read in /bin/sh appears to be VERY cpu costly.
George Michaelson
ggm at brolga.cc.uq.oz.au
Wed May 8 11:30:13 AEST 1991
I have written a very crude shellscript to do while loops over a read
command. This is to permit a user attached to a terminal that cannot
do control characters (!) to get access to unix and do some useful stuff
with MH and editors.
I have just found out she incurred around 300 seconds of CPU time on a
sun 4 in 1 login session.
simple tests using time on a shellscript of:
while 1
do
read INP
echo $INP
done
seem to suggest that read is incredibly expensive on the CPU.
Is this true, and is there any "cheaper" way to do interactive input
from a terminal within shellscripts?
Is this a "feature" in SunOS 4.1.1 /bin/sh?
-George
--
G.Michaelson
Internet: G.Michaelson at cc.uq.oz.au Phone: +61 7 365 4079
Postal: George Michaelson, the Prentice Centre,
The University of Queensland, St Lucia, QLD Australia 4072.
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