24
Wed, Jul
0 New Articles

TechTip: From a PC Text File to a System i Physical File in One or Two Easy Steps

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

Let's wrap up our three-part FTP series by performing an import.

 

In part 1 of this TechTip series, I explained how to automate FTP transfers. In part 2, I showed how to use the procedure in a real-life situation. Now, part 3 will focus on how to import a text file into a physical file.

 

It all depends on how the input file is formatted. Basically, it comes down to a very simple thing: it either has fields with fixed lengths or uses some sort of character to separate the values (like a CSV uses the comma).

 

My approach to the first type would be to create a physical file with the same field structure (i.e., same field lengths and types) as your text file and transfer the text file directly into the physical file using FTP. This doesn't require any programming, just the steps described in part 1 with a little twist: instead of changing the directory to an IFS folder, you'll need to change to the library where your physical file resides.

 

To import the second type, two steps are required: the text file is sent to an IFS folder (via FTP, for example), and then it's copied to the receiving physical file via the CPYFRMIMPF command. Let's assume for a moment that I want to transfer file myfile.txt to a physical file called IMPORTFILE and that the text file uses the semi-colon (;) as the field separator. The command to import the file would be this:

 

CPYFRMIMPF FROMSTMF('/textfiledir/myfile.txt') TOFILE(IMPORTFILE) MBROPT(*REPLACE) RCDDLM(*CRLF) FLDDLM(';') RPLNULLVAL(*FLDDFT)

 

Since IMPORTFILE is a temporary input file, I'm using MBROPT(*REPLACE), which will clear the first member of the file (default value of the TOFILE parameter for the file's member) before copying the data.

 

Then, RCDDLM(*CRLF) means that each line, terminated by a hard return + line feed or [ENTER] character, represents a record. If the input file is generated by a program, this is the most usual "record delimiter character."

 

Next, the most important parameter: FLDDLM(';') indicates that the field delimiter character is the semi-colon. This is the parameter that varies from one file format to another. In some cases, it might be a comma; in others, the semi-colon or some other character. It doesn't matter, as long as you change the FLDDLM parameter to the appropriate value.

 

Last, but not least, RPLNULLVAL(*FLDDFT) tells the system to replace the NULL values of the input file's fields with the temporary physical file's fields' default value. For instance, if there's no value for an integer field on the physical file, it will be replaced by (or converted to) zero.

 

Now, how to avoid the repetitive task of copying the text file into the physical file?

 

The objective is to get the data into the database. Obviously, there will be some sort of field validation/business rules checks. For that, there will be an RPG program. We can use the same program to transfer the data, validate it, and import it to the database, but there's a catch: once you declare the import file and the program starts running, the file will be locked and the CPYFRMIMPF command will not run. The trick is declaring the file as user-open (USROPN keyword in the file declaration line):

 

FIMPORTFILEIF   E             Disk    UsrOpn

 

Then, copy the data using CPYFRMIMPF before opening the file (as shown below).

 

      ...

        //Prepare the data copy command

         P_Cmdlin = 'CPYFRMIMPF FROMSTMF(' + '''' + '//textfiledir/myfile.txt' +

                    '''' + ') TOFILE(IMPORTFILE) MBROPT(*REPLACE) ' +

                    'RCDDLM(*CRLF) FLDDLM(' + '''' + ';' + '''' + ') ' +

                    'DECPNT(*COMMA) RPLNULLVAL(*FLDDFT)';

        //Execute the data copy command

       ExecCmd(P_CmdLin);

      //Open the file to process the data

      Open IMPORTFILE;

      ...

 

I'm using procedure ExecCmd, but you can also use QCMDEXC to execute the command. Just remember to close the file before the end of the program!

 

This concludes the second method of getting data into System i and processing it automatically.

 

Note that the procedures described in these three TechTips have some drawbacks. Keep in mind that storing a user's password in a text file (I mean the FTP script file) is a security risk, which can be mitigated with adequate file access authorities and file concealing tricks, like hiding it with an inconspicuous name among other files or changing the extension (it's not required to be .scp) to nfo, dll, or whatever you prefer.

 

There are other alternatives to transfer files, like dedicated FTP and SFTP software, available on the market. If it can be invoked via a command line, it can be used in a batch file, like the plain and simple FTP used in part 2.

 

Then, email is not 100 percent reliable, so weigh carefully the pros and cons of the solution proposed in part 2.

 

The bottom line is that you can automate those tedious file-transfer-run-program tasks by using any kind of FTP data transfer that can be invoked via the command line and RMTCMD (or its equivalent on non-iSeries Access software).

 

Next, I'll explain how to invoke programs from a PC-based application and get the results in real-time using ODBC!

Rafael Victoria-Pereira

Rafael Victória-Pereira has more than 20 years of IBM i experience as a programmer, analyst, and manager. Over that period, he has been an active voice in the IBM i community, encouraging and helping programmers transition to ILE and free-format RPG. Rafael has written more than 100 technical articles about topics ranging from interfaces (the topic for his first book, Flexible Input, Dazzling Output with IBM i) to modern RPG and SQL in his popular RPG Academy and SQL 101 series on mcpressonline.com and in his books Evolve Your RPG Coding and SQL for IBM i: A Database Modernization Guide. Rafael writes in an easy-to-read, practical style that is highly popular with his audience of IBM technology professionals.

Rafael is the Deputy IT Director - Infrastructures and Services at the Luis Simões Group in Portugal. His areas of expertise include programming in the IBM i native languages (RPG, CL, and DB2 SQL) and in "modern" programming languages, such as Java, C#, and Python, as well as project management and consultancy.


MC Press books written by Rafael Victória-Pereira available now on the MC Press Bookstore.

Evolve Your RPG Coding: Move from OPM to ILE...and Beyond Evolve Your RPG Coding: Move from OPM to ILE...and Beyond
Transition to modern RPG programming with this step-by-step guide through ILE and free-format RPG, SQL, and modernization techniques.
List Price $79.95

Now On Sale

Flexible Input, Dazzling Output with IBM i Flexible Input, Dazzling Output with IBM i
Uncover easier, more flexible ways to get data into your system, plus some methods for exporting and presenting the vital business data it contains.
List Price $79.95

Now On Sale

SQL for IBM i: A Database Modernization Guide SQL for IBM i: A Database Modernization Guide
Learn how to use SQL’s capabilities to modernize and enhance your IBM i database.
List Price $79.95

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: