usr/src/lib/libbc/libc/sys/common/gettimeofday.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 1995 Sun Microsystems, Inc. All rights reserved.
  24  */
  25
  26 #ident  "%Z%%M% %I%     %E% SMI"
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <time.h>
  31 #include <tzfile.h>
  32 #include <sys/time.h>
  33
  34 static int get_tzp_info(void);
  35 extern long _timezone, _altzone;        /* from the base libc */
  36
  37
  38 /*
  39  * The second parameter to gettimeofday() did not work correctly on
  40  * 4.x, and it was documented that localtime() should be used instead.
  41  * This is an attempt to provide correctly what 4.x meant to do. There
  42  * are shortcomings, however. See notes for DST_RUM and DST_AUSTALT.
  43  */
  44
  45 int
  46 gettimeofday(tp, tzp)
  47 struct timeval *tp;
  48 struct timezone *tzp;
  49 {
  50         int ret = 0;
  51
  52         if (tp != NULL)
  53                 if ((ret = _gettimeofday(tp)) == -1)
  54                         maperror();
  55
  56         /*
  57          * We should call localtime() with the current time and
  58          * set tz_minuteswest to _altzone/SECSPERMIN if tm_isdst
  59          * is set. But we want to be bug-for-bug compatible with
  60          * 4.x, which would never adjust for DST. Futher comments
  61          * are in get_tzp_info().
  62          */
  63         if (tzp != NULL) {
  64                 _tzset();
  65                 tzp->tz_dsttime = get_tzp_info();
  66                 tzp->tz_minuteswest = _timezone/SECSPERMIN;
  67         }
  68
  69         return(ret);
  70 }
  71
  72 static int
  73 get_tzp_info()
  74 {
  75         char    *zonename = getenv("TZ");
  76
  77         if ((zonename == NULL) || (*zonename == '\0'))
  78                 return (DST_NONE);
  79
  80         if ((strncmp(zonename, "US/", 3) == 0) ||
  81             (strcmp(zonename, "PST8PDT") == 0) ||
  82             (strcmp(zonename, "MST7MDT") == 0) ||
  83             (strcmp(zonename, "CST6CDT") == 0) ||
  84             (strcmp(zonename, "EST5EDT") == 0) ||
  85             (strncmp(zonename, "America/", 8) == 0))
  86                 return (DST_USA);
  87
  88         if (strncmp(zonename, "Australia/", 10) == 0)
  89                 return (DST_AUST);
  90
  91         if (strcmp(zonename, "WET") == 0)
  92                 return (DST_WET);
  93
  94         if (strcmp(zonename, "MET") == 0)
  95                 return (DST_MET);
  96
  97         if (strcmp(zonename, "EET") == 0)
  98                 return (DST_EET);
  99
 100         if (strncmp(zonename, "Canada/", 7) == 0)
 101                 return (DST_CAN);
 102
 103         if ((strcmp(zonename, "GB") == 0) ||
 104             (strcmp(zonename, "GB-Eire") == 0))
 105                 return (DST_GB);
 106
 107         /*
 108          * what's the corresponding DST_RUM: Rumanian DST?
 109          * There was not Rumanian timezone on 4.x.
 110          */
 111
 112         if (strcmp(zonename, "Turkey") == 0)
 113                 return (DST_TUR);
 114
 115         /*
 116          * How do we differentiate between DST_AUST and DST_AUSTALT?
 117          * It seems that all of our current Australia timezones do
 118          * not have the 1986 shift, so we never will return DST_AUSTALT.
 119          */
 120
 121         return (DST_NONE);
 122 }