一.低级通信--信号通信
signal.c
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
/*捕捉到信号sig之后，执行预先预定的动作函数*/
void sig_alarm(int sig)
{
printf("---the signal received is %d. /n", sig)
signal(SIGINT, SIG_DFL)//SIGINT终端中断信号，SIG_DFL：恢复默认行为，SIN_IGN：忽略信号
}
int main()
{
signal(SIGINT, sig_alarm)//捕捉终端中断信号
while(1)
{
printf("waiting here!/n")
sleep(1)
}
return 0
}
二.管道通信
pipe.c
#include <stdio.h>
#define BUFFER_SIZE 30
int main()
{
int x
int fd[2]
char buf[BUFFER_SIZE]
char s[BUFFER_SIZE]
pipe(fd)//创建管道
while((x=fork())==-1)//创建管道失败时，进入循环
/*进入子进程，子进程向管道中写入一个字符串*/
if(x==0)
{
sprintf(buf,"This is an example of pipe!/n")
write(fd[1],buf,BUFFER_SIZE)
exit(0)
}
/*进入父进程，父进程从管道的另一端读出刚才写入的字符串*/
else
{
wait(0)//等待子进程结束
read(fd[0],s,BUFFER_SIZE)//读出字符串，并将其储存在char s[]中
printf("%s",s)//打印字符串
}
return 0
}
三.进程间通信——IPC
①信号量通信
sem.c
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
/*联合体变量*/
union semun
{
int val//信号量初始值
struct semid_ds *buf
unsigned short int *array
struct seminfo *__buf
}
/*函数声明，信号量定义*/
static int set_semvalue(void)//设置信号量
static void del_semvalue(void)//删除信号量
static int semaphore_p(void) //执行P *** 作
static int semaphore_v(void) //执行V *** 作
static int sem_id//信号量标识符
int main(int argc, char *argv[])
{
int i
int pause_time
char op_char = 'O'
srand((unsigned int)getpid())
sem_id = semget((key_t)1234, 1, 0666 | IPC_CREAT)//创建一个信号量,IPC_CREAT表示创建一个新的信号量
/*如果有参数，设置信号量，修改字符*/
if (argc >1)
{
if (!set_semvalue())
{
fprintf(stderr, "Failed to initialize semaphore/n")
exit(EXIT_FAILURE)
}
op_char = 'X'
sleep(5)
}
for(i = 0i <10i++)
{
/*执行P *** 作*/
if (!semaphore_p())
exit(EXIT_FAILURE)
printf("%c", op_char)
fflush(stdout)
pause_time = rand() % 3
sleep(pause_time)
printf("%c", op_char)
fflush(stdout)
/*执行V *** 作*/
if (!semaphore_v())
exit(EXIT_FAILURE)
pause_time = rand() % 2
sleep(pause_time)
}
printf("/n%d - finished/n", getpid())
if (argc >1)
{
sleep(10)
del_semvalue()//删除信号量
}
exit(EXIT_SUCCESS)
}
/*设置信号量*/
static int set_semvalue(void)
{
union semun sem_union
sem_union.val = 1
if (semctl(sem_id, 0, SETVAL, sem_union) == -1)
return(0)
return(1)
}
/*删除信号量*/
static void del_semvalue(void)
{
union semun sem_union
if (semctl(sem_id, 0, IPC_RMID, sem_union) == -1)
fprintf(stderr, "Failed to delete semaphore/n")
}
/*执行P *** 作*/
static int semaphore_p(void)
{
struct sembuf sem_b
sem_b.sem_num = 0
sem_b.sem_op = -1/* P() */
sem_b.sem_flg = SEM_UNDO
if (semop(sem_id, &sem_b, 1) == -1)
{
fprintf(stderr, "semaphore_p failed/n")
return(0)
}
return(1)
}
/*执行V *** 作*/
static int semaphore_v(void)
{
struct sembuf sem_b
sem_b.sem_num = 0
sem_b.sem_op = 1/* V() */
sem_b.sem_flg = SEM_UNDO
if (semop(sem_id, &sem_b, 1) == -1)
{
fprintf(stderr, "semaphore_v failed/n")
return(0)
}
return(1)
}
②消息队列通信
send.c
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#define MAX_TEXT 512
/*用于消息收发的结构体--my_msg_type：消息类型，some_text：消息正文*/
struct my_msg_st
{
long int my_msg_type
char some_text[MAX_TEXT]
}
int main()
{
int running = 1//程序运行标识符
struct my_msg_st some_data
int msgid//消息队列标识符
char buffer[BUFSIZ]
/*创建与接受者相同的消息队列*/
msgid = msgget((key_t)1234, 0666 | IPC_CREAT)
if (msgid == -1)
{
