times(3) - NetBSD Manual Pages

TIMES(3)                NetBSD Library Functions Manual               TIMES(3)


NAME

     times -- process times


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

     #include <sys/times.h>

     clock_t
     times(struct tms *tp);


DESCRIPTION

     This interface is obsoleted by getrusage(2) and gettimeofday(2).

     The times() function returns the value of time in clock ticks since 0
     hours, 0 minutes, 0 seconds, January 1, 1970, Coordinated Universal Time
     (UTC).

     The number of clock ticks per second may be determined by calling
     sysconf(3) with the _SC_CLK_TCK request.  It is generally (but not
     always) between 60 and 1024.

     Note that at the common rate of 100 ticks per second on many NetBSD
     ports, and with a 32-bit unsigned clock_t, this value first wrapped in
     1971.

     The times() call also fills in the structure pointed to by tp with time-
     accounting information.

     The tms structure is defined as follows:

           typedef struct {
                   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_utime s and tms_cutime s of the child pro-
                 cesses.

     tms_cstime  The sum of the tms_stimes and tms_cstimes of the child pro-
                 cesses.

     All times are measured in clock ticks, as defined above.  Note that at
     100 ticks per second, and with a 32-bit unsigned clock_t, the values wrap
     after 497 days.

     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) functions
     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), sysconf(3)


STANDARDS

     The times() function conforms to ISO/IEC 9945-1:1990 (``POSIX.1'').

NetBSD 9.0                       June 4, 1993                       NetBSD 9.0