New approach to handling time zone specs in REM command.

src/dorem.c

@@ -18,6 +18,7 @@
 #include <string.h>
 
 #include <stdlib.h>
+#include <time.h>
 
 #include "types.h"
 #include "globals.h"
@@ -32,6 +33,79 @@ static int ParseUntil (ParsePtr s, Trigger *t, int type);
 static int ShouldTriggerBasedOnWarn (Trigger const *t, int dse, int *err);
 static int ComputeTrigDuration(TimeTrig const *t);
 
+static int CalledEnterTimezone = 0;
+
+static void ExitTimezone(char const *tz)
+{
+    if (!CalledEnterTimezone) {
+        fprintf(stderr, "ExitTimezone called without EnterTimezone!!!\n");
+        abort();
+    }
+    CalledEnterTimezone = 0;
+    if (!tz || !*tz) {
+        /* Nothing to do */
+        return;
+    }
+    DSEToday = LocalDSEToday;
+    SysTime = LocalSysTime;
+    FromDSE(DSEToday, &CurYear, &CurMon, &CurDay);
+
+    if (DebugFlag & DB_SWITCH_ZONE) {
+        fprintf(stderr, "TZ exit %s: %04d-%02d-%02d %02d:%02d\n", tz,
+                CurYear, CurMon+1, CurDay, SysTime / 60, SysTime % 60);
+    }
+}
+
+
+static void EnterTimezone(char const *tz)
+{
+    struct tm tm;
+    int y, m, d;
+    time_t t;
+
+    if (CalledEnterTimezone) {
+        fprintf(stderr, "EnterTimezone called twice in a row!!!\n");
+        abort();
+    }
+
+    CalledEnterTimezone = 1;
+
+    if (!tz || !*tz) {
+        /* Stay in local timezone */
+        return;
+    }
+
+    FromDSE(LocalDSEToday, &y, &m, &d);
+    tm.tm_sec   = 0;
+    tm.tm_min   = LocalSysTime % 60;
+    tm.tm_hour  = LocalSysTime / 60;
+    tm.tm_mday  = d;
+    tm.tm_mon   = m;
+    tm.tm_year  = y - 1900;
+    tm.tm_wday  = 0;  /* Ignored by mktime */
+    tm.tm_yday  = 0;  /* Ignored by mktime */
+    tm.tm_isdst = -1; /* Information not available */
+
+    t = mktime(&tm);    /* Convert local time to seconds */
+
+    /* Set target timezone */
+    (void) tz_set_tz(tz);
+
+    /* Update our variables */
+    (void) localtime_r(&t, &tm);
+
+    CurDay   = tm.tm_mday;
+    CurMon   = tm.tm_mon;
+    CurYear  = tm.tm_year + 1900;
+    DSEToday = DSE(CurYear, CurMon, CurDay);
+    SysTime  = tm.tm_min + (tm.tm_hour * 60);
+
+    if (DebugFlag & DB_SWITCH_ZONE) {
+        fprintf(stderr, "TZ enter %s: %04d-%02d-%02d %02d:%02d\n", tz,
+                CurYear, CurMon+1, CurDay, SysTime / 60, SysTime % 60);
+    }
+}
+
 void remove_trailing_newlines(DynamicBuffer *buf)
 {
     char *s = (char *) DBufValue(buf) + DBufLen(buf) - 1;

src/funcs.c

@@ -206,7 +206,6 @@ static int FWkdaynum       (func_info *);
 static int FYear           (func_info *);
 
 static int SunStuff        (int rise, double cosz, int dse);
-static int tz_set_tz       (char const *tz);
 
