Lock Instruction

Syntax:

Lock StreamNum

-or-

Lock StreamNum, RecordNum

-or-

Lock StreamNum, [start] To end

Group: File

Description:
Form 1: Lock all of StreamNum.

Form 2: Lock a record (or byte) of StreamNum.

Form 3: Lock a range of records (or bytes) of StreamNum. If start is omitted then lock starting at the first record (or byte).

Note: Be sure to Unlock for each Lock instruction.
Note: For sequential files (Input, Output and Append) lock always affects the entire file.

Parameter Description

StreamNum Streams 1 through 255 are private to each macro. Streams 256 through 511 are shared by all macros.

RecordNum For Random mode files this is the record number. The first record is 1. Otherwise, it is the byte position. The first byte is 1.

start First record (or byte) in the range.

end Last record (or byte) in the range.

See Also: Open, Unlock.

Example:

Sub Main
  Dim V As Variant
  Open "SAVE_V.DAT" For Binary As #1
  Lock #1
  Get #1, 1, V
  V = "Hello"
  Put #1, 1, V
  Unlock #1
  Close #1
End Sub