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Copyright 1991 David Jurgens |
INT 21,5C - Lock/Unlock File Access (DOS 3.0+)
AH = 5C
AL = 00 lock file
= 01 unlock file
BX = file handle
CX = most significant word of region offset
DX = least significant word of region offset
SI = most significant word of region length
DI = least significant word of region length
on return:
AX = error code if CF set (see DOS ERROR CODES)
- used for networking and multi-tasking system to preserve
data integrity
- duplicated handles inherit access to locked regions
- EXEC'd programs do not inherit access to locked regions
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| Esc or Alt-X to exit |
int 21,5c |
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