/* * Copyright (C) 2010 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #define LOG_TAG "MtpUtils" #include <stdio.h> #include <time.h> #include "MtpUtils.h" namespace android { /* DateTime strings follow a compatible subset of the definition found in ISO 8601, and take the form of a Unicode string formatted as: "YYYYMMDDThhmmss.s". In this representation, YYYY shall be replaced by the year, MM replaced by the month (01-12), DD replaced by the day (01-31), T is a constant character 'T' delimiting time from date, hh is replaced by the hour (00-23), mm is replaced by the minute (00-59), and ss by the second (00-59). The ".s" is optional, and represents tenths of a second. This is followed by a UTC offset given as "[+-]zzzz" or the literal "Z", meaning UTC. */ bool parseDateTime(const char* dateTime, time_t& outSeconds) { int year, month, day, hour, minute, second; if (sscanf(dateTime, "%04d%02d%02dT%02d%02d%02d", &year, &month, &day, &hour, &minute, &second) != 6) return false; // skip optional tenth of second const char* tail = dateTime + 15; if (tail[0] == '.' && tail[1]) tail += 2; // FIXME: "Z" means UTC, but non-"Z" doesn't mean local time. // It might be that you're in Asia/Seoul on vacation and your Android // device has noticed this via the network, but your camera was set to // America/Los_Angeles once when you bought it and doesn't know where // it is right now, so the camera says "20160106T081700-0800" but we // just ignore the "-0800" and assume local time which is actually "+0900". // I think to support this (without switching to Java or using icu4c) // you'd want to always use timegm(3) and then manually add/subtract // the UTC offset parsed from the string (taking care of wrapping). // mktime(3) ignores the tm_gmtoff field, so you can't let it do the work. bool useUTC = (tail[0] == 'Z'); struct tm tm = {}; tm.tm_sec = second; tm.tm_min = minute; tm.tm_hour = hour; tm.tm_mday = day; tm.tm_mon = month - 1; // mktime uses months in 0 - 11 range tm.tm_year = year - 1900; tm.tm_isdst = -1; outSeconds = useUTC ? timegm(&tm) : mktime(&tm); return true; } void formatDateTime(time_t seconds, char* buffer, int bufferLength) { struct tm tm; localtime_r(&seconds, &tm); snprintf(buffer, bufferLength, "%04d%02d%02dT%02d%02d%02d", tm.tm_year + 1900, tm.tm_mon + 1, // localtime_r uses months in 0 - 11 range tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec); } } // namespace android