selsub.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static	char	*sccsid = "@(#)selsub.c	4.1	(ULTRIX)	7/17/90";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1986, 1988 by			*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/
/*
 * Modification history
 *
 * 15 Sep 1988 - D. Long
 *	Fixed null pointer problems for PMAX.
 */
#include "stdio.h"
#include "sys/types.h"
#include "sys/stat.h"
#include "lrnref.h"

selsub(argc,argv)
char *argv[];
{
	char ans1[100];
	static char ans2[30];
	static char dirname[20];
	static char subname[20];
	struct stat statbuf;

	if (argc > 1 && argv[1][0] == '-') {
		direct = argv[1]+1;
		argc--;
		argv++;
	}
	if (chdir(direct) != 0) {
		perror(direct);
		fprintf(stderr, "Selsub:  couldn't cd to non-standard directory\n");
		exit(1);
	}
	sname = argc > 1 ? argv[1] : 0;
	if (argc > 2) {
		strcpy (level=ans2, argv[2]);
		if (strcmp(level, "-") == 0)	/* no lesson name is - */
			ask = 1;
		else
			again = 1;	/* treat as if "again" lesson */
	}
	else
		level = 0;
	if (argc > 3 )
		speed = atoi(argv[3]);
	if (!sname) {
		printf("These are the available courses -\n");
		list("Linfo");
		printf("If you want more information about the courses,\n");
		printf("or if you have never used 'learn' before,\n");
		printf("press RETURN; otherwise type the name of\n");
		printf("the course you want, followed by RETURN.\n");
		fflush(stdout);
		if (gets(sname=subname) == NULL)
			exit(0);
		if (sname[0] == '\0') {
			list("Xinfo");
			do {
				printf("\nWhich subject?  ");
				fflush(stdout);
				if (gets(sname=subname) == NULL)
					exit(0);
			} while (sname[0] == '\0');
		}
	}
	chknam(sname);
	stat(sname, &statbuf);
	total = statbuf.st_size / 16 - 2;	/* size/dirsize-(.+..) */
	if (!level) {
		printf("If you were in the middle of this subject\n");
		printf("and want to start where you left off, type\n");
		printf("the last lesson number the computer printed.\n");
		printf("If you don't know the number, type in a word\n");
		printf("you think might appear in the lesson you want,\n");
		printf("and I will look for the first lesson containing it.\n");
		printf("To start at the beginning, just hit RETURN.\n");
		fflush(stdout);
		if (gets(ans2) == NULL)
			exit(0);
		if (ans2[0]==0)
			strcpy(ans2,"0");
		level=ans2;
	}

	/* make new directory for user to play in */
	if (chdir("/tmp") != 0) {
		perror("/tmp");
		fprintf(stderr, "Selsub:  couldn't cd to public directory\n");
		exit(1);
	}
	(void) sprintf(dir=dirname, "pl%da", getpid());
	(void) sprintf(ans1, "mkdir %s", dir);
	system(ans1);
	if (chdir(dir) < 0) {
		perror(dir);
		fprintf(stderr, "Selsub:  couldn't make play directory with %s.\nBye.\n", ans1);
		exit(1);
	}
	/* after this point, we have a working directory. */
	/* have to call wrapup to clean up */
	(void) sprintf(ans1, "%s/%s/Init", direct, sname);
	if (access(ans1, 04)==0) {
		(void) sprintf(ans1, "%s/%s/Init %s", direct, sname, level);
		if (system(ans1) != 0) {
			printf("Leaving learn.\n");
			wrapup(1);
		}
	}
}

chknam(name)
char *name;
{
	if (access(name, 05) < 0) {
		printf("Sorry, there is no subject or lesson named %s.\nBye.\n", name);
		exit(1);
	}
}