Added LICENSE file

LICENSE

@@ -0,0 +1,15 @@
+Copyright (C) 2014 Jack-Benny Persson <jack-benny@cyberinfo.se>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

README.md

@@ -0,0 +1,28 @@
+# Netcalc #
+This is a simple CLI network calculator made in PHP. Usage is pretty straight
+forward. For example, let say you want to know how many usable addresses you
+will get with a 26 bit netmask, simply run the script as below:
+
+    php netcalc.php 26
+
+Or you `chmod +x netcalc.php` and run it as below:
+
+    ./netcalc.php 26
+
+The above command will give you the following outut:
+
+    Netmask
+    -------
+    In slash notation: 26
+    In dotted decimal: 255.255.255.192
+    In dotted binary: 11111111.11111111.11111111.11000000
+
+    Network size
+    ------------
+    Total number of addresses: 64
+    Number of usable addresses for hosts: 62
+
+## Copyright ##
+Netcalc is written by Jack-Benny Persson and released under GNU GPL version 2.
+
+

netcalc.php

@@ -1,4 +1,27 @@
+#!/usr/bin/php
 <?php
+
+/*
+Copyright (C) 2014 Jack-Benny Persson <jack-benny@cyberinfo.se>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+/* Netcalc is a simple PHP CLI script to calculate the size of a network
+   from a given netmask in slash notation */
+
 $version="0.1";
 
 function print_usage()
@@ -10,6 +33,88 @@ function print_usage()
     print "Example: php netcalc.php 24\n";
 }
 
+function print_netmask($number)
+{
+    $number = $number-1;
+    $mask = $number+1;
+
+    $ones = 1;
+    $zeros = 0;
+
+    $num_zeros = 32-$number-2;
+
+    // Itterate the binary ones, adding one 1 for every run
+    for ($i = 0; $i < $number; $i++) 
+    {
+        $ones .= 1;
+    }
+    unset($i);
+
+    // Itterate the binary zeros, adding one 0 for every run
+    for ($i = 0; $i < $num_zeros; $i++)
+    {
+        $zeros .= 0;
+    }
+    unset($i);
+
+    // Special cases when netmask is 0 or 32
+    if ($mask == 0)
+    {
+        // If the network mask is 0, then just put 32 zeros in the string
+        $binary = "00000000000000000000000000000000";
+    }
+    elseif ($mask == 32)
+    {
+        // If the network mask is 32, then just put 32 ones in the string
+        $binary = "11111111111111111111111111111111";
+    }
+    else
+    {
+        // Else put the ones and zeros together in a binary string
+        $binary = "$ones$zeros";
+    }
+
+    // Make it dotted binary format
+    $dotted_binary = substr_replace($binary, ".", 8, 0);
+    $dotted_binary = substr_replace($dotted_binary, ".", 17, 0);
+    $dotted_binary = substr_replace($dotted_binary, ".", 26, 0);
+
+    // Make it dotted decimal format
+    $firstOctet = base_convert(substr($binary, 0, 8), 2, 10);
+    $secondOctet = base_convert(substr($binary, 8, 8), 2, 10);
+    $thirdOctet = base_convert(substr($binary, 16, 8), 2, 10);
+    $forthOctet = base_convert(substr($binary, 24, 8),2, 10);
+
+    // Print it in different formats
+    print "Netmask\n" ;
+    print "-------\n";
+    print "In slash notation: $mask\n";
+    print "In dotted decimal: $firstOctet.$secondOctet.$thirdOctet.$forthOctet\n";
+    print "In dotted binary: $dotted_binary";
+    print "\n\n";
+}
+
+function print_values($value)
+{
+    // Calculate the network size and usable addresses
+    $base=32-$value;
+    $netsize=pow(2, $base);
+    $hosts=$netsize-2;
+
+    // We don't want negative values
+    if ($hosts < 0)
+    {
+        $hosts = 0;
+    }
+
+    // Print the network size and usable addresses
+    print "Network size\n";
+    print "------------\n";
+    print "Total number of addresses: $netsize\n";
+    print "Number of usable addresses for hosts: $hosts\n";
+}
+
+// MAIN
 // Check if first argument is set and and if not, print usage
 if (!isset($argv[1]))
 {
@@ -17,35 +122,28 @@ if (!isset($argv[1]))
     exit(1);
 }
 
-$value=$argv[1];
+$input=$argv[1];
 
 // Check if our argument was a numeric value or not
-if (!is_numeric($value)) 
+if (!is_numeric($input)) 
 {
     print "Please enter numbers only (between 0 and 32)\n";
     exit(1);
 }
 
 // Check if the value is between 0 and 32
-if ($value < 0 || $value > 32)
+if ($input < 0 || $input > 32)
 {
     print "Please enter an integer between 0 and 32 only\n";
     exit(1);
 }
 
-// Calculate the diffrent values
+// Print the netmask first
-$base=32-$value;
+print_netmask($input);
-$netsize=pow(2, $base);
+
-$hosts=$netsize-2;
+// And now, finally, print the network size and usable addresses
-if ($hosts < 0)
+print_values($input);
-{
-    $hosts = 0;
-}
 
-// And now, finally, print the values
-print "Netmask: $value\n";
-print "Total number of addresses: $netsize\n";
-print "Number of usable addresses for hosts: $hosts\n";
 exit(0);
 
 ?>