Legacy Document

Inside Macintosh: Devices /

Chapter 2 - Slot Manager / Slot Manager Reference

Slot Manager Routines / Getting Information From sResources

SGetCString

You can use the SGetCString function to determine the value of a string pointed to by the offset field of an sResource entry.

FUNCTION SGetCString (spBlkPtr: SpBlockPtr): OSErr;

spBlkPtr

A pointer to a Slot Manager parameter block.

<--	spResult	Ptr	A pointer to a copy of the cString data structure.
-->	spsPointer	Ptr	A pointer to an sResource (described in "The sResource," beginning on page 2-7).
-->	spID	SignedByte	The ID of the sResource entry.
X	spSize	LongInt
X	spOffsetData	LongInt
X	spByteLanes	SignedByte
X	spFlags	SignedByte

DESCRIPTION

The SGetCString function returns a copy of the cString data structure pointed to by the offset field of an sResource entry.

You provide a pointer to the sResource in the spsPointer field and specify the ID of the entry in the spID field.

The SGetCString function allocates a memory buffer, copies the value of the cString data structure into it, and returns a pointer to it in the spResult field. You should dispose of this pointer by using the Memory Manager procedure DisposePtr.

SPECIAL CONSIDERATIONS

The SGetCString function may alter the values of the spSize, spOffsetData, spByteLanes, and spFlags fields of the parameter block. Your application should not depend on the values returned in these fields.

SPECIAL CONSIDERATIONS

The SGetCString function allocates memory; your application should not call this function at interrupt time.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the SGetCString function are

Trap macro	Selector
_SlotManager	$0003

You must set up register D0 with the routine selector and register A0 with the address of the Slot Manager parameter block. When _SlotManager returns, register D0 contains the result code.

Registers on entry
A0	Address of the parameter block
D0	$0003

Registers on exit
D0	Result code

RESULT CODES

noErr	0	No error
smNoMoresRsrcs	-344	Requested sResource not found

SEE ALSO

For more information about the cString data structure, see "Firmware," beginning on page 2-7.