NAME
Text::ANSI::Util - Routines for text containing ANSI color codes
VERSION
This document describes version 0.234 of Text::ANSI::Util (from Perl
distribution Text-ANSI-Util), released on 2023-02-27.
SYNOPSIS
use Text::ANSI::Util qw(
ta_add_color_resets
ta_detect
ta_extract_codes
ta_highlight
ta_highlight_all
ta_length
ta_length_height
ta_pad
ta_split_codes
ta_split_codes_single
ta_strip
ta_substr
ta_trunc
ta_wrap
);
# detect whether text has ANSI color codes?
say ta_detect("red"); # => false
say ta_detect("\e[31mred"); # => true
# calculate length of text (excluding the ANSI color codes)
say ta_length("red"); # => 3
say ta_length("\e[31mred"); # => 3
# strip ANSI color codes
say ta_strip("\e[31mred"); # => "red"
# split codes (ANSI color codes are always on the even positions)
my @parts = ta_split_codes("\e[31mred"); # => ("", "\e[31m", "red")
# wrap text to a certain column width, handle ANSI color codes
say ta_wrap("....", 40);
# pad (left, right, center) text to a certain width
say ta_pad("foo", 10); # => "foo "
say ta_pad("foo", 10, "left"); # => " foo"
say ta_pad("foo\nbarbaz\n", 10, "center", "."); # => "...foo....\n..barbaz..\n"
# truncate text to a certain width while still passing ANSI color codes
use Term::ANSIColor;
my $text = color("red")."red text".color("reset"); # => "\e[31mred text\e[0m"
say ta_trunc($text, 5); # => "\e[31mred t\e[0m"
# highlight the first occurrence of some string within text
say ta_highlight("some text", "ome", "\e[7m\e[31m");
# ditto, but highlight all occurrences
say ta_highlight_all(...);
# get substring
my $substr = ta_substr("...", $pos, $len);
# return text but with substring replaced with replacement
say ta_substr("...", $pos, $len, $replacement);
DESCRIPTION
This module provides routines for dealing with text that contains ANSI
color codes, e.g. for determining its length/width (excluding the color
codes), stripping the color codes, extracting the color codes, and so
on.
For functions that support wide characters, see Text::ANSI::WideUtil.
Current caveats:
* Other ANSI codes (non-color codes) are ignored
These are codes like for altering cursor positions, etc.
* Single-character CSI (control sequence introducer) currently ignored
Only "ESC+[" (two-character CSI) is currently parsed.
BTW, in ASCII terminals, single-character CSI is 0x9b. In UTF-8
terminals, it is "0xc2, 0x9b" (2 bytes).
* Private-mode- and trailing-intermediate character currently not
parsed
* Only color reset code \e[0m is recognized
For simplicity, currently multiple SGR parameters inside a single
ANSI color code is not parsed. This means that color reset code like
"\e[1;0m" or "\e[31;47;0m" is not recognized, only "\e[0m" is. I
believe this should not be a problem with most real-world text out
there.
FUNCTIONS
ta_add_color_resets(@text) => LIST
Make sure that a color reset command (add "\e[0m") to the end of each
element and a replay of all the color codes from the previous element,
from the last color reset) to the start of the next element, and so on.
Return the new list.
This makes each element safe to be combined with other array of text
into a single line, e.g. in a multicolumn/tabular layout. An example:
Without color resets:
my @col1 = split /\n/, "\e[31mred\nmerah\e[0m";
my @col2 = split /\n/, "\e[32mgreen\e[1m\nhijau tebal\e[0m";
printf "%s | %s\n", $col1[0], $col2[0];
printf "%s | %s\n", $col1[1], $col2[1];
the printed output:
\e[31mred | \e[32mgreen
merah\e[0m | \e[1mhijau tebal\e[0m
The "merah" text on the second line will become green because of the
effect of the last color command printed ("\e[32m"). However, with
ta_add_color_resets():
my @col1 = ta_add_color_resets(split /\n/, "\e[31mred\nmerah\e[0m");
my @col2 = ta_add_color_resets(split /\n/, "\e[32mgreen\e[1m\nhijau tebal\e[0m");
printf "%s | %s\n", $col1[0], $col2[0];
printf "%s | %s\n", $col1[1], $col2[1];
the printed output ("<...>") marks the code added by
ta_add_color_resets():
\e[31mred<\e[0m> | \e[32mgreen\e[1m<\e[0m>
<\e[31m>merah\e[0m | <\e[32m\e[1m>hijau tebal\e[0m
All the cells are printed with the intended colors.
