/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <stdio.h> #define	NETCHLEN	16		/* max network challenge length	*/ char *	argv0;int	debug;int	delete; char *	root = "/n/emelie";char *	user;char	file[64];char	challenge[NETCHLEN];char	response[NETCHLEN]; voidusage(void){	printf("usage: %s [-d] username\n", argv0);	exit(1);} voidmain(int argc, char **argv){	int fd, n; 	for(argv0=*argv++,--argc; argc>0; ++argv,--argc){		if(argv[0][0] != '-' || argv[0][1] == '-')			break;		switch(argv[0][1]){		case 'D':			++debug;			break;		case 'd':			++delete;			break;		case 'r':			root = argv[0][2] ? &argv[0][2] : (--argc, *++argv);			break;		default:			usage();			break;		}	}	if(argc != 1)		usage();	user = argv[0];	snprintf(file, sizeof file, "%s/#%s", root, user);	if(debug)		printf("debug=%d, file=%s\n", debug, file);	if(delete){		fd = creat(file, 0600);		if(fd < 0){			perror(file);			exit(1);		}		exit(0);	}	fd = open(file, 2);	if(fd < 0){		perror(file);		exit(1);	}	n = read(fd, challenge, NETCHLEN);	if(debug)		printf("read %d\n", n);	if(n <= 0){		printf("read %d: ", n);		perror("");		exit(1);	}	printf("challenge: %s\n", challenge);	write(1, "response: ", 10);	read(0, response, NETCHLEN-1);	lseek(fd, 0, 0);	n = write(fd, response, NETCHLEN);	if(debug)		printf("write %d\n", n);	if(n <= 0){		printf("write %d: ", n);		perror("");		exit(1);	}	exit(0);}