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    Length: 2445 (0x98d)
    Types: TextFile
    Names: »uptime.c«

└─⟦a0efdde77⟧ Bits:30001252 EUUGD11 Tape, 1987 Spring Conference Helsinki
    └─⟦this⟧ »EUUGD11/euug-87hel/sec8/uptime/uptime.c« 

TextFile

/*
 *	uptime.c -- Print how long the system has been up 
 *				System V Implmenentation
 *
 *	(sjm@dayton)	Steven McDowall
 *
 *	cc -O -o uptime uptime.c
 *	chown root uptime
 *	chmod u+s uptime			So we can read /dev/kmem
 */

# include <sys/types.h>			/* system types */
# include <sys/sysinfo.h>		/* sysinfo structure */
# include <sys/param.h>			/* for HZ */
# include <stdio.h>
# include <nlist.h>
# include <fcntl.h>
# include <time.h>

#define	MINUTES	60
#define HOURS	(MINUTES * 60)
#define DAYS	(HOURS * 24)

# define SYSTEM "/unix"
# define KMEM "/dev/kmem"

struct nlist nl[] = {
# define NL_SYSINFO 0
        { "sysinfo" },			/* 0 */
# define NL_LBOLT 1
	{ "lbolt" },			/* 1 */
        { 0 }
};


int		memfd;
char	*system = SYSTEM;
char	*kmem = KMEM;
char	*argv0;

main(argc, argv)
int  argc;
char *argv[];
{
	time_t	boothz, uptime;
	void	ptime();

	argv0 = argv[0];
	init_nlist();			/* get name values, open kmem */

/*
	Now read kmem to get the boot time
*/
	l_lseek(memfd, (long)nl[NL_LBOLT].n_value, 0);
	r_read(memfd, (char *)&boothz, sizeof( boothz ) );
	uptime = (boothz / HZ);
	ptime(uptime);
} /* main */
\f


init_nlist()
{
	nlist(system, nl);		/* get system values */

    if(nl[NL_SYSINFO].n_value == 0)
	{
	    fprintf(stderr, "%s: can't find sysinf structure\n", argv0);
        exit(1);
    } /* no value */

	if ((memfd = open(kmem, O_RDONLY)) < 0)
	{
		fprintf(stderr, "%s: no mem\n", argv0);
		exit(1);
	} /* could not open kmem */

} /* init_nlist */

/* lseek with error checking */
l_lseek(fd, offset, whence)
int fd, whence;
long	offset;
{
	if (lseek(fd, offset, whence) == -1)
	{
		fprintf(stderr, "%s: error on lseek\n", argv0);
		exit(1);
	}
}

/* read with error checking */
r_read (fd, buf, nbytes)
int	fd, nbytes;
char	*buf;
{
	if (read(fd, buf, nbytes) != nbytes)
	{
		fprintf(stderr, "%s: error on read\n", argv0);
		exit(1);
	}
}
\f


/*
	Print the time in a nice format 
*/
void ptime(secs)
time_t secs;
{
	short	days, hours, minutes;

	secs -= (days = secs / DAYS) * DAYS;
	secs -= (hours = secs / HOURS) * HOURS;
	secs -= (minutes = secs / MINUTES) * MINUTES;

	printf("The system has been up for ");
	if (days != 0)
		printf("%d %s ", days, (days == 1 ? "day" : "days"));
	if (hours != 0)
		printf("%d %s ", hours, (hours == 1 ? "hour" : "hours"));
	if (minutes != 0)
		printf("%d %s ", minutes, (minutes == 1 ? "minute" : "minutes"));
	printf("and %d %s.\n", secs, (secs == 1 ? "second" : "seconds"));
}