ta_detect($text) => BOOL
Return true if $text contains ANSI color codes, false otherwise.
ta_extract_codes($text) => STR
This is the opposite of "ta_strip()", return only the ANSI codes in
$text.
ta_highlight($text, $needle, $color) => STR
Highlight the first occurrence of $needle in $text with <$color>, taking
care not to mess up existing colors.
$needle can be a string or a Regexp object.
Implementation note: to not mess up colors, we save up all color codes
from the last reset ("\e[0m") before inserting the highlight color +
highlight text. Then we issue "\e[0m" and the saved up color code to
return back to the color state before the highlight is inserted. This is
the same technique as described in "ta_add_color_resets()".
ta_highlight_all($text, $needle, $color) => STR
Like "ta_highlight()", but highlight all occurrences instead of only the
first.
ta_length($text) => INT
Count the number of characters in $text, while ignoring ANSI color
codes. Equivalent to "length(ta_strip($text))". See also:
"ta_mbswidth()" in Text::ANSI::WideUtil.
ta_length_height($text) => [INT, INT]
Like "ta_length()", but also gives height (number of lines). For
example, "ta_length_height("foobar\nb\n")" gives "[6, 3]".
See also: "ta_mbswidth_height()" in Text::ANSI::WideUtil.
ta_pad($text, $width[, $which[, $padchar[, $truncate]]]) => STR
Return $text padded with $padchar to $width columns. $which is either
"r" or "right" for padding on the right (the default if not specified),
"l" or "left" for padding on the right, or "c" or "center" or "centre"
for left+right padding to center the text.
$padchar is whitespace if not specified. It should be string having the
width of 1 column.
Does *not* handle multiline text; you can split text by "/\r?\n/"
yourself.
See also: "ta_mbpad()" in Text::ANSI::WideUtil.
ta_split_codes($text) => LIST
Split $text to a list containing alternating ANSI color codes and text.
ANSI color codes are always on the second element, fourth, and so on.
Example:
ta_split_codes(""); # => ()
ta_split_codes("a"); # => ("a")
ta_split_codes("a\e[31m"); # => ("a", "\e[31m")
ta_split_codes("\e[31ma"); # => ("", "\e[31m", "a")
ta_split_codes("\e[31ma\e[0m"); # => ("", "\e[31m", "a", "\e[0m")
ta_split_codes("\e[31ma\e[0mb"); # => ("", "\e[31m", "a", "\e[0m", "b")
ta_split_codes("\e[31m\e[0mb"); # => ("", "\e[31m\e[0m", "b")
so you can do something like:
my @parts = ta_split_codes($text);
while (my ($text, $ansicode) = splice(@parts, 0, 2)) {
...
}
ta_split_codes_single($text) => LIST
Like "ta_split_codes()" but each ANSI color code is split separately,
instead of grouped together. This routine is currently used internally
e.g. for "ta_wrap()" and "ta_highlight()" to trace color reset/replay
codes.
ta_strip($text) => STR
Strip ANSI color codes from $text, returning the stripped text.
ta_substr($text, $pos, $len[ , $replacement ]) => STR
A bit like Perl's "substr()". If $replacement is not specified, will
return the substring. If $replacement is specified, will return $text
with the substring replaced by $replacement.
