option.

$ sdif --visible ht=1 --tabhead=T --tabspace=.

If the option value is longer than single character, it is evaluated as unicode name.

$ sdif --visible ht=1 \
       --tabhead="MEDIUM SHADE" \
       --tabspace="LIGHT SHADE"

See https://www.unicode.org/charts/charindex.html for Unicode names.

cdif shows non-space control characters visible by default. See "--visible" in cdif.

--tabstyle=[space,dot,symbol,shade,bar,dash...]

Option --tabstyle allow to set --tabhead and --tabspace characters at once according to the given style name. Select from space, dot, symbol, shade, bar, dash and others. See "tabstyle" in Text::ANSI::Fold for available styles.

Multiple styles can be mixed up like symbol,space. In this case, tabhead and tabspace are taken from symbol and space style respectively.

Setting tabstyle implies ht being visible. If you want to set tabstyle by default, but don't want to make tab visible always, disable it explicitly.

option default --tabstyle=symbol,space --visible ht=0

Then you can enable it at the time of execution.

$ sdif --visible ht=1
--tabstop=n

Specify tab stop. Default is 8.

--colormap=colormap, --cm=colormap

Basic colormap format is :

FIELD=COLOR

where the FIELD is one from these :

OLD       NEW       MERGED    UNCHANGED
--------- --------- --------- ---------
OCOMMAND  NCOMMAND  MCOMMAND           : Command line
OFILE     NFILE     MFILE              : File name
OMARK     NMARK     MMARK     UMARK    : Mark
OLINE     NLINE     MLINE     ULINE    : Line number
OTEXT     NTEXT     MTEXT     UTEXT    : Text

If UMARK and/or ULINE is empty, OMARK/NMARK and/or OLINE/NLINE are used instead.

You can make multiple fields same color joining them by = :

FIELD1=FIELD2=...=COLOR

Also wildcard can be used for field name :

*CHANGE=BDw

Multiple fields can be specified by repeating options

--cm FILED1=COLOR1 --cm FIELD2=COLOR2 ...

or combined with comma (,) :

--cm FILED1=COLOR1,FIELD2=COLOR2, ...

Color specification is a combination of single uppercase character representing 8 colors :

R  Red
G  Green
B  Blue
C  Cyan
M  Magenta
Y  Yellow
K  Black
W  White

and alternative (usually brighter) colors in lowercase :

r, g, b, c, m, y, k, w

or RGB values and 24 grey levels if using ANSI 256 or full color terminal :

(255,255,255)      : 24bit decimal RGB colors
#000000 .. #FFFFFF : 24bit hex RGB colors
#000    .. #FFF    : 12bit hex RGB 4096 colors
000 .. 555         : 6x6x6 RGB 216 colors
L00 .. L25         : Black (L00), 24 grey levels, White (L25)

or color names enclosed by angle bracket :

<red> <blue> <green> <cyan> <magenta> <yellow>
<aliceblue> <honeydue> <hotpink> <moccasin>
<medium_aqua_marine>

with other special effects :

D  Double-struck (boldface)
I  Italic
U  Underline
S  Stand-out (reverse video)

Above color spec is simplified summary so if you want complete information, read Getopt::EX::Colormap.

Defaults are :

OCOMMAND => "555/010"  or "GS"
NCOMMAND => "555/010"  or "GS"
MCOMMAND => "555/010"  or "GS"
OFILE    => "551/010D" or "GDS"
NFILE    => "551/010D" or "GDS"
MFILE    => "551/010D" or "GDS"
OMARK    => "010/444"  or "G/W"
NMARK    => "010/444"  or "G/W"
MMARK    => "010/444"  or "G/W"
UMARK    => ""
OLINE    => "220"      or "Y"
NLINE    => "220"      or "Y"
MLINE    => "220"      or "Y"
ULINE    => ""
OTEXT    => "K/454"    or "G"
NTEXT    => "K/454"    or "G"
MTEXT    => "K/454"    or "G"
UTEXT    => ""

This is equivalent to :

sdif --cm '?COMMAND=555/010,?FILE=555/010D' \
     --cm '?MARK=010/444,UMARK=' \
     --cm '?LINE=220,ULINE=' \
     --cm '?TEXT=K/454,UTEXT='
--colormap=&func
--colormap=sub{...}

You can also set the name of perl subroutine name or definition to be called handling matched words. Target word is passed as variable $_, and the return value of the subroutine will be displayed.

See "FUNCTION SPEC" in Getopt::EX::Colormap for detail.

MODULE OPTIONS

default

default      --autocolor
--nop        do nothing

-Mcolors

Following options are available by default. Use `perldoc -m App::sdif::colors` to see actual setting.

--light
--green
--cmy
--mono

--dark
--dark-green
--dark-cmy
--dark-mono

ENVIRONMENT

Environment variable SDIFOPTS is used to set default options.

AUTHOR

Kazumasa Utashiro
https://github.com/kaz-utashiro/sdif-tools

LICENSE

Copyright 1992-2023 Kazumasa Utashiro

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

cdif(1), watchdiff(1)

Getopt::EX::Colormap

Getopt::EX::termcolor

App::sdif::colors

https://taku910.github.io/mecab/

App::ansicolumn