wrap.pl revision 04b94745 
1#!/usr/bin/env perl
2# $XTermId: wrap.pl,v 1.12 2007/07/13 00:15:28 tom Exp $
3# -----------------------------------------------------------------------------
4# Copyright 2007 by Thomas E. Dickey
5#
6#                         All Rights Reserved
7#
8# Permission is hereby granted, free of charge, to any person obtaining a
9# copy of this software and associated documentation files (the
10# "Software"), to deal in the Software without restriction, including
11# without limitation the rights to use, copy, modify, merge, publish,
12# distribute, sublicense, and/or sell copies of the Software, and to
13# permit persons to whom the Software is furnished to do so, subject to
14# the following conditions:
15#
16# The above copyright notice and this permission notice shall be included
17# in all copies or substantial portions of the Software.
18#
19# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
20# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
22# IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
23# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
24# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
25# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26#
27# Except as contained in this notice, the name(s) of the above copyright
28# holders shall not be used in advertising or otherwise to promote the
29# sale, use or other dealings in this Software without prior written
30# authorization.
31# -----------------------------------------------------------------------------
32# Generates a series of wrapping lines, according to the terminal width.
33# The wrapping text optionally includes double-width or other characters
34# encoded in UTF-8.
35use strict;
36
37use Getopt::Std;
38
39our ($opt_i, $opt_n, $opt_r, $opt_w);
40our ($lineno, $test_string, $term_width);
41
42# Return a string of two-column characters given an ASCII alpha/numeric string
43sub double_cells($) {
44	my $value = $_[0];
45	$value =~ s/ /  /g;
46	pack("U*",
47	map { ($_ <= 32 || $_ > 127)      # if non-ASCII character...
48	       ? 32                       # ...just show a blank
49	       : (0xff00 + ($_ - 32))     # map to "Fullwidth Form"
50	} unpack("C*", $value));          # unpack unsigned-char characters
51}
52
53# Insert a character using escape sequences to push the existing text to the
54# right, write the actual character and then move left one column so succeeding
55# calls will do the same.  This will not cause the pushed-text to wrap, but
56# will exercise the right-margin logic in other ways.
57#
58# Since this script does not modify the autowrap mode, you can reset that
59# outside the script and compare the default (unwrapped) versus the "-i"
60# option.
61sub insert_char($$) {
62	my $value = $_[0];
63	my $final = $_[1];
64	my $cells = defined($opt_w) ? 2 : 1;
65	printf "\x1b[%d@", $cells;
66	printf "%s", defined($opt_w) ? double_cells($value) : $value;
67	if ( ! $final ) {
68		printf "\x1b[%dD", $cells;
69	}
70}
71
72# vary the starting point of each line, to make a more interesting pattern
73sub starts_of($) {
74	my $value = $_[0];
75	if (defined($opt_w)) {
76		# 0,1,1,2,2,3,3,...
77		$value = (($value + 1) / 2) % length($test_string);
78	} else {
79		$value %= length($test_string);
80	}
81	return $value;
82}
83
84# Vary the length of each line from $term_width - 5 to $term_width + 5, then
85# double it, and then repeat.  That's 22/cycle.
86sub length_of($) {
87	my $value = $_[0];
88	my $cycle = $value % 22;
89	if ( $cycle < 11 ) {
90		$value = $term_width;
91	} else {
92		$value = $term_width * 2;
93		$cycle /= 2;
94	}
95	return $value + $cycle - 5;
96}
97
98# Write the text for the given line-number.
99sub testit($) {
100	my $number = $_[0];
101	my $length = length_of($number);
102	if ( defined($opt_n) ) {
103		printf "%5d ", $number % 99999;
104		$length -= 6;
105	}
106	# If we're printing double-column characters, we have half as much
107	# space effectively - but don't forget the remainder, so we can push
108	# the characters by single-columns.
109	my $starts = starts_of($number);
110	if ( defined($opt_w) ) {
111		printf " ", if ( ($number % 2 ) != 0);
112		$length = ($length + (($number + 1) % 2)) / 2;
113	}
114	my $string = substr($test_string, $starts);
115	while ( length($string) < $length ) {
116		$string = $string . $test_string;
117	}
118	$string = substr($string, 0, $length);
119	if ( defined($opt_i) ) {
120		my ($n, $c);
121		for ($n = length($string) - 1; $n >= 0; $n--) {
122			insert_char(substr($string, $n, 1), $n == 0);
123		}
124		printf "\n";
125	} else {
126		if ( defined($opt_w) ) {
127			$string = double_cells($string);
128		}
129		printf "%s\n", $string;
130	}
131}
132
133sub main::HELP_MESSAGE() {
134	printf STDERR <<EOF
135Usage: $0 [options]
136
137Options:
138
139-i   construct lines by inserting characters on the left
140-n   write line-numbers
141-r   repeat indefinitely
142-w   write wide-character test-string
143EOF
144;
145	exit;
146}
147
148&getopts('inrw') || die();
149
150$term_width=`tput cols`;
151
152$test_string="0123456789 abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ";
153
154binmode(STDOUT, ":utf8");
155if ( defined($opt_r) ) {
156	for ($lineno = 0; ; ++$lineno) {
157		testit($lineno);
158	}
159} else {
160	for ($lineno = 0; $lineno < 24; ++$lineno) {
161		testit($lineno);
162	}
163}
164
165exit;
166