See also: "ta_mbsubstr()" in Text::ANSI::WideUtil.
ta_trunc($text, $width) => STR
Truncate $text to $width columns while still including all the ANSI
color codes. This ensures that truncated text still reset colors, etc.
Does *not* handle multiline text; you can split text by "/\r?\n/"
yourself.
See also: "ta_mbtrunc()" in Text::ANSI::WideUtil.
ta_wrap($text, $width, \%opts) => STR
Like Text::WideChar::Util's "wrap()" except handles ANSI color codes.
Perform color reset at the end of each line and a color replay at the
start of subsequent line so the text is safe for combining in a
multicolumn/tabular layout.
Options:
* flindent => STR
First line indent. Currently must not contain ANSI color codes or
wide characters.
* slindent => STR
Subsequent line indent. Currently must not contain ANSI color codes
or wide characters.
* tab_width => INT (default: 8)
* pad => BOOL (default: 0)
If set to true, will pad each line to $width. This is convenient if
you need the lines padded, saves calls to ta_pad().
* return_stats => BOOL (default: 0)
If set to true, then instead of returning the wrapped string,
function will return "[$wrapped, $stats]" where $stats is a hash
containing some information like "max_word_width", "min_word_width".
* keep_trailing_space => BOOL (default: 0)
If set to true, then trailing space that separates words will be
kept at the end of wrapped lines. This option is useful if you want
to rejoin the lines later. Without this option set to true, wrapping
this line at width=4 (quotes shown):
"some long line"
will result in:
"some"
"long"
"line"
While if this option is set to true, the result will be:
"some "
"long "
"line"
Performance: ~500/s on my Core i5 1.7GHz laptop for a ~1KB of text (with
zero to moderate amount of color codes).
See also: "ta_mbwrap()" in Text::ANSI::WideUtil.
FAQ
Why split functionalities of wide character and color support into multiple modules/distributions?
Performance (see numbers in the function description), dependency
(Unicode::GCString is used for wide character support), and overhead
(loading Unicode::GCString).
How do I highlight a string case-insensitively?
You can currently use a regex for the $needle and use the "i" modifier.
Example:
use Term::ANSIColor;
ta_highlight($text, qr/\b(foo)\b/i, color("bold red"));
HOMEPAGE
Please visit the project's homepage at
<https://metacpan.org/release/Text-ANSI-Util>.
SOURCE
Source repository is at
<https://github.com/perlancar/perl-Text-ANSI-Util>.
SEE ALSO
String::Pad provides padding function for strings that do not contain
ASCII escape codes nor wide characters.
Text::NonWideChar::Util provides some other functions for strings that
do not contain ASCII escape codes nor wide characters.
Text::WideChar::Util provides utilities for strings that do not contain
ANSI escape codes *but* contain wide characters.
Text::ANSI::WideUtil provides utilities for strings that contain ANSI
escape codes *and* wide characters.
AUTHOR
perlancar <perlancar@cpan.org>
CONTRIBUTOR
Steven Haryanto <stevenharyanto@gmail.com>
CONTRIBUTING
To contribute, you can send patches by email/via RT, or send pull
requests on GitHub.
Most of the time, you don't need to build the distribution yourself. You
can simply modify the code, then test via:
% prove -l
If you want to build the distribution (e.g. to try to install it locally
on your system), you can install Dist::Zilla,
Dist::Zilla::PluginBundle::Author::PERLANCAR,
Pod::Weaver::PluginBundle::Author::PERLANCAR, and sometimes one or two
other Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps
required beyond that are considered a bug and can be reported to me.
COPYRIGHT AND LICENSE
This software is copyright (c) 2023, 2021, 2016, 2015, 2014, 2013 by
perlancar <perlancar@cpan.org>.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
BUGS
Please report any bugs or feature requests on the bugtracker website
<https://rt.cpan.org/Public/Dist/Display.html?Name=Text-ANSI-Util>
When submitting a bug or request, please include a test-file or a patch
to an existing test-file that illustrates the bug or desired feature.