利用共享存储实现父子进程间的通信

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <sys/ipc.h>#include <sys/shm.h>#define SHMSIZE 4096*2int main(int argc, char *argv[]){int shmid=shmget(IPC_PRIVATE, SHMSIZE, IPC_CREAT|0666);if( -1==shmid ){perror("shmget");exit(1);}char* p_map=(char*)shmat(shmid, NULL, 0);if( (char*)-1==p_map ){perror("shmat");exit(1);}pid_t pid=fork();if( pid<0 ){perror("fork");exit(1);}else if( 0==pid )//子进程负责读{char buf[20];memset(buf, 0, 20);sleep(1);strncpy(buf, p_map, 20);printf("%s/n", buf);exit(0);}else //父进程负责写{strncpy(p_map, "Hello World!", sizeof("Hello World!"));wait(NULL);if( -1==shmdt(p_map) ){perror("shmdt");exit(1);}if( -1==shmctl(shmid, IPC_RMID, NULL) ){perror("shmctl");exit(1);}exit(0);}}