who.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

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

/************************************************************************
 *									*
 *			Copyright (c) 1985 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.	*
 *									*
 ************************************************************************/
/*static char *sccsid = "@(#)who.c	4.6 (Berkeley) 8/19/83";*/
/*
 * who
 */

/* 
 *	Modified by :	Aki Hirai , Digital Equipment Corp.
 *			30 - May - 1985
 *	
 *	/aki00/ -------	Fix the file name problem in error message.
 *	/aki01/ ------- Fix the printing table problem when arguments
 *			more than two.
 */

#include <stdio.h>
#include <utmp.h>
#include <pwd.h>
#include <ctype.h>

#define NMAX sizeof(utmp.ut_name)
#define LMAX sizeof(utmp.ut_line)
#define	HMAX sizeof(utmp.ut_host)

struct	utmp utmp;
struct	passwd *pw;
struct	passwd *getpwuid();
char	hostname[32];

char	*ttyname(), *rindex(), *ctime(), *strcpy();

main(argc, argv)
	int argc;
	char **argv;
{
	register char *tp, *s;
	register FILE *fi;

	s = "/etc/utmp";
	if(argc == 2)
		s = argv[1];
	if (argc == 3) {
		tp = ttyname(0);
		if (tp)
			tp = rindex(tp, '/') + 1;
		else {	/* no tty - use best guess from passwd file */
			pw = getpwuid(getuid());
			strncpy(utmp.ut_name, pw ? pw->pw_name : "?", NMAX);
			strcpy(utmp.ut_line, "tty??");
			time(&utmp.ut_time);
			putline();
			exit(0);
		}
	}
	if ((fi = fopen(s, "r")) == NULL) {
/**aki00**/
		printf("who: cannot open %s\n", s);
/**aki01 end**/
		exit(1);
	}
	while (fread((char *)&utmp, sizeof(utmp), 1, fi) == 1) {
		if (argc == 3) {
			gethostname(hostname, sizeof (hostname));
			if (strcmp(utmp.ut_line, tp))
				continue;
			printf("%s!", hostname);
			putline();
			exit(0);
		}
/** aki01 **/
		if (utmp.ut_name[0] == '\0' && argc == 1 || argc > 3)
/** aki01 end **/
			continue;
		putline();
	}
}

putline()
{
	register char *cbuf;

	printf("%-*.*s %-*.*s",
		NMAX, NMAX, utmp.ut_name,
		LMAX, LMAX, utmp.ut_line);
	cbuf = ctime(&utmp.ut_time);
	printf("%.12s", cbuf+4);
	if (utmp.ut_host[0])
		printf("\t(%.*s)", HMAX, utmp.ut_host);
	putchar('\n');
}