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DUP(2)			      System Calls Manual			DUP(2)

NAME
       dup, dup2 - duplicate an	open file descriptor

SYNOPSIS
       dup(fildes)
       int fildes;

       dup2(fildes, fildes2)
       int fildes, fildes2;

DESCRIPTION
       Given a file descriptor returned	from an	open, pipe, or creat call, dup
       allocates another file descriptor synonymous with  the  original.   The
       new file	descriptor is returned.

       In  the	second form of the call, fildes	is a file descriptor referring
       to an open file,	and fildes2 is a non-negative integer  less  than  the
       maximum	value  allowed	for file descriptors (approximately 19).  Dup2
       causes fildes2 to refer to the same file	as fildes.  If fildes2 already
       referred	to an open file, it is closed first.

SEE ALSO
       creat(2), open(2), close(2), pipe(2)

DIAGNOSTICS
       The  value  -1  is  returned  if: the given file	descriptor is invalid;
       there are already too many open files.

ASSEMBLER
       (dup = 41.)
       (file descriptor	in r0)
       (new file descriptor in r1)
       sys dup
       (file descriptor	in r0)

       The dup2	entry is implemented by	adding 0100 to fildes.

									DUP(2)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | DIAGNOSTICS | ASSEMBLER

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