QRegExp problem

Question

I have written

QRegExp rx("<img src=\"\\S+\"\\s+width=\"(\\d+)\"\\s+height\"(\\d+)\"\\s+/>");

RegExp in order to match

 <img src="file://c/Users/Narek/Desktop/WClub.jpg" width="95" height="113.04" />

kind of substring in a string, in order to extract the width and height. But this does not match. Please tel me what I have done wrong.

A minor note is that it is usually considered a bad idea to process HTML using regular expressions. See for example http://stackoverflow.com/questions/2179477/best-way-to-parse-html-in-qt on how to parse HTML in Qt. — pafcu, Dec 17 '10 at 15:07
This link is for parsing only, but I parse in order to edit, so I dont find convenient the method proposed in the question whose link is written above. May be there is a better aproach then the QRegExp but not this one. — Narek, Dec 17 '10 at 15:16

score 4 · Answer 1 · edited May 23 '17 at 12:18

4

\d does not match the period in your height.

A regular expression that would work would be something like:

<img src=\"[^"]*\"\s+width=\"(\d+(?:\.\d+)?)\"\s+height=\"(\d+(?:\.\d+)?)\"\s+/>

Also, the obligatory comment that it is a bad idea to parse HTML using Regex.

edited May 23 '17 at 12:18

Community

answered Dec 17 '10 at 14:49

Dave Mateer

Yes, right, but even can not be matched :( – Narek Dec 17 '10 at 14:59
@Joel: Thanks, I also forgot the capture groups. That's why one should use a HTML parser, huh? :) – Dave Mateer Dec 17 '10 at 15:01
@Narek: The decimal and digits after are optional. That is what the non-capturing group `(?:\.\d+)?` does. – Dave Mateer Dec 17 '10 at 15:02
This is the best answer so far. An alternative to `\"[^"]*\"` is a call to `setMinimal(true)` to make quantifiers non-greedy. – Sergei Tachenov Dec 17 '10 at 15:04

score 2 · Accepted Answer · edited Oct 12 '11 at 15:53

2

The last \d doesn't take account of the dot inside the number, and you are missing '=' after 'height'.

edited Oct 12 '11 at 15:53

Brian Mains

answered Dec 17 '10 at 14:51

Simone

score 0 · Answer 3 · answered Dec 17 '10 at 14:43

0

What about :

QRexExp rx("<img src=[^<]+/\> ");

Hope it helps !

answered Dec 17 '10 at 14:43

Andy M

3 Answers3