29
Fri, Nov
0 New Articles
  1. You are here:  
  2. Home
  3. Programming
  4. RPG
  5. Tips and Techniques: Compare and Ignore Case

Tips and Techniques: Compare and Ignore Case

RPG
Typography
  • Smaller Small Medium Big Bigger
  • Default Helvetica Segoe Georgia Times

For years, I hoped IBM would provide RPG IV programmers with the ability to compare two fields while ignoring upper/lowercase. Eventually, I decided to add such a function to my RPG xTools in the form of a CompNoCase() subprocedure.

To use CompNoCase(), you simply add it to an IF statement, as follows:

 

     C                   if        CompNoCase(CMPNAM : 'xyz')
     **  Do something when they are equal
     C                   endif

 

This works very well and is very efficient. But I recently realized that a slightly different variation on the CompNoCase() subprocedure is available in the C runtime library. That function is memicmp(), and you can use it in your RPG IV programs by adding the following prototype to your source code:

 

     D memicmp         PR            10I 0 ExtProc('__memicmp')
     D  pValue1                        *   Value
     D  pValue2                        *   Value
     D  nBufLen                      10U 0 Value

 

In addition, you must include the BNDDIR('QC2LE') keyword on your header specification (H-spec).

This function compares one value to another for the given length. Unlike a "normal" RPG-style compare that ignores trailing blanks, memicmp() uses trailing blanks in the comparison. However, you tell it the number of characters to compare, so this subtle difference really isn't an issue.

The memicmp() procedure begins comparing the two values character by character until either the nCompLen (compare length) value is reached or the two characters at the given position do not match. When the procedure detects a mismatch, the position of the mismatch is returned.

So if the two values are ABCxEFG and abc8efg, memicmp() will return a value of 3 to indicate that in offset 3 the two values don't match. Why 3 and not 4? Because C uses zero-based offsets, rather than absolute positions. You always need to add 1 to the result to determine the correct position.

When I use memicmp(), I tend not to use the result value for anything other than a yes/no test condition, as follows:

C                   if        memicmp(CMPNAM:'xyz':%len(%TrimR(CMPNAM)))=0
**  Do something when they are equal
C                   endif

 

This is the statement:

if  memicmp(CMPNAM:'xyz':%len(%TrimR(CMPNAM)))=0

 

I use %TRIMR to remove trailing blanks. Of course 'xyz' would more than likely be a field or named constant. Use this statement to compare the result of memicmp() to zero. If it equals zero, then the two strings are equal (ignoring upper/lowercase).

Not a bad little function, considering everyone has it on their system today, even if you're still on V4R1.

One caveat about memicmp(): The actual C runtime function name is '__memicmp'. That's two underscore characters followed by a lowercase 'memicmp'. If you put one underscore in your prototype, it will not compile!

The best way to obtain C runtime function prototypes is to download them for free from my Web site. Visit www.rpgiv.com/downloads and then click on the corresponding source file name to view a list of members for downloading. Note: I keep prototypes for C and MI function in a source file named QCPYSRC ("Q Copy Source").

 

 

 

Bob Cozzi is a programmer/consultant, writer/author, and software developer of the RPG xTools, a popular add-on subprocedure library for RPG IV. His book The Modern RPG Language has been the most widely used RPG programming book for nearly two decades. He, along with others, speaks at and runs the highly-popular RPG World conference for RPG programmers.

 

BOB COZZI

Bob Cozzi is a programmer/consultant, writer/author, and software developer. His popular RPG xTools add-on subprocedure library for RPG IV is fast becoming a standard with RPG developers. His book The Modern RPG Language has been the most widely used RPG programming book for more than a decade. He, along with others, speaks at and produces the highly popular RPG World conference for RPG programmers.

MC Press books written by Robert Cozzi available now on the MC Press Bookstore.

RPG TnT RPG TnT
Get this jam-packed resource of quick, easy-to-implement RPG tips!
List Price $65.00

Now On Sale

The Modern RPG IV Language The Modern RPG IV Language
 Cozzi on everything RPG! What more could you want?
List Price $99.95

Now On Sale
BLOG COMMENTS POWERED BY DISQUS

LATEST COMMENTS

Support MC Press Online

$

Book Reviews

Resource Center

  • SB Profound WC 5536 Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application. You can find Part 1 here. In Part 2 of our free Node.js Webinar Series, Brian May teaches you the different tooling options available for writing code, debugging, and using Git for version control. Brian will briefly discuss the different tools available, and demonstrate his preferred setup for Node development on IBM i or any platform. Attend this webinar to learn:

  • SB Profound WP 5539More than ever, there is a demand for IT to deliver innovation. Your IBM i has been an essential part of your business operations for years. However, your organization may struggle to maintain the current system and implement new projects. The thousands of customers we've worked with and surveyed state that expectations regarding the digital footprint and vision of the company are not aligned with the current IT environment.

