socket C语言的接口的介绍:
服务器开发虽然不是直接拿socketAPI进行开发但也需要了解
伯克利API:
API的历史:
头文件:
API函数:
最简单的服务器和对应的客户端C语言的实现
服务器部分:
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
int main(int argc, char** argv) {
char hello[] = "hello world";
struct sockaddr_in sa;
int SocketFD = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (-1 == SocketFD) {
perror("cannot create socket");
exit(EXIT_FAILURE);
}
memset(&sa, 0, sizeof sa);
sa.sin_family = AF_INET;
sa.sin_port = htons(2222);
sa.sin_addr.s_addr = htonl(INADDR_ANY);
if (-1 == bind(SocketFD, (struct sockaddr*)&sa, sizeof sa)) {
perror("bind failed");
close(SocketFD);
exit(EXIT_FAILURE);
}
if (-1 == listen(SocketFD, 10)) {
perror("listen failed");
close(SocketFD);
exit(EXIT_FAILURE);
}
for (;;) {
int ConnectFD = accept(SocketFD, NULL, NULL);
if (0 > ConnectFD) {
perror("accept failed");
close(SocketFD);
exit(EXIT_FAILURE);
}
int writeSize = 0;
size_t totalWrite = 0;
while (totalWrite < sizeof(hello)) {
writeSize =
write(ConnectFD, hello + totalWrite, sizeof(hello) - totalWrite);
if (-1 == writeSize) {
perror("write failed");
close(ConnectFD);
close(SocketFD);
exit(EXIT_FAILURE);
}
totalWrite += writeSize;
}
if (-1 == shutdown(ConnectFD, SHUT_RDWR)) {
perror("shutdown failed");
close(ConnectFD);
close(SocketFD);
exit(EXIT_FAILURE);
}
close(ConnectFD);
}
close(SocketFD);
return EXIT_SUCCESS;
}
客户端部分:
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
int main(int argc, char** argv) {
struct sockaddr_in sa;
int res;
int SocketFD = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (-1 == SocketFD) {
perror("cannot create socket");
exit(EXIT_FAILURE);
}
memset(&sa, 0, sizeof sa);
sa.sin_family = AF_INET;
sa.sin_port = htons(2222);
res = inet_pton(AF_INET, "127.0.0.1", &sa.sin_addr);
if (-1 == connect(SocketFD, (struct sockaddr*)&sa, sizeof sa)) {
perror("connect failed");
close(SocketFD);
exit(EXIT_FAILURE);
}
char buffer[512];
int totalRead = 0;
for (;;) {
int readSize = 0;
readSize = read(SocketFD, buffer + totalRead, sizeof(buffer) - totalRead);
if (readSize == 0) {
// read all
break;
} else if (readSize == -1) {
perror("read failed");
close(SocketFD);
exit(EXIT_FAILURE);
}
totalRead += readSize;
}
buffer[totalRead] = 0;
printf("get from server: %s\n", buffer);
/* perform read write operations ... */
(void)shutdown(SocketFD, SHUT_RDWR);
close(SocketFD);
return EXIT_SUCCESS;
}