Determine whether IMEI or meId is valid

/*-----------------------------------------------
* Determines whether the IMEI or meid represented by this string is legal
* @ Param IMEI
* @ Author helin 2014-08-21 add
* @ Return boolen
* IMEI verification code algorithm:
* (1). multiply the number of even digits by 2 to calculate the sum of single digits and ten digits respectively.
* (2) Add the odd digit number and the value calculated in the previous step.
* (3). If the number of digits obtained is 0, the check digit is 0. Otherwise, the value is 10 minus the single digit.
* For example: 35 89 01 80 69 72 41 even digits multiply by 2 get 5*2 = 10 9*2 = 18 1*2 = 02 0*2 = 00 9*2 = 18 2*2 = 04 1*2 = 02, calculate the sum of odd digits and even digits. 3 + (1 + 0) + 8 + (1 + 8) + 0 + (0 + 2) + 8 + (0 + 0) + 6 + (1 + 8) + 7 + (0 + 4) + 4 + (0 + 2) = 63 => check bits 10-3 = 7
-----------------------------------------------*/

Function is_imei ($ IMEI = '') {If (! $ IMEI) {return false ;}$ imeilen = strlen ($ IMEI); $ deorhex = 10; // initialization. Assume that this string is IMEI :: pure numeric for ($ J = 0; $ j <$ imeilen; $ J ++) {$ c = $ IMEI [$ J]; If (is_numeric ($ C )) {continue;} else if ($ C >='a' & $ C <= 'F ') | ($ C> = 'A' & $ C <= 'F') {$ deorhex = 16 ;} else {// If any character other than the number or hexadecimal number is displayed, return false if it is invalid.} if ($ deorhex = 10 & $ imeilen! = 15) {// All numbers (IMEI), and the length is not 15 return false;} if ($ deorhex = 16) {// contains valid hexadecimal number (meid) if ($ imeilen = 14) {// new rule, 14-bit meid, which is directly legal without verifying return true ;} if ($ imeilen! = 14 & $ imeilen! = 15) {return false; // If the meid length is not 14 or 15, it is determined that it is invalid without verification.} $ COUNT = 0; For ($ I = 0; $ I <7; $ I ++) {$ tmp1 = hexdec ($ IMEI [$ I * 2]); // if it is a hexadecimal character, convert to 10: hexdec ('A') = 10; $ tmp2 = hexdec ($ IMEI [$ I * 2 + 1]) * 2; $ count + = $ tmp1 + floor ($ tmp2/$ deorhex) + $ tmp2 % $ deorhex;} $ endint = $ count % $ deorhex; // The last digit of the number $ paritybit = $ endint> 0? $ Deorhex-$ endint: 0; // check bit return $ paritybit = hexdec ($ IMEI [14]);} $ IMEI = 'a0000020.d46cd'; // '123 '; echo is_imei ($ IMEI )? 1:0; echo '<HR> ';

 

Determine whether IMEI or meId is valid