1 #include <stdio.h>
  2 #include <stdlib.h>
  3 #include <string.h>
  4
  5
  6 void print_validity(char * address, terminators, length);
  7
  8 void print_validity(char * address, terminators, length)
  9 {
 10         printf("The string %s is ", address);
 11         if (!isValidEmailAddress(address, terminators, length) printf("not "));
 12
 13
 14                         printf("a valid email address\n");
 15 }
 16
 17
 18                         int main()
 19                         {
 20                         const int length = 5;
 21                         char * terminators[length];
 22                         char * address1, address2;
 23
 24                         terminators[0] = "com";
 25                         terminators[1] = "net";
 26                         terminators[2] = "edu";
 27                         terminators[3] = "ie";
 28                         terminators[4] = "tv";
 29
 30                         address1 = "santa.claus@north.pole.com";
 31                         address2 = "I.am@fish";
 32
 33                         print_validity(address1, terminators, length);
 34                         print_validity(address2, terminators, length);
 35
 36                         return 0;
 37                         }
 38
 39
 40
 41
 42
 43         int isValidEmailAdress(address, terminators, length){
 44
 45           while(str[i]!='@'){

 46
 47                           if(isdigit(str[i])!=0&&isalpha(str[i])!=0&&str[i]!=    '.'&&str[i]!="_"){
 48                           return 0;
 49   }
 50
 51
 52
 53 }
 54
 55
 56
 57 int tokenise(char str[], int start, char result[]){
 58           int i=start;
 59           int j=0;
 60
 61           while(str[i]!='@'){
 62
 63                         if(isdigit(str[i])!=0&&isalpha(str[i])!=0&&str[i]!='.'&&str[i]!="_"){
 64                         return 0;
 65 }
 66
 67
 68                   else{
 69                         return 1;
 70                 }
 71
 72
 73                   while(str[i]!=' '){
 74
 75
 76
 77                                   if(str[i]=='\0'){
 78                                           result[j]='\0';
 79                                           return -1;
 80                                 }
 81                                   i++;
 82
 83                   }
 84                   result[j]='\0';
 85                   return i;
 86         }
 87   }
 88