简单的正则表达式问题 C#

Question

I need to match the string that is shown in the window displayed below:

8% of setup_av_free.exe from software-files-l.cnet.com Completed

98% of test.zip from 65.55.72.119 Completed

[numeric]%of[filename]from[hostname | IP address]Completed

I have written the regex pattern halfway

if (Regex.IsMatch(text, @"[\d]+%[\s]of[\s](.+?)(\.[^.]*)[\s]from[\s]"))
    MessageBox.Show(text);

and I now need to integrate the following regex into my code above

ValidIpAddressRegex = "^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$";  

ValidHostnameRegex = "^(([a-zA-Z]|[a-zA-Z][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z]|[A-Za-z][A-Za-z0-9\-]*[A-Za-z0-9])$"; 

The 2 regex were taken from this link . These 2 regex works well when i use the Regex.ismatch to match "123.123.123.123" and "software-files-l.cnet.com". However i cannot get it to work when i intergrate both of them to my existin regex code. I tried several variant but not able to get it to work. Can someone guide me to integrate the 2 regex to my existing code. Thanks in advance.

Answer 1

You can certainly combine all these regular expressions into one, but I'd recommend against it. Consider this method, first it checks wether your input text has the correct form overall, then it checks if the "from" part is an IP address or a hostname.

bool CheckString(string text) {
    const string ValidIpAddressRegex = @"^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$";  

    const string ValidHostnameRegex = @"^(([a-zA-Z]|[a-zA-Z][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z]|[A-Za-z][A-Za-z0-9\-]*[A-Za-z0-9])$"; 

    var match = Regex.Match(text, @"[\d]+%[\s]of[\s](.+?)(\.[^.]*)[\s]from[\s](\S+)");
    if(!match.Success)
        return false;        

    string address = match.Groups[3].Value;

    return Regex.IsMatch(address, ValidIpAddressRegex) ||
           Regex.IsMatch(address, ValidHostnameRegex); 
}

It does what you want and is much more readable and than single monster-sized regular expression. If you aren't going to call this method millions of time in a loop there is no reason to be concerned about it being less performant that single regex.

Also, in case you aren't aware of that the brackets around \d or \s aren't necessary.

Answer 2

The "Problem" that those two regexes do not match your string is that they start with ^ and end with $

^ means match the start of the string (or row if the m modifier is activated)
$ means match the end of the string (or row if the m modifier is activated)

When you try it this is true but in your real text they are in the middle of the string, so it is not matched.

Try just remove the ^ at the very beginning and the $ at the very end.

Answer 3

Here you go.

^[\d]+%[\s+]of[\s+](.+?)(\.[^.]*)[\s+]from[\s+]((([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])|((([a-zA-Z]|[a-zA-Z][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z]|[A-Za-z][A-Za-z0-9\-]*[A-Za-z0-9])))[\s+]Completed

Remove the ^ and $ characters from the ValidIpAddressRegex and ValidHostnameRegex samples above, and add them separated by the or character (|) enclosed by parentheses.

Answer 4

You could use this, its should work for all cases. I mightve accidentally deleted a character while formatting so let me know if it doesnt work.

string captureString = "8% of setup_av_free.exe from software-files-l.cnet.com Completed";
Regex reg = new Regex(@"(?<perc>\d+)% of (?<file>\w+\.\w+) from (?<host>" +
    @"(\d+\.\d+.\d+.\d+)|(((https?|ftp|gopher|telnet|file|notes|ms-help):" +
    @"((//)|(\\\\))+)?[\w\d:#@%/;$()~_?\+-=\\\.&]*)) Completed");
Match m = reg.Match(captureString);
string perc = m.Groups["perc"].Value;
string file = m.Groups["file"].Value;
string host = m.Groups["host"].Value;