fscanf printing replacement character

Question

#include <assert.h>
#include <ctype.h>
#include <math.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, char *argv[]) {
    
    //opening collection.txt using ptr 
    FILE *ptr;
    
    char data[1000];
    ptr = fopen("collection.txt", "r");
    
    printf("Hello world \n");
    
    fscanf(ptr, "%s", data);
    printf("%s \n", data);
    
    fclose(ptr);
    
    return 0;       
}

collection.txt:

hi my name is 

When I run this program I'm getting:

Hello world 
P7k

P7k is a memory location I assume.

I've looked at multiple websites and articles and I'm unable to figure out what I can do to print the text in collection.txt

Answer 1

"%s" only scans until it finds a white character. My suggestion would be to scan the file letter by letter ("%c") until you find end of file. Something like:

while(!feof(ptr)) { 
  fscanf(ptr, %c, data + counter); counter++;
}

Answer 2

Problems include

Not testing for fopen() success

FILE *ptr;
// add
if (ptr == NULL) {
  fprintf(stderr, "Fail to open\n");
  return -1;
}

Not testing for fscanf() success

// fscanf(ptr, "%s", data);
if (fscanf(ptr, "%s", data) != 1) {
  fprintf(stderr, "Fail to read\n");
  return -1;
}

Not limiting input

char data[1000];
// fscanf(ptr, "%s", data);
fscanf(ptr, "%999s", data);

Not reporting all data

"%s" does not save white space, so white-space from the file is not printed.

Use fgets() to read a line of input. To read all, use a loop.

while (fgets(data, sizeof data, ptr)) {
  printf("%s", ptr);
}