C语言实现父进程主动终止子进程的方法总结

 
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <linux/input.h>
#include <linux/uinput.h>
#include <stdio.h>
#include <unistd.h>
#include <wait.h>
void mn_key(int fd,int kval)
{
	struct input_event event;
	event.type = EV_KEY;
	event.value = 1;
	event.code = kval;
	write(fd,&event,sizeof(event)) ;
	event.type = EV_SYN;
	event.code = SYN_REPORT;
	event.value = 0;
    write(fd, &event, sizeof(event));
	memset(&event, 0, sizeof(event));
	event.type = EV_KEY;
	event.code = kval;
	event.value = 0;
	write(fd, &event, sizeof(event));
	event.type = EV_SYN;
	event.code = SYN_REPORT;
	event.value = 0;
    write(fd, &event, sizeof(event));
}
int main()
{   int stat;
    pid_t pid=fork();
	if(pid==0){
		while(1){
		    char c[20];
	    	scanf("%s",c);
			if(!strcmp(c,"0")){       //接收到0字符，子进程退出
				puts("zjc over");
				return 0;
			}
		    printf("zjc:%s\n",c);
		}
	}
	sleep(10);  //10秒后，中止子进程的运行。   
    int	fd = open("/dev/input/event3",O_RDWR);  //每个机器的event(n)可能不同。
	if(fd<=0){
	    puts("keyboad error");        //dev/input/event3  权限chmod 777 要能读写
		return -1;
	}
	mn_key(fd,KEY_0);
	mn_key(fd,KEY_ENTER);
    mn_key(fd,KEY_ENTER);      //不清楚为什麽要两行
	wait(&stat);
	close(fd);
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <wait.h>
#include <signal.h>
#include <sys/prctl.h>
#include <sys/types.h>
int main(void){
//	int stat;
	int zf[2];
	pipe(zf);         //此句必须放在fork（）语句前
	pid_t pid=fork();
	if(pid==0){
		pid_t pid1=getpid();
		printf("z:%d\n",pid1);
		write(zf[1],&pid1,4);
	     while(1){
			char c[10];
			scanf("%s",c);
			if(!strcmp(c,"~")){
				puts("zjc over");
				exit(0);
			}
			printf("%s\n",c);
		 }
	}
	sleep(3);       
	pid_t bz;
	read(zf[0],&bz,4);     //父进程取得子进程号
	printf("f:%d\n",bz);  
    kill(bz,1);            //关闭子进程
//	wait(&stat);     
	return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <wait.h>
#include <sys/types.h>
#include <signal.h>
int main(void){
	 union sigval si;
	 si.sival_int=0;
	int stat;
	pid_t zf[2];
	pipe(zf);
	pid_t pid=fork();
	if(pid==0){
		pid_t id=getpid();
		write(zf[1],&id,4);
		int t=1;
		void handle(int sig){
			printf("%d\n",sig);
			t=0;                
		}
		signal(20,&handle);    
		while(t){
			puts("zjc");
			sleep(1);
		}
		printf("%d\n",t);    //t=0
		exit(0);
	}
	int bz;
	read(zf[0],&bz,4);
	sleep(2);
    sigqueue(bz,20,si);
	wait(&stat);
	return 0;
}