Issue

I came across the following statement while I was going through a C program for client/server message handling in Unix.

int main(int argc, char* argv[])
{
    (void)sscanf(argv[1],"%d",&port);
}

It would be helpful if you can explain the above statement.

Edit: I don't know why people feel my question is not clear... I just wanted to know that if scanf takes input from keyboard then the above statement sscanf also does the same job indirectly. Is that correct?

Solution

sscanf() reads formatted input from a string.

scanf() reads formatted input from stdin.

So in your example sscanf reads from the first argument of the program and saves it in the variable port.

As a little example what sscanf does:

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

int main() {
    
    int day;
    char str[100];

   strcpy(str, "21" );
   sscanf(str, "%d", &day);

   printf("day: %d", day);
    
   return(0);
}

Output:

day: 21

Answered By - Rizier123

Wednesday, December 29, 2021

[SOLVED] How is sscanf different from scanf in the following statements?

Issue

Solution