Originální popis anglicky:
sys/select.h - select types
Návod, kniha: POSIX Programmer's Manual
#include <sys/select.h>
The
<sys/select.h> header shall define the
timeval structure
that includes at least the following members:
time_t tv_sec Seconds.
suseconds_t tv_usec Microseconds.
The
time_t and
suseconds_t types shall be defined as described in
<sys/types.h> .
The
sigset_t type shall be defined as described in
<signal.h> .
The
timespec structure shall be defined as described in
<time.h> .
The
<sys/select.h> header shall define the
fd_set type as a
structure.
Each of the following may be declared as a function, or defined as a macro, or
both:
- void FD_CLR(int fd, fd_set
* fdset)
-
Clears the bit for the file descriptor fd in the file descriptor set
fdset.
- int FD_ISSET(int fd, fd_set
* fdset)
-
Returns a non-zero value if the bit for the file descriptor fd is set
in the file descriptor set by fdset, and 0 otherwise.
- void FD_SET(int fd, fd_set
* fdset)
-
Sets the bit for the file descriptor fd in the file descriptor set
fdset.
- void FD_ZERO(fd_set
*fdset)
-
Initializes the file descriptor set fdset to have zero bits for all
file descriptors.
If implemented as macros, these may evaluate their arguments more than once, so
applications should ensure that the arguments they supply are never
expressions with side effects.
The following shall be defined as a macro:
- FD_SETSIZE
-
Maximum number of file descriptors in an fd_set structure.
The following shall be declared as functions and may also be defined as macros.
Function prototypes shall be provided.
int pselect(int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
const struct timespec *restrict, const sigset_t *restrict);
int select(int, fd_set *restrict, fd_set *restrict, fd_set *restrict,
struct timeval *restrict);
Inclusion of the
<sys/select.h> header may make visible all symbols
from the headers
<signal.h>,
<sys/time.h>, and
<time.h>.
The following sections are informative.
None.
None.
None.
<signal.h> ,
<sys/time.h> ,
<sys/types.h>
,
<time.h> , the System Interfaces volume of
IEEE Std 1003.1-2001,
pselect(),
select()
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html
.
