Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!tut.cis.ohio-state.edu!att!cbnewse!fredriks
From: fredriks@cbnewse.ATT.COM (lars.fredriksen)
Newsgroups: comp.os.minix
Subject: RE: cut
Message-ID: <12544@cbnewse.ATT.COM>
Date: 12 Jan 90 16:21:52 GMT
Reply-To: fredriks@cbnewse.ATT.COM (lars.fredriksen,ih,)
Organization: AT&T Bell Laboratories
Lines: 68

Hi!
	I tried to extract columns from a file, just as ast tried to do with
cut, but I used the shell. Correct me if I am wrong, but it
would seem to me that the following should work:

	while read COL1 COL2 COL3 ; do
		echo $COL2 $COL3
	done

Let say the script is called "extract", then you could do 

	extract < listing > output

or whatever you want to do..

The only hitch with this scheme is that the shell is broken. The documentation
on the Bourne shell says that read reads a line from stdin, then assigning
the first word to the first variable, second word to the second variable,..
rest of the line to the last variable.
	That means that if the listing file in the above example contained:
	
	011090 45000 cu.c

COL1 should be equal to 011090, COL2 = 45000, and COL3 = cu.c. 

With the minix shell this is what you get:

COL1 = 011090, COL2 = " ", COL3 = 45000. 

We could work around this by using variables for the spaces too. That holds 
true for a file that has the same number of spaces between each column, but 
not if the file looks like the one following:

	011090 4500 cu.c
	011190  500 temp.out
	011290	  0 empty.out

It is even  possible to handle this, but it becomes a mess in a hurry.


Another thing that the shell seems to do wrong(This has probably been 
pointed out already) is the following:

FILES=`/bin/ls *.c`

for i in $FILES ; do
	echo $i
done

The shell varible dosn't have the right format for this to work. If my 
memory server me right, only the last file will be echoed.

I haven't tested this under 1.5.0 yet.


PS. In regards to system V's version of cut; here is an extract from the man
pages:

-d char	The character following -d is the field delimiter (-f option only).
	Default if tab. Space or other characters with special meaning to the
	shell must be quoted.

-flist	The list following -f is a list of fileds assumed to be separated by
	the delimiter character specified by the -d option;e.q., -f1,7 copies

	the first and seventh field only.
	Sincerely
		Lars Fredriksen