sprintf and sscanf

Does anyone know what the purpose of the sprintf and sscanf statements for this program are for? I do not understand these 2 functions at all. Thanks......

Code:

---

#include <stdio.h>
#include <conio.h>

int main()
{
        char array[80];
        int num1=1;
        int num2=2;

        sprintf(array,"%d" "%d", num1, num2);
        puts(array);

        char data[]="$23.45 10";
        char dol;
        float price;
        int units;

        scanf(data,"%c%f %d", &dol,&price,&units);
        printf("\n%c%5.2f %d\n", dol, price, units);

        getch();
        return 0;
}

---

*****Output with the SSCANF and SPRINTF Function********
/*
12

$23.45 10
*/
*****Output with the SCANF and SPRINTF Function*********
/*
12
*/

Here is an example. Basicly, sprintf prints from a string. sscanf scans into a string (buffer). Just like their non-"s" counter parts.

Quzah.

i think you have that backwards.....sprintf prints to a string, and sscanf reads from a string?

Yeah. What he said. :D I know what I meant. ;)

Quzah.

i know you did..just wanted to clarify for him

Thanks for the info guys. Are these functions used a lot? What's a good example of using them? Thanks again for your help. Tommy

here

Code:

---

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

int main(void){
        char buffer[BUFSIZ];
        int x;

        printf("Enter a number:  ");
        fflush(stdout);
        if(!(fgets(buffer,sizeof buffer,stdin))){
              fprintf(stderr,"Error getting input\n");
              exit(0);
        }
        sscanf(buffer,"%d",&x);
        printf("Now x is a digit!!\n");
        printf("X == %i\n",x);  /*%i is interchangeable with %d here*/
        return 0;
}

---

>Are these functions used a lot?
sscanf is used a great deal as the preferred method for parsing a string read by fgets. This combination is a replacement for scanf because scanf bites, and also gives you a better chance for error handling when reading from files (instead of fscanf).

>What's a good example of using them?
Converting numeric data to and from strings in a standard and portable way.

Quote:

---

Originally Posted by tommy69

What's a good example of using them?

---

I guess you didn't actually read the link to the FAQ then...

Quzah.

Quote:

---

Originally Posted by linuxdude

here

Code:

---

#include <stdio.h>
 #include <stdlib.h>
 
 int main(void){
        char buffer[BUFSIZ];
        int x;
 
        printf("Enter a number:  ");
        fflush(stdout);
        if(!(fgets(buffer,sizeof buffer,stdin))){
                fprintf(stderr,"Error getting input\n");
                exit(0);
        }
sscanf(buffer,"%d",&x);
        printf("Now x is a digit!!\n");
        printf("X == %i\n",x);  /*%i is interchangeable with %d here*/
        return 0;
 }

---

---

Where you say "x is now a digit", you're sort of wrong, and right, all at the same time ;) x was always a number, as its an int type variable, it just started the program with an unpredictable value. Unfortunately, even after sscanf() has done it's magic, x still has an unpredictable value, as parsing might have failed. Remember to always check the return code from sscanf() to ensure it did what it was supposed to.

>>fprintf(stderr,"Error getting input\n");
This would be better replaced with perror("Error getting input");

I hate you people :D