Jump to content United States-English
HP.com Home Products and Services Support and Drivers Solutions How to Buy
» Contact HP
More options
HP.com home
HP-UX Reference > T


HP-UX 11i Version 3: February 2007

Technical documentation

» Feedback
Content starts here

 » Table of Contents

 » Index


times — get process and child process times


#include <sys/times.h>

clock_t times(struct tms *buffer);


times() fills the structure pointed to by buffer with time-accounting information. The structure defined in <sys/times.h> is as follows:

struct tms { clock_t tms_utime; /* user time */ clock_t tms_stime; /* system time */" clock_t tms_cutime; /* user time, children */ clock_t tms_cstime; /* system time, children */ };

This information comes from the calling process and each of its terminated child processes for which it has executed a wait(), wait3(), or waitpid(). The times are in units of 1/CLK_TCK seconds, where CLK_TCK is processor dependent. The value of CLK_TCK can be queried using the sysconf() function (see sysconf(2)).

tms_utime is the CPU time used while executing instructions in the user space of the calling process.

tms_stime is the CPU time used by the system on behalf of the calling process.

tms_cutime is the sum of the tms_utimes and tms_cutimes of the child processes.

tms_cstime is the sum of the tms_stimes and tms_cstimes of the child processes.


Upon successful completion, times() returns the elapsed real time, in units of 1/CLK_TCK of a second, since an arbitrary point in the past (such as system start-up time). This point does not change from one invocation of times() to another. If times() fails, (clock_t) -1 is returned and errno is set to indicate the error.


times() has a granularity of one tick. Processes which run less than one tick may not register any value.



times() fails if buffer points to an illegal address. The reliable detection of this error is implementation dependent.


Not all CPU time expended by system processes on behalf of a user process is counted in the system CPU time for that process.


times(): AES, SVID2, SVID3, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1

Printable version
Privacy statement Using this site means you accept its terms Feedback to webmaster
© 1983-2007 Hewlett-Packard Development Company, L.P.