preg_match/replace to fix a search query

[fienen]

I am working on a script to handle a search query. In some instances,
the query could come through as "isbn:%20#############" (where %20 is
an encoded space and the colon is optional). Basically I want to
strip off the ISBN portion and leave just the numbers if that is the
case.

Orignally I was trying
$value = $_GET["query"];
if (preg_match("isbn:?%20", $value))
{
$isbn = preg_replace("isbn:?%20", "", $value)
}
else
{
$isbn = $value
}

Doesn't seem to work though. Any thoughts?

[fsidler]

On Mar 16, 5:19 pm, "[e-mail]" <[e-mail]:

I am working on a script to handle a search query. In some instances,
the query could come through as "isbn:%20#############" (where %20 is
an encoded space and the colon is optional). Basically I want to
strip off the ISBN portion and leave just the numbers if that is the
case.

Orignally I was trying
$value = $_GET["query"];
if (preg_match("isbn:?%20", $value))
{
$isbn = preg_replace("isbn:?%20", "", $value)}

else
{
$isbn = $value

}

Doesn't seem to work though. Any thoughts?

I wouldn't use regex unless really nessessary.
I assume your problem lies with the space character. Usually, the
script transforms encoded url characters back into their original
form. I suggest using a normal space char in the script, and just to
make sure, a str_replace("%20", " ", $string) in the beginning.

[Sjoerd]

fi****@gmail.com wrote:

if (preg_match("isbn:?%20", $value))
...
Doesn't seem to work though. Any thoughts?

- The pattern of preg_match needs delimiters. Mostly slashes are used
for this: /pattern/
- Each statement should be ended with a semicolon;
- Note that PHP automatically URL-decodes the GET parameters, so %20 in
the URL will become a space in the GET variable.
- You can use the matches parameter to retrieve the ISBN number.
- When asking a question here, "doesn't seem to work" is not good
enough. Insert echo statements to see whether the preg_match actually
matches and report any error you get in your post.

if (preg_match("/isbn:? ([0-9X]*)/", $value, $match))
{
$isbn = $match[1];
}
else
{
$isbn = $value;
}

Sjoerd

[fienen]

Thanks for all the input. My solution ended up somewhat different,
but in the same vein.

Another script handed off the data based on a regex trigger, therefore
I knew if this was invoked, it had to be a valid ISBN number, so no
need to actually test if it matched since I know it does. If the
query started with "ISBN" or "ISBN:", regardless of the number the
total length would be 13, which is the longest the input could be
and be a valid ISBN, so I used:

if (strlen($bookISBN) 13)
{
$bookISBN = preg_replace('/(\w+)(:)? (\d=)/', '$3', $bookISBN);
}

So far, so good. Everything works just as it should now.

On Mar 16, 1:15 pm, Sjoerd <[e-mail]:

[e-mail] wrote:

if (preg_match("isbn:?%20", $value))
...
Doesn't seem to work though. Any thoughts?

- The pattern of preg_match needs delimiters. Mostly slashes are used
for this: /pattern/
- Each statement should be ended with a semicolon;
- Note that PHP automatically URL-decodes the GET parameters, so %20 in
the URL will become a space in the GET variable.
- You can use the matches parameter to retrieve the ISBN number.
- When asking a question here, "doesn't seem to work" is not good
enough. Insert echo statements to see whether the preg_match actually
matches and report any error you get in your post.

if (preg_match("/isbn:? ([0-9X]*)/", $value, $match))
{
$isbn = $match[1];}

else
{
$isbn = $value;

}

Sjoerd