ISFDTYPE(3) BSD Programmer's Manual ISFDTYPE(3)
isfdtype - determine whether a file descriptor is of a specific type
#include <sys/stat.h> int isfdtype(int fd, int fdtype);
The isfdtype() function checks whether or not the file descriptor fd is of type fdtype. A list of possible file types may be found in stat(2) and the <sys/stat.h> include file.
The isfdtype() function returns 1 if fd is of type fdtype and 0 if it is not. If isfdtype() fails, a value of -1 is returned and the global vari- able errno is set to indicate the error.
The following error codes may be set in errno: [EBADF] fd is not a valid open file descriptor. [EIO] An I/O error occurred while reading from or writing to the filesystem.
stat(2)
The isfdtype() function is expected to conform to POSIX 1003.1g.
The isfdtype() function first appeared in OpenBSD 3.3. MirBSD #10-current October 15, 2002 1