C++ 的 get_time 和 put_time 函数
为了快速的时间格式转换. C++ 引进了 get_time 和 put_time 函数
#include <iostream>
#include<iomanip>
#include<ctime>
int main()
{
std::time_t t = std::time(NULL);
std::tm tm = *std::localtime(&t);
std::cout.imbue(std::locale("CHS"));
std::cout <<std::put_time(&tm,"%Y-%m-%d %H:%M:%S") << '\n';
// std::cout.imbue(std::locale("ja_JP.utf8"));
// std::cout << "ja_JP: " << std::put_time(&tm, "%c %Z") << '\n';
system("pause");
}
| 下面是时间函数格式串的一些特定转义参数: 带E前缀的表示在当地语言环境中的表示...
常用 时:分:秒 %H:%M:%S <==> %T (C++11标准)
年-月-日 %Y:%m:%d <==> %F (C++11标准)
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以下 为 std::get_time 一些转义参数
| Conversion specifier |
Explanation | Writes to fields |
|---|---|---|
| % | matches a literal %. The full conversion specification must be %%. | (none) |
| t | matches any whitespace. | (none) |
| n | matches any whitespace. | (none) |
| Year | ||
| Y | parses full year as a 4 digit decimal number, leading zeroes permitted but not required | tm_year |
| EY | parses year in the alternative representation, e.g.平成23年 (year Heisei 23) which writes 2011 to tm_year in ja_JP locale | tm_year |
| y | parses last 2 digits of year as a decimal number. Range [69,99] results in values 1969 to 1999, range [00,68] results in 2000-2068 | tm_year |
| Oy | parses last 2 digits of year using the alternative numeric system, e.g. 十一 is parsed as 11 in ja_JP locale | tm_year |
| Ey | parses year as offset from locale's alternative calendar period %EC | tm_year |
| C | parses the first 2 digits of year as a decimal number (range [00,99]) | tm_year |
| EC | parses the name of the base year (period) in the locale's alternative representation, e.g. 平成 (Heisei era) in ja_JP | tm_year |
| Month | ||
| b | parses the month name, either full or abbreviated, e.g. Oct | tm_mon |
| h | synonym of b | tm_mon |
| B | synonym of b | tm_mon |
| m | parses the month as a decimal number (range [01,12]), leading zeroes permitted but not required | tm_mon |
| Om | parses the month using the alternative numeric system, e.g. 十二 parses as 12 in ja_JP locale | tm_mon |
| Week | ||
| U | parses the week of the year as a decimal number (Sunday is the first day of the week) (range[00,53]), leading zeroes permitted but not required | tm_year,tm_wday,tm_yday |
| OU | parses the week of the year, as by %U, using the alternative numeric system, e.g. 五十二 parses as 52 in ja_JP locale | tm_year,tm_wday,tm_yday |
| W | parses the week of the year as a decimal number (Monday is the first day of the week) (range[00,53]), leading zeroes permitted but not required | tm_year,tm_wday,tm_yday |
| OW | parses the week of the year, as by %W, using the alternative numeric system, e.g. 五十二 parses as 52 in ja_JP locale | tm_year,tm_wday,tm_yday |
| Day of the year/month | ||
| j | parses day of the year as a decimal number (range [001,366]), leading zeroes permitted but not required | tm_yday |
| d | parses the day of the month as a decimal number (range [01,31]), leading zeroes permitted but not required | tm_mday |
| Od | parses the day of the month using the alternative numeric system, e.g 二十七 parses as 23 in ja_JP locale, leading zeroes permitted but not required | tm_mday |
| e | synonym of d | tm_mday |
| Oe | synonym of Od | tm_mday |
| Day of the week | ||
| a | parses the name of the day of the week, either full or abbreviated, e.g. Fri | tm_wday |
| A | synonym of a | tm_wday |
| w | parses weekday as a decimal number, where Sunday is 0 (range [0-6]) | tm_wday |
| Ow | parses weekday as a decimal number, where Sunday is 0, using the alternative numeric system, e.g. 二 parses as 2 in ja_JP locale | tm_wday |
| Hour, minute, second | ||
| H | parses the hour as a decimal number, 24 hour clock (range [00-23]), leading zeroes permitted but not required | tm_hour |
| OH | parses hour from 24-hour clock using the alternative numeric system, e.g. 十八 parses as 18 in ja_JP locale | tm_hour |
| I | parses hour as a decimal number, 12 hour clock (range [01,12]), leading zeroes permitted but not required | tm_hour |
| OI | parses hour from 12-hour clock using the alternative numeric system, e.g. 六 reads as 06 in ja_JP locale | tm_hour |
| M | parses minute as a decimal number (range [00,59]), leading zeroes permitted but not required | tm_min |
| OM | parses minute using the alternative numeric system, e.g. 二十五 parses as 25 in ja_JP locale | tm_min |
| S | parses second as a decimal number (range [00,60]), leading zeroes permitted but not required | tm_sec |
| OS | parses second using the alternative numeric system, e.g. 二十四 parses as 24 in ja_JP locale | tm_sec |
| Other | ||
| c | parses the locale's standard date and time string format, e.g. Sun Oct 17 04:41:13 2010 (locale dependent) | all |
| Ec | parses the locale's alternative date and time string format, e.g. expecting 平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale | all |
| x | parses the locale's standard date representation | all |
| Ex | parses the locale's alternative date representation, e.g. expecting 平成23年 (year Heisei 23) instead of 2011年 (year 2011) in ja_JP locale | all |
| X | parses the locale's standard time representation | all |
| EX | parses the locale's alternative time representation | all |
| D | equivalent to "%m / %d / %y " | tm_mon,tm_mday,tm_year |
| r | parses locale's standard 12-hour clock time (in POSIX, "%I : %M : %S %p") | tm_hour,tm_min,tm_sec |
| R | equivalent to "%H : %M" | tm_hour,tm_min |
| T | equivalent to "%H : %M : %S" | tm_hour,tm_min,tm_sec |
| p | parses the locale's equivalent of a.m. or p.m. | tm_hour |