fprintf(stderr, "msgget failed with error: %d/n", errno)
exit(EXIT_FAILURE)
}
/*向消息队列中发送消息*/
while(running)
{
printf("Enter some text: ")
fgets(buffer, BUFSIZ, stdin)
some_data.my_msg_type = 1
strcpy(some_data.some_text, buffer)
if (msgsnd(msgid, (void *)&some_data, MAX_TEXT, 0) == -1)
{
fprintf(stderr, "msgsnd failed/n")
exit(EXIT_FAILURE)
}
if (strncmp(buffer, "end", 3) == 0)
{
running = 0
}
}
exit(EXIT_SUCCESS)
}
receive.c
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
/*用于消息收发的结构体--my_msg_type：消息类型，some_text：消息正文*/
struct my_msg_st
{
long int my_msg_type
char some_text[BUFSIZ]
}
int main()
{
int running = 1//程序运行标识符
int msgid//消息队列标识符
struct my_msg_st some_data
long int msg_to_receive = 0//接收消息的类型--0表示msgid队列上的第一个消息
/*创建消息队列*/
msgid = msgget((key_t)1234, 0666 | IPC_CREAT)
if (msgid == -1)
{
fprintf(stderr, "msgget failed with error: %d/n", errno)
exit(EXIT_FAILURE)
}
/*接收消息*/
while(running)
{
if (msgrcv(msgid, (void *)&some_data, BUFSIZ,msg_to_receive, 0) == -1)
{
fprintf(stderr, "msgrcv failed with error: %d/n", errno)
exit(EXIT_FAILURE)
}
printf("You wrote: %s", some_data.some_text)
if (strncmp(some_data.some_text, "end", 3) == 0)
{
running = 0
}
}
/*删除消息队列*/
if (msgctl(msgid, IPC_RMID, 0) == -1)
{
fprintf(stderr, "msgctl(IPC_RMID) failed/n")
exit(EXIT_FAILURE)
}
exit(EXIT_SUCCESS)
}
③共享内存通信
share.h
#define TEXT_SZ 2048 //申请共享内存大小
struct shared_use_st
{
int written_by_you//written_by_you为1时表示有数据写入，为0时表示数据已经被消费者提走
char some_text[TEXT_SZ]
}
producer.c
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include "share.h"
int main()
{
int running = 1//程序运行标志位
void *shared_memory = (void *)0
struct shared_use_st *shared_stuff
char buffer[BUFSIZ]
int shmid//共享内存标识符
/*创建共享内存*/
shmid = shmget((key_t)1234, sizeof(struct shared_use_st), 0666 | IPC_CREAT)
if (shmid == -1)
{
fprintf(stderr, "shmget failed/n")
exit(EXIT_FAILURE)
}
/*将共享内存连接到一个进程的地址空间中*/
shared_memory = shmat(shmid, (void *)0, 0)//指向共享内存第一个字节的指针
if (shared_memory == (void *)-1)
{
fprintf(stderr, "shmat failed/n")
exit(EXIT_FAILURE)
}
printf("Memory attached at %X/n", (int)shared_memory)
shared_stuff = (struct shared_use_st *)shared_memory
/*生产者写入数据*/
while(running)
{
while(shared_stuff->written_by_you == 1)
{
sleep(1)
printf("waiting for client.../n")
}
printf("Enter some text: ")
fgets(buffer, BUFSIZ, stdin)
strncpy(shared_stuff->some_text, buffer, TEXT_SZ)
shared_stuff->written_by_you = 1
if (strncmp(buffer, "end", 3) == 0)
{
running = 0
}
}
/*该函数用来将共享内存从当前进程中分离,仅使得当前进程不再能使用该共享内存*/
if (shmdt(shared_memory) == -1)
{
fprintf(stderr, "shmdt failed/n")
exit(EXIT_FAILURE)
}
printf("producer exit./n")
exit(EXIT_SUCCESS)
}
customer.c
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include "share.h"
int main()
{
int running = 1//程序运行标志位
void *shared_memory = (void *)0
struct shared_use_st *shared_stuff
int shmid//共享内存标识符
srand((unsigned int)getpid())
/*创建共享内存*/
shmid = shmget((key_t)1234, sizeof(struct shared_use_st), 0666 | IPC_CREAT)
if (shmid == -1)
{
fprintf(stderr, "shmget failed/n")
exit(EXIT_FAILURE)
}
/*将共享内存连接到一个进程的地址空间中*/
shared_memory = shmat(shmid, (void *)0, 0)//指向共享内存第一个字节的指针
