National Instruments 320682C Formatting and I/O Library Programming Examples

Chapter 2 Formatting and I/O Library

Some formats may have been correctly detected in the input, and the corresponding target

parameters will have been filled in. Formats situated after the literal which did not appear,

however, will not have been executed.

The function return value can be used to determine exactly how many target parameters were

actually fulfilled by the input. You can use the function NumFmtdBytes to determine the

number of bytes consumed from the source parameter.

Because the left side of the > symbol must be a single format specifier, literal characters, if

present, must be on the right side of the symbol. Literals on the left side, or more than one

format specifier on the left side, result in a -1 error, indicating a faulty format string. The

function GetFmtErrNdx can then be used to determine exactly where in the format string the

error lies.

The characters %, [, ], <, and > have special meaning in the format strings. To specify that these

characters be taken literally, they should be preceded by %.

Formatting and I/O Library Programming Examples

This section contains examples of program code that use the Formatting and I/O Library

functions. The formatting and scanning functions are the basis of most of the examples.

The Fmt/FmtFile/FmtOut examples are logically organized as shown:

Integer to String

Long Integer to String

Real to String in Floating-Point Notation

Real to String in Scientific Notation

Integer and Real to String with Literals

Two Integers to ASCII File with Error Checking

Real Array to ASCII File in Columns and with Comma Separators

Integer Array to Binary File, Assuming a Fixed Number of Elements

Real Array to Binary File, Assuming a Fixed Number of Elements

Real Array to Binary File, Assuming a Variable Number of Elements

A Variable Portion of a Real Array to a Binary File

Concatenating Two Strings

Appending to a String

Creating an Array of File Names

Writing a Line Containing an Integer with Literals to the Standard Output

Writing to the Standard Output without a Linefeed/Carriage Return

The Scan/ScanFile/ScanIn examples are logically organized as shown:

String to Integer

String to Long Integer

String to Real