linux man page for isfdtype

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

NAME
       isfdtype - test file type of a file descriptor

SYNOPSIS
       #include <sys/stat.h>
       #include <sys/socket.h>

       int isfdtype(int fd, int fdtype);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       isfdtype():
	   Since glibc 2.20:
	       _DEFAULT_SOURCE
	   Before glibc 2.20:
	       _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION
       The  isfdtype()	function  tests  whether the file descriptor fd refers to a file of type fdtype.  The fdtype argument specifies one of the
       S_IF* constants defined in <sys/stat.h> and documented in stat(2) (e.g., S_IFREG).

RETURN VALUE
       The isfdtype() function returns 1 if the file descriptor fd is of type fdtype and 0 if it is not.  On error, -1 is returned  and  errno	is
       set to indicate the cause.

ERRORS
       The isfdtype() function can fail with any of the same errors as fstat(3).

CONFORMING TO
       The  isfdtype()	function  is  not  specified in any standard, but did appear in the draft POSIX.1g standard.  It is present on OpenBSD and
       Tru64 UNIX (where the required header file in both cases is just <sys/stat.h>, as shown in the POSIX.1g draft), and possibly other systems.

NOTES
       Portable applications should use fstat(3) instead.

SEE ALSO
       fstat(3)

Linux								    2014-03-13							       ISFDTYPE(3)