Linux TCP Server测试工具代码
实现了接受数据并输出文本和十六制字符串

#include <stdio.h>
#include<string.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <signal.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>#define SERVER_PORT		8081
#define SERVER_IP		"0.0.0.0"
void ByteToHexStr(const unsigned char* source, char* dest, int sourceLen); 
int listen_fd = -1;void signal_handler(int arg)
{printf("close listen_fd(signal = %d)\n", arg);close(listen_fd);exit(0);
}int main(int argc,  char *argv[])
{int port=80;printf("argc:%d\r\n",argc);if (argc>1){printf("raw data:%s",argv[1]);port=atoi(argv[1]);printf("port:%d\r\n",port);}int new_fd  = -1;struct sockaddr_in server;struct sockaddr_in client;socklen_t saddrlen = sizeof(server);socklen_t caddrlen = sizeof(client);signal(SIGINT, signal_handler);memset(&server, 0, sizeof(server));memset(&client, 0, sizeof(client));listen_fd = socket(AF_INET, SOCK_STREAM, 0);if (listen_fd < 0){printf("socket error!\n");return -1;}int opt = 1;setsockopt(listen_fd,SOL_SOCKET,SO_REUSEADDR,&opt,sizeof( opt ));server.sin_family = AF_INET;server.sin_port = htons(port);server.sin_addr.s_addr = inet_addr(SERVER_IP);if (bind(listen_fd, (struct sockaddr *)&server, saddrlen) < 0){printf("bind error!\n");return -1;}printf("listen:%d\r\n",port); if (listen(listen_fd, 5) < 0){printf("listen error!\n");return -1;}char rbuf[256] = {0};char hexStr[1024]={0};int read_size = 0;while (1){/*socket()创建的套接字默认是阻塞的，所以accept()在该套接字上进行监听时，如果没有客户端连接请求过来，accept()函数会一直阻塞等待；换句话说，程序就停在accept()函数这里，不会继续往下执行，直到有新的连接请求发送过来，唤醒accept()。*/new_fd = accept(listen_fd, (struct sockaddr *)&client, &caddrlen);if (new_fd < 0){perror("accept");return -1;}printf("new client connected.IP:%s,port:%u\n", inet_ntoa(client.sin_addr), ntohs(client.sin_port));while (1){memset(&rbuf,0,sizeof(rbuf));read_size = read(new_fd, rbuf, sizeof(rbuf));if (read_size < 0){printf("read error!\n");continue;}else if (read_size == 0){printf("client (%d) is closed!\n", new_fd);close(new_fd);break;}printf("recv:%s\n", rbuf);memset(&hexStr, 0, sizeof(hexStr));ByteToHexStr(rbuf,hexStr,read_size);printf("recv HexStr:%s\n",hexStr);}}close(listen_fd);return 0;
}
void ByteToHexStr(const unsigned char* source, char* dest, int sourceLen)
{short i;unsigned char highByte, lowByte;for (i = 0; i < sourceLen; i++){highByte = source[i] >> 4;lowByte = source[i] & 0x0f;highByte += 0x30;if (highByte > 0x39)dest[i * 2] = highByte + 0x07;elsedest[i * 2] = highByte;lowByte += 0x30;if (lowByte > 0x39)dest[i * 2 + 1] = lowByte + 0x07;elsedest[i * 2 + 1] = lowByte;}return;
}

编译

# 编译gcc tcpserver.c -o tcpserver
# 运行
./tcpserver 8081