fdes_to_drivername(2)

NAME
     fdes_to_drivername - determine the driver name for the device

C SYNOPSIS
     #include <invent.h>

     char * fdes_to_drivername (int fd, char *buf, int *length);

OVERVIEW
     fdes_to_drivername is useful to determine the name of the driver handling
     the device corresponding to the special file descriptor.  Note that this
     file descriptor can correspond to any of the different alias names for
     the device.

DESCRIPTION
     The fdes_to_drivername function provides a way to retrieve the name of
     the driver handling the device corresponding to the special file
     descriptor.

     fd identifies the device, buf is the placeholder for the driver name and
     length is an input/output argument that on the call to fdes_to_drivername
     should contain the maximum size of the name the process is willing to
     accept.  On return, the length will have been modified to show the actual
     size of the driver name returned.

     fdes_to_drivername will fail if one or more of the following are true:

     [E2BIG]
          The driver name  is too large to fit into the buffer.  The integer
          that the valuelength argument points to has been modified to show
          the actual number of bytes that would be required to store the value
          of that attribute.

     [EBADF]
          Fd does not refer to a valid descriptor.

     [EPERM]
          The effective user ID does not match the owner of the file and the
          effective user ID is not super-user.

     [EFAULT]
          Buf, or length points outside the allocated address space of the
          process.

SEE ALSO
     attr(1), hwgraph(4)

DIAGNOSTICS
     Upon successful completion, the name is returned.  Otherwise, a value of
     NULL is returned and errno is set to indicate the error.