$_='|value 1|value two|"|Value 3 was "NULL"|2001/06/06|';
s/(\|.*?)(")(?!")(.*?\|)/$1$3/;
print;
there are 4 sets of parens in the regex, I'll try to break them down :
the first one looks for a pipe, then any number of characters (but not being greedy about it)
the second grabs the lone quote
the third is a negative lookahead. This is where is golden nugget of regular expression goodness lies!
the negative lookahead makes sure that there's no quote following the one from the second backreference. Also, since it's a zero-width assertion, it doesn't create a backreference of its own.
Finally, the last set of parens describes "the rest of the string" up to the ending pipe-delimiter.
So,
"look for a pipe, and then any characters up to a quote, make sure it's not followed by another quote, and then the rest of the string, up to a pipe"
Now the one caveat for this re is that it will misbehave on "", but my reg-fu is not strong enough to determine the handler for that contingency.
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.
|