INT 21H (0x21)
Function 5AH (0x5A or 90) --> Create temporary
file
Call with: AH = 5AH
CX = attribute (bits may be combined)
DS: DX = segment: offset of ASCIIZ path
Returns: If function is successful
Carry flag = clear
AX = handle
DS: DX = segment: offset of complete ASCIIZ
pathname
If function is unsuccessful
Carry flag = set
AX = error code
Comments:
This function creates a file with a unique name, in the current or specified directory on the default or specified disk drive, and returns a handle that can be used by the program by the program for subsequent access to the file. The name generated for the file is also returned in a buffer specified by the program.
If any element of the pathname does not exist or the file is being created in the root directory, and the root directory is full the function fails.
INT 21H (0x21)
Function 5BH (0x5B or 91) --> Create new file
Call with: AH = 5BH
CX = attribute (bits may be combined)
DS: DX = segment: offset of ASCIIZ pathname
Returns: If function is successful
Carry flag = clear
AX = handle
If function is unsuccessful
Carry flag = set
AX = error code
Comments:
This function creates a file in the designated or default directory on the designated or default drive, and returns a handle that can be used by the program for subsequent access to the file for a given ASCIIZ pathname.
If a file with the same name and path already exists or any element of the specified path does not exist or the file is being created in the root directory, and the root directory is full or the user has insufficient access rights, the function fails.
INT 21H (0x21)
Function 5CH (0x5C or 92) --> Lock or unlock file
region
Call with: AH = 5CH
AL = 00H if locking region
01H if unlocking region
BX = handle
CX = high part of region offset
DX = low part of region offset
SI = high part of region length
DI = low part of region length
Returns: If function successful
Carry flag = clear
If function unsuccessful
Carry flag = set
AX = error code
Comments:
This function locks or unlocks the specified region of a file. This function is not available unless the file-sharing module (such as SHARE.EXE) is loaded.
INT 21H (0x21)
Function 5DH (0x5D or 93) --> Reserved
INT 21H (0x21)
Function 5EH (0x5E or 94), sub function 00H (0x00)
--> Get machine name
Call with: AH = 5EH
AL = 00H
DS: DX = segment: offset of buffer to receive
string
Returns: If function is successful
Carry flag = clear
CH = 00H if name not defined
<> 00H if name defined
CL = netBIOS name number (if CH <> 0)
DX: DX = segment: offset of identifier (if CH
<> 0)
If function is unsuccessful
Carry flag = set
AX = error code
Comments:
This sub function returns the address of an ASCIIZ string identifying the local computer. This function call is only available when the Microsoft Network is running.
INT 21H (0x21)
Function 5EH (0x5E or 94), sub function 02H (0x02)
--> Set printer setup string
Call with: AH = 5EH
AL = 02H
BX = redirection list index
CX = length of setup string
DS: SI = segment: offset of setup string
Returns: If function successful
Carry flag = clear
If function unsuccessful
Carry flag = set
AX = error code
Comments:
This sub function specifies a string to be sent in front of all files directed to a particular network printer, allowing users at different network nodes to specify individualized operating modes on the same printer.
INT 21H (0x21)
Function 5EH (0x5E or 94), sub function 03H (0x03)
--> Get printer setup string
Call with: AH = 5EH
AL = 03H
BX