86 lines
2.1 KiB
C
86 lines
2.1 KiB
C
/*
|
|
* timetrim.c
|
|
*
|
|
* "timetrim" allows setting and adjustment of the system clock frequency
|
|
* trim parameter on Silicon Graphics machines. The trim value native
|
|
* units are nanoseconds per second (10**-9), so a trim value of 1 makes
|
|
* the system clock step ahead 1 nanosecond more per second than a value
|
|
* of zero. Xntpd currently uses units of 2**-20 secs for its frequency
|
|
* offset (drift) values; to convert to a timetrim value, multiply by
|
|
* 1E9 / 2**20 (about 954).
|
|
*
|
|
* "timetrim" with no arguments just prints out the current kernel value.
|
|
* With a numeric argument, the kernel value is set to the supplied value.
|
|
* The "-i" flag causes the supplied value to be added to the kernel value.
|
|
* The "-n" option causes all input and output to be in xntpd units rather
|
|
* than timetrim native units.
|
|
*
|
|
* Note that there is a limit of +-3000000 (0.3%) on the timetrim value
|
|
* which is (silently?) enforced by the kernel.
|
|
*
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <ctype.h>
|
|
#include <sys/syssgi.h>
|
|
|
|
#define abs(X) (((X) < 0) ? -(X) : (X))
|
|
#define USAGE "usage: timetrim [-n] [[-i] value]\n"
|
|
#define SGITONTP(X) ((double)(X) * 1048576.0/1.0e9)
|
|
#define NTPTOSGI(X) ((LONG)((X) * 1.0e9/1048576.0))
|
|
|
|
main(argc, argv)
|
|
int argc;
|
|
char **argv;
|
|
{
|
|
char *rem;
|
|
int c, incremental = 0, ntpunits = 0;
|
|
LONG timetrim;
|
|
double value, strtod();
|
|
|
|
while (--argc && **++argv == '-' && isalpha(argv[0][1])) {
|
|
switch (argv[0][1]) {
|
|
case 'i':
|
|
incremental++;
|
|
break;
|
|
case 'n':
|
|
ntpunits++;
|
|
break;
|
|
default:
|
|
fprintf(stderr, USAGE);
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
if (syssgi(SGI_GETTIMETRIM, &timetrim) < 0) {
|
|
perror("syssgi");
|
|
exit(2);
|
|
}
|
|
|
|
if (argc == 0) {
|
|
if (ntpunits)
|
|
fprintf(stdout, "%0.5lf\n", SGITONTP(timetrim));
|
|
else
|
|
fprintf(stdout, "%ld\n", timetrim);
|
|
} else if (argc != 1) {
|
|
fprintf(stderr, USAGE);
|
|
exit(1);
|
|
} else {
|
|
value = strtod(argv[0], &rem);
|
|
if (*rem != '\0') {
|
|
fprintf(stderr, USAGE);
|
|
exit(1);
|
|
}
|
|
if (ntpunits)
|
|
value = NTPTOSGI(value);
|
|
if (incremental)
|
|
timetrim += value;
|
|
else
|
|
timetrim = value;
|
|
if (syssgi(SGI_SETTIMETRIM, timetrim) < 0) {
|
|
perror("syssgi");
|
|
exit(2);
|
|
}
|
|
}
|
|
}
|