POKE

POKE

Writes a value directly into memory

Category: Special

Syntax
Arguments
Details
See Also

Syntax

POKE(source,pointer<,length>)

Arguments

source

specifies a SAS expression that contains a value to write into memory.

pointer

specifies a numeric SAS expression that contains the virtual address of the data that the POKE function alters.

length

specifies a numeric SAS expression that contains the number of bytes to write from the source to the address indicated by pointer. If you omit length, the action that the POKE function takes depends on whether source is a character value or a numeric value:

If source is a character value, then the POKE routine copies the entire value of source to the specified memory location.
If source is a numeric value, then the POKE function converts source into a long integer and writes into memory the number of bytes that constitute a pointer.
Operating Environment Information: Under OS/390, pointers are 3 or 4 bytes long, depending on the situation.

Details

CAUTION:: The POKE function is intended only for experienced programmers in specific cases. If you plan to use this function, use extreme care both in your programming and in your typing. Writing directly into memory can cause devastating problems. It bypasses the normal safeguards that prevent you from destroying a vital element in your SAS session or in another piece of software that is active at the time.

If you do not have access to the memory location that you specify, the POKE function returns an "Invalid argument" error.

See Also

Functions:

ADDR

PEEK

PEEKC

CALL Routine:

CALL POKE

Chapter Contents
Previous
Next
Top of Page