Difference between revisions of "cpp/chrono/c/ctime"
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This function returns a pointer to static data and is not thread-safe. In addition, it modifies the static {{lc|std::tm}} object which may be shared with {{lc|std::gmtime}} and {{lc|std::localtime}}. POSIX marks this function obsolete and recommends {{lc|std::strftime}} instead. | This function returns a pointer to static data and is not thread-safe. In addition, it modifies the static {{lc|std::tm}} object which may be shared with {{lc|std::gmtime}} and {{lc|std::localtime}}. POSIX marks this function obsolete and recommends {{lc|std::strftime}} instead. | ||
| − | The behavior may be undefined for the values of time_t that result in the string longer than 25 characters (e.g. year 10000) | + | The behavior may be undefined for the values of {{lc|std::time_t}} that result in the string longer than 25 characters (e.g. year 10000) |
===Example=== | ===Example=== | ||
Revision as of 01:52, 26 July 2021
| Defined in header <ctime>
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| char* ctime( const std::time_t* time ); |
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Converts given time since epoch to a calendar local time and then to a textual representation, as if by calling std::asctime(std::localtime(time)). The resulting string has the following format:
Www Mmm dd hh:mm:ss yyyy
Www- the day of the week (one ofMon,Tue,Wed,Thu,Fri,Sat,Sun).Mmm- the month (one ofJan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec).dd- the day of the monthhh- hoursmm- minutesss- secondsyyyy- years
The function does not support localization.
Contents |
Parameters
| time | - | pointer to a std::time_t object specifying the time to print |
Return value
Pointer to a static null-terminated character string holding the textual representation of date and time. The string may be shared between std::asctime and std::ctime, and may be overwritten on each invocation of any of those functions.
Notes
This function returns a pointer to static data and is not thread-safe. In addition, it modifies the static std::tm object which may be shared with std::gmtime and std::localtime. POSIX marks this function obsolete and recommends std::strftime instead.
The behavior may be undefined for the values of std::time_t that result in the string longer than 25 characters (e.g. year 10000)
Example
#include <ctime> #include <iostream> int main() { std::time_t result = std::time(nullptr); std::cout << std::ctime(&result); }
Possible output:
Tue Dec 27 17:21:29 2011
See also
| converts a std::tm object to a textual representation (function) | |
| converts a std::tm object to custom textual representation (function) | |
| (C++11) |
formats and outputs a date/time value according to the specified format (function template) |
| C documentation for ctime
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