isfdtype(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

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

NAME         top

       isfdtype - test file type of a file descriptor

SYNOPSIS         top

       #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         top

       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         top

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

ERRORS         top

       The isfdtype() function can fail with any of the same errors as
       fstat(2).

CONFORMING TO         top

       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         top

       Portable applications should use fstat(2) instead.

SEE ALSO         top

       fstat(2)

COLOPHON         top

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Linux                          2021-03-22                    ISFDTYPE(3)