Re: [GENERAL] Desperately Seeking Regular Expression (fwd)

At 15:31 +0300 on 29/04/1999, Thomas Good wrote:


>
> 0) use awk to create tabs where whitespace exists as a field separator.
> 1) use perl to tr tabs back to whitespace within double quoted strings.
> 2) use sed to change "" to \N  (PROGRESS nulls are idiosyncratic/idiotic)
> 3) use sed to change ? (the PROGRESS unknown value) to \N
> 4) use sed to strip the remaining single quotes

Why not do them all in perl? Why run through 4 separate steps if you are
already going through perl?

And did you mean remaining single quotes (') or remaining double quotes (")?

You can first unify steps 0 and 1. Your perl program splits by
double-quotes, and processes every second element (which indicates it's
inside the quotes). You should use the same principle, but process only the
even-numbered strings, changing spaces to tabs, not the other way around.

> 		foreach $elem (@ln) {
> 			if ( $i % 2) {
> 				print '"';
> 				$elem =~ tr/\t/ /;
> 				print $elem;
> 				print '"';
> 			} else {
> 				print $elem;
> 			}
> 			$i++;

Instead:

		foreach $elem (@ln) {
			if ( $i % 2) {
				print '"'.$elem.'"';
			} else {
				$elem =~ tr/ /\t/;
				print $elem;
			}
			$i++;

(May need modifications, especially in the initialization part, but you get
the idea).

Adding the other modifications (assuming you meant remaining double
quotes), you get something along the lines of:

		foreach $elem (@ln) {
			if ( $i % 2) {
				if ( $elem eq "" ) {
					print "\\N";
				} else {
					print $elem;
				}
			} else {
				$elem =~ tr/ /\t/;
				$elem =~ s/?/\\N/;
				print $elem;
			}
			$i++;

Herouth

--
Herouth Maoz, Internet developer.
Open University of Israel - Telem project
http://telem.openu.ac.il/~herutma