Linux socket 进程间通信

落日映苍穹つ 2022-10-12 05:38 241阅读 0赞

# Socket进程间通信 #

--------------------

## 服务端 ##

#include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <sys/stat.h>
    #include <sys/socket.h>
    #include <sys/types.h>
    #include <sys/un.h>
    #include <errno.h>
    #include <stddef.h>
    #include <unistd.h>
    #include <pthread.h>
    
    #define MAX_CONNECT_NUM 2
    #define BUFFER_SIZE 1024
    const char *filename = "uds-tmp";
    static pthread_t th;
    static pthread_t th1;
    
    void *thread_recv(void *ptr)
    { 
        int fd = *(int *)ptr;
        char buffer[BUFFER_SIZE];
        bzero(buffer, BUFFER_SIZE);
    
        while (1)
        { 
            printf("waiting recv...\n");
            int ret = recv(fd, buffer, BUFFER_SIZE, 0);
    
            if (ret <= 0)
            { 
                printf("recv failed\n");
                close(fd);
                pthread_cancel(th1);
                return NULL;
            }
    
            printf("%s\n", buffer);
    
            if (strncmp("end", buffer, 3) == 0)
            { 
                close(fd);
                exit(0);
            }
        }
    }
    
    void *thread_send(void *ptr)
    { 
        int fd = *(int *)ptr;
        while(1)
        { 
            char buff[128] = { 0};
            fgets(buff, 128, stdin);
    
            int ret = send(fd, buff, 128, 0);
            if (ret <= 0)
            { 
                close(fd);
                pthread_cancel(th);
                return NULL;
            }
        }
    }
    
    int main()
    { 
        int fd, new_fd, len, i;
        struct sockaddr_un un;
        fd = socket(AF_UNIX, SOCK_STREAM, 0);
        if (fd < 0)
        { 
            printf("Request socket failed!\n");
            return -1;
        }
        un.sun_family = AF_UNIX;
        unlink(filename);
        strcpy(un.sun_path, filename);
        if (bind(fd, (struct sockaddr *)&un, sizeof(un)) < 0)
        { 
            printf("bind failed!\n");
            return -1;
        }
        if (listen(fd, MAX_CONNECT_NUM) < 0)
        { 
            printf("listen failed!\n");
            return -1;
        }
        while (1)
        { 
            printf("wait to accept...\n");
    
            new_fd = accept(fd, NULL, NULL);
    
            printf("new accept.\n");
    
            if (new_fd < 0)
            { 
                printf("accept failed\n");
                return -1;
            }
            pthread_create(&th, NULL, thread_recv, (void *)(&new_fd));
            pthread_create(&th1, NULL, thread_send, (void *)(&new_fd));
    
        }
        close(fd);
    }

## 客户端 ##

#include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <sys/stat.h>
    #include <sys/socket.h>
    #include <sys/types.h>
    #include <sys/un.h>
    #include <errno.h>
    #include <stddef.h>
    #include <unistd.h>
    #include <pthread.h>
    #define BUFFER_SIZE 1024
    const char *filename = "uds-tmp";
    
    void *thread_recv(void *ptr)
    { 
        int sock_fd = *(int *)ptr;
        char buffer[128] = { 0};
        while (1)
        { 
            int ret = recv(sock_fd, buffer, 128, 0);
            if (ret <= 0)
            { 
                printf("recv error: %s\n", strerror(ret));
                close(sock_fd);
                //exit(EXIT_FAILURE);
            } else { 
                printf("%s\n", buffer);
            }
        }
    }
    
    int main()
    { 
        while (1)
        { 
            struct sockaddr_un un;
            int sock_fd;
            char buffer[BUFFER_SIZE] = "hello world";
            un.sun_family = AF_UNIX;
            strcpy(un.sun_path, filename);
            sock_fd = socket(AF_UNIX, SOCK_STREAM, 0);
            if (sock_fd < 0)
            { 
                printf("Request socket failed\n");
                return -1;
            }
            if (connect(sock_fd, (struct sockaddr *)&un, sizeof(un)) < 0)
            { 
                printf("connect socket failed\n");
                return -1;
            }
    
            pthread_t pth;
    
            pthread_create(&pth, NULL, thread_recv, (void *)(&sock_fd));
    
            while (1)
            { 
                memset(buffer, 0, BUFFER_SIZE);
                fgets(buffer, BUFFER_SIZE, stdin);
    
                printf("send data: %s\n", buffer);
    
                int error = 0;
                socklen_t len = sizeof(error);
                int retval = getsockopt(sock_fd, SOL_SOCKET, SO_ERROR, &error, &len);
    
                if (retval != 0)
                { 
                    /* there was a problem getting the error code */
                    fprintf(stderr, "error getting socket error code: %s\n", strerror(retval));
                    return 0;
                }
    
                if (error != 0)
                { 
                    /* socket has a non zero error status */
                    fprintf(stderr, "socket error: %s\n", strerror(error));
                    return 0;
                }
    
                ssize_t size = send(sock_fd, buffer, BUFFER_SIZE, MSG_NOSIGNAL);
    
                if (size <= 0)
                { 
                    // close(sock_fd);
                    // return 0;
                    printf("send data failed.\n");
                }
            }
        }
    
        return 0;
    }

## 测试 ##

先打开服务端，再打开客户端。  
服务端发送：`socket server send data`。  
客户端发送：`socket client send data` 和 `test`。  
关闭客户端后，重新打开客户端。  
客户端发送：`client send data`。  
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