Add timezone switch

[i3/i3status] / src / print_time.c

diff --git a/src/print_time.c b/src/print_time.c
index 00a619636decd905bf9b9e40108c055df165bbb1..c124e1a7223624366ab2f4acce716eb967175ef4 100644 (file)
--- a/src/print_time.c
+++ b/src/print_time.c
@@ -1,18 +1,88 @@
-// vim:ts=8:expandtab
+// vim:ts=4:sw=4:expandtab
 #include <time.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdbool.h>
+#include <locale.h>
 #include <yajl/yajl_gen.h>
 #include <yajl/yajl_version.h>
 
 #include "i3status.h"
 
-void print_time(yajl_gen json_gen, char *buffer, const char *format, struct tm *current_tm) {
-        char *outwalk = buffer;
-        if (current_tm == NULL)
-                return;
-        /* Get date & time */
-        outwalk += strftime(outwalk, 4095, format, current_tm);
-        *outwalk = '\0';
-        OUTPUT_FULL_TEXT(buffer);
+static bool local_timezone_init = false;
+static const char *local_timezone = NULL;
+static const char *current_timezone = NULL;
+
+void set_timezone(const char *tz) {
+    if (!local_timezone_init) {
+        /* First call, initialize. */
+        local_timezone = getenv("TZ");
+        local_timezone_init = true;
+    }
+    if (tz == NULL || tz[0] == '\0') {
+        /* User wants localtime. */
+        tz = local_timezone;
+    }
+    if (tz != current_timezone) {
+        if (tz) {
+            setenv("TZ", tz, 1);
+        } else {
+            unsetenv("TZ");
+        }
+        current_timezone = tz;
+    }
+    tzset();
+}
+
+void print_time(yajl_gen json_gen, char *buffer, const char *title, const char *format, const char *tz, const char *locale, const char *format_time, bool only_when_tz_different, time_t t) {
+    const char *walk;
+    char *outwalk = buffer;
+    struct tm local_tm, tm;
+    char timebuf[1024];
+
+    if (title != NULL)
+        INSTANCE(title);
+
+    set_timezone(NULL);
+    localtime_r(&t, &local_tm);
+
+    set_timezone(tz);
+    localtime_r(&t, &tm);
+
+    // When only_when_tz_different is true, compare local and target time to display only if different
+    time_t local_t = mktime(&local_tm);
+    double diff = difftime(local_t, t);
+    if (only_when_tz_different && diff == 0.0) {
+        return;
+    }
+
+    if (locale != NULL) {
+        setlocale(LC_ALL, locale);
+    }
+
+    if (format_time == NULL) {
+        strftime(timebuf, sizeof(timebuf), format, &tm);
+        maybe_escape_markup(timebuf, &outwalk);
+    } else {
+        for (walk = format; *walk != '\0'; walk++) {
+            if (*walk != '%') {
+                *(outwalk++) = *walk;
+
+            } else if (BEGINS_WITH(walk + 1, "time")) {
+                strftime(timebuf, sizeof(timebuf), format_time, &tm);
+                maybe_escape_markup(timebuf, &outwalk);
+                walk += strlen("time");
+
+            } else {
+                *(outwalk++) = '%';
+            }
+        }
+    }
+
+    if (locale != NULL) {
+        setlocale(LC_ALL, "");
+    }
+
+    *outwalk = '\0';
+    OUTPUT_FULL_TEXT(buffer);
 }