#!/usr/bin/perl
# histogram - a utility to solve Scan of the Month No.16
# Usage: histogram [-g] -f infile > outfile
# -g generates graphic output (html tables)
use Getopt::Std;
getopts('gf:');
sub numerically { $histogram{$b} <=> $histogram{$a}; };
sub html_header {
print "\n\n\tHistogram for $opt_f\n\n\n";
print "\n";
};
sub html_footer {
print "\n\n";
};
open(INPUT, "<".$opt_f) || die "$0: unable to open $opt_f: $!\n";
$characters = 0;
while(sysread(INPUT, $char, 1)) {
$histogram{$char} += 1;
$characters += 1;
};
close INPUT;
&html_header if ($opt_g);
if ($opt_g) {
print "Histogram for $opt_f
\n";
print "$characters characters read.\n";
} else {
print "File read: $opt_f\n";
print "Characters read: $characters\n\n";
};
if ($opt_g) {
print "
Frequency by Character
\n";
print "\n";
print "\t\n";
print "\t\t| ASCII | Frequency | \n";
print "\t
\n\t\n";
print "\t\t| dec | hex | \n";
print "\t\tabs | rel | \n";
print "\t
\n";
} else {
print "Frequency by Character:\n";
};
for ($i=0;$i<=255;$i++) {
if ($opt_g) {
print "\t\n";
printf "\t\t| %d | \n", $i;
printf "\t\t%2X | \n", $i;
printf "\t\t%d | \n", $histogram{chr($i)};
printf "\t\t%f | \n", $histogram{chr($i)}/$characters;
printf "\t\t![](\"bar.gif\") | \n",
$histogram{chr($i)}/$characters*1000;
print "\t
\n";
} else {
printf "%3d (%2X) : %10d (%f)\n",
$i, $i, $histogram{chr($i)}, $histogram{chr($i)}/$characters;
};
};
if ($opt_g) {
print "
\n";
};
if ($opt_g) {
print "Character by Frequency
\n";
print "\n";
print "\t\n";
print "\t\t| ASCII | Frequency | \n";
print "\t
\n\t\n";
print "\t\t| dec | hex | \n";
print "\t\tabs | rel | \n";
print "\t
\n";
} else {
print "\nCharacter by Frequency:\n";
};
foreach $char (sort numerically keys(%histogram)) {
if ($opt_g) {
print "\t\n";
printf "\t\t| %d | \n", ord($char);
printf "\t\t%2X | \n", ord($char);
printf "\t\t%d | \n", $histogram{$char};
printf "\t\t%f | \n", $histogram{$char}/$characters;
printf "\t\t | \n",
$histogram{$char}/$characters*1000;
print "\t
\n";
} else {
printf "%3d (%2X) : %10d (%f)\n",
ord($char), ord($char), $histogram{$char}, $histogram{$char}/$characters;
};
};
if ($opt_g) {
print "
\n";
};
&html_footer if ($opt_g);