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 descriptor.

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

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