Solved

File name pattern matching

Posted on 2007-04-04
15
3,399 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
 
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
Do You Know the 4 Main Threat Actor Types?

Do you know the main threat actor types? Most attackers fall into one of four categories, each with their own favored tactics, techniques, and procedures.

 

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

How to run any project with ease

Manage projects of all sizes how you want. Great for personal to-do lists, project milestones, team priorities and launch plans.
- Combine task lists, docs, spreadsheets, and chat in one
- View and edit from mobile/offline
- Cut down on emails

Join & Write a Comment

Introduction This article is the last of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article covers our test design approach and then goes through a simple test case example, how …
Java functions are among the best things for programmers to work with as Java sites can be very easy to read and prepare. Java especially simplifies many processes in the coding industry as it helps integrate many forms of technology and different d…
Video by: Michael
Viewers learn about how to reduce the potential repetitiveness of coding in main by developing methods to perform specific tasks for their program. Additionally, objects are introduced for the purpose of learning how to call methods in Java. Define …
Viewers will learn about basic arrays, how to declare them, and how to use them. Introduction and definition: Declare an array and cover the syntax of declaring them: Initialize every index in the created array: Example/Features of a basic arr…

744 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

Need Help in Real-Time?

Connect with top rated Experts

13 Experts available now in Live!

Get 1:1 Help Now