1 #ifdef sgi 2 /* 3 * timetrim.c 4 * 5 * "timetrim" allows setting and adjustment of the system clock frequency 6 * trim parameter on Silicon Graphics machines. The trim value native 7 * units are nanoseconds per second (10**-9), so a trim value of 1 makes 8 * the system clock step ahead 1 nanosecond more per second than a value 9 * of zero. Xntpd currently uses units of 2**-20 secs for its frequency 10 * offset (drift) values; to convert to a timetrim value, multiply by 11 * 1E9 / 2**20 (about 954). 12 * 13 * "timetrim" with no arguments just prints out the current kernel value. 14 * With a numeric argument, the kernel value is set to the supplied value. 15 * The "-i" flag causes the supplied value to be added to the kernel value. 16 * The "-n" option causes all input and output to be in xntpd units rather 17 * than timetrim native units. 18 * 19 * Note that there is a limit of +-3000000 (0.3%) on the timetrim value 20 * which is (silently?) enforced by the kernel. 21 * 22 */ 23 24 #ifdef HAVE_CONFIG_H 25 #include <config.h> 26 #endif 27 28 #include <stdio.h> 29 #include <ctype.h> 30 #include <stdlib.h> 31 #ifdef HAVE_SYS_SYSSGI_H 32 # include <sys/syssgi.h> 33 #endif 34 35 #define abs(X) (((X) < 0) ? -(X) : (X)) 36 #define USAGE "usage: timetrim [-n] [[-i] value]\n" 37 #define SGITONTP(X) ((double)(X) * 1048576.0/1.0e9) 38 #define NTPTOSGI(X) ((long)((X) * 1.0e9/1048576.0)) 39 40 int 41 main( 42 int argc, 43 char *argv[] 44 ) 45 { 46 char *rem; 47 int incremental = 0, ntpunits = 0; 48 long timetrim; 49 double value; 50 51 while (--argc && **++argv == '-' && isalpha((int)argv[0][1])) { 52 switch (argv[0][1]) { 53 case 'i': 54 incremental++; 55 break; 56 case 'n': 57 ntpunits++; 58 break; 59 default: 60 fprintf(stderr, USAGE); 61 exit(1); 62 } 63 } 64 65 if (syssgi(SGI_GETTIMETRIM, &timetrim) < 0) { 66 perror("syssgi"); 67 exit(2); 68 } 69 70 if (argc == 0) { 71 if (ntpunits) 72 fprintf(stdout, "%0.5f\n", SGITONTP(timetrim)); 73 else 74 fprintf(stdout, "%ld\n", timetrim); 75 } else if (argc != 1) { 76 fprintf(stderr, USAGE); 77 exit(1); 78 } else { 79 value = strtod(argv[0], &rem); 80 if (*rem != '\0') { 81 fprintf(stderr, USAGE); 82 exit(1); 83 } 84 if (ntpunits) 85 value = NTPTOSGI(value); 86 if (incremental) 87 timetrim += value; 88 else 89 timetrim = value; 90 if (syssgi(SGI_SETTIMETRIM, timetrim) < 0) { 91 perror("syssgi"); 92 exit(2); 93 } 94 } 95 return 0; 96 } 97 #endif 98