How to Read Data Using sscanf() in C?

In C, sscanf() function stands for "String Scan Formatted". This function is used for parsing the formatted strings, unlike scanf() that reads from the input stream, the sscanf() function extracts data from a string. In this article, we will learn how to read data using sscanf() function in C.

Example:

Input: 
char *str = "Ram Manager 30";

Output:
Name: Ram
Designation: Manager     //parsed string
Age: 30

Read Data Using sscanf Function in C

In C, the sscanf() function can be used to read formatted data from a string rather than a standard input or keyboard. Pass the string to be parsed, a format specifier that defines the expected data types and structure of the input string (like %d, %f, %c, etc), and the list of variables where we want to store the formatted data as a parameter to the sscanf() functions to get the parsed string.

Syntax of sscanf() in C

sscanf(input_str, format, store1, store2, ...);

Here,

• input_str is the string from which data needs to be read.
• format tells the type and format of data to be read
• store1, store2, ... represents the variables where the read data will be stored.

C Program to Read Data Using sscanf()

The below program demonstrates how we can read data using sscanf() function in C.

// C program to Read Data Using sscanf()

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

int main()
{
    // Define a string containing the data to be parsed.
    char* str = "Ram Manager 30";

    // Define variables to hold the parsed data.
    char name[10], designation[10];
    int age, ret;

    // Use sscanf to parse the string into the variables.
    ret = sscanf(str, "%s %s %d", name, designation, &age);

    // Print the parsed data.
    printf("Name: %s\n", name);
    printf("Designation: %s\n", designation);
    printf("Age: %d\n", age);

    return 0;
}

Name: Ram
Designation: Manager
Age: 30

Time complexity: O(n), where n is the length of the input string.
Auxilliary Space: O(1)

Explanation: In this program, sscanf() reads three items from the string str, so 3 will be assigned to ret. The printf() function is then used to display name, designation, and age.

Note: If the input string does not match the specified format, sscanf() might fail to extract data correctly and may lead to parsing errors.