qstring

Hi
qString str=“Hi my name is Dave, I am using Qt to do my project.”

Can I use some thing like * or ?
str2="hi my name is ?, I am using ? to do my project."

if I compare str2 with str, It should give me Dave and Qt. Something like string Template match.
Please guide.
Thank you

See QRegExp

Code:

---

QString str="my name is dave";
    QRegExp rx("my name is *");
    rx.setPatternSyntax(QRegExp::Wildcard);
   int pos = 0;
   while ((pos = rx.indexIn(str, pos)) != -1) {
qDebug()<< rx.capturedTexts();
 
   qDebug() << rx.cap(1);
   pos += rx.matchedLength();
   }

---

This is not working...please help...thank you

In order to capture parts of the matched text you need to mark the parts you want in the expression with capturing parentheses. Capturing parentheses are not part of the QRegExp::Wildcard matching scheme, you need to use the default regular expression mode.

See Capturing Text in the friendly manual.

Thanks Chris...
I removed rx.setPatternSyntax(QRegExp::Wildcard)...
and modified as below...still I am unable to get my required answer that is Dave.

Code:

---

QRegExp rx("my name is ((s*))");

---

I Even tried //s*. w*...
Not getting...Regex is too hard.

((s*)) means "any number of "s" characters". Is that really what you want?

Code:

---

QString str="my name is dave. I am learning QT";
   QRegExp rx("my name is (\\w*). I am learning (\\w*)");

---

working fine....
I am able to extract dave and Qt

You need escape characters before special characters in regexp, or they'll be treated as plain characters.
Don't forget to escape escape character in code :D
For your example:

Code:

---

QString str="my name is dave";
QRegExp rx("my name is (\\w+)");
int pos = 0;
 
while ((pos = rx.indexIn(str, pos)) != -1) {
	qDebug() << rx.capturedTexts();
	qDebug() << rx.cap(1);
 
	pos += rx.matchedLength();
};

---

Also there's site that I use when trying to come up with particular regexp, hope you find it useful:
http://gskinner.com/RegExr/

the string read from the file is below
reject tcp any any -> any any (content:"twitter.com";msg:"TWITTER1 BEING ACESSED";sid:41325;rev:001;)

Code:

---

QRegExp re("(\\w*) tcp (\\w*) any -> any any \\(content:((\"([A-Za-z0-9_\\./\\-$\\s]*)\"));msg:((\"([A-Za-z0-9_\\./\\-$\\s]*)\"));sid:(\\w*);");
 
 while((pos=re.indexIn(str, pos))!=-1){
 
            list << re.cap(1);//gives first field from string
            list << re.cap(2);//gives 3rd field
            list << re.cap(3);//gives content
            list << re.cap(6);//gives msg
            list << re.cap(9);//gives sid
 
            pos+=re.matchedLength();
 
        }

---

The above regex gives me reject, any, twitter.com, twitter being accessed, 41325
but for that i have to choose 1,2,3,6,9 fields out of the re.cap coz the line has multiple line of quotes.

but the same doesn't work for the below string
alert tcp 192.168.1.9 any -> any any (content:"www.gmail.com";msg:"gmail being ACCESSED";sid:41330;rev:001;)


please help

I suggest you used a number of simple regexps instead of one complex one trying to capture everything.
For example your string is "word word ip word -> word word parenthesized_expr"
So I would captured it like that (double backslashes omitted for clarity)
"(\w+)\s+(\w+)\s+([0-9\.])\s+(\w+)\s*->\s*(\w+)\s+(\w+)\s*(\([^\)]*)\))"
Then take a look at parenthesized_expr (which is in your capture group 7)
(content:"address";msg:"text";sid:num;rev:num; )
Then write a couple of regexps, like "content:\"([A-Za-z0-9_\./\-$\s]*)\"" and others.
Divide and conquer :D

Do you expect "\\w*" to match "192.168.1.9"? You have a few redundant sets of () in the expression that make it uglier than it needs to be.

Try these (you will have to escape the backslashes in C++):

Code:

---

(\S+)\s+tcp\s+(\S+)\s+any\s+->\s+any\s+any\s+\(content:"([^"]+)";msg:"([^"]+)";sid:(\d+)
(\S+)\s+tcp\s+(\S+)\s+any\s+->(?:\s+any){2}\s+\(content:"([^"]+)";msg:"([^"]+)";sid:(\d+)
(\S+)\s+tcp\s+(\S+)[^(]+\(content:"([^"]+)";msg:"([^"]+)";sid:(\d+)

---

Move some parentheses if you want the quotes that surround content and msg to be captured. If acceptable for your purposes you could run QString::simplified() over the test string first and remove the need to look for repeated whitespace separators.

Thanks Cris I realized after posting that...now using this 1..its serving my purpose...but its ugly..I am trying ur suggestions

Code:

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QRegExp re("(\\w*) tcp ([a-zA-Z0-9.]*) any -> any any \\(content:((\"([A-Za-z0-9._:\\./\\-$\\s]*)\"));msg:((\"([A-Za-z0-9_\\./\\-$\\s]*)\"));sid:(\\w*);")

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