test.c

字符驱动程序

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>

main()
{
	int dev,i,j;
	char buf[10];
	dev=open("/dev/mychar",O_RDWR);
	if(dev==-1){
		printf("Cann't open the character device 'mychar'!\n");
		exit(0);
	}
	printf("The character device 'mychar' has been open!\n");
	while(1){
		printf("\nSelect your choice:\n");
		printf("1. Read\n2. Write\n3. Quit\n");
		scanf("%d",&i);
		switch(i){
			case 1:	printf("Start reading!\n");
				j=read(dev,buf,10);
				if(j){
					for (i=0; i<10; i++)  printf("%d ",buf[i]);
					printf("\nFinish reading!\n");
				}
				else printf("Reading failed!\n");
				break;
			case 2:	printf("Start writing!\n");
				strcpy(buf,"abcdefghij");
				j=write(dev,buf,10);
				if(j) printf("\nFinish writing!\n");
				else printf("Writng failed!\n");
				break;
			case 3:	close(dev);
				printf("The character device 'mychar' has been closed!\n");
				exit(1);
			default:	printf("Input error!\n");
				break;
		}
	}
}