Make Qshell Clean Up After Itself
December 18, 2002 Timothy Prickett Morgan
I’ve written a Qshell script that creates some work files that are needed only for the duration of the script. I want the script to delete them before it ends. Here’s the problem: There are several places where the script can end normally and plenty of places where execution of the script could end abnormally. In CL, I’d use a goto command to branch to an end-of-job routine, where I could put commands to clean up, but Qshell does not have a goto command.
I never thought I’d wish for a goto command, but I do. Do you have any suggestions?
Qshell doesn’t have a goto command, but it does have other mechanisms for handling tasks that goto handles in other languages.
In this case, you should trap the EXIT event. Traps are asynchronous monitors. That is, they take over whenever something happens. The EXIT event happens when the script ends.
The following short script creates two work files. The $$ special variable returns the process ID. Placing the process ID within a file name is a good way to create work files that other jobs will not bother. A process ID is an integer number. If the process ID is 8406, for example, the work files will be named temp.1.8406 and temp.2.8406. When the script ends, the EXIT trap kicks in and runs the rm command to delete the work files.
trap 'rm *.$$' EXIT > temp.1.$$ > temp.2.$$ ls temp.*.* exit
For another example of how to use a trap, see the article, “Tracing a Qshell Variable,” which published in the June 19 issue of Midrange Guru, OS/400 Edition.
What is it? Why do you need it?
CASS stands for “Coding Accuracy Support System.” This is a test developed by the U.S. Postal Service to determine whether ZIP Code software can accurately assign ZIP Codes to mailing addresses. CASS-certified software is intended to improve the accuracy of carrier route, 5-digit ZIP, ZIP+4, and delivery point codes.
CASS certified means the software has passed the test. When you use CASS software to update and maintain your mailing file, then your mailing file becomes CASS certified. What does this mean to you?
CASS certification is the first step in qualifying for postage discounts. Look at the mail you receive at home and at work; you will see that a lot of it was mailed for less than the regular 37 cent rate.
Despite all the glitz and glamour of the Internet, email, and such, the wheels of America’s economy are lubricated by the ordinary envelope and the U.S. Postal Service.
If your company sends out a lot of mail, there is a good chance CASS certification can cut your postage expense. There are other steps you must perform to get these discounts, but CASS is the first step.
Your mail must be printed, sorted, and then packaged according to postal regulations. It takes some effort, but the potential savings make it worthwhile.
Exactly what happens when you process your mailing files with CASS software? The software breaks the address down into its individual elements: state, city, street name, and so forth. Then the information is compared to the national ZIP+4 database. If a match is found, the ZIP Code, ZIP+4, delivery point, and carrier route are assigned. Also the delivery line is standardized to comply with Postal Service preferences.
If an address can’t be matched, no action is taken. This has the positive effect of allowing you to identify addresses in your mailing files which possibly can’t be delivered, will be delayed in delivery, or at the very minimum need some minor correction to one of the address elements.
Using CASS certified software has many side benefits. You will be able to identify addresses that are potentially undeliverable. It has been estimated that as much as 30% of all advertising mail is never delivered.
That means the costs of postage, printing, paper, and overhead for undelivered mail are wasted. That means if you spend $100,000 on a direct mail campaign, as much as $30,000 could be completely wasted.
CASS software provides a number of intangible benefits. With CASS certification and bar coding there is a good likelihood that that your mail will be delivered sooner. If your invoices are delivered one day sooner, you may receive payment one day sooner.
If you CASS certify your mailing file, you can move on to the next step which is postal automation. This means applying a POSTNET bar code.
POSTNET is that little row of tall and short bars you see on your mail. POSTNET is a special bar code used by the Postal Service to allow automatic sorting machines to work.
It has been reported that bar code standard class (the old third class) mail gets delivered about as soon as first class, instead of the usual 2 or 3 weeks.
The bottom line is that using CASS software will help you keep your customers’ address information in much better shape than they would be otherwise. Your mail may be delivered sooner at less cost and that means more bottom-line dollars for your company.
If you would like more information about CASS and CASS software,
Are FedEx, United Parcel, and Airborne charges
Every bad address can result in a $5 to $10 charge. Even seemingly small addressing errors such as misspelled street names, or missing suite numbers can result in the same penalty as if the address were totally wrong.
Our PER/ZIP4 addressing matching software will match your addresses to the national ZIP+4 postal database. Based on the match PER/ZIP4, will update your addresses to postal standards. Our sophisticated address logic can add missing directionals, correct minor misspellings, and standardize the address format. If PER/ZIP4 can’t match the address, then you know that there is likely a serious error in the address that needs to be corrected.
PER/ZIP4 can be used in a batch mode to update an entire file or interactively to update individual address one at a time. We provide a search function so that you can search the national ZIP+4 database to verify a specific address.
Visit our Web site www.worksright.com for more information and to order a free, no-hassle, 30-day trial. Or call WorksRight Software, Inc., at 601-856-8337.