Re: awk tutorial confusion

Ed Morton <morton@[EMAIL PROTECTED]
> writes:

> Only one problem: the script doesn't work. ... You need to turn off the
quoting
> when the variable is seen. This can be done by ending the quoting, and
> restarting it after the variable:
>
> #!/bin/sh
> column=$1
> awk '{print $'$column'}'
> ----------------------
>
> which is the worst possible way to pass the value of a shell
>variable to an awk program (see
>http://cfaj.freeshell.org/shell/cus-faq-2.html#24
for the right way).

I have always felt that it is essential to understand this particular
mechanism because it solves many shell programming problems. Your
suggestion can *only* be used with AWK and cannot be applied to sed,
grep, bash, etc.  I prefer to teach the more versatile approach.

If you continue reading, I give 4 more variations of this
"Column" function, including version 5, which is:

-------------
#!/bin/sh
awk '{print $c}' c=${1:-1}
------------

(it defaults to printing column #1 if no arguments are given.)

When I wrote this tutorial in 1994, I described the only versions that
worked in the old "classic" AWK. I admit that my tutorial is not up to
date.
I try to do what I can.

But you do make a good point so I added a link to the FAQ you references 
to cover the newer AWKs.







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