| 1 | /* |
| 2 | * Copyright (c) 1980 Regents of the University of California. |
| 3 | * All rights reserved. The Berkeley software License Agreement |
| 4 | * specifies the terms and conditions for redistribution. |
| 5 | */ |
| 6 | |
| 7 | #ifndef lint |
| 8 | static char sccsid[] = "@(#)timezone.c 5.1 (Berkeley) %G%"; |
| 9 | #endif not lint |
| 10 | |
| 11 | /* |
| 12 | * The arguments are the number of minutes of time |
| 13 | * you are westward from Greenwich and whether DST is in effect. |
| 14 | * It returns a string |
| 15 | * giving the name of the local timezone. |
| 16 | * |
| 17 | * Sorry, I don't know all the names. |
| 18 | */ |
| 19 | |
| 20 | static struct zone { |
| 21 | int offset; |
| 22 | char *stdzone; |
| 23 | char *dlzone; |
| 24 | } zonetab[] = { |
| 25 | -1*60, "MET", "MET DST", /* Middle European */ |
| 26 | -2*60, "EET", "EET DST", /* Eastern European */ |
| 27 | 4*60, "AST", "ADT", /* Atlantic */ |
| 28 | 5*60, "EST", "EDT", /* Eastern */ |
| 29 | 6*60, "CST", "CDT", /* Central */ |
| 30 | 7*60, "MST", "MDT", /* Mountain */ |
| 31 | 8*60, "PST", "PDT", /* Pacific */ |
| 32 | #ifdef notdef |
| 33 | /* there's no way to distinguish this from WET */ |
| 34 | 0, "GMT", 0, /* Greenwich */ |
| 35 | #endif |
| 36 | 0*60, "WET", "WET DST", /* Western European */ |
| 37 | -10*60, "EST", "EST", /* Aust: Eastern */ |
| 38 | -10*60+30, "CST", "CST", /* Aust: Central */ |
| 39 | -8*60, "WST", 0, /* Aust: Western */ |
| 40 | -1 |
| 41 | }; |
| 42 | |
| 43 | char *timezone(zone, dst) |
| 44 | { |
| 45 | register struct zone *zp; |
| 46 | static char czone[10]; |
| 47 | char *sign; |
| 48 | register char *p, *q; |
| 49 | char *getenv(), *index(); |
| 50 | |
| 51 | if (p = getenv("TZNAME")) { |
| 52 | if (q = index(p, ',')) { |
| 53 | if (dst) |
| 54 | return(++q); |
| 55 | else { |
| 56 | *q = '\0'; |
| 57 | strncpy(czone, p, sizeof(czone)-1); |
| 58 | czone[sizeof(czone)-1] = '\0'; |
| 59 | *q = ','; |
| 60 | return (czone); |
| 61 | } |
| 62 | } |
| 63 | return(p); |
| 64 | } |
| 65 | for (zp=zonetab; zp->offset!=-1; zp++) |
| 66 | if (zp->offset==zone) { |
| 67 | if (dst && zp->dlzone) |
| 68 | return(zp->dlzone); |
| 69 | if (!dst && zp->stdzone) |
| 70 | return(zp->stdzone); |
| 71 | } |
| 72 | if (zone<0) { |
| 73 | zone = -zone; |
| 74 | sign = "+"; |
| 75 | } else |
| 76 | sign = "-"; |
| 77 | sprintf(czone, "GMT%s%d:%02d", sign, zone/60, zone%60); |
| 78 | return(czone); |
| 79 | } |