 /* Caches for extracting months, days, years from dates - may
    improve performance slightly. */
@@ -3879,7 +3878,7 @@ static void unsetenv(char const *varname)
 /*  Conversion between different timezones.                    */
 /*                                                             */
 /***************************************************************/
-static int tz_set_tz(char const *tz)
+int tz_set_tz(char const *tz)
 {
     int r;
     if (tz == NULL) {

src/globals.h

@@ -48,7 +48,6 @@ EXTERN  FILE *ErrFp;
 EXTERN  int     DSEToday;
 EXTERN  int     RealToday;
 EXTERN  int     LocalDSEToday;
-EXTERN  int     LocalRealToday;
 EXTERN  int     CurDay;
 EXTERN  int     CurMon;
 EXTERN  int     CurYear;
@@ -104,6 +103,7 @@ EXTERN  INIT(   int     LocalSysTime, -1);
 EXTERN  INIT(   int     ParseUntriggered, 0);
 
 EXTERN  char    const *InitialFile;
+EXTERN  char    const *LocalTimeZone;
 EXTERN  int     FileAccessDate;
 
 EXTERN  INIT(   int     WeekdayOmits, 0);

src/init.c

@@ -179,6 +179,16 @@ void InitRemind(int argc, char const *argv[])
 
     dse = NO_DATE;
 
+    /* Initialize local time zone */
+    LocalTimeZone = getenv("TZ");
+    if (LocalTimeZone) {
+        LocalTimeZone = StrDup(LocalTimeZone);
+        if (!LocalTimeZone) {
+            fprintf(stderr, "Out of memory!\n");
+            exit(1);
+        }
+    }
+
     /* Initialize variable hash table */
     InitVars();
 
@@ -221,7 +231,6 @@ void InitRemind(int argc, char const *argv[])
         fprintf(ErrFp, "\n");
         exit(EXIT_FAILURE);
     }
-    LocalRealToday = RealToday;
     DSEToday = RealToday;
     LocalDSEToday = DSEToday;
     FromDSE(DSEToday, &CurYear, &CurMon, &CurDay);
@@ -648,6 +657,7 @@ void InitRemind(int argc, char const *argv[])
                     case 'q': case 'Q': DebugFlag |= DB_TRANSLATE;   break;
                     case 'n': case 'N': DebugFlag |= DB_NONCONST;    break;
                     case 'u': case 'U': DebugFlag |= DB_UNUSED_VARS; break;
+                    case 'z': case 'Z': DebugFlag |= DB_SWITCH_ZONE; break;
                     default:
                         fprintf(ErrFp, GetErr(M_BAD_DB_FLAG), *(arg-1));
                         fprintf(ErrFp, "\n");
@@ -1148,7 +1158,6 @@ ProcessLongOption(char const *arg)
 
         /* Update RealToday because of TestMode */
         RealToday = SystemDate(&CurYear, &CurMon, &CurDay);
-        LocalRealToday = RealToday;
         DSEToday = RealToday;
         LocalDSEToday = DSEToday;
         FromDSE(DSEToday, &CurYear, &CurMon, &CurDay);

src/main.c

@@ -1439,6 +1439,11 @@ static int DoDebug(ParsePtr p)
             if (val) DebugFlag |= DB_UNUSED_VARS;
             else     DebugFlag &= ~DB_UNUSED_VARS;
             break;
+        case 'z':
+        case 'Z':
+            if (val) DebugFlag |= DB_SWITCH_ZONE;
+            else     DebugFlag &= ~DB_SWITCH_ZONE;
+            break;
         default:
             Wprint(GetErr(M_BAD_DB_FLAG), ch);
             break;

src/protos.h

@@ -296,3 +296,4 @@ void remove_trailing_newlines(DynamicBuffer *buf);
 void set_cloexec(int fd);
 int system_to_stderr(char const *cmd);
 int system1(char const *cmd);
+int tz_set_tz (char const *tz);

src/types.h

@@ -226,6 +226,7 @@ typedef Parser *ParsePtr;  /* Pointer to parser structure */
 #define DB_TRANSLATE    0x100
 #define DB_NONCONST     0x200
 #define DB_UNUSED_VARS  0x400
+#define DB_SWITCH_ZONE  0x800
 
 /* Enumeration of the tokens */
 enum TokTypes