Linux 创建共享内存从一个程序写一个程序读

野性酷女 2022-10-01 02:49 165阅读 0赞

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读取c 文件图右

#include <stdio.h> #include<sys/shm.h> #include<unistd.h> #include<stdlib.h> #include "shmdata.h" int main() { int runing=1; struct share_use_st *shared; void *shm=NULL; int shmid; shmid = shmget((key_t)1234,sizeof(struct share_use_st),IPC_CREAT |0644); if(shmid == -1) { perror("shmget error"); exit(0); } //创建内存 shm = shmat(shmid,NULL,0); if((void *)-1== shm) { perror("shmat error"); exit(0); } printf("Shmat memory attached at %p\n",shm); //映射内存 shared=(struct share_use_st *)shm; shared->written=0; while(runing) { if(shared->written !=0) { printf("you wrote:%s\n",shared->text); sleep(rand() %3 ); shared->written = 0; if(strncmp(shared->text,"end",3)==0) { runing=0; } } else { sleep(1); } } if(shmdt(shm)!=-1) { perror("shmdt fail"); } if(shmctl(shmid,IPC_RMID,NULL)==-1) { perror("shmctl error"); } return 0; }

写入c文件图左

#include <stdio.h> #include<sys/shm.h> #include<unistd.h> #include<stdlib.h> #include<string.h> #include "shmdata.h" #define BUFFER_SIZE 2048 int main() { int runing=1; struct share_use_st *shared; void *shm=NULL; int shmid; char buffer[BUFFER_SIZE]; shmid = shmget((key_t)1234,sizeof(struct share_use_st),IPC_CREAT |0644); if(shmid == -1) { perror("shmget error"); exit(0); } //创建内存 shm = shmat(shmid,NULL,0); if((void *)-1== shm) { perror("shmat error"); exit(0); } printf("Shmat memory attached at %p\n",shm); //映射内存 shared=(struct share_use_st *)shm; while(runing) { if(shared->written == 1) { sleep(1); printf("waitting...\n"); } printf("please input some text:\n"); fgets(buffer,BUFFER_SIZE,stdin); buffer[strlen(buffer)-1]='\0'; strncpy(shared->text,buffer,strlen(buffer)+1); shared->written = 1; if(strncmp(buffer,"end",3)==0) { runing=0; } } if(shmdt(shm)==-1) { perror("shmdt fail"); exit(-1); } sleep(1); return 0; }

结构体 .h 文件 作用--内存映射/内容传递作用

#define SIZE 2048 struct share_use_st { int written; char text[SIZE]; };

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