How to print text with formatting

Question

My problem is when I try to print text with a "\n", this special characters are invisible for printf and puts after echoing it to file, and reading it again.

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

int main()
{   
    FILE *f;
    char *s = (char*) malloc (2919);
    strcpy(s, "printf 'H4sIAIM4aFYCAwtJLS6JyQsBklwAMrDLnwsAAAA=' | base64 -d | gunzip > r"); //Test\nTest after decoding
    system(s);
    f = fopen("r", "r");
    fseek(f, SEEK_SET, 0);
    fread(s, 2919, 1, f);
    printf("%s", s); //puts(s); gives the same result
    fclose(f);
    system("rm r");
    free(s);
    return 0;
}

Output should look like:

Test
Test

and it looks like Test\nTest. What am I doing wrong? Learning purpose, so please be nice.

Answer 1

The text you've encoded looks like this:

Test\nTest

This is a 10 character string with "\" for the fifth character and "n" for the sixth. This is different from this:

char str[]="Test\nTest";

Which is a 9 character string with a newline for the fifth character.

If you want to print a newline, your encoded string needs to contain it. Either that, or you have to parse the resulting string and perform the newline substitution manually.