testproc.c

Linux设备管理源码 字符设备驱动程序：设计两个终端设备文件实现一个字符设备驱动程序

/************************************************************/
/***** testproc.c, this is a test program for chardev.c *****/
/************************************************************/

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include "chardev.h"

void write_proc(void);
void read_proc(void);

main(int argc,char **argv) {
	if(argc==1) {
		puts("syntax: testprog[write|read]!");
		exit(0);
	}
	if(!strcmp(argv[1],"write")) {
		write_porc();
	}
	else if(!strcmp(argv[1],"read")) {
		read_proc();
	}
	else {
		puts("testprog: invalid command!");
	}
	return 0;
}

void write_proc() {
	int fd,len,quit=0;
	int dbg;
	char buf[100];
	fd=open("cdev0",O_WRONLY);
	if(fd<=0) {
		printf("Error opening device for writing!\n");
		exit(1);
	}
	while(!quit) {
		printf("\n write>>");
		gets(buf);
		if(!strcmp(buf,"exit"))
			quit=1;
		while(ioctl(fd,DYNCHAR_QUERY_NEW_MSG))
			usleep(1000);
		len=write(fd,buf,strlen(buf));
		if(len<0) {
			;
			printf("Error writing to device!\n");
			close(fd);
			exit(1);
		}
		printf("%d bytes written to device!\n",len);
	}
	close(fd);
}


void read_proc() {
	int fd,len,quit=0;
	char *buf=NULL;
	fd=open("cdev1",O_RDONLY);
	if(fd<0) {
		printf("Error opening device for reading!\n");
		exit(1);
	}
	while(!quit) {
		printf("\n read>>");
		while(!ioctl(fd,DYNCHAR_QUERY_NEW_MSG))
			usleep(1000);
		// get the msg length
		len=ioctl(fd,DYNCHAR_QUERY_MSG_LENGTH,NULL);
		if(len) {
			if(buf!=NULL)
				free(buf);
			buf=malloc(sizeof(char)*(len+1));
			len=read(fd,buf,len);
			if(len<0) {
				printf("Error reading from device!");
			}
			else {
				if(!strcmp(buf,"exit")) {
					;
					ioctl(fd,DYNCHAR_RESET);     // reset
					quit=1;
				}
				else 
					printf("%s\n",buf);
			}
		}
	}
	free(buf);
	close(fd);
}