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From: chris@mimsy.UUCP (Chris Torek)
Newsgroups: comp.protocols.tcp-ip,comp.unix.questions
Subject: Re: ftp/rcp can't copy devices
Message-ID: <13292@mimsy.UUCP>
Date: 30 Aug 88 00:05:08 GMT
References: <779@philmds.UUCP>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 15

In article <779@philmds.UUCP> hulsebos@philmds.UUCP (Rob Hulsebos) writes:
>When I use the 'ftp' or 'rcp' command, and want to copy a disk-partition
>(accessed via /dev/rdsk/*) to the other end, both utilities
>complain: "not a plain file".
>
>Of course, the manual doesn't mention that only plain files can be
>transferred. Does anybody know why ftp and rcp behave this way?

Both attempt to determine the size of the file before sending it.
(Only rcp's protocol actually requires this.)  There is no way to
find the size of a special file without reading it, and in the process
the data may vanish (e.g., reading /dev/tty or a socket).
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@mimsy.umd.edu	Path:	uunet!mimsy!chris