Lex program for validation of Email-Add. (Consider Email Add. from any domain e.g. @gmail.com)

%{

#include<stdio.h>

%}

%%

^[a-z][a-z0-9_]*(@[A-Za-z]+)(\.[a-z]+)+ {printf("valid");}

.* {printf("invalid");}

%%

main()

{

yylex();

}

ScreenShot: