Prev: urgent opening for database SQL Server developer with direct client in Bellevue,WA contract6months
Next: JNI - Passing and returning complex values
From: James on 3 Jul 2008 21:12
I`m trying to use regex to match/replace a word in parentheses.
The regular expression

private static final Pattern java_proc =
Pattern.compile("(java)");

does not work, because parentheses are treated as groupings.

Using "\" to designate the parentheses as literal characters does
not work --- not sure why:

private static final Pattern java_proc = Pattern.compile("\(java
\)");

I searched for and read a related post here, but it did not
help. I seem to be having a different problem than they. Or I just
don`t understand the post.

What am I doing wrong? Thanks, Alan
From: James on 3 Jul 2008 21:23
OK, I finally found the words about using double slashes in front of
parentheses. So, now, why won`t the following regular expression
pattern compile?

private static final Pattern java_proc = Pattern.compile("\\\\.+\
\Process\\(java\\)\\");

The error says:

java.lang.ExceptionInInitializerError
Caused by: java.util.regex.PatternSyntaxException: Unknown character
property name {r} near index 6
\\.+\Process\(java\)\
^

This does not make sense to me.

I`m trying to match text of the form (example):

\\GOLLY\Process(java)\% Processor Time

Thanks, Alan
From: Joshua Cranmer on 3 Jul 2008 21:31
James wrote:
> OK, I finally found the words about using double slashes in front of
> parentheses. So, now, why won`t the following regular expression
> pattern compile?
>
> private static final Pattern java_proc = Pattern.compile("\\\\.+\
> \Process\\(java\\)\\");
>
> The error says:
>
> java.lang.ExceptionInInitializerError
> Caused by: java.util.regex.PatternSyntaxException: Unknown character
> property name {r} near index 6
> \\.+\Process\(java\)\
> ^

This is what the regex is seeing. Don't forget that `\' is also a
metacharacter in regexes. So to match a '\' in regex requires you to use
'\\\\', which causes the regex to see '\\', which is what it uses to
match as a '\'. So the regex you're probably trying to compile:
"\\\\{2}.+\\\\Process\\(java\\)\\\\" (The {2} is so that you don't have
to type in 8 slashes)


--
Beware of bugs in the above code; I have only proved it correct, not
tried it. -- Donald E. Knuth
From: James on 3 Jul 2008 21:44
Thank you.

I have one last remaining problem. The full data I`m working with,
in CSV format, looks like this:

"(PDH-CSV 4.0) (Eastern Daylight Time)(240)","\\GOLLY\Memory\%
Committed Bytes In Use","\\GOLLY\Process(java)\% Processor Time"

I want to match on

\\GOLLY\Process(java)\

so I can replace it.

The regular expression

\\\\{2}.+\\\\Process\\(java\\).

matches, but it matches too much of it:


\\GOLLY\Memory\% Committed Bytes In Use","\\GOLLY\Process(java)\

How can I get it to only match the part I want?

Thanks again, Alan
From: Joshua Cranmer on 3 Jul 2008 21:52
James wrote:
> The regular expression
>
> \\\\{2}.+\\\\Process\\(java\\).
>
> matches, but it matches too much of it:

In that case, you probably want this regex:
\\\\{2}[^\\\\]+\\\\Process\\(java\\)
--
Beware of bugs in the above code; I have only proved it correct, not
tried it. -- Donald E. Knuth
 |  Next  |  Last
Pages: 1 2 3
Prev: urgent opening for database SQL Server developer with direct client in Bellevue,WA contract6months
Next: JNI - Passing and returning complex values