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The Latest

Changing the Environment Inside a Program

Question: How do I change the environment inside a program (filename.4gl)? Example: setenv TBCONFIG $tbconfig.01 Answer: I don’t think you can do it. If you’re running a 4gl program, you

Informix 4GL Translators

Question: I want to purchase some software that will translate Informix 4GL to any of the following: Java, C, C++, or Perl. We have two applications that we need to

The const pass-by-value

Question: void foo(const int x) { // not altering x} Herb Sutter in Exceptional C++, pg.177 says, “const pass-by-value is unuseful and misleading at best.” I disagree, at a glance

Can 16-Bit Software Run in Windows 2000?

Question: Can 16-bit software run in Windows 2000 platform? Answer: The answer is yes and no. Many 16-bit software programs run just fine in W2K, as they did in NT

JavaScript Not Working with IE 5.5

Question: Why will this code not work with IE 5.5? Answer: It’s not a question in this case of JavaScript not working with IE 5.5, but of Java not working

Deprecated APIs

Question: How do I make a method deprecated? Answer: Deprecating a method or entire class is as simple as using the “@deprecated javadoc” tag in its documentation. For example: /**

Using cin.good() to Check Inputted Numbers

Question: I’m trying to make a calculator program using switch statements for +,-,* and /. I know how to handle and divide by zero error. I also have to use

Loading a New Window from a Frame.

Question: I have a frameset that consists of two frames. The top frame is a horizontal frame that displays a bulletin message in a banner if there is some sort

Passing Value to an Online Form

Question: Is it possible to use JavaScript to create a custom page and pass all the values in the page to an online form such that I do not have

Significance of const Return

Question: What is the significance of const return type from a function?Similar to: const int func1(); Answer: The const in this position guarantees that the caller of the function doesn’t

Java Profiler

Question: Is there a profiler like JProbe which supports the Microsoft Virtual Machine? I already tried the -prof switch on the command line, but that doesn’t do everything I need.

Reverse DNS

Question: If I can use the “InetAddress” class to acquire the IP address of a computer, is there a way to get the computer’s name from an IP address? Answer:

Using errno in DLLs

C++ inherited from C the global variable errno which indicates the success status of a previous operations. An errno value of 0 indicates that the previous operation was successful whereas

The vector::data() Member Function

In a previous tip, I discussed techniques for treating a vector object as an array. The two main forms of obtaining the internal array’s address are: &*v.begin(); // obtain address

Uninitialized enum Variables

The value of an uninitialized automatic enum variable is indeterminate. Uninitialized global and static enum variables have a zero value by default. In this regard, enum variables are similar to

The Modulus Operator

The operator % returns the remainder of dividing its two operands. For example: b=10%3; // b equals 1 Don’t confuse the modulus operator with the division operator: c=10/3; // division,

Designing Custom Forms

Question: Is it possible to make changes to the text on the tabs? Answer: Sure, with the tab you want to change selected, just click Form > Rename This Page.

Informix Backups Error Message

Question: We have Informix IDS 7.30 running under SCO 5.0.5. Backups by ontape fail with an error: “I/O read chunk 90, pagenum 2, pagecnt 1 –> errno = 9″But when

Locking a Row

Question: How can I lock a row in a table from a stored procedure? Answer: You shouldn’t have to worry about locking. It’s done automatically by the engine when you

Upgrading from AIX 4.2 to AIX 4.3

Question: We have plans to upgrade our AIX operating system to version 4.3. We are using Informix 7.31. Do we need any new Informix components (compilers etc.)? Answer: You probably

SQLLog Wizard

The SQLLog Wizard is used to specify which tables are to be audited. The output of the wizard is a SQL script that that can be run in the Query

Oracle OLE DB and MTS

Trying to figure out how to use the Oracle OLE DB Provider under MTS or COM+ and with Oracle’s OS Authentication? This article explains how these parts fit together and

Image Changeovers

Question: I have seen plenty of text on script dealing with mouseovers, or ‘animation’ where an image can change every few seconds, but is there a way I can write

Form Validation

Question: I need to perform a validation on five fields in a form. The logic is: If field1 length >0 then disallow form submission if field2,field3, field4, and field5 are

Pop-up Window with Links to New Pages

Question: I want to set up a series of links in a pop-up window which, when clicked, will (a) close the popup window and (b) redirect the main page to

Checking the State of a Stream

The iostream family of classes provides the following member functions and operators for checking the stream’s state: bool good() // returns true if no error flag is setbool eof() //

Comma Separated Expressions

An expression may consist of one or more subexpressions. You can group several expressions in one statement and separate them with commas. For example: if(++x, –y, cin.good()) // three expressions

The Semantics of const_iterator

A recent subscriber of one of the C++ newsgroups posted the following question:Why did the C++ standardization committee created a const_iterator instead of a const iterator? Or, at least, why