1. Cititi despre SUID aici
2. Compilati programul de mai jos.
3. Setati bitul de SUID pe binarul creat. (puteti folosi sudo)
4. Afisati /etc/shadow folosind binarul creat fara a folosi sudo. (./binar)

#include <stdio.h> 
#include <stdlib.h> // For exit() 
 
int main() 
{ 
	FILE *fptr; 
 
	char filename[100], c; 
 
	printf("Enter the filename to open \n"); 
	scanf("%s", filename); 
 
	// Open file 
	fptr = fopen(filename, "r"); 
	if (fptr == NULL) 
	{ 
		printf("Cannot open file \n"); 
		exit(0); 
	} 
 
	// Read contents from file 
	c = fgetc(fptr); 
	while (c != EOF) 
	{ 
		printf ("%c", c); 
		c = fgetc(fptr); 
	} 
 
	fclose(fptr); 
	return 0; 
}