Lex program to search for a word in a file

Lex program to search a word in a file - This program will search a word in the file input.txt and display the message FOUND or NOT FOUND

*************************************

%{

#include<string.h>

void search(char *);

%}

%option noyywrap

/* Rule Section */

%%

[a-zA-Z]+ search(yytext);

%%

int main()

{

        // The function that starts the analysis

        yylex();

        return 0;

}

void search(char *str)

{/* fp as pointer

        of File type */

        FILE *fp;

        char temp[30];

        /* fp points to the file input.txt

        and opens it in read mode */

        fp=fopen("input.txt", "r");

        while((fscanf(fp, "%s", temp))!=EOF)

        {

                if(!(strcmp(temp, str)))

                {

                        printf("FOUND\n");

                        return;

                }

        }

        printf("NOT FOUND\n");

                return;

}

Execution

input.txt file

$ cat input.txt

binu

biju

biji

bini

aji

vidhu

avani

aditi

pooja

abhijith

abhi

padma

arpita

deepa

$flex searchwrd.lex

$ gcc lex.yy.c

$ ./a.out

manu

NOT FOUND

binu

FOUND

avani

FOUND

aji

FOUND