Table of Contents
Note: This API call is for DOS personality only. Use Family API for portability.
Int 21H, AH=5cH, AL=00H
3 and higher
lock region of file
AH = 5Ch AL = 00h lock region of file BX = file handle CX:DX = start offset of region within file SI:DI = length of region in bytes
CF clear if successful CF set on error AX = error code (01h,06h,21h,24h) (see #01680)
error returned unless SHARE or network installed an unlock call must specify the same region as some prior lock call locked regions become entirely inaccessible to other processes duplicate handles created with AH=45h or AH=46h inherit locks, but handles inherited by child processes (see AH=4Bh) do not under DR DOS 3.41 and 5.0, if a process opens a file without the no- inherit flag and then starts a child, any locks set by the parent are ignored, and the child will only get an error if it tries to lock an area previously locked by the parent process. Under Novell DOS 7, this function is fully supported as in MS-DOS.
AX=440Bh,AH=BCh,AH=BEh,INT 2F/AX=110Ah,INT 2F/AX=110Bh
Text based on Ralf Brown Interrupt List Release 61