Posted by Al on 10/20/21 11:30

Jason Gerfen wrote:
> I am having a problem with a couple of function I have written to check
> for a type of string, attempt to fix it and pass it back to the main
> function. Any help is appreciated.
>
> <?php
>
> /*
> * ex. 00:AA:11:BB:22:CC
> */
> function chk_mac( $mac ) {
> if( ( eregi(
> "^[0-9A-Fa-f]{2}\:[0-9A-Fa-f]{2}\:[0-9A-Fa-f]{2}\:[0-9A-Fa-f]{2}\:[0-9A-Fa-f]{2}\:[0-9A-Fa-f]{2}$",
> $mac ) ) || ( !eregi( "^[0-9a-fA-F]$", $mac ) ) {
> return 0;
> } else {
> return 1;
> }
> }
>
> /*
> * check validity of MAC & do replacements if necessary
> */
> function fix_mac( $mac ) {
> global $mac;
>
> if( eregi( "^[0-9A-Fa-f-\:]$", $mac ) ) {
> $mac1 = $mac;
> echo "MAC: $mac1<br>";
> }
>
> /* strip the dash & replace with a colon */
> if( eregi(
> "^[0-9A-Fa-f]{2}\-[0-9A-Fa-f]{2}\-[0-9A-Fa-f]{2}\-[0-9A-Fa-f]{2}\-[0-9A-Fa-f]{2}\-[0-9A-Fa-f]{2}$",
> $mac ) ) {
> $mac1 = preg_replace( "/\-/", ":", $mac );
> echo "MAC: $mac1<br>";
> }
> /* add a colon for every two characters */
> if( eregi( "^[0-9A-Fa-f]{12}$", $mac ) ) {
> /* split up the MAC and assign new var names */
> @list( $mac_1, $mac_2, $mac_3, $mac_4, $mac_5, $mac_6 ) = @str_split(
> $mac, 2 );
> /* put it back together with the required colons */
> $mac1 = $mac_1 . ":" . $mac_2 . ":" . $mac_3 . ":" . $mac_4 . ":" .
> $mac_5 . ":" . $mac_6;
> echo "MAC: $mac1<br>";
> }
> return $mac1;
> }
>
> // do our checks to make sure we are using these damn things right
> $mac1 = "00aa11bb22cc";
> $mac2 = "00-aa-11-bb-22-cc";
> $mac3 = "00:aa:11:bb:22:cc";
> $mac4 = "zz:00:11:22:ff:xx";
>
> if( chk_mac( $mac1 ) != 0 ) {
> $mac = fix_mac( $mac1 );
> echo $mac1 . " converted to " . $mac . "<br>";
> } else {
> echo "$mac1 is valid.<br>";
> }
>
> if( chk_mac( $mac2 ) != 0 ) {
> $mac = fix_mac( $mac2 );
> echo $mac2 . " converted to " . $mac . "<br>";
> } else {
> echo "$mac2 is valid.<br>";
> }
>
> if( chk_mac( $mac3 ) != 0 ) {
> $mac = fix_mac( $mac3 );
> echo $mac3 . " converted to " . $mac . "<br>";
> } else {
> echo "$mac3 is valid.<br>";
> }
>
> if( chk_mac( $mac4 ) != 0 ) {
> $mac = fix_mac( $mac4 );
> echo $mac4 . " converted to " . $mac . "<br>";
> } else {
> echo "$mac4 is valid.<br>";
> }
>
>
> ?>
>

For what it's worth..

I'm moderately good with regex; but, I wouldn't even try to get an expression like yours to work properly, with all
possiblities and exceptions.

Suggest breaking it up into several separate tests.

[Back to original message]