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Diffstat (limited to 'usr.bin/pom/pom.c')
| -rw-r--r-- | usr.bin/pom/pom.c | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/usr.bin/pom/pom.c b/usr.bin/pom/pom.c new file mode 100644 index 0000000..5f18bb3 --- /dev/null +++ b/usr.bin/pom/pom.c @@ -0,0 +1,241 @@ +/* + * Copyright (c) 1989, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software posted to USENET. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#if 0 +#ifndef lint +static const char copyright[] = +"@(#) Copyright (c) 1989, 1993\n\ + The Regents of the University of California. All rights reserved.\n"; +#endif /* not lint */ + +#ifndef lint +static const char sccsid[] = "@(#)pom.c 8.1 (Berkeley) 5/31/93"; +#endif /* not lint */ +#endif +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +/* + * Phase of the Moon. Calculates the current phase of the moon. + * Based on routines from `Practical Astronomy with Your Calculator', + * by Duffett-Smith. Comments give the section from the book that + * particular piece of code was adapted from. + * + * -- Keith E. Brandt VIII 1984 + * + */ + +#include <stdio.h> +#include <stdlib.h> +#include <math.h> +#include <string.h> +#include <sysexits.h> +#include <time.h> +#include <unistd.h> + +#ifndef PI +#define PI 3.14159265358979323846 +#endif +#define EPOCH 85 +#define EPSILONg 279.611371 /* solar ecliptic long at EPOCH */ +#define RHOg 282.680403 /* solar ecliptic long of perigee at EPOCH */ +#define ECCEN 0.01671542 /* solar orbit eccentricity */ +#define lzero 18.251907 /* lunar mean long at EPOCH */ +#define Pzero 192.917585 /* lunar mean long of perigee at EPOCH */ +#define Nzero 55.204723 /* lunar mean long of node at EPOCH */ +#define isleap(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0) + +static void adj360(double *); +static double dtor(double); +static double potm(double); +static void usage(char *progname); + +int +main(int argc, char **argv) +{ + time_t tt; + struct tm GMT, tmd; + double days, today, tomorrow; + int ch, cnt, pflag = 0; + char *odate = NULL, *otime = NULL; + char *progname = argv[0]; + + while ((ch = getopt(argc, argv, "d:pt:")) != -1) + switch (ch) { + case 'd': + odate = optarg; + break; + case 'p': + pflag = 1; + break; + case 't': + otime = optarg; + break; + default: + usage(progname); + } + + argc -= optind; + argv += optind; + + if (argc) + usage(progname); + + /* Adjust based on users preferences */ + time(&tt); + if (otime != NULL || odate != NULL) { + /* Save today in case -d isn't specified */ + localtime_r(&tt, &tmd); + + if (odate != NULL) { + tmd.tm_year = strtol(odate, NULL, 10) - 1900; + tmd.tm_mon = strtol(odate + 5, NULL, 10) - 1; + tmd.tm_mday = strtol(odate + 8, NULL, 10); + /* Use midnight as the middle of the night */ + tmd.tm_hour = 0; + tmd.tm_min = 0; + tmd.tm_sec = 0; + } + if (otime != NULL) { + tmd.tm_hour = strtol(otime, NULL, 10); + tmd.tm_min = strtol(otime + 3, NULL, 10); + tmd.tm_sec = strtol(otime + 6, NULL, 10); + } + tt = mktime(&tmd); + } + + gmtime_r(&tt, &GMT); + days = (GMT.tm_yday + 1) + ((GMT.tm_hour + + (GMT.tm_min / 60.0) + (GMT.tm_sec / 3600.0)) / 24.0); + for (cnt = EPOCH; cnt < GMT.tm_year; ++cnt) + days += isleap(1900 + cnt) ? 366 : 365; + today = potm(days) + .5; + if (pflag) { + (void)printf("%1.0f\n", today); + return (0); + } + (void)printf("The Moon is "); + if ((int)today == 100) + (void)printf("Full\n"); + else if (!(int)today) + (void)printf("New\n"); + else { + tomorrow = potm(days + 1); + if ((int)today == 50) + (void)printf("%s\n", tomorrow > today ? + "at the First Quarter" : "at the Last Quarter"); + else { + (void)printf("%s ", tomorrow > today ? + "Waxing" : "Waning"); + if (today > 50) + (void)printf("Gibbous (%1.0f%% of Full)\n", + today); + else if (today < 50) + (void)printf("Crescent (%1.0f%% of Full)\n", + today); + } + } + + return 0; +} + +/* + * potm -- + * return phase of the moon + */ +static double +potm(double days) +{ + double N, Msol, Ec, LambdaSol, l, Mm, Ev, Ac, A3, Mmprime; + double A4, lprime, V, ldprime, D, Nm; + + N = 360 * days / 365.2422; /* sec 42 #3 */ + adj360(&N); + Msol = N + EPSILONg - RHOg; /* sec 42 #4 */ + adj360(&Msol); + Ec = 360 / PI * ECCEN * sin(dtor(Msol)); /* sec 42 #5 */ + LambdaSol = N + Ec + EPSILONg; /* sec 42 #6 */ + adj360(&LambdaSol); + l = 13.1763966 * days + lzero; /* sec 61 #4 */ + adj360(&l); + Mm = l - (0.1114041 * days) - Pzero; /* sec 61 #5 */ + adj360(&Mm); + Nm = Nzero - (0.0529539 * days); /* sec 61 #6 */ + adj360(&Nm); + Ev = 1.2739 * sin(dtor(2*(l - LambdaSol) - Mm)); /* sec 61 #7 */ + Ac = 0.1858 * sin(dtor(Msol)); /* sec 61 #8 */ + A3 = 0.37 * sin(dtor(Msol)); + Mmprime = Mm + Ev - Ac - A3; /* sec 61 #9 */ + Ec = 6.2886 * sin(dtor(Mmprime)); /* sec 61 #10 */ + A4 = 0.214 * sin(dtor(2 * Mmprime)); /* sec 61 #11 */ + lprime = l + Ev + Ec - Ac + A4; /* sec 61 #12 */ + V = 0.6583 * sin(dtor(2 * (lprime - LambdaSol))); /* sec 61 #13 */ + ldprime = lprime + V; /* sec 61 #14 */ + D = ldprime - LambdaSol; /* sec 63 #2 */ + return(50 * (1 - cos(dtor(D)))); /* sec 63 #3 */ +} + +/* + * dtor -- + * convert degrees to radians + */ +static double +dtor(double deg) +{ + + return(deg * PI / 180); +} + +/* + * adj360 -- + * adjust value so 0 <= deg <= 360 + */ +static void +adj360(double *deg) +{ + + for (;;) + if (*deg < 0) + *deg += 360; + else if (*deg > 360) + *deg -= 360; + else + break; +} + +static void +usage(char *progname) +{ + + fprintf(stderr, "Usage: %s [-p] [-d yyyy.mm.dd] [-t hh:mm:ss]\n", + progname); + exit(EX_USAGE); +} |
