sys/time.h — time types
[XSI] #include <sys/time.h>
The <sys/time.h> header shall define the fd_set type and the timeval structure, as described in <sys/select.h>.
The <sys/time.h> header shall define the time_t and suseconds_t types as described in <sys/types.h>.
The <sys/time.h> header shall define the following as described in <sys/select.h>: FD_CLR() FD_ISSET() FD_SET() FD_ZERO() FD_SETSIZE
The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.
int select(int, fd_set *restrict, fd_set *restrict, fd_set *restrict, struct timeval *restrict); int utimes(const char *, const struct timeval [2]);Inclusion of the <sys/time.h> header may make visible all symbols from the <sys/select.h> header.
None.
The <sys/time.h> header refers to <sys/select.h> for the definition of the timeval structure, instead of the other way round, because <sys/time.h> is an optional (XSI) header whereas <sys/select.h> is mandatory.
None.
First released in Issue 4, Version 2.
The type of tv_usec is changed from long to suseconds_t.
The restrict keyword is added to the prototypes for gettimeofday(), select(), and setitimer().
The note is added that inclusion of this header may also make symbols visible from <sys/select.h>.
The utimes() function is marked LEGACY.
This reference page is clarified with respect to macros and symbolic constants.
Austin Group Defect 1171 is applied, replacing the timeval structure definition with a reference to its description in <sys/select.h>.
Austin Group Defect 1330 is applied, removing obsolescent interfaces.
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