Solved

File name pattern matching

Posted on 2007-04-04
15
3,403 Views
Last Modified: 2008-01-09
I want to use regular expression to match a file name with a given file name pattern. The pattern can be like "*.log", or "*.log.2*".

For example, I have a file name like this: "xxx.log.2007.04.04"

Then "*.log" will not match this file name.

But "*.log.2*" will match this file name.

How do I construct the regular expression to use the pattern "*.log" and "*.log.2*" then? Thanks.
0
Comment
Question by:integrosys
15 Comments
 
LVL 11

Expert Comment

by:elfe69
ID: 18849181
In that case, I would simply use standard String functions:

if ((filename.endsWith(".log")) || (filename.indexOf(".log.2") > -1)) {
    // the filename matches one of the patterns
}
0
 

Author Comment

by:integrosys
ID: 18849209
In that case, the code would have to search and remove those * from the pattern. This is very troublesome.
0
 

Author Comment

by:integrosys
ID: 18849228
The contents of the following method is what I need:

public boolean match(String fileName, String pattern) {
  // return true if fileName matches pattern; false otherwise
}

So if I call match("xxx.log.2007.04.04", "*.log"), it will return false.

If I call match("xxx.log", "*.log"), it will return true.

If I call match("xxx.log.2007.04.04", "*.log.2*"), it will return true.
0
What is SQL Server and how does it work?

The purpose of this paper is to provide you background on SQL Server. It’s your self-study guide for learning fundamentals. It includes both the history of SQL and its technical basics. Concepts and definitions will form the solid foundation of your future DBA expertise.

 
LVL 11

Accepted Solution

by:
elfe69 earned 25 total points
ID: 18849271
Use standard Java regex:
http://java.sun.com/j2se/1.4.2/docs/api/java/util/regex/Pattern.html

public boolean match(String fileName, String pattern) {
  Pattern p = Pattern.compile(pattern);
  Matcher m = p.matcher(filename);
  return m.matches();
}


0
 

Author Comment

by:integrosys
ID: 18849296
Your solution does not work at all. Have you actually tried running it at all?
0
 
LVL 11

Expert Comment

by:elfe69
ID: 18849338
My solution work if you use regular expression patterns (".*\\.log" instead of "*.log").

If you want other regular expression syntax, I think you have to write your own method.
0
 

Author Comment

by:integrosys
ID: 18849363
You don't seem to get my question. My question is how to write that method using regular expression. If I can write it myself, I wouldn't need to post the question here.
0
 
LVL 11

Expert Comment

by:elfe69
ID: 18849371
What is the expression syntax you want to support ? Only * tokens to replace one or more characters ?
0
 

Author Comment

by:integrosys
ID: 18849422
I need the code for the following method:

public boolean match(String fileName, String pattern) {
  ...
}

So if I call match("xxx.log.2007.04.04", "*.log"), it will return false.

If I call match("xxx.log", "*.log"), it will return true.

If I call match("xxx.log.2007.04.04", "*.log.2*"), it will return true.

NOTE: I do not want to change the pattern that I pass in. This pattern is provided by the users. The users do not understand regular expression. So if they pass in "*.log", then the method itself has to convert to the proper regular expression itself.

Thanks.
0
 
LVL 11

Expert Comment

by:elfe69
ID: 18849633
Use a tokenizer to traverse the pattern and check if you can find all the tokens in the filename in the right order.
0
 

Author Comment

by:integrosys
ID: 18855337
Can you be more specific? Not sure what you mean.
0
 
LVL 4

Assisted Solution

by:funnyveryfunny
funnyveryfunny earned 25 total points
ID: 18994881
String regex = (pattern.equals(*.log))? "^.+\\.log$":"^[\\w]+\\.log[.\\d]+$";
return fileName.matches(regex);

Something like this should do the trick assuming xxx is a character class.
0
 
LVL 1

Expert Comment

by:Computer101
ID: 20143927
Forced accept.

Computer101
EE Admin
0

Featured Post

Optimizing Cloud Backup for Low Bandwidth

With cloud storage prices going down a growing number of SMBs start to use it for backup storage. Unfortunately, business data volume rarely fits the average Internet speed. This article provides an overview of main Internet speed challenges and reveals backup best practices.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
maven project error 5 55
iterator/ListIterator approach 17 26
ejb on wildfly 5 20
Is there a simpler dropbox system? 10 19
This was posted to the Netbeans forum a Feb, 2010 and I also sent it to Verisign. Who didn't help much in my struggles to get my application signed. ------------------------- Start The idea here is to target your cell phones with the correct…
Introduction This article is the first of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article explains our test automation goals. Then rationale is given for the tools we use to a…
Viewers learn how to read error messages and identify possible mistakes that could cause hours of frustration. Coding is as much about debugging your code as it is about writing it. Define Error Message: Line Numbers: Type of Error: Break Down…
This tutorial covers a step-by-step guide to install VisualVM launcher in eclipse.

770 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question