if (shared_memory == (void *)-1)
{
fprintf(stderr, "shmat failed/n")
exit(EXIT_FAILURE)
}
printf("Memory attached at %X/n", (int)shared_memory)
shared_stuff = (struct shared_use_st *)shared_memory
shared_stuff->written_by_you = 0
/*消费者读取数据*/
while(running)
{
if (shared_stuff->written_by_you)
{
printf("You wrote: %s", shared_stuff->some_text)
sleep( rand() % 4 )
shared_stuff->written_by_you = 0
if (strncmp(shared_stuff->some_text, "end", 3) == 0)
{
running = 0
}
}
}
/*该函数用来将共享内存从当前进程中分离,仅使得当前进程不再能使用该共享内存*/
if (shmdt(shared_memory) == -1)
{
fprintf(stderr, "shmdt failed/n")
exit(EXIT_FAILURE)
}
/*将共享内存删除,所有进程均不能再访问该共享内存*/
if (shmctl(shmid, IPC_RMID, 0) == -1)
{
fprintf(stderr, "shmctl(IPC_RMID) failed/n")
exit(EXIT_FAILURE)
}
exit(EXIT_SUCCESS)
}
摘自：http://blog.csdn.net/piaojun_pj/article/details/5943736
OK#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/ip.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <string.h>
int main(int argc,char *argv[])
{
int sockfd,new_socket
int sock_value
char buf[] = "hello! China!I Love You\n"
struct sockaddr_in client_
struct sockaddr_in server_
int SIZE = sizeof(struct sockaddr_in)
if(argc != 2){
fprintf(stderr,"The two number!\n")
exit(1)
}
if((sock_value = atoi(argv[1])) <0){
fprintf(stderr,"socket error!\n")
exit(1)
}
if((sockfd = socket(PF_INET,SOCK_STREAM, 0)) == -1){
perror("socket")
exit(1)
}
bzero(&server_,SIZE)
server_.sin_family = PF_INET
server_.sin_port = htons(sock_value)
server_.sin_addr.s_addr = INADDR_ANY
if(bind(sockfd,(struct sockaddr *)(&server_),SIZE) == -1){
perror("bind")
exit(1)
}
if(listen(sockfd, 12) == -1){
perror("listen")
exit(1)
}
printf("Waiting ... ...\n")
while(1){
if((new_socket = accept(sockfd,(struct sockaddr *)(&client_),&SIZE)) == -1){
perror("accept")
exit(1)
}
printf("The client IP is %s\n",inet_ntoa(client_.sin_addr))
printf("The socket is %d\n",ntohs(client_.sin_port))
if(write(new_socket,buf,strlen(buf)) == -1){
perror("write")
exit(1)
}
int my
char mybuf[1024]
if((my = read(new_socket, mybuf,1024)) == -1){
perror("read")
exit(1)
}
mybuf[my] = '\0'
printf("#++++#++++#:%s\n",mybuf)
close(new_socket)
}
close(sockfd)
return 0
}
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/ip.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
int main(int argc,char *argv[])
{
int sockfd
int sock_value
char buf[1024]
char mybuf[] = "Linux\n"
int read_count
struct sockaddr_in client_
struct sockaddr_in server_
int SIZE = sizeof(struct sockaddr_in)
if(argc != 3){
fprintf(stderr,"The two number!\n")
exit(1)
}
if((sock_value = atoi(argv[2])) <0){
fprintf(stderr,"socket error!\n")
exit(1)
}
if((sockfd = socket(PF_INET,SOCK_STREAM, 0)) == -1){
perror("socket")
exit(1)
}
bzero(&client_,SIZE)
bzero(&server_,SIZE)
client_.sin_family = PF_INET
client_.sin_port = htons(52252)
client_.sin_addr.s_addr = INADDR_ANY
server_.sin_family = PF_INET
server_.sin_port = htons(sock_value)
server_.sin_addr.s_addr = inet_addr(argv[1])
if(connect(sockfd,(struct sockaddr *)(&server_),SIZE) == -1){
perror("connect")
exit(1)
}
if((read_count = read(sockfd,buf,1024)) == -1){
perror("read")
exit(1)
}
