simplify localtime code

Signed-off-by: Rosen Penev <[email protected]>

app/actions.cpp

@@ -75,9 +75,6 @@ int str2Tm(const std::string& timeStr, tm* tm);
 //! Convert a localtime to a string "YYYY:MM:DD HH:MI:SS", "" on error
 std::string time2Str(time_t time);
 
-//! Convert a tm structure to a string "YYYY:MM:DD HH:MI:SS", "" on error
-std::string tm2Str(const tm* tm);
-
 /*!
   @brief Copy metadata from source to target according to Params::copyXyz
 
@@ -630,7 +627,7 @@ int Rename::run(const std::string& path) {
       std::cerr << _("Image file creation timestamp not set in the file") << " " << path << "\n";
       return 1;
     }
-    tm tm;
+    std::tm tm;
     if (str2Tm(v, &tm) != 0) {
       std::cerr << _("Failed to parse timestamp") << " `" << v << "' " << _("in the file") << " " << path << "\n";
       return 1;
@@ -1394,7 +1391,7 @@ int Adjust::adjustDateTime(Exiv2::ExifData& exifData, const std::string& key, co
       std::cout << " " << adjustment_ << _("s");
     }
   }
-  tm tm;
+  std::tm tm;
   if (str2Tm(timeStr, &tm) != 0) {
     if (Params::instance().verbose_)
       std::cout << '\n';
@@ -1645,21 +1642,20 @@ int str2Tm(const std::string& timeStr, tm* tm) {
 }  // str2Tm
 
 std::string time2Str(time_t time) {
-  auto tm = localtime(&time);
-  return tm2Str(tm);
-}  // time2Str
-
-std::string tm2Str(const tm* tm) {
+  std::tm r;
+#ifdef _WIN32
+  auto tm = localtime_s(&r, &time) ? nullptr : &r;
+#else
+  auto tm = localtime_r(&time, &r);
+#endif
   if (!tm)
     return "";
 
-  std::ostringstream os;
-  os << std::setfill('0') << tm->tm_year + 1900 << ":" << std::setw(2) << tm->tm_mon + 1 << ":" << std::setw(2)
-     << tm->tm_mday << " " << std::setw(2) << tm->tm_hour << ":" << std::setw(2) << tm->tm_min << ":" << std::setw(2)
-     << tm->tm_sec;
-
-  return os.str();
-}  // tm2Str
+  const size_t m = 20;
+  char s[m];
+  std::strftime(s, m, "%Y:%m:%d %T", tm);
+  return s;
+}  // time2Str
 
 std::string temporaryPath() {
   static int count = 0;

samples/geotag.cpp

@@ -373,34 +373,17 @@ time_t parseTime(const char* arg, bool bAdjust) {
 
 // West of GMT is negative (PDT = Pacific Daylight = -07:00 == -25200 seconds
 int timeZoneAdjust() {
-  [[maybe_unused]] time_t now = time(nullptr);
-  int offset;
-
 #if defined(_WIN32)
   TIME_ZONE_INFORMATION TimeZoneInfo;
   GetTimeZoneInformation(&TimeZoneInfo);
-  offset = -(TimeZoneInfo.Bias + TimeZoneInfo.DaylightBias * 60);
-#elif defined(__CYGWIN__)
-  struct tm lcopy = *localtime(&now);
-  time_t gmt = timegm(&lcopy);  // timegm modifies lcopy
-  offset = (int)(((long signed int)gmt) - ((long signed int)now));
-#elif defined(OS_SOLARIS) || defined(__sun__)
-  struct tm local = *localtime(&now);
-  time_t local_tt = mktime(&local);
-  time_t time_gmt = mktime(gmtime(&now));
-  offset = time_gmt - local_tt;
+  return -(TimeZoneInfo.Bias + TimeZoneInfo.DaylightBias * 60);
 #else
-  struct tm local = *localtime(&now);
-  offset = local.tm_gmtoff;
-
-#ifdef EXIV2_DEBUG_MESSAGES
-  struct tm utc = *gmtime(&now);
-  printf("utc  :  offset = %6d dst = %d time = %s", 0, utc.tm_isdst, asctime(&utc));
-  printf("local:  offset = %6d dst = %d time = %s", offset, local.tm_isdst, asctime(&local));
-  printf("timeZoneAdjust = %6d\n", offset);
-#endif
+  std::tm r;
+
+  auto now = std::time(nullptr);
+  auto local = localtime_r(&now, &r);
+  return local->tm_gmtoff;
 #endif
-  return offset;
 }
 
 std::string getExifTime(const time_t t) {

src/crwimage_int.cpp

@@ -728,22 +728,22 @@ void CrwMap::decode0x180e(const CiffComponent& ciffComponent, const CrwMapping*
   ULongValue v;
   v.read(ciffComponent.pData(), 8, byteOrder);
   time_t t = v.value_.at(0);
-  tm r;
+  std::tm r;
 #ifdef _WIN32
   auto tm = localtime_s(&r, &t) ? nullptr : &r;
 #else
   auto tm = localtime_r(&t, &r);
 #endif
-  if (tm) {
-    const size_t m = 20;
-    char s[m];
-    std::strftime(s, m, "%Y:%m:%d %H:%M:%S", tm);
-
-    ExifKey key(pCrwMapping->tag_, Internal::groupName(pCrwMapping->ifdId_));
-    AsciiValue value;
-    value.read(std::string(s));
-    image.exifData().add(key, &value);
-  }
+  if (!tm)
+    return;
+  const size_t m = 20;
+  char s[m];
+  std::strftime(s, m, "%Y:%m:%d %T", tm);
+
+  ExifKey key(pCrwMapping->tag_, Internal::groupName(pCrwMapping->ifdId_));
+  AsciiValue value;
+  value.read(s);
+  image.exifData().add(key, &value);
 }  // CrwMap::decode0x180e
 
 void CrwMap::decode0x1810(const CiffComponent& ciffComponent, const CrwMapping* pCrwMapping, Image& image,
@@ -920,7 +920,7 @@ void CrwMap::encode0x180e(const Image& image, const CrwMapping& pCrwMapping, Cif
   time_t t = 0;
   const ExifKey key(pCrwMapping.tag_, Internal::groupName(pCrwMapping.ifdId_));
   if (auto ed = image.exifData().findKey(key); ed != image.exifData().end()) {
-    tm tm = {};
+    std::tm tm = {};
     if (exifTime(ed->toString().c_str(), &tm) == 0) {
       t = ::mktime(&tm);
     }