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From: brian@awfulhak.demon.co.uk (Brian Somers)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: sh command shell script writing. i'm stuck
Date: 31 Jul 1996 22:13:11 +0100
Organization: Coverform Ltd.
Lines: 36
Message-ID: <4toi97$ar@anorak.coverform.lan>
References: <4t02d1$nec@cliff.island.net> <Pine.HPP.3.91.960722171415.29481F-100000@lint.cisco.com> <Dv4rGs.2nv@rockyd.rockefeller.edu>
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Dan Ts'o (dan@dnn.rockefeller.edu) wrote:
: Others have given you solutions as to how to read in one line at a
: time into a script. But these are all a little nasty (because they run awk
: or grep, which is pretty big and then that program re-reads the whole file
: just to pick out another line). Perhaps you could expand on just what you
: are trying to do. There maybe a more efficient way.
: For example, how about something like:
: (
: while read line
: do
: # Do whatever
: echo "Here is another line: $line"
: done
: ) < input_file
If you're gonna complain about the overhead of awk, why do you put the
parenthesis in ? This just loads another shell - for sure. With zsh
(I'm told) and ksh (not pdksh), the following is even better:
x=1
while read line
do
test $x -eq TheNumberIWant && {
echo $line
break
}
done <input_file
The shell will execute everything internally. Of course, you had better
not be particular about your whitespace... and don't forget about the
"break" - ya don't want to read the whole file - do ya ?
--
Brian <brian@awfulhak.demon.co.uk>
Don't _EVER_ lose your sense of humour....