vbscript, Regular expressions question

Regular expressions question

Author	Message
John O'Connel #1 / 5	Regular expressions question I'm trying to match the <script> ... </script> in the following HTML text using a regular expression: <script language="vbscr>ipt" for="idDoit" event="onclick"> Dim re, Match, Matches, s, m Set re = new RegExp re.Pattern = idPattern.value re.Global = true re.IgnoreCase = true s = idInput.value m = "" Set Matches = re.Execute(s) for each Match in Matches m = m & Match.Value & vbCrLf next idOutput.innerText = m </script> and using the pattern: <.?script.>[.\s] As far as my knowledge of regexps goes, that pattern should match everything after the first line right up to and including the last line. However, the pattern actually only matches as follows (starting position is indicated): _________________________________________________ 0: <script language="vbscr>ipt" for="idDoit" event="onclick"> 357: </script> _________________________________________________ My question is: how can I match opening and closing HTML tags and their content when spread across lines in a string? TIA John O'Connell
Mon, 16 Jun 2003 23:43:20 GMT

Mark Bosle #2 / 5	Regular expressions question Perl has a flag whereby you can tell the Regex engine that dot (.) should also match newlines and crs. VBScript doesn't have that, but a simplework around comes with [^\v] this matches any character except a vertical tab (whatever that is). So, my solution would be re.Pattern = "<script[^\v>]>[^\v]?</script>" Note that the non-greedy quantifier are important (the ? after * makes it non-greedy). Without it, the regex will match the first <script and the very last </script>-Not what you want if there are multiple blocks. Cheers, Mark Bosley Check out Chris Stefano's RegExTools at http://www.vbxml.com/regextools/
Tue, 17 Jun 2003 06:30:06 GMT

John O'Connel #3 / 5	Regular expressions question Thanks for that. I tried your exact solution but that caused an "Unexpected quantifier" error when the regexp was executed. I removed the optional match (?) and it worked okay but the greediness of the * becomes a problem. I'm using VBScript 5.1, so perhaps I should try your solution with 5.5 or 5.6. I'm fairly new to RegExps (I'm currently working through Mastering Regular Expressions) and don't see why the following doesn't work... <script[.\s>]>[.\s]</script> ...given that . (dot) matches any character and \s matches any whitespace char including CR, LF etc . Thanks again John O'Connell
Wed, 18 Jun 2003 02:52:37 GMT

Mark Bosle #4 / 5	Regular expressions question Whoops, right after I turned my computer I realized I should have mentioned this needs VBScript 5.5 (available at http://www.microsoft.com/msdownload/vbscript/scripting.asp) This brings you much of what Perl offers (in terms of patterns, although Regex's are integrated into Perl to a remarkable degree) Why do you need the non-greedy ? quantifier? Consider the following: <html> <body> <script language="JavaScript"> function foo() { return true; Quote: } </script> <h1>Text</h1> <script language="JavaScript"> function faa() { return false; Quote: } </script> </body> </html> With <script[.\s>]>[.\s]</script> the regex engine matches <script language="JavaScript"> With [.\s] the Regex engine matches everything to the end of the text. Then it begins to back up looking to match </script> This gives one match: <html> <body> <script language="JavaScript"> function foo() { return true; Quote: } </script> <h1>Text</h1> <script language="JavaScript"> function faa() { return false; Quote: } </script> </body> </html> By adding ? to , the regex engine is matching [.\s] and looking for </script> at the same time. Thus with <script[.\s>]>[.\s]?</script>, we get two matches <html> <body> <script language="JavaScript"> function foo() { return true; Quote: } </script> <h1>Text</h1> <script language="JavaScript"> function faa() { return false; Quote: } </script> </body> </html> matches zero to infinite with a preference towards the infinite. ? matches zero to infinite with a preference towards zero. + matches one to infinite with a preference towards the infinite. +? matches one to infinite with a preference towards one. If you have plenty of free time, you can check out my page at http://www.vbxml.com/people/bosley/rgxpage.asp This is not a substitute for Mastering Regular Expressions Cheers, Mark Thanks for that. I tried your exact solution but that caused an "Unexpected quantifier" error when the regexp was executed. I removed the optional match (?) and it worked okay but the greediness of the becomes a problem. I'm using VBScript 5.1, so perhaps I should try your solution with 5.5 or 5.6. I'm fairly new to RegExps (I'm currently working through Mastering Regular Expressions) and don't see why the following doesn't work... <script[.\s>]>[.\s]</script> ...given that . (dot) matches any character and \s matches any whitespace char including CR, LF etc . Thanks again John O'Connell
Wed, 18 Jun 2003 06:06:22 GMT

John O'Connel #5 / 5	Regular expressions question Thanks for that info Mark. Yep I sussed that I'd need 5.5 Thanks again John Whoops, right after I turned my computer I realized I should have mentioned this needs VBScript 5.5 (available at http://www.microsoft.com/msdownload/vbscript/scripting.asp) This brings you much of what Perl offers (in terms of patterns, although Regex's are integrated into Perl to a remarkable degree) Why do you need the non-greedy ? quantifier? Consider the following: <html> <body> <script language="JavaScript"> function foo() { return true; } </script> <h1>Text</h1> <script language="JavaScript"> function faa() { return false; } </script> </body> </html> With <script[.\s>]>[.\s]</script> the regex engine matches <script language="JavaScript"> With [.\s] the Regex engine matches everything to the end of the text. Then it begins to back up looking to match </script> This gives one match: <html> <body> <script language="JavaScript"> function foo() { return true; } </script> <h1>Text</h1> <script language="JavaScript"> function faa() { return false; } </script> </body> </html> By adding ? to , the regex engine is matching [.\s] and looking for </script> at the same time. Thus with <script[.\s>]>[.\s]?</script>, we get two matches <html> <body> <script language="JavaScript"> function foo() { return true; } </script> <h1>Text</h1> <script language="JavaScript"> function faa() { return false; } </script> </body> </html> matches zero to infinite with a preference towards the infinite. ? matches zero to infinite with a preference towards zero. + matches one to infinite with a preference towards the infinite. +? matches one to infinite with a preference towards one. If you have plenty of free time, you can check out my page at http://www.vbxml.com/people/bosley/rgxpage.asp This is not a substitute for Mastering Regular Expressions Cheers, Mark Thanks for that. I tried your exact solution but that caused an "Unexpected quantifier" error when the regexp was executed. I removed the optional match (?) and it worked okay but the greediness of the becomes a problem. I'm using VBScript 5.1, so perhaps I should try your solution with 5.5 or 5.6. I'm fairly new to RegExps (I'm currently working through Mastering Regular Expressions) and don't see why the following doesn't work... <script[.\s>]>[.\s]</script> ...given that . (dot) matches any character and \s matches any whitespace char including CR, LF etc . Thanks again John O'Connell
Fri, 20 Jun 2003 04:24:24 GMT

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