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_strtime_s, _wstrtime_s

 

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Copy the current time to a buffer. These are versions of _strtime, _wstrtime with security enhancements as described in Security Features in the CRT.

errno_t _strtime_s(  
   char *buffer,  
   size_t numberOfElements  
);  
errno_t _wstrtime_s(  
   wchar_t *buffer,  
   size_t numberOfElements  
);  
template <size_t size>  
errno_t _strtime_s(  
   char (&buffer)[size]  
); // C++ only  
template <size_t size>  
errno_t _wstrtime_s(  
   wchar_t (&buffer)[size]  
); // C++ only  

Parameters

[out] buffer
A buffer, at least 10 bytes long, where the time will be written.

[in] numberOfElements
The size of the buffer.

Zero if successful.

If an error condition occurs, the invalid parameter handler is invoked, as described in Parameter Validation. The return value is an error code if there is a failure. Error codes are defined in ERRNO.H; see the following table for the exact errors generated by this function. For more information on error codes, see errno Constants.

Error Conditions

buffernumberOfElementsReturnContents of buffer
NULL(any)EINVALNot modified
Not NULL (pointing to valid buffer)0EINVALNot modified
Not NULL (pointing to valid buffer)0 < size < 9EINVALEmpty string
Not NULL (pointing to valid buffer)Size > 90Current time formatted as specified in the remarks

Passing in an invalid non-NULL value for the buffer will result in an access violation if the numberOfElements parameter is greater than 9.

Passing a value for numberOfElements that is greater than the actual size of the buffer will result in buffer overrun.

These functions provide more secure versions of _strtime and _wstrtime. The _strtime_s function copies the current local time into the buffer pointed to by timestr. The time is formatted as hh:mm:ss where hh is two digits representing the hour in 24-hour notation, mm is two digits representing the minutes past the hour, and ss is two digits representing seconds. For example, the string 18:23:44 represents 23 minutes and 44 seconds past 6 P.M. The buffer must be at least 9 bytes long; the actual size is specified by the second parameter.

_wstrtime is a wide-character version of _strtime; the argument and return value of _wstrtime are wide-character strings. These functions behave identically otherwise.

In C++, using these functions is simplified by template overloads; the overloads can infer buffer length automatically (eliminating the need to specify a size argument) and they can automatically replace older, non-secure functions with their newer, secure counterparts. For more information, see Secure Template Overloads.

Generic-Text Routine Mapping:

TCHAR.H routine_UNICODE & _MBCS not defined_MBCS defined_UNICODE defined
_tstrtime_s_strtime_s_strtime_s_wstrtime_s
RoutineRequired header
_strtime_s<time.h>
_wstrtime_s<time.h> or <wchar.h>

For additional compatibility information, see Compatibility in the Introduction.

// strtime_s.c  
  
#include <time.h>  
#include <stdio.h>  
  
int main()  
{  
    char tmpbuf[9];  
    errno_t err;  
  
    // Set time zone from TZ environment variable. If TZ is not set,  
    // the operating system is queried to obtain the default value   
    // for the variable.   
    //  
    _tzset();  
  
    // Display operating system-style date and time.   
    err = _strtime_s( tmpbuf, 9 );  
    if (err)  
    {  
       printf("_strdate_s failed due to an invalid argument.");  
      exit(1);  
    }  
    printf( "OS time:\t\t\t\t%s\n", tmpbuf );  
    err = _strdate_s( tmpbuf, 9 );  
    if (err)  
    {  
       printf("_strdate_s failed due to an invalid argument.");  
       exit(1);  
    }  
    printf( "OS date:\t\t\t\t%s\n", tmpbuf );  
  
}  

OS time:            14:37:49  
OS date:            04/25/03  

Time Management
asctime_s, _wasctime_s
ctime_s, _ctime32_s, _ctime64_s, _wctime_s, _wctime32_s, _wctime64_s
gmtime_s, _gmtime32_s, _gmtime64_s
localtime_s, _localtime32_s, _localtime64_s
mktime, _mktime32, _mktime64
time, _time32, _time64
_tzset

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