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From: dattier@vpnet.chi.il.us (David W. Tamkin)
Newsgroups: comp.unix.shell
Subject: Re: How to read sequentially from a file in SH (not KSH)
Message-ID: <1991Apr30.205732.10742@vpnet.chi.il.us>
Date: 30 Apr 91 20:57:32 GMT
References: <1991Apr27.012336.2732@shibaya.lonestar.org> <232@bria.UUCP> <1991Apr29.105329.20148@spider.co.uk>
Organization: VPnet Public Access Unix, Villa Park, Illinois  60181-2206
Lines: 26

mark@spider.co.uk (Mark Valentine) wrote in
<1991Apr29.105329.20148@spider.co.uk>, quoting two other people:

| afc> while read VAR1 VAR2 < $FILENAME; do
| afc>   echo $VAR1 $VAR2
| afc> done
| afc>
| afc> but I keep reading the first line in the file over and over.  Nothing in
| afc> the manual page seems to be usable in this situation.  How is this done
| afc> under SH?  Is it possible?

| mike> cat $FILENAME | while read VAR1 VAR2
| mike> do echo $VAR1 $VAR2
| mike> done

Mike was onto it, but the extra fork for cat is unnecessary:

while read VAR1 VAR2
do echo $VAR1 $VAR2
done < $FILENAME

The trick is to redirect the entire loop and not just the read command.
Mark Valentine's suggested solution is not needed for this simple case.

David Tamkin  PO Box 7002  Des Plaines IL  60018-7002  dattier@vpnet.chi.il.us
GEnie:D.W.TAMKIN  CIS:73720,1570  MCIMail:426-1818  708 518 6769  312 693 0591