Re: ereg_replace with user defined function?

10 okt 2006 kl. 19.25 skrev Roman Neuhauser:

# frank.arensmeier@nikehydraulics.se / 2006-10-09 22:01:34 +0200:

Thank you Ilaria and Roman for your input. I did not know that preg is able to deal with PCRE patterns.

    "preg" is obviously short for "Perl REGular expressions", while
    PCRE positively means Perl-Compatible Regular Expressions.
    The regexp syntax from Perl is a superset of POSIX "extended"
    regexps, so anything ereg_ function accept will be good for
    preg_ as well (but beware of pattern delimiters).

Thanks for the info. I didn't know that.

As a matter of fact I came up with the following solution (if someone is interested):

    What problem does it solve? I mean, why are you trying to avoid
    preg_replace_callback() in the first place?

Maybe because I didn't know better? Initially, I was using ereg_replace for replacing metric numbers with imperial ones. But obviously, ereg_replace replaces all instances in the given text string. A text containing more than one instance of the same unit, was replaced by the calculated replacement string of the first finding. So I had to think about other ways to do this - which brought me to preg_replace_callback (as I already said - I didn't know that preg takes POSIX patterns as well). Would you suggest a different way? Would it be faster to do the replacement with preg_replace_callback compared to the function I wrote? A page like this one: http://www.nikehydraulics.com/products/product_chooser_gb.php?productMaingroup=5&productSubgroup=33 .. gets converted within 0.32 / 0.34 seconds which I think is quite ok. /frank

the function takes a text and an array with converters like: $converters[] = array ( "metric" => "mm", "imperial" => "in", "ratio" => 0.039370079, "round" => 1 ); $converters[] = array ( "metric" => "m", "imperial" => "ft", "ratio" => 3.280839895, "round" => 1 ); function convertTextString ( $text, $convertTable ) { # this function takes a text string, searches for numbers to convert, convert those numbers and returns # the complete text again. if ( !ereg ( "[[:digit:]]", $text ) ) // if the text does not contain any numbers, return the text as it is { return $text; } foreach ( $convertTable as $convertKey => $convertUnit ) { $pattern = "((\d{1,10}[,|.]*\d{0,10})*(\s)(%s)([$|\s|.|,|\)|/]+| $))"; // this regex looks for a number followed by white space, followed by the metric unit, followed by a closing character like ".", "," or ")" $pattern = sprintf ( $pattern, $convertUnit['metric'] ); while ( preg_match ( $pattern, $text, $matches ) ) { $matches[1] = str_replace ( ",", ".", $matches[1] ); // in case numbers are written like "6,6 m", we need to replace "," with "." // because we do not want to return 0, we have to make shure that the new value is not zero. $itterator = 0; do { $value = round ( ( $matches[1] * $convertUnit['ratio'] ), $convertUnit['round'] + $itterator ); ++$itterator; } while ( $value == 0 || $itterator == 10 ); $replacement = $value . "$2" . $convertUnit['imperial'] . "$4"; $text = preg_replace ( $pattern, $replacement, $text, 1 ); } } return $text; }

--How many Vietnam vets does it take to screw in a light bulb? You don't know, man. You don't KNOW.

Cause you weren't THERE.             http://bash.org/?255991