Non-Printing Characters

ASCII characters with value less than 32 or greater than 126 do not have printable representations. Such characters can be included in string constants by specifying their ASCII value as a byte argument to the STRING function.

For example, to represent the TAB character, use the expression

STRING(9B)

This syntax can be used when comparing strings or performing regular expression matching. For example, to find the position of the first TAB character in a string:

pos = STREGEX(input_string, STRING(9b))

where input_string is a variable containing the string to be searched.

The following table lists the some ASCII characters you might commonly want to represent as IDL strings.

Table 14-3: Selected ASCII Characters
and Their Byte Values
ASCII Character	Byte Value
Bell	7B
Backspace	8B
Horizontal Tab	9B
Linefeed	10B
Vertical Tab	11B
Formfeed	12B
Carriage Return	13B
Escape	27B

For a complete list, consult a standard ASCII table.

Note
ASCII characters may have different effects (or no effect) on platforms that do not support ASCII terminal commands.