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Re: How to notice abrupt tcp connection losses in server/client?
From: |
Chris Vine |
Subject: |
Re: How to notice abrupt tcp connection losses in server/client? |
Date: |
Sat, 23 Jun 2018 12:42:52 +0100 |
On Fri, 22 Jun 2018 22:17:51 +0200
Zelphir Kaltstahl <address@hidden> wrote:
[snip]
> ... it returns 0 for end of file (what is the difference between this
> and end of file object?
R6RS states that "The end-of-file object is returned by various I/O
procedures when they reach end of file". It can be obtained by invoking
the R6RS eof-object procedure and can be queried with the eof-object?
predicate, so '(eof-object? (eof-object))' will evaluate to true. R6RS
also says "The end-of-file object is not a datum value, and thus has no
external representation".
0 is an integer. POSIX read() and recv() indicate end-of-file by
unblocking and returning 0. Subsequent calls to read() or recv() might
return -1 indicating an error, in which case recv! would throw an
exception.