Home- new_handle = old_handle:dup()
- new_handle = rawio.dup(fd)
SYNOPSIS
DESCRIPTION
Creates a copy of a file handle. The new file handle refers to the same file as the old handle, but is
completely independent otherwise. The first form takes an existing rawio file handle, while the second
takes an already open file descriptor.
RETURN VALUE
On success, a rawio handle is returned. On error, three values are returned: nil, a string
describing the error (The result of the C library call strerror() on the errno code) and the errno number from
the standard C library.
NOTES
Useful pre-existing file descriptors are 0 (Standard input), 1 (Standard output),
2 (Standard error output).
EXAMPLE
Creates a duplicate of standard output, writes its file descriptor and closes the duplicate. Note that the
normal standard output keeps working after the close, as the original file handle is not affected.
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handle = rawio.dup(1)
handle:write(string.format("fd=%d\n", handle:fd()))
handle:close()
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