Topic       : TOS - The Operating System
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Version     : tos.hyp (December 19, 2008)
Subject     : Programmieren/Atari
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Compiled on : Atari
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View Ref-File5.10.9  Fdup                                                       TOS

 Name:         »File duplicate« - Duplicate a file handle.

 Opcode:       69

 Syntax:       int16_t Fdup ( int16_t handle );

 Description:  The GEMDOS routine Fdup duplicates a standard file 
               handle (0-5) and assigns it a new handle (>6) for a 
               standard channel. The following apply:

                handle  Meaning

                0       Keyboard (stdin:)
                1       Screen (stdout:)
                2       Serial port (stdaux:)
                3       Parallel port (stdprn:)

               Note: In all known GEMDOS versions (up to and including 
               0.19) errors occur if, after an Fdup, a program is 
               started with Pexec. As of MagiC 4, one can also use 
               this function to the device files -1, -2, -3 (system 
               global) and -4 (NULL device).

 Return value: The function returns the following results:

                ENHNDL :     No more handles available.
                EIHNDL :     Incorrect file handle.
                Otherwise :  The desired new handle.

 Availability: All GEMDOS versions.

 Group:        File functions

 See also:     Binding   Fforce