12 int calculateRelativeHumidity(int temp, int dew) {
14 rh = 100.0 * powf ((112 - (0.1 * temp)+dew ) / (112 + (0.9 * temp)), 8);
18 int calculateWindChill(int temperatureC, int windKn) {
19 double windKmh = knTokph(windKn);
20 return (int)(13.112+0.6215*temperatureC - 11.37*powf(windKmh,.16) + 0.3965*temperatureC*powf(windKmh,.16) );
23 int knTokph(int knSpeed ){
24 return (knSpeed * 1.852);
27 const char *calculateWindDirectionString(int degree) {
30 } else if (degree < 67.5){
32 } else if (degree < 112.5) {
34 } else if (degree < 157.5) {
36 } else if (degree < 202.5){
38 } else if (degree < 247.5) {
40 } else if (degree < 292.5) {
42 } else if (degree < 337.5){
48 const char*calculateShortWindDirectionString(int degree){
51 } else if (degree < 67.5){
53 } else if (degree < 112.5) {
55 } else if (degree < 157.5) {
57 } else if (degree < 202.5){
59 } else if (degree < 247.5) {
61 } else if (degree < 292.5) {
63 } else if (degree < 337.5){
70 void ftpData(void *userData, const char *data, int len)
83 // try three times if it fails
87 /* this happens too often, so i'll leave it commented fprintf(stderr, "METAR update failed for some reason, retry %i\n", tries); */
88 sleep(15); /* give it some time in case the server is busy or down */
91 if ( strlen(metar_station) != 8 ){
92 fprintf(stderr,"You didn't supply a valid station code\n");
95 if (metar_server == NULL)
96 metar_server = strdup("weather.noaa.gov");
97 if (metar_path == NULL)
98 metar_path = strdup("/data/observations/metar/stations");
102 res = connectFtp(metar_server, 0);
104 fprintf(stderr, "Couldn't connect to %s\n", metar_server);
107 res = changeFtpDirectory(metar_path);
109 fprintf(stderr, "Metar update failed (couldn't CWD to %s)\n", metar_path);
115 "Metar update failed\n");
118 if (getFtp(ftpData, NULL, metar_station) < 0) {
119 fprintf(stderr, "Failed to get file %s\n", metar_station);
124 dcdNetMETAR(line, &data);
134 } while (ftp_ok == 0 && tries < 3);
138 static pthread_t thread1;
140 void update_metar() {
144 iret1 = pthread_create( &thread1, NULL, fetch_ftp, NULL);
146 else if (status == 2) { /* thread is still running. what else can we do? */
150 pthread_join( thread1, NULL);
152 iret1 = pthread_create( &thread1, NULL, fetch_ftp, NULL);