www.pudn.com > 医学算法.rar > bgr.c

/*
	insert black cross hatch on the comtal
 */

char	com[] =  "/dev/ct0";

main(argc,argv)
	int	argc;
	char	**argv;
{
	int	fd,width;
	register	i,j;
	char	buf[512];

	if(argc != 3){
		printf("syntax: bgr # width\n");
		exit(1);
	}
	com[7] = **++argv;
	if((fd = open(com,2)) == -1){
		printf("can't open: %s\n",com);
		exit(1);
	}
	width = atoi(*++argv);

	for(i=0;i<512;i++){
		read(fd,buf,512);
		for(j=256-(width>>1);j<=256+(width>>1);buf[j++]=0);
		if(i>=256-(width>>1) && i<=256+(width>>1))
			for(j=0;j<512;buf[j++]=0);
		lseek(fd,(long)-1,4);
		write(fd,buf,512);
	}
}