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.

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.

See Also            Open, Unlock.

Example            '#Language "WWB-COM"
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