Retrieves file implementation characteristics.

    Format

      #include  <unistd.h>

      long int fpathconf  (int filedes, int name);

1  –  Arguments

 filedes

    An open file descriptor.

 name

    The configuration attribute to query. If this attribute is
    not applicable to the file specified by the filesdes argument,
    fpathconf returns an error.

2  –  Description

    The fpathconf function allows an application to retrieve the
    characteristics of operations supported by the file system
    underlying the filenamed by the filesdes argument. Read, write,
    or execute permission of the named file is not required, but you
    must be able to search all directories in the path leading to the
    file.

    Symbolic values for the name argument are defined in the
    <unistd.h> header file as follows:

    _PC_LINK_MAX   The maximum number of links to the file. If the
                   filedes argument refers to a directory, the value
                   returned applies to the directory itself.
    _PC_MAX_       The maximum number of bytes in a canonical input
    CANON          line. This is applicable only to terminal devices.
    _PC_MAX_       The number of types allowed in an input queue.
    INPUT          This is applicable only to terminal devices.
    _PC_NAME_MAX   Maximum number of bytes in a filename (not
                   including a terminating null). The byte range
                   value is between 13 and 255. This is applicable
                   only to a directory file. The value returned
                   applies to filenames within the directory.
    _PC_PATH_MAX   Maximum number of bytes in a pathname (not
                   including a terminating null). The value is never
                   larger than 65,535. This is applicable only to a
                   directory file. The value returned is the maximum
                   length of a relative pathname when the specified
                   directory is the working directory.
    _PC_PIPE_BUF   Maximum number of bytes guaranteed to be written
                   atomically. This is applicable only to a FIFO. The
                   value returned applies to the referenced object.
                   If the path argument refers to a directory, the
                   value returned applies to any FIFO that exists or
                   can be created within the directory.
    _PC_CHOWN_     The value returned applies to any files (other
    RESTRICTED     than directories) that exist or can be created
                   within the directory. This is applicable only to a
                   directory file.
    _PC_NO_TRUNC   Returns 1 if supplying a component name longer
                   than allowed by NAME_MAX causes an error. Returns
                   0 (zero) if long component names are truncated.
                   This is applicable only to a directory file.
    _PC_VDISABLE   This is always 0 (zero); no disabling character
                   is defined. This is applicable only to a terminal
                   device.

3  –  Return Values

    x                  The resultant value for the configuration
                       attribute specified in the name argument.
    -1                 Indicates an error; errno is set to one of the
                       following values:

                       o  EINVAL - The name argument specifies an
                          unknown or inapplicable characteristic.

                       o  EBADF - the filedes argument is not a valid
                          file descriptor.