  • SB HelpSystems ROBOT Generic IBM announced the E1080 servers using the latest Power10 processor in September 2021. The most powerful processor from IBM to date, Power10 is designed to handle the demands of doing business in today’s high-tech atmosphere, including running cloud applications, supporting big data, and managing AI workloads. But what does Power10 mean for your data center? In this recorded webinar, IBMers Dan Sundt and Dylan Boday join IBM Power Champion Tom Huntington for a discussion on why Power10 technology is the right strategic investment if you run IBM i, AIX, or Linux. In this action-packed hour, Tom will share trends from the IBM i and AIX user communities while Dan and Dylan dive into the tech specs for key hardware, including:

  • Magic MarkTRY the one package that solves all your document design and printing challenges on all your platforms. Produce bar code labels, electronic forms, ad hoc reports, and RFID tags – without programming! MarkMagic is the only document design and print solution that combines report writing, WYSIWYG label and forms design, and conditional printing in one integrated product. Make sure your data survives when catastrophe hits. Request your trial now!  Request Now.

  • SB HelpSystems ROBOT GenericForms of ransomware has been around for over 30 years, and with more and more organizations suffering attacks each year, it continues to endure. What has made ransomware such a durable threat and what is the best way to combat it? In order to prevent ransomware, organizations must first understand how it works.

  • SB HelpSystems ROBOT GenericIT security is a top priority for businesses around the world, but most IBM i pros don’t know where to begin—and most cybersecurity experts don’t know IBM i. In this session, Robin Tatam explores the business impact of lax IBM i security, the top vulnerabilities putting IBM i at risk, and the steps you can take to protect your organization. If you’re looking to avoid unexpected downtime or corrupted data, you don’t want to miss this session.

  • SB HelpSystems ROBOT GenericCan you trust all of your users all of the time? A typical end user receives 16 malicious emails each month, but only 17 percent of these phishing campaigns are reported to IT. Once an attack is underway, most organizations won’t discover the breach until six months later. A staggering amount of damage can occur in that time. Despite these risks, 93 percent of organizations are leaving their IBM i systems vulnerable to cybercrime. In this on-demand webinar, IBM i security experts Robin Tatam and Sandi Moore will reveal:

  • FORTRA Disaster protection is vital to every business. Yet, it often consists of patched together procedures that are prone to error. From automatic backups to data encryption to media management, Robot automates the routine (yet often complex) tasks of iSeries backup and recovery, saving you time and money and making the process safer and more reliable. Automate your backups with the Robot Backup and Recovery Solution. Key features include:

  • FORTRAManaging messages on your IBM i can be more than a full-time job if you have to do it manually. Messages need a response and resources must be monitored—often over multiple systems and across platforms. How can you be sure you won’t miss important system events? Automate your message center with the Robot Message Management Solution. Key features include:

  • FORTRAThe thought of printing, distributing, and storing iSeries reports manually may reduce you to tears. Paper and labor costs associated with report generation can spiral out of control. Mountains of paper threaten to swamp your files. Robot automates report bursting, distribution, bundling, and archiving, and offers secure, selective online report viewing. Manage your reports with the Robot Report Management Solution. Key features include:

  • FORTRAFor over 30 years, Robot has been a leader in systems management for IBM i. With batch job creation and scheduling at its core, the Robot Job Scheduling Solution reduces the opportunity for human error and helps you maintain service levels, automating even the biggest, most complex runbooks. Manage your job schedule with the Robot Job Scheduling Solution. Key features include:

  • LANSA Business users want new applications now. Market and regulatory pressures require faster application updates and delivery into production. Your IBM i developers may be approaching retirement, and you see no sure way to fill their positions with experienced developers. In addition, you may be caught between maintaining your existing applications and the uncertainty of moving to something new.

  • LANSAWhen it comes to creating your business applications, there are hundreds of coding platforms and programming languages to choose from. These options range from very complex traditional programming languages to Low-Code platforms where sometimes no traditional coding experience is needed. Download our whitepaper, The Power of Writing Code in a Low-Code Solution, and:

  • LANSASupply Chain is becoming increasingly complex and unpredictable. From raw materials for manufacturing to food supply chains, the journey from source to production to delivery to consumers is marred with inefficiencies, manual processes, shortages, recalls, counterfeits, and scandals. In this webinar, we discuss how:

  • The MC Resource Centers bring you the widest selection of white papers, trial software, and on-demand webcasts for you to choose from. >> Review the list of White Papers, Trial Software or On-Demand Webcast at the MC Press Resource Center. >> Add the items to yru Cart and complet he checkout process and submit

  • Profound Logic Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application.

  • SB Profound WC 5536Join us for this hour-long webcast that will explore:

  • Fortra IT managers hoping to find new IBM i talent are discovering that the pool of experienced RPG programmers and operators or administrators with intimate knowledge of the operating system and the applications that run on it is small. This begs the question: How will you manage the platform that supports such a big part of your business? This guide offers strategies and software suggestions to help you plan IT staffing and resources and smooth the transition after your AS/400 talent retires. Read on to learn: