ftime函数

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本文介绍了ftime()函数的使用方法及注意事项。该函数用于获取当前时间并填充到指定的timeb结构中，包括秒数和毫秒数。文章还提供了获取当前时间的示例代码，并建议在应用程序中使用time()或clock_gettime()来替代ftime()。

NAME

ftime - get date and time ( LEGACY)

SYNOPSIS

^[XSI] #include <sys/timeb.h> int ftime(struct timeb *tp);

DESCRIPTION

The ftime() function shall set the time and millitm members of the timeb structure pointed to by tp to contain the seconds and milliseconds portions, respectively, of the current time in seconds since the Epoch. The contents of the timezone and dstflag members of tp after a call to ftime() are unspecified.

The system clock need not have millisecond granularity. Depending on any granularity (particularly a granularity of one) renders code non-portable.

RETURN VALUE

Upon successful completion, the ftime() function shall return 0; otherwise, -1 shall be returned.

ERRORS

No errors are defined.

The following sections are informative.

EXAMPLES

Getting the Current Time and Date

The following example shows how to get the current system time values using the ftime() function. The timeb structure pointed to by tp is filled with the current system time values for time and millitm.
#include <sys/timeb.h>


struct timeb tp;
int          status;
...
status = ftime(&tp);

APPLICATION USAGE

For applications portability, the time() function should be used to determine the current time instead of ftime(). Realtime applications should use clock_gettime() to determine the current time instead of ftime().

RATIONALE

None.

FUTURE DIRECTIONS

This function may be withdrawn in a future version.

CHANGE HISTORY

First released in Issue 4, Version 2.

Issue 5

Moved from X/OPEN UNIX extension to BASE.

Normative text previously in the APPLICATION USAGE section is moved to the DESCRIPTION.

Issue 6

This function is marked LEGACY.

The DESCRIPTION is updated to refer to "seconds since the Epoch" rather than "seconds since 00:00:00 UTC (Coordinated Universal Time), January 1 1970" for consistency with other time functions.