Shulou(Shulou.com)06/01 Report--

这篇文章主要介绍"Linux进程间如何通信"，在日常操作中，相信很多人在Linux进程间如何通信问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答"Linux进程间如何通信"的疑惑有所帮助!接下来，请跟着小编一起来学习吧!

题目如下：

"父进程从键盘上接受1000个数据，对其求和sum1，子进程对这1000个数平方和sum2，结果传给父进程，父进程将sum1+sum2后，打印结果。"

要求：用大小为10的共享区传递1000个数据;子进程用消息机制将sum2传给父进程。

主要利用共享内存实现进程间通信，使用管道实现进程间竞争关系，freebsd下测试通过。代码如下：时间有限，有可能有些不足，希望高手给予指点。

#include #include #include #include #include const int key = 0x12345678;static int pfd1[2], pfd2[2];#define shm_len (10*1024)#define val_num 5int init_shm() { int shmid = -1; shmid = shmget((key_t)key, shm_len, 0666 | ipc_creat); if (shmid < 0) { printf("shmget failed!\n"); exit(-1); } return shmid;}void cancel_shm(int shmid) { if (shmctl(shmid, ipc_rmid, 0) == -1) { printf("shmctl failed!\n"); exit(-1); } printf("cancel_shm successfully!\n");}void *shm_get(int shmid) { void *mem = null; mem = shmat(shmid, 0, 0); if (mem == (void *)-1) { printf("shmat failed!\n"); exit(-1); } return mem;}int get_val(int *val, int num) { int i; for (i = 0; i < num; i++) { printf("please input a num:"); scanf("%d", val + i); }}void show_val (int *val, int num) { int i; for (i = 0; i < num; i++) { printf("%d\t", *(val + i)); } printf("\n");}int add_val (int *val, int num) { int result = 0; int i; for (i = 0; i < num; i++) { result += *(val + i); } return result;}int square_val (int *val, int num) { int result = 0; int i, tmp; for (i = 0; i < num; i++) { tmp = *(val + i); result += (tmp * tmp); } return result;}void tell_wait (void) { if (pipe(pfd1) < 0 || pipe(pfd2) < 0) { printf("pipe error!\n"); exit(-1); }}void tell_parent (pid_t pid) { if (write(pfd2[1], "c", 1) != 1) { printf("write error!\n"); exit(-1); }}void wait_parent (void) { char c; if (read(pfd1[0], &c, 1) != 1) { printf("read error!\n"); exit(-1); }}void tell_child (pid_t pid) { if (write(pfd1[1], "p", 1) != 1) { printf("write error!\n"); exit(-1); }}void wait_child (void) { char c; if (read(pfd2[0], &c, 1) != 1) { printf("read error!\n"); exit(-1); }}int main(int argc, char *argv[]) { void *mem = null; int shmid = -1; pid_t pid = -1; int val[val_num]; int result = 0; shmid = init_shm(); tell_wait(); if ((pid = fork()) < 0) { //error printf("fork error!\n"); exit(-1); } else if (pid == 0) { //child int result = 0; wait_parent(); mem = shm_get(shmid); //get share memery memcpy(val, mem, sizeof(int) * val_num); result = square_val(val, val_num); *(int *)((void *)mem + shm_len - 4) = result; tell_parent(pid); exit(1); } else { //parent int child_result = 0; mem = shm_get(shmid); //get share memery get_val(val, val_num); //get user input memcpy(mem, val, sizeof(int) * val_num); //copy user input to share memery tell_child(pid); result = add_val(val, val_num); wait_child(); child_result = *(int *)((void *)mem + shm_len - 4); printf("result:%d, child_result:%d, all:%d\n", result, child_result, result + child_result); } cancel_shm(shmid); return 0;}到此，关于"Linux进程间如何通信"的学习就结束了，希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习，快去试试吧!若想继续学习更多相关知识，请继续关注网站，小编会继续努力为大家带来更多实用的文章!

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