regex mystery

[Red]

In netscape bookmark files, there are lots of lines like this:
<DT><A HREF="http://www.commondreams.org/" ADD_DATE="1091500674"
LAST_CHARSET="ISO-8859-1" ID="rdf:#$uiYyb3">Common Dreams</A>

I want to eliminate the excess attributes and values to get this:
<DT><A HREF="http://www.commondreams.org/">Common Dreams</A>

I almost succeed with this:
$lines[]=preg_replace("{(<A HREF=\".*\")( ADD.*)(>.*</A>)}","\\1\\3",
$line);

The only problem is the explicit "ADD". The code only works is there is
an ADD_DATE attribute immediately after the url. I tried replacing (
ADD.*) with ( .*), which I thought would match everything up to the ">":
$lines[]=preg_replace("{(<A HREF=\".*\")( .*)(>.*</A>)}","\\1\\3", $line);

For some reason, this does not find a match. Since " ADD" is the same as
..*, I don't understand why I need the explicit " ADD".

How do I match without the explicit " ADD"

[steve]

"Red" wrote:

In netscape bookmark files, there are lots of lines like this:
<DT><A HREF="http://www.commondreams.org/"
ADD_DATE="1091500674"
LAST_CHARSET="ISO-8859-1" ID="rdf:#$uiYyb3">Common Dreams</A>

I want to eliminate the excess attributes and values to get this:
<DT><A HREF="http://www.commondreams.org/">Common
Dreams</A>

I almost succeed with this:
$lines[]=preg_replace("{(<A HREF=\".*\")(
ADD.*)(>.*</A>)}","\1\3",
$line);

The only problem is the explicit "ADD". The code only works is there is
an ADD_DATE attribute immediately after the url. I tried replacing (
ADD.*) with ( .*), which I thought would match everything up to the
">":
$lines[]=preg_replace("{(<A HREF=\".*\")(
.*)(>.*</A>)}","\1\3", $line);

For some reason, this does not find a match. Since " ADD" is the same as
..*, I don’t understand why I need the explicit " ADD".

How do I match without the explicit " ADD"

I could not follow the code, but this should work
ADD_DATE="1091500674"

$changedlined = preg_replace("/ADD_DATE\=\"\d+\"/", ’’,
$originalline);

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[Michael Fesser]

.oO(Red)

In netscape bookmark files, there are lots of lines like this:
<DT><A HREF="http://www.commondreams.org/" ADD_DATE="1091500674"
LAST_CHARSET="ISO-8859-1" ID="rdf:#$uiYyb3">Common Dreams</A>

I want to eliminate the excess attributes and values to get this:
<DT><A HREF="http://www.commondreams.org/">Common Dreams</A>

I almost succeed with this:
$lines[]=preg_replace("{(<A HREF=\".*\")( ADD.*)(>.*</A>)}","\\1\\3",
$line);

The only problem is the explicit "ADD". The code only works is there is
an ADD_DATE attribute immediately after the url. I tried replacing (
ADD.*) with ( .*), which I thought would match everything up to the ">":
$lines[]=preg_replace("{(<A HREF=\".*\")( .*)(>.*</A>)}","\\1\\3", $line);

For some reason, this does not find a match. Since " ADD" is the same as
.*, I don't understand why I need the explicit " ADD".

It's because of the default greediness of the quantifiers. The .* after
the HREF=\" in your second pattern is quite hungry and eats up every-
thing until the last " in the tag, including the ADD_DATE and everything
else. You can change this behaviour with the U-modifier, e.g.

$pattern = '#(<a href=".*").*(>.*</a>)#iU';
$replace = '$1$2';
$lines[] = preg_replace($pattern, $replace, $line);

Pattern Modifiers
<http://www.php.net/manual/en/pcre.pattern.modifiers.php>

HTH
Micha

[Red]

Michael Fesser wrote:

.oO(Red)

In netscape bookmark files, there are lots of lines like this:
<DT><A HREF="http://www.commondreams.org/" ADD_DATE="1091500674"
LAST_CHARSET="ISO-8859-1" ID="rdf:#$uiYyb3">Common Dreams</A>

I want to eliminate the excess attributes and values to get this:
<DT><A HREF="http://www.commondreams.org/">Common Dreams</A>

I almost succeed with this:
$lines[]=preg_replace("{(<A HREF=\".*\")( ADD.*)(>.*</A>)}","\\1\\3",
$line);

The only problem is the explicit "ADD". The code only works is there is
an ADD_DATE attribute immediately after the url. I tried replacing (
ADD.*) with ( .*), which I thought would match everything up to the ">":
$lines[]=preg_replace("{(<A HREF=\".*\")( .*)(>.*</A>)}","\\1\\3", $line);

For some reason, this does not find a match. Since " ADD" is the same as
.*, I don't understand why I need the explicit " ADD".

It's because of the default greediness of the quantifiers. The .* after
the HREF=\" in your second pattern is quite hungry and eats up every-
thing until the last " in the tag, including the ADD_DATE and everything
else. You can change this behaviour with the U-modifier, e.g.

$pattern = '#(<a href=".*").*(>.*</a>)#iU';
$replace = '$1$2';
$lines[] = preg_replace($pattern, $replace, $line);

Pattern Modifiers
<http://www.php.net/manual/en/pcre.pattern.modifiers.php>

HTH
Micha

What a handy modifier, thanks.

red