CLOCK(3)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Linux Programmer’s Manual\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 CLOCK(3)<\/p>\n
NAME<\/p>\n
clock – determine processor time<\/p>\n
SYNOPSIS<\/p>\n
#include <time.h><\/p>\n
clock_t clock(void);<\/p>\n
DESCRIPTION<\/p>\n
The clock() function returns an approximation of processor time used
\nby the program.<\/p>\n
RETURN VALUE<\/p>\n
The value returned is the CPU time used so far as a clock_t; to get
\nthe number of seconds used, divide by CLOCKS_PER_SEC.\u00a0 If the
\nprocessor time used is not available or its value cannot be
\nrepresented, the function returns the value (clock_t) -1.<\/p>\n
CONFORMING TO<\/p>\n
C89, C99, POSIX.1-2001.\u00a0 POSIX requires that CLOCKS_PER_SEC equals
\n1000000 independent of the actual resolution.<\/p>\n
NOTES<\/p>\n
The C standard allows for arbitrary values at the start of the
\nprogram; subtract the value returned from a call to clock() at the
\nstart of the program to get maximum portability.<\/p>\n
Note that the time can wrap around.\u00a0 On a 32-bit system where
\nCLOCKS_PER_SEC equals 1000000 this function will return the same
\nvalue approximately every 72 minutes.<\/p>\n
On several other implementations, the value returned by clock() also
\nincludes the times of any children whose status has been collected
\nvia wait(2) (or another wait-type call).\u00a0 Linux does not include the
\ntimes of waited-for children in the value returned by clock().\u00a0 The
\ntimes(2) function, which explicitly returns (separate) information
\nabout the caller and its children, may be preferable.<\/p>\n
In glibc 2.17 and earlier, clock() was implemented on top of
\ntimes(2).\u00a0 For improved accuracy, since glibc 2.18, it is implemented
\non top of clock_gettime(2) (using the CLOCK_PROCESS_CPUTIME_ID
\nclock).<\/p>\n
SEE ALSO<\/p>\n
clock_gettime(2), getrusage(2), times(2)<\/p>\n
COLOPHON<\/p>\n
This page is part of release 3.76 of the Linux man-pages project.\u00a0 A
\ndescription of the project, information about reporting bugs, and the
\nlatest version of this page, can be found at
\nhttp:\/\/www.kernel.org\/doc\/man-pages\/.<\/p>\n
GNU\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 2014-09-21\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 CLOCK(3)<\/p>\n","protected":false},"excerpt":{"rendered":"
CLOCK(3)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Linux Programmer’s Manual\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 CLOCK(3) NAME clock – determine processor time SYNOPSIS #include <time.h> clock_t clock(void); DESCRIPTION The clock() function returns an approximation of processor time used by the program. RETURN VALUE The value returned is the CPU time used so far as a clock_t; to get the number of seconds used, divide by CLOCKS_PER_SEC.\u00a0 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_sitemap_exclude":false,"_sitemap_priority":"","_sitemap_frequency":"","footnotes":""},"categories":[8],"tags":[],"class_list":["post-298","post","type-post","status-publish","format-standard","hentry","category-shell"],"_links":{"self":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/posts\/298","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=298"}],"version-history":[{"count":0,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=\/wp\/v2\/posts\/298\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=298"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=298"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.linuxboxen.dk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=298"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}