linux_c语言实现父子进程共享内存

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具体代码实现部分：

#include<stdio.h>#include<sys/shm.h>#include<sys/ipc.h>#include<sys/types.h>extern int etext,edata,end;int main(int argc,char *argv[ ]){int shmid;int proj_id;key_t key;int shm_size;char *shm_addr,*addr;pid_t pid;if(argc!=3){printf("usage:%s shared_memory_size info\n",argv[0]);return 1;}shm_size=atoi(argv[1]);proj_id=2;key=ftok("./",proj_id);if(key==-1){perror("cannot generate the ipc key");return 1;}shmid=shmget(key,shm_size,IPC_CREAT | 0660);if(shmid==-1){perror("cannot create a shared memory segment ");return 1;}addr=(char*)shmat(shmid,NULL,0);shm_addr=addr;if(shm_addr==(char*)(-1)){perror("cannot attach the shared memory to process");return 1;}printf("\n");printf("==========address information==========\n");printf("etext address:%x\n",&etext);printf("edata address:%x\n",&edata);printf("end address :%x\n",&end);printf("shared memory segment address:%x\n",shm_addr);printf("=======================================\n");strcpy(shm_addr,argv[2]);printf("the input string is:%s\n",argv[2]);printf("before fork,int shared memory segment the string is:%s\n",shm_addr);pid=fork();if(pid==-1){perror("cannot creat new process");return 1;}else if(pid==0){printf("in child process,the string is:%s\n",shm_addr);printf("modify the content in shared memory\n");*shm_addr +=1;_exit(0);}else{wait(NULL);printf("after fork,int shared memory segment the string is: %s\n",shm_addr);if(shmdt(shm_addr)==-1){perror("cannot release the memory");return 1;}if(shmctl(shmid,IPC_RMID,NULL)==-1){perror("cannot delete existing shared memory segment");return 1;}}return 0; }

然后就是编译运行了：

#gcc -o share_memory share_memory.c

#./share_memory 1024 message_to_shared_memory

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