freeaddrinfo (C)

c

Definition

freeaddrinfo (C)

#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
 
void freeaddrinfo(struct addrinfo *res);

The freeaddrinfo() function frees the memory that was allocated for the dynamically allocated linked list res (created via getaddrinfo.

Examples

Example: HTTP Client

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <netdb.h>
 
int main(int argc, char *argv[]) {
    if (argc < 2) return 1;
 
    // 1. resolve host (ipv4 & ipv6)
    struct addrinfo hints = {0}, *res;
    hints.ai_family = AF_UNSPEC;     // Allow IPv4 or IPv6
    hints.ai_socktype = SOCK_STREAM; // TCP
 
    if (getaddrinfo(argv[1], "80", &hints, &res) != 0) return 2;
 
    // 2. create socket
    int s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
    if (s < 0) {
        freeaddrinfo(res);
        return 3;
    }
    
    // 3. connect
    if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
        freeaddrinfo(res);
        return 3;
 
    }
    
    freeaddrinfo(res); // Clean up memory
	
	// ...
}