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getdtablesize(3) [x11r4 man page]

GETDTABLESIZE(3)					     Linux Programmer's Manual						  GETDTABLESIZE(3)

NAME
getdtablesize - get file descriptor table size SYNOPSIS
#include <unistd.h> int getdtablesize(void); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): getdtablesize(): Since glibc 2.12: /* Glibc since 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE || ! (_POSIX_C_SOURCE >= 200112L) Before glibc 2.12: _BSD_SOURCE || _XOPEN_SOURCE >= 500 DESCRIPTION
getdtablesize() returns the maximum number of files a process can have open, one more than the largest possible value for a file descrip- tor. RETURN VALUE
The current limit on the number of open files per process. ERRORS
On Linux, getdtablesize() can return any of the errors described for getrlimit(2); see NOTES below. ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7). +----------------+---------------+---------+ |Interface | Attribute | Value | +----------------+---------------+---------+ |getdtablesize() | Thread safety | MT-Safe | +----------------+---------------+---------+ CONFORMING TO
SVr4, 4.4BSD (the getdtablesize() function first appeared in 4.2BSD). It is not specified in POSIX.1; portable applications should employ sysconf(_SC_OPEN_MAX) instead of this call. NOTES
getdtablesize() is implemented as a libc library function. The glibc version calls getrlimit(2) and returns the current RLIMIT_NOFILE limit, or OPEN_MAX when that fails. SEE ALSO
close(2), dup(2), getrlimit(2), open(2) COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/. Linux 2016-03-15 GETDTABLESIZE(3)

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GETW(3)                                                      Linux Programmer's Manual                                                     GETW(3)

NAME
getw, putw - input and output of words (ints) SYNOPSIS
#include <stdio.h> int getw(FILE *stream); int putw(int w, FILE *stream); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): getw(), putw(): Since glibc 2.3.3: _XOPEN_SOURCE && ! (_POSIX_C_SOURCE >= 200112L) || /* Glibc since 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE Before glibc 2.3.3: _SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE DESCRIPTION
getw() reads a word (that is, an int) from stream. It's provided for compatibility with SVr4. We recommend you use fread(3) instead. putw() writes the word w (that is, an int) to stream. It is provided for compatibility with SVr4, but we recommend you use fwrite(3) instead. RETURN VALUE
Normally, getw() returns the word read, and putw() returns 0. On error, they return EOF. ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7). +---------------+---------------+---------+ |Interface | Attribute | Value | +---------------+---------------+---------+ |getw(), putw() | Thread safety | MT-Safe | +---------------+---------------+---------+ CONFORMING TO
SVr4, SUSv2. Not present in POSIX.1. BUGS
The value returned on error is also a legitimate data value. ferror(3) can be used to distinguish between the two cases. SEE ALSO
ferror(3), fread(3), fwrite(3), getc(3), putc(3) COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/. GNU 2016-03-15 GETW(3)
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