Solved

alphanumeric - finding one less!

Posted on 2002-05-08
4
192 Views
Last Modified: 2010-03-05
Hi

I need some help to chamge the end character in a string of letters to the character or number which is one less based on alphanumeric characters and maintaining case

example string 1 - " /YEZ/NOZ1/B2FREE/fixed "
example string 2 - " /YEZ/NOZ1/B2FRE3/fixed "

I want to become

example string 1 - " /YEZ/NOZ1/B2FRED/fixed "
example string 2 - " /YEZ/NOZ1/B2FRE2/fixed "

I have tried using "$string =~ s/$end/$end -1/"

but it doesn't work becase it is not a number and sometimes it finishes with "a letter/fixed" sometimes "a number/fixed"

"fixed" is the known string which is always constant...
"/APHANUM/APHANUM/APHANUM/" is the dynamic bit and it is always the character before "/fixed" that I need to be one less...

Can anyone tell me how to do it?

thanks

Jilly  
0
Comment
Question by:jillybabe
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
4 Comments
 
LVL 6

Accepted Solution

by:
holli earned 100 total points
ID: 6996554
this is one way:

$b="/YEZ/NOZ1/B2FREE/fixed";
$a="/YEZ/NOZ1/B2FRE3/fixed";

$a=~s|(.{1})/fixed|chr(ord($1)-1).'/fixed'|e;
$b=~s|(.{1})/fixed|chr(ord($1)-1).'/fixed'|e;

print "$a\$b";


regards,

holli
0
 
LVL 1

Expert Comment

by:japhyRPI
ID: 6998068
What should "BAA" decrease to?  "AZZ"?  And how about "FR0"?  That's a zero, so should it be "FQ9"?  We need more assistance with these boundary cases.  It's far easier to INCREMENT than to decrement.
0
 

Author Comment

by:jillybabe
ID: 6998242
Great that did it !

Thanks holli and you too japhyRPI

Jilly
0
 
LVL 1

Expert Comment

by:japhyRPI
ID: 6998715
Jilly, I'm just warning you that the current response turns "BAA" into "BA@", "FR0" into "FR/", and "STa" into "ST`".  To overcome these situations, you're going to need a slightly different regex.
0

Featured Post

[Webinar] Learn How Hackers Steal Your Credentials

Do You Know How Hackers Steal Your Credentials? Join us and Skyport Systems to learn how hackers steal your credentials and why Active Directory must be secure to stop them. Thursday, July 13, 2017 10:00 A.M. PDT

Question has a verified solution.

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

On Microsoft Windows, if  when you click or type the name of a .pl file, you get an error "is not recognized as an internal or external command, operable program or batch file", then this means you do not have the .pl file extension associated with …
I have been pestered over the years to produce and distribute regular data extracts, and often the request have explicitly requested the data be emailed as an Excel attachement; specifically Excel, as it appears: CSV files confuse (no Red or Green h…
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions. Consider email address RFCs: Look at HTML5 form input element (with type=email) regex pattern: T…
Six Sigma Control Plans

617 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