22 Oct
2019
22 Oct
'19
12:29 p.m.
On Mon, Oct 21, 2019 at 12:37:20PM +1000, Warren Toomey wrote:
On Sun, Oct 20, 2019 at 07:31:55PM -0700, Ken Thompson
via TUHS wrote:
Aha indeed, Ken & Warren!
chdir seems to be a syscall in 7 (sys4.c), its handling in sh mostly in xec.c,
a real workout for the preprocessor ;)
--
I love deadlines. I love the whooshing noise as they fly by.
i was writing the small utilities for the first
pdp-11 unix. (rm ls date ....)
so, cd was next.
% pwd
/usr/ken
% cd /tmp
% pwd
/usr/ken
Aha!
As in, 'cd' has to be built into the shell. If it's external, the forked
child gets to change directory and the parent shell doesn't. I'm just
putting this in for those who didn't spot the nuance immediately -- took
me a few tens of seconds.
But wasn't "chdir" built into the PDP-7 Unix shell?
Thanks, Warren