CLOCK_GETCPUCLOCKID man page on Fedora

Man page or keyword search:  
man Server   31170 pages
apropos Keyword Search (all sections)
Output format
Fedora logo
[printable version]

CLOCK_GETCPUCLOCKID(3)	   Linux Programmer's Manual	CLOCK_GETCPUCLOCKID(3)

NAME
       clock_getcpuclockid - obtain ID of a process CPU-time clock

SYNOPSIS
       #include <time.h>

       int clock_getcpuclockid(pid_t pid, clockid_t *clock_id);

       Link with -lrt.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       clock_getcpuclockid():
	   _XOPEN_SOURCE >= 600 || _POSIX_C_SOURCE >= 200112L

DESCRIPTION
       The clock_getcpuclockid() function obtains the ID of the CPU-time clock
       of the process whose ID is pid, and returns it in the location  pointed
       to  by  clock_id.   If  pid  is zero, then the clock ID of the CPU-time
       clock of the calling process is returned.

RETURN VALUE
       On success, clock_getcpuclockid() returns 0; on error, it  returns  one
       of the positive error numbers listed in ERRORS.

ERRORS
       ENOSYS The  kernel  does not support obtaining the per-process CPU-time
	      clock of another process, and pid does not specify  the  calling
	      process.

       EPERM  The caller does not have permission to access the CPU-time clock
	      of the process specified by  pid.	  (Specified  as  an  optional
	      error in POSIX.1-2001; does not occur on Linux unless the kernel
	      does not support obtaining the  per-process  CPU-time  clock  of
	      another process.)

       ESRCH  There is no process with the ID pid.

VERSIONS
       The  clock_getcpuclockid() function is available in glibc since version
       2.2.

CONFORMING TO
       POSIX.1-2001.

NOTES
       Calling clock_gettime(2) with the  clock	 ID  obtained  by  a  call  to
       clock_getcpuclockid()  with  a pid of 0, is the same as using the clock
       ID CLOCK_PROCESS_CPUTIME_ID.

EXAMPLE
       The example program below obtains the CPU-time clock ID of the  process
       whose  ID  is given on the command line, and then uses clock_gettime(2)
       to obtain the time on that clock.  An example run is the following:

	   $ ./a.out 1		       # Show CPU clock of init process
	   CPU-time clock for PID 1 is 2.213466748 seconds

   Program source

       #define _XOPEN_SOURCE 600
       #include <stdio.h>
       #include <unistd.h>
       #include <stdlib.h>
       #include <time.h>

       int
       main(int argc, char *argv[])
       {
	   clockid_t clockid;
	   struct timespec ts;

	   if (argc != 2) {
	       fprintf(stderr, "%s <process-ID>\n", argv[0]);
	    exit(EXIT_FAILURE);
	   }

	   if (clock_getcpuclockid(atoi(argv[1]), &clockid) != 0) {
	    perror("clock_getcpuclockid");
	    exit(EXIT_FAILURE);
	   }

	   if (clock_gettime(clockid, &ts) == -1) {
	    perror("clock_gettime");
	    exit(EXIT_FAILURE);
	   }

	   printf("CPU-time clock for PID %s is %ld.%09ld seconds\n",
		argv[1], (long) ts.tv_sec, (long) ts.tv_nsec);
	   exit(EXIT_SUCCESS);
       }

SEE ALSO
       clock_getres(2), timer_create(2), pthread_getcpuclockid(3), time(7)

COLOPHON
       This page is part of release 3.35 of the Linux  man-pages  project.   A
       description  of	the project, and information about reporting bugs, can
       be found at http://man7.org/linux/man-pages/.

Linux				  2010-09-10		CLOCK_GETCPUCLOCKID(3)
[top]

List of man pages available for Fedora

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net