Linux简单的服务器程序

#include <stdio.h>
#include <stdbool.h>
#include <signal.h>
#include <libgen.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <assert.h>
#include <netinet/in.h>
#include <strings.h>
#include <arpa/inet.h>
#include <unistd.h>

static bool stop = false;

// SIGTERM信号的处理函数,触发时结束主程序中的循环
static void handle_term(int sig) {
    stop = true;
}


int main(int argc, char* argv[]) {
    // 捕捉SIGTERM信号
    signal(SIGTERM, handle_term);

    if (argc <= 3) {
        printf("usage: %s ip_address port_number backlog\n", basename(argv[0]));
        return 1;
    }

    const char* ip = argv[1];
    int port = atoi(argv[2]);
    int backlog = atoi(argv[3]);

    // 创建socket
    int sock = socket(PF_INET, SOCK_STREAM, 0);
    assert(sock >= 0);

    // 创建一个ipv4 sock地址
    struct sockaddr_in address;
    bzero(&address, sizeof(address));

    address.sin_family = AF_INET;
    // 转为网络字节序保存在address.sin_addr中
    inet_pton(AF_INET, ip, &address.sin_addr);
    // htons将主机字节序的port转换为网络字节序
    address.sin_port = htons(port);

    // 将开始创建的sock绑定到指定的address上
    int ret = bind(sock, (struct sockaddr*) &address, sizeof(address));
    assert(ret != -1);

    // 开始监听
    ret = listen(sock, backlog);
    assert(ret != -1);
    while (!stop) {
        sleep(1);
    }
    
    // 处理客户端连接
    struct sockaddr_in client;
    socklen_t client_addrlength = sizeof(client);
    int connfd = accept(sock, (struct sockadd*)&client, &client_addrlength);

    if (connfd < 0) {
        printf("errno is: %d\n", errno);
    } else {
        // 接受连接成功则打印出客户端的IP地址和端口号
        char remote[INET_ADDRSTRLEN];
        printf("connected with ip: %s and port: %d\n", inet_ntop(AF_INET, &client.sin_addr, remote, INET_ADDRSTRLEN),
               ntohs(client.sin_port));
        close(connfd);
    }

    close(sock);

    return 0;
}