From mboxrd@z Thu Jan 1 00:00:00 1970 From: jnc@mercury.lcs.mit.edu (Noel Chiappa) Date: Tue, 28 Nov 2017 08:19:42 -0500 (EST) Subject: [TUHS] Dash options Message-ID: <20171128131942.6705918C092@mercury.lcs.mit.edu> > Multics had some kind of `attach' and `detach' of I/O streams, well > known to Ossanna, so perhaps dup(2), and a Thompson-shell syntax to go > with it meant `>' was earmarked early on. According to "The Evolution of the Unix Timesharing System", full path names arrived later than I/O redirection, so by they time they needed a separator, '>' and '<' were gone. '/' also has the advantage of being a non-shift character! Noel PS: Re-reading that, I see that early Unix did not have an exec() call (as I was just discussing); it was done in user mode, with normal read and write calls.