How do I compare a string that is part of a txt file and another one typed by the user in C?

Question

I’m a beginner in programming and I’m learning how to manipulate strings, but I’m still a little confused on some kkkkkk things. Finally, regarding the exercise, we have a txt file containing the following content "maria Joao maria maria maria". The user when typing a name (maria or joão) the program returns an integer with the amount of times this name appears in the file.

Entree: Maria

exit: 3

I couldn’t make much progress on the show, but he’s like this:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>  
int main()
{
  FILE *file;
  char frase [27];
  char palavra [8];

  file = fopen ("arquivo.txt", "r");

    if (file == NULL)
    {
        printf ("Erro na abertura do arquivo");
        exit(0);
        }
    scanf ("%s", &palavra);
    
    while (fgets(frase, 27, file)!= NULL){
        retorno = strcmp (palavra, frase); 
    }
    
    printf ("O número de vezes e %d", retorno);
    fclose (file);


}

So I was thinking of going through the user-typed string, character by character, and comparing if each value of that in the strcmp function returns zero and then trying something.

Answer 1

Compare to this version

#include <stdio.h>
#include <string.h>

int main(void)
{
    FILE *file = fopen("arquivo.txt", "r");
    if (file == NULL)
    {   printf("Erro na abertura do arquivo");
        return(-1);
    }
    char palavra[8] = "joao";
    char     frase[80];
    unsigned total     = 0;
    while (fscanf(file, "%s", frase) == 1)
        total += (strcmp(palavra, frase) == 0);
    printf("O número de vezes e %d", total);
    fclose(file);
}

And understand that it can be simpler to use fscanf() to read the file. So already receives one word at a time and can compare directly.

Always test the return of scanf(). It is naive not to do this: in your case for example, if you have not read the word you will look for what?

    unsigned total     = 0;
    while (fscanf(file, "%s", frase) == 1)
        total += (strcmp(palavra, frase) == 0);

A loop like this makes the account you want. Understand that fscanf() will return 1 if you can read a data, and strcmp() will return 0 if the strings are equal. Compare with your original code. What you want is to count how many times fscanf() read the word sought.