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Chapter 5 - Text Utilities / Text Utilities Reference

Routines / Determining Sorting Order for Strings in the Same Language

CompareString

The CompareString function compares two Pascal strings, making use of the string comparison information from a resource that you specify as a parameter. It takes both primary and secondary sorting orders into consideration and returns a value that indicates the sorting order of the first string relative to the second string.

FUNCTION CompareString(aStr, bStr: Str255;
                       itl2Handle: Handle): Integer;

aStr

One of the Pascal strings to be compared.

bStr

The other Pascal string to be compared.

itl2Handle

The handle to the string-manipulation resource that contains string comparison information.

DESCRIPTION

CompareString returns -1 if the first string is less than the second string, 0 if the
first string is equal to the second string, and 1 if the first string is greater than
the second string.

The itl2Handle parameter is used to specify a string-manipulation resource. If the value of this parameter is NIL, CompareString makes use of the resource for the current script. The string-manipulation resource includes routines and tables for modifying string comparison and tables for case conversion and stripping of
diacritical marks.

Specifying a resource as a parameter is described in the section "Obtaining Resource Information," beginning on page 5-4.

SPECIAL CONSIDERATIONS

CompareString may move memory; your application should not call this function at interrupt time.

ASSEMBLY-LANGUAGE INFORMATION

There is no trap macro for the CompareString function. Instead, you must convert the Pascal string into a text string by creating a pointer to its first character and finding its length, and then use the same macro as you do for the CompareText function, which is described next.