The data already existed, so when I wrote the program I tried to do as little work as possible to format it. I disagree with the 'apparent need', though, since if there was no need there wouldn't be an ascii man page on the systems that have one (of course, on those systems with an ascii man page, I agree that there is no apparent need for this script).
I thought about using printf to format the numbers rather than leaving them hard coded, but at the time I liked the idea of leaving it hard-coded for easy viewing and re-usability of the data (and it required less work on my part). And using $. is a good idea, but likewise I'd rather be able to look at the data and see which line is which.
If I were to use formats, format and write would probably have to be formline and $^A since the format is dynamic, but that and EBCDIC and locale specific code pages and unicode are left as projects for those with more time than I have :-)
Taking out the hard coding of the hex and binary numbers wasn't too hard though, so here's my first pass at that (I may add octal later)(Update: Added octal - didn't want to do it until I tested it, and zentara is right, it was easy enough):
#!/usr/bin/perl -l
#
# Display ascii table
# (Some unix systems have an 'ascii' man page which displays
# an ascii table; this one doesn't, so I cooked this up)
# takes optional format string
# Usage: ascii [D|a|k|d|b|h|o]...
# D=Description a=abbreviation k=Keyboard d=Decimal b=Binary h=Hex o=o
+ctal
# e.g.: ascii hD
# (Default is "ha")
#
use strict;
use warnings;
my $display = @ARGV ? join('', @ARGV) : "ha";
$display =~ tr/-//d;
my @names = qw(Description Abbr Keybd Dec Binary Hex Oct);
my @lengths=qw(-21 -3 -7 3 8 2 3);
my %lengths; @lengths{@names} = @lengths;
my %show;
my @show = qw(D a k d b h o);
@show{@show} = @names;
my %fmt = (Dec=>"%3d", Binary=>"%08b", Hex=>"%02X", Oct=>"%03o");
my $show_str = join("|", @show);
my $usage_str = <<EOT;
Usage: ascii [$show_str]...
D = description
a = abbreviation
k = keybd
d = decimal
b = binary
h = hex
o = octal
(Default: ha)
EOT
my @display = map { $show{$_} || die "Bad field $_\n$usage_str"
} split '', $display;
die "No fields to display\n" unless @display;
my @ascii;
while (<DATA>) {
chomp;
next if /^#/ or /^\s*$/;
my @fields;
# Read in pipe delimited file (pipes are escaped)
push @fields, $1 while /((?:\\.|[^|])+)/g;
s/\\(.)/$1/g for @fields;
my %fields; @fields{@names} = @fields;
push @ascii, \%fields;
}
my $max = 70;
my $spaces = 3;
my $hdr = ' ' x $spaces;
my $hdr_txt = sprintf
join('',
map { "%-" . (abs($lengths{$_})+$spaces) ."s" } @display
),
@display;
$hdr .= $hdr_txt while length($hdr.$hdr_txt)-$spaces <= $max;
print $hdr;
my $line = '';
for my $asc (@ascii) {
my $tmp_line = '';
for my $fld (@display) {
$tmp_line .= " - " if $tmp_line;
$tmp_line .= sprintf($fmt{$fld} || "%$lengths{$fld}s",
$fmt{$fld} ? $asc->{Dec} : $asc->{$fld});
}
if ((length($line) + length($tmp_line) + 3) > $max) {
print $line;
$line = " $tmp_line";
} else {
$line .= " $tmp_line";
}
}
print $line if $line;
__DATA__
# Description|Abbrev|Keybd|Decimal|Binary|Hex
Null|NUL|Ctrl @|0
Start of Heading|SOH|Ctrl A|1
Start of Text|STX|Ctrl B|2
End of Text|ETX|Ctrl C|3
End of Transmit|EOT|Ctrl D|4
Enquiry|ENQ|Ctrl E|5
Acknowledge|ACK|Ctrl F|6
Bell|BEL|Ctrl G|7
Back Space|BS|Ctrl H|8
Horizontal Tab|TAB|Ctrl I|9
Line Feed|LF|Ctrl J|10
Vertical Tab|VT|Ctrl K|11
Form Feed|FF|Ctrl L|12
Carriage Return|CR|Ctrl M|13
Shift Out|SO|Ctrl N|14
Shift In|SI|Ctrl O|15
Data Line Escape|DLE|Ctrl P|16
Device Control 1|DC1|Ctrl Q|17
Device Control 2|DC2|Ctrl R|18
Device Control 3|DC3|Ctrl S|19
Device Control 4|DC4|Ctrl T|20
Negative Acknowledge|NAK|Ctrl U|21
Synchronous Idle|SYN|Ctrl V|22
End of Transmit Block|ETB|Ctrl W|23
Cancel|CAN|Ctrl X|24
End of Medium|EM|Ctrl Y|25
Substitute|SUB|Ctrl Z|26
Escape|ESC|Ctrl [|27
File Separator|FS|Ctrl \\|28
Group Separator|GS|Ctrl ]|29
Record Separator|RS|Ctrl ^|30
Unit Separator|US|Ctrl _|31
Space| | |32
Exclamation Point|!|Shift 1|33
Double Quote|"|Shift `|34
Pound/Number Sign|#|Shift 3|35
Dollar Sign|$|Shift 4|36
Percent Sign|%|Shift 5|37
Ampersand|&|Shift 7|38
Single Quote|'|'|39
Left Parenthesis|(|(|40
Right Parenthesis|)|)|41
Asterisk|*|*|42
Plus|+|+|43
Comma|,|,|44
Hyphen / Minus Sign|-|-|45
Period|.|.|46
Forward Slash|/|/|47
Zero Digit|0|0|48
One Digit|1|1|49
Two Digit|2|2|50
Three Digit|3|3|51
Four Digit|4|4|52
Five Digit|5|5|53
Six Digit|6|6|54
Seven Digit|7|7|55
Eight Digit|8|8|56
Nine Digit|9|9|57
Colon|:|Shift ;|58
Semicolon|;|;|59
Less-Than Sign|<|Shift ,|60
Equals Sign|=|=|61
Greater-Than Sign|>|Shift .|62
Question Mark|?|Shift /|63
At Sign|@|Shift 2|64
Capital A|A|Shift A|65
Capital B|B|Shift B|66
Capital C|C|Shift C|67
Capital D|D|Shift D|68
Capital E|E|Shift E|69
Capital F|F|Shift F|70
Capital G|G|Shift G|71
Capital H|H|Shift H|72
Capital I|I|Shift I|73
Capital J|J|Shift J|74
Capital K|K|Shift K|75
Capital L|L|Shift L|76
Capital M|M|Shift M|77
Capital N|N|Shift N|78
Capital O|O|Shift O|79
Capital P|P|Shift P|80
Capital Q|Q|Shift Q|81
Capital R|R|Shift R|82
Capital S|S|Shift S|83
Capital T|T|Shift T|84
Capital U|U|Shift U|85
Capital V|V|Shift V|86
Capital W|W|Shift W|87
Capital X|X|Shift X|88
Capital Y|Y|Shift Y|89
Capital Z|Z|Shift Z|90
Left Bracket|[|[|91
Backward Slash|\\|\\|92
Right Bracket|]|]|93
Caret|^|Shift 6|94
Underscore|_|Shift -|95
Back Quote|`|`|96
Lower-case A|a|A|97
Lower-case B|b|B|98
Lower-case C|c|C|99
Lower-case D|d|D|100
Lower-case E|e|E|101
Lower-case F|f|F|102
Lower-case G|g|G|103
Lower-case H|h|H|104
Lower-case I|I|I|105
Lower-case J|j|J|106
Lower-case K|k|K|107
Lower-case L|l|L|108
Lower-case M|m|M|109
Lower-case N|n|N|110
Lower-case O|o|O|111
Lower-case P|p|P|112
Lower-case Q|q|Q|113
Lower-case R|r|R|114
Lower-case S|s|S|115
Lower-case T|t|T|116
Lower-case U|u|U|117
Lower-case V|v|V|118
Lower-case W|w|W|119
Lower-case X|x|X|120
Lower-case Y|y|Y|121
Lower-case Z|z|Z|122
Left Brace|{|Shift [|123
Vertical Bar|\||Shift \\|124
Right Brace|}|Shift ]|125
Tilde|~|Shift `|126
Delete|Del|Del|127
