count vowels and consonants lex program

 %{

#include <stdio.h>

int vowel_count = 0;

int consonant_count = 0;

%}

%option noyywrap

%%

[aAeEiIoOuU]      { vowel_count++; }

[A-Za-z]          { consonant_count++; }

[^a-zA-Z]         { /* ignore non-alphabetic characters */ }

%%

int main() {

    yylex();

   printf("Number of vowels: %d\n", vowel_count);

   printf("Number of consonants: %d\n", consonant_count);

   return 0;

}

Execution

$flex vow.lex

$ gcc lex.yy.c

$ ./a.out

this is test

Number of vowels: 3

Number of consonants: 7