clock(3)clock(3)NAMEclock - Report CPU time used
Standard C Library (libc)
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
clock(): XPG4, XPG4-UNIX
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
The clock() function reports the amount of processor time used by the
calling process and each of its terminated child processes for which a
wait function has been executed. When a child process does not wait for
its children, its child-process times are not included in its times.
The clock() function returns the amount of processor time (in microsec‐
onds) used since the first call to clock(). To convert the time to
seconds, divide it by CLOCKS_PER_SEC (which is defined to be 1,000,000
in <time.h>). If the processor time used is not available or its value
cannot be represented, the clock() function returns (clock_t)-1.
Functions: ctime(3), getrusage(2), times(3), wait(2)