diff options
Diffstat (limited to 'lib/libc/gen/timezone.c')
| -rw-r--r-- | lib/libc/gen/timezone.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/lib/libc/gen/timezone.c b/lib/libc/gen/timezone.c new file mode 100644 index 0000000..5f0fa66 --- /dev/null +++ b/lib/libc/gen/timezone.c @@ -0,0 +1,129 @@ +/* + * Copyright (c) 1987, 1993 + * The Regents of the University of California. All rights reserved. + * + * 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. + * 4. 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 defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "@(#)timezone.c 8.1 (Berkeley) 6/4/93"; +#endif /* LIBC_SCCS and not lint */ +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/types.h> +#include <sys/time.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#define TZ_MAX_CHARS 255 + +char *_tztab(int, int); + +/* + * timezone -- + * The arguments are the number of minutes of time you are westward + * from Greenwich and whether DST is in effect. It returns a string + * giving the name of the local timezone. Should be replaced, in the + * application code, by a call to localtime. + */ + +static char czone[TZ_MAX_CHARS]; /* space for zone name */ + +char * +timezone(int zone, int dst) +{ + char *beg, + *end; + + if ( (beg = getenv("TZNAME")) ) { /* set in environment */ + if ( (end = index(beg, ',')) ) {/* "PST,PDT" */ + if (dst) + return(++end); + *end = '\0'; + (void)strncpy(czone,beg,sizeof(czone) - 1); + czone[sizeof(czone) - 1] = '\0'; + *end = ','; + return(czone); + } + return(beg); + } + return(_tztab(zone,dst)); /* default: table or created zone */ +} + +static struct zone { + int offset; + char *stdzone; + char *dlzone; +} zonetab[] = { + {-1*60, "MET", "MET DST"}, /* Middle European */ + {-2*60, "EET", "EET DST"}, /* Eastern European */ + {4*60, "AST", "ADT"}, /* Atlantic */ + {5*60, "EST", "EDT"}, /* Eastern */ + {6*60, "CST", "CDT"}, /* Central */ + {7*60, "MST", "MDT"}, /* Mountain */ + {8*60, "PST", "PDT"}, /* Pacific */ +#ifdef notdef + /* there's no way to distinguish this from WET */ + {0, "GMT", 0}, /* Greenwich */ +#endif + {0*60, "WET", "WET DST"}, /* Western European */ + {-10*60,"EST", "EST"}, /* Aust: Eastern */ + {-10*60+30,"CST", "CST"}, /* Aust: Central */ + {-8*60, "WST", 0}, /* Aust: Western */ + {-1} +}; + +/* + * _tztab -- + * check static tables or create a new zone name; broken out so that + * we can make a guess as to what the zone is if the standard tables + * aren't in place in /etc. DO NOT USE THIS ROUTINE OUTSIDE OF THE + * STANDARD LIBRARY. + */ +char * +_tztab(int zone, int dst) +{ + struct zone *zp; + char sign; + + for (zp = zonetab; zp->offset != -1;++zp) /* static tables */ + if (zp->offset == zone) { + if (dst && zp->dlzone) + return(zp->dlzone); + if (!dst && zp->stdzone) + return(zp->stdzone); + } + + if (zone < 0) { /* create one */ + zone = -zone; + sign = '+'; + } + else + sign = '-'; + (void)snprintf(czone, sizeof(czone), + "GMT%c%d:%02d",sign,zone / 60,zone % 60); + return(czone); +} |
