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times(3) [osx man page]

TIMES(3)						   BSD Library Functions Manual 						  TIMES(3)

times -- process times LIBRARY
Standard C Library (libc, -lc) SYNOPSIS
#include <sys/times.h> clock_t times(struct tms *buffer); DESCRIPTION
This interface is obsoleted by getrusage(2) and gettimeofday(2). The times() function returns the value of time in CLK_TCK's of a second since 0 hours, 0 minutes, 0 seconds, January 1, 1970, Coordinated Universal Time. It also fills in the structure pointed to by buffer with time-accounting information. The tms structure is defined as follows: struct tms { clock_t tms_utime; clock_t tms_stime; clock_t tms_cutime; clock_t tms_cstime; }; The elements of this structure are defined as follows: tms_utime The CPU time charged for the execution of user instructions. tms_stime The CPU time charged for execution by the system on behalf of the process. tms_cutime The sum of the tms_utimes and tms_cutimes of the child processes. tms_cstime The sum of the tms_stimes and tms_cstimes of the child processes. All times are in CLK_TCK's of a second. The times of a terminated child process are included in the tms_cutime and tms_cstime elements of the parent when one of the wait(2) func- tions returns the process ID of the terminated child to the parent. If an error occurs, times() returns the value ((clock_t)-1), and sets errno to indicate the error. ERRORS
The times() function may fail and set the global variable errno for any of the errors specified for the library routines getrusage(2) and gettimeofday(2). SEE ALSO
time(1), getrusage(2), gettimeofday(2), wait(2), clocks(7) STANDARDS
The times() function conforms to IEEE Std 1003.1-1988 (``POSIX.1''). BSD
June 4, 1993 BSD

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TIMES(2)						     Linux Programmer's Manual							  TIMES(2)

times - get process times SYNOPSIS
#include <sys/times.h> clock_t times(struct tms *buf); DESCRIPTION
The times() function stores the current process times in the struct tms that buf points to. The struct tms is as defined in <sys/times.h>: struct tms { clock_t tms_utime; /* user time */ clock_t tms_stime; /* system time */ clock_t tms_cutime; /* user time of children */ clock_t tms_cstime; /* system time of children */ }; The tms_utime field contains the CPU time spent executing instructions of the calling process. The tms_stime field contains the CPU time spent in the system while executing tasks on behalf of the calling process. The tms_cutime field contains the sum of the tms_utime and tms_cutime values for all waited-for terminated children. The tms_cstime field contains the sum of the tms_stime and tms_cstime values for all waited-for terminated children. Times for terminated children (and their descendants) is added in at the moment wait(2) or waitpid(2) returns their process ID. In particu- lar, times of grandchildren that the children did not wait for are never seen. All times reported are in clock ticks. RETURN VALUE
The function times returns the number of clock ticks that have elapsed since an arbitrary point in the past. For Linux this point is the moment the system was booted. This return value may overflow the possible range of type clock_t. On error, (clock_t) -1 is returned, and errno is set appropriately. NOTES
The number of clock ticks per second can be obtained using sysconf(_SC_CLK_TCK); In POSIX-1996 the symbol CLK_TCK (defined in <time.h>) is mentioned as obsolescent. It is obsolete now. On Linux, if the disposition of SIGCHLD is set to SIG_IGN then the times of terminated children are automatically included in the tms_cstime and tms_cutime fields, although POSIX 1003.1-2001 says that this should only happen if the calling process wait()s on its chil- dren. Note that clock(3) returns values of type clock_t that are not measured in clock ticks but in CLOCKS_PER_SEC. CONFORMING TO
SVr1-3 returns long and the struct members are of type time_t although they store clock ticks, not seconds since the epoch. V7 used long for the struct members, because it had no type time_t yet. On older systems the number of clock ticks per second is given by the variable HZ. SEE ALSO
time(1), getrusage(2), wait(2), clock(3), sysconf(3) Linux 2002-06-14 TIMES(2)
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