buf[read_count] = '\0'
printf("#----#----#:%s\n",buf)
if(write(sockfd, mybuf,6) == -1){
perror("write")
exit(1)
}
close(sockfd)
exit(0)
return 0
}
这个问题很好办啦，服务器接受一个连接请求，然后开一个线程或者进程都可以，再在线程或者进程里面采用其他技术实现同时收发(比如I/O复用，比如非阻塞I/O)。客户端也可以采用I/O复用。推荐资料的话，《unix网络编程》这本书很好，公认的经典，当教科书用，这本书里有你想要的所有内容。
ps:你基础太差，多补补吧，别想一下吃个胖子。
另外我这里正好有个例子满足你的要求,贴给你，自己写的，不是网上找的,用的是多进程加I/O复用技术:
server端:
/****************************************************************
**
**
**
****************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include <sys/wait.h>
#include <sys/select.h>
#include <sys/time.h>
#include <unistd.h>
#define BUFLEN 1024
#define MAX(a,b) ((a)>(b)?(a):(b))
typedef void Sigfunc (int)
void str_echo(FILE *,int)
//Sigfunc *signal(int, Sigfunc *)
int main(int argc,char **argv)
{
int connfd,listenfd
pid_t childpid
socklen_t clilen
struct sockaddr_in cliaddr,servaddr
void sig_chld(int)
listenfd = socket(AF_INET, SOCK_STREAM, 0)
memset(&servaddr,0,sizeof(servaddr))
servaddr.sin_family = AF_INET
servaddr.sin_addr.s_addr = htonl(INADDR_ANY)
servaddr.sin_port = htons(5358)
bind(listenfd,(struct sockaddr*)&servaddr,sizeof(servaddr))
listen(listenfd,8)
signal(SIGCHLD,sig_chld)
while(1)
{
clilen = sizeof(cliaddr)
if((connfd = accept(listenfd,(struct sockaddr*)&cliaddr,&clilen)) <0)
{
if(errno == EINTR)
{
fputs("accept error: EINTR\n",stdout)
continue
}
else
{
fputs("accept error..\n",stdout)
}
}
if((childpid = fork()) == 0)
{
close(listenfd)
str_echo(stdin,connfd)
exit(0)
}
close(connfd)
}
}
void str_echo(FILE *fp,int sockfd)
{
int n = 0
char sendbuf[BUFLEN] = { 0 },recvbuf[BUFLEN] = { 0 }
int maxfdp
fd_set rset
FD_ZERO(&rset)
while(1)
{
FD_SET(fileno(fp),&rset)
FD_SET(sockfd, &rset)
maxfdp = MAX(fileno(fp),sockfd)+1
select(maxfdp, &rset ,NULL, NULL, NULL)
if(FD_ISSET(sockfd, &rset))
{
if(n = read(sockfd, recvbuf, BUFLEN) == 0)
{
return
}
if(n == -1)
{
break
}
printf("%s\n",recvbuf)
memset(recvbuf,0,BUFLEN)
}
if(FD_ISSET(fileno(fp),&rset))
{
scanf("%s",sendbuf)
write(sockfd, sendbuf,strlen(sendbuf))
}
}
}
void sig_chld (int signo)
{
pid_t pid
int stat
while ((pid = waitpid(-1,&stat, WNOHANG)) >0)
{
printf("child %d terminated\n",pid)
}
return
}
client端:
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/select.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <string.h>
#define MAX(a,b) (a)>(b)?(a):(b)
int main()
{
int s,connectReturn, maxfd
fd_set rset
char sendbuf[1024] = {0}
char recvbuf[1024] = {0}
long port=5358
s=socket(PF_INET,SOCK_STREAM,0)
struct sockaddr_in sa
sa.sin_family=AF_INET
sa.sin_addr.s_addr=inet_addr("127.0.0.1")
sa.sin_port=htons(port)
connectReturn=connect(s,(struct sockaddr *)&sa,sizeof(sa))
printf("%d\n",connectReturn)
FD_ZERO(&rset)
while(1)
{
FD_SET(fileno(stdin), &rset)
FD_SET(s, &rset)
maxfd=MAX(fileno(stdin), s) + 1
select(maxfd, &rset, NULL, NULL, NULL)
if(FD_ISSET(fileno(stdin), &rset))
{
scanf("%s",sendbuf)
send(s,sendbuf,strlen(sendbuf),0)
bzero(sendbuf, 1024)
}
else if(FD_ISSET(s, &rset))
{
memset(recvbuf,0,1024)
recv(s,recvbuf,1024,0)
printf("remote: %s\n",recvbuf)
}
}
return 0
}
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