Arie Folger wrote:
>Hi,
>
>I am trying to implement a conditional regexp by inserting perl code in a
>regexp, as per the perlre man page, but am having no success. Anybody know
>how to fix the code below?
>
> [afolger@localhost afolger]$ perl -e '
> > $_ = "abcdefg";
> > s/bc(?{if (/e/){$a = "hi"}else{$a = "HI"}})e/bc${a}e/;
> > print $_."\n";
> > '
> Sequence (?{...}) not terminated or not {}-balanced at -e line 3, within
> pattern
> Sequence (?{...}) not terminated or not {}-balanced before HERE mark in regex
> m/bc(?{ << HERE if (/ at -e line 3.
> [afolger@localhost afolger]$
>
>
The error you see is the result of perl terminating the 'lookup part' of
the s/// statement with the first slash in 'if (/e/)'. the zero-width
code execution assertion does not protect against illegal use of the
bracketing character with in the regular expression. to solve that ,
either escape the slashes in the if expression with a backslash, or
change the brackting character of either regular expression (s/// or
m//) to something else, for example - a pipe.
Another problem I see, is that your code regular expression will always
fail. as the code execution assertion is a zero-width assertion,
discarding the code block for a second here, your regular expression
would look like this :
s/bce/bc${a}e/
which will ofcourse always fail for the input "abcdefg".
you probably wanted to do
s/bc.*(?{if (m|e|){$a = "hi"}else{$a = "HI"}})e/bc${a}e/;
--
Oded Arbel
m-Wise mobile solutions
[EMAIL PROTECTED]
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