File In C language

Question

I have a file in this following format:

https://mega.nz/#! Dwxxrizk (link to download read file);

[105][32][55][10][32][32][32][32][32][32][32][32][32][32][32][32][32][32][32][32][32][82][101][108][101][97][115][101]...

I need to read the data in this format:

105 32 55 10 32 32 32 32 32...[32][32][32][32][32][32][32][32][32][32][32][32][82][101][108][101][97][115][101]...

I’m using the code snippet:

while( c != EOF) {

    fscanf(ler, "%c", &c);
    fscanf(ler, "%d", &num);
    fscanf(ler, "%c", &a);

    fprintf(traduzido, "%d ", num);

}

but the looping never ends, I’m also using this:

while(fscanf(ler, "%c", &c)  && fscanf(ler, "%d", &num)   &&   fscanf(ler, "%c", &a)   != EOF) {

    fprintf(traduzido, "%d ", num);

}

but he won’t stop reading the file, it always goes from two to three lines.

What is the error and why of the error? How can I read this file and leave it in the way I want, if there is an easier way?

Look at the code in full:

int main(void)

int num;
char c;

FILE *ler;
FILE *traduzido;

ler = fopen("readme.code.txt", "r");
traduzido = fopen("traduzido.txt", "w");

if(ler == NULL || traduzido == NULL) {
    printf("Erro Na aberura do Arquivo");
}

while(1) {
    if (fscanf(ler, "%c", &c) <= 0){
        break;
    }

    fscanf(ler, "%d", &num);
    fscanf(ler, "%c", &c);

    fprintf(traduzido,"%d ", num);
}

while(fscanf(traduzido, "%d", &num) != EOF) {
    printf("%c", num);
}
system("pause");

Answer 1

The fscanf return:

• The number of elements read and assigned to variables
• 0 if you could not associate any element
• EOF, which corresponds to -1 if you have reached the end of the archive

In this case and assuming that the structure of your file is always [numero] may specifically test at or below 0 in the first fscanf:

while(1) { //agora while infinito
    if (fscanf(ler, "%c", &c) <= 0){
        break; //se não conseguiu ler o próximo [ termina o while
    }

    fscanf(ler, "%d", &num);
    fscanf(ler, "%c", &c);

    fprintf(traduzido, "%d ", num);
}

Note that you can use the same variable c because you’re not doing anything to her.

If you want to play it safe, and become resistant to changes in formats you can test all fscanf:

while(1) {
    if (fscanf(ler, "%c", &c) <= 0 ||  
        fscanf(ler, "%d", &num) <= 0 || 
        fscanf(ler, "%c", &c) <= 0){
        break;
    }

    fprintf(traduzido, "%d ", num);
}

Test of the program changing fprintf for printf to be easier to see:

Test with the suggested file readme.code.txt :

Edit:

For the rest of the program that has the problem is reading a file that has been opened for writing.

Close the file traduzido after writing and open it again for reading:

while(1) {
    if (fscanf(ler, "%c", &c) <= 0){
        break;
    }

    fscanf(ler, "%d", &num);
    fscanf(ler, "%c", &c);

    fprintf(traduzido,"%d ", num);
}

fclose(traduzido); //fechar a escrita
traduzido = fopen("traduzido.txt", "r"); //agora abrir para leitura

while(fscanf(traduzido, "%d", &num) != EOF) {
    printf("%c", num);
}

However more efficient was simply writing the content of what is being read directly on the screen, instead of using the file traducao to write and then to read:

while(1) {
    if (fscanf(ler, "%c", &c) <= 0){
        break;
    }

    fscanf(ler, "%d", &num);
    fscanf(ler, "%c", &c);

    fprintf(traduzido,"%d ", num); //grava no arquivo a tradução
    printf("%c",num); //e simultaneamente escreve na tela a conversão
}

It’s much more efficient and simple.

Answer 2

I just came here to show you a lot of possibilities reply from @Isac, using resources from scanf to remove this formatting.

To begin with, I found it strange to read the value of a character in a temporary variable to ignore. I remembered then that somewhere I had seen something about reading that did not fulfill the values (see documentation), the reading indicated by the modifier *; for example, scanf("%*c") will read a character from the input and ignore it. So I ran a test on this reading ignoring characters:

#include <stdio.h>

int main(void) {
    int i;

    scanf("%*c%d%*c", &i);
    printf("%d\n", i);

    return 0;
}

To the entrance [123], the result was 123, as expected.

Then I remembered that it is possible to ignore the actual formatting of the input. Just put the desired characters to be ignored on the left before the %d, and the characters to be ignored on the right after the %d. In this case, the format would be [%d], because I wish to ignore the clasps [ to the left and the clasps ] on the right:

#include <stdio.h>

int main(void) {
    int i;

    scanf(" [%d]", &i);
    printf("%d\n", i);

    return 0;
}

I tested for the entrance [145], getting 145 as a way out. If you pay attention, I put a space at the beginning of the format string to avoid conflicts with line breaks, as my test involved a number between brackets per line. You can see my complete test on ideone.

So this means that the @Isac reading could be replaced by one of these options.

Original:

while(1) {
    if (fscanf(ler, "%c", &c) <= 0){
        break;
    }

    fscanf(ler, "%d", &num);
    fscanf(ler, "%c", &c);

    fprintf(traduzido,"%d ", num); //grava no arquivo a tradução
    printf("%c",num); //e simultaneamente escreve na tela a conversão
}

Proposal 1, with %*c:

while(1) {
    if (fscanf(ler, "%*c%d%*c", &num) <= 0){
        break;
    }

    fprintf(traduzido,"%d ", num); //grava no arquivo a tradução
    printf("%c",num); //e simultaneamente escreve na tela a conversão
}

Proposal 2, with format string ignoring brackets:

while(1) {
    if (fscanf(ler, "[%d]", &num) <= 0){
        break;
    }

    fprintf(traduzido,"%d ", num); //grava no arquivo a tradução
    printf("%c",num); //e simultaneamente escreve na tela a conversão
}