isfdtype(3) - Linux manual page (original) (raw)

isfdtype(3) Library Functions Manual isfdtype(3)

NAME top

   isfdtype - test file type of a file descriptor

LIBRARY top

   Standard C library (_libc_, _-lc_)

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)](../man2/stat.2.html) (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](../man3/errno.3.html)_ is set to indicate the error.

ERRORS top

   The **isfdtype**() function can fail with any of the same errors as
   [fstat(2)](../man2/fstat.2.html).

VERSIONS top

   Portable applications should use [fstat(2)](../man2/fstat.2.html) instead.

STANDARDS top

   None.

HISTORY top

   It appeared 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).

SEE ALSO top

   [fstat(2)](../man2/fstat.2.html)

COLOPHON top

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Linux man-pages 6.10 2024-07-23 isfdtype(3)