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)

COLOPHON

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Linux                                              2020-08-13                                        ISFDTYPE(3)