Unix/Linux Go Back    


CentOS 7.0 - man page for tcl_settimeproc (centos section 3)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)


Tcl_GetTime(3)			      Tcl Library Procedures			   Tcl_GetTime(3)

_________________________________________________________________________________________________

NAME
       Tcl_GetTime, Tcl_SetTimeProc, Tcl_QueryTimeProc - get date and time

SYNOPSIS
       #include <tcl.h>

       Tcl_GetTime(timePtr)

       Tcl_SetTimeProc(getProc, scaleProc, clientData)

       Tcl_QueryTimeProc(getProcPtr, scaleProcPtr, clientDataPtr)

ARGUMENTS
       Tcl_Time * timePtr (out) 	Points	to  memory  in	which  to store the date and time
					information.

       Tcl_GetTimeProc * getProc (in)	       Pointer to  handler  function  replacing  Tcl_Get-
					       Time's access to the OS.

       Tcl_ScaleTimeProc * scaleProc (in)	   Pointer to handler function for the conversion
						   of time delays in the virtual domain to  real-
						   time.

       ClientData * clientData (in)	     Value passed through to the two handler functions.

       Tcl_GetTimeProc ** getProcPtr (inout)	   Pointer  to place the currently registered get
						   handler function into.

       Tcl_ScaleTimeProc ** scaleProcPtr (inout)       Pointer to place the currently  registered
						       scale handler function into.

       ClientData ** clientDataPtr (inout)	 Pointer  to place the currently registered pass-
						 through value into.
_________________________________________________________________

DESCRIPTION
       The Tcl_GetTime function retrieves the current time as a Tcl_Time structure in memory  the
       caller provides.  This structure has the following definition:
	      typedef struct Tcl_Time {
		  long sec;
		  long usec;
	      } Tcl_Time;

       On  return,  the  sec member of the structure is filled in with the number of seconds that
       have elapsed since the epoch: the epoch is the point in time of 00:00 UTC, 1 January 1970.
       This number does not count leap seconds - an interval of one day advances it by 86400 sec-
       onds regardless of whether a leap second has been inserted.

       The usec member of the structure is filled in with the number of  microseconds  that  have
       elapsed	since  the  start  of  the second designated by sec.  The Tcl library makes every
       effort to keep this number as precise as possible, subject to the limitations of the  com-
       puter  system.	On  multiprocessor variants of Windows, this number may be limited to the
       10- or 20-ms granularity of the system clock.  (On single-processor Windows  systems,  the
       usec field is derived from a performance counter and is highly precise.)

       The  Tcl_SetTime function registers two related handler functions with the core. The first
       handler function is a replacement for  Tcl_GetTime,  or	rather	the  OS  access  made  by
       Tcl_GetTime.  The other handler function is used by the Tcl notifier to convert wait/block
       times from the virtual domain into real time.

       The Tcl_QueryTime function returns the  currently  registered  handler  functions.  If  no
       external  handlers were set then this will return the standard handlers accessing and pro-
       cessing the native time of the OS. The arguments to the function are allowed to	be  NULL;
       and any argument which is NULL is ignored and not set.

       Any  handler  pair specified has to return data which is consistent between them. In other
       words, setting one handler of the pair to something assuming a 10-times slowdown, and  the
       other  handler  of  the	pair  to something assuming a two-times slowdown is wrong and not
       allowed.

       The set handler functions are allowed to run the delivered time	backwards,  however  this
       should  be  avoided.  We have to allow it as the native time can run backwards as the user
       can fiddle with the system time one way or other. Note that the	insertion  of  the  hooks
       will  not  change  the  behaviour  of the Tcl core with regard to this situation, i.e. the
       existing behaviour is retained.

SEE ALSO
       clock

KEYWORDS
       date, time

Tcl					       8.4				   Tcl_GetTime(3)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums


All times are GMT -4. The time now is 05:09 PM.