Re: q and escaping paired delimiters

On Sun, 27 Jul 1997 chrisn@rock.petersons.com wrote:

> $\ = "\n";
> print '\'this\'';
> print q{'this'};
> print q{{this}};
> print q{\{this\}};
> 
> I would expect the output to be:
> 
> 'this'
> 'this'
> {this}
> {this}

That this should be fixed makes perfect sense to me. You can view easily
view backwhacking both sides as a generalization of backwhacking the quote
for an unbalanced q''.

In fact, the code in toke.c looks a little suspicious, as if a cut'n'paste
error happened, and the balanced branch didn't get the cleanup it
deserved. There's a "if term != '\\'" statement that does nothing, for
example.

Here'a patch over 5.004_01 (although I'd expect it to work with most
versions) to allow you to escape both the starting and end quotes for q
(unbalanced and qq is unchanged), and the obligatory addition to the
tests. If nobody has any complaints, I expect this will be in _02.

Credited: Gurusamy Sarathy <gsar@engin.umich.edu>

p5p-msgid: Pine.LNX.3.93.970727172201.350K-100000@kjahds.com

1 files changed, 2 insertions, 2 deletions

diff --git a/toke.c b/toke.c
index f443af7442..ff3be0dc84 100644
--- a/toke.c
+++ b/toke.c
@@ -4953,8 +4953,8 @@ char *start;
 	    for (; s < bufend; s++,to++) {
 		if (*s == '\n' && !rsfp)
 		    curcop->cop_line++;
-		if (*s == '\\' && s+1 < bufend && term != '\\') {
-		    if (s[1] == term)
+		if (*s == '\\' && s+1 < bufend) {
+		    if ((s[1] == multi_open) || (s[1] == term))
 			s++;
 		    else
 			*to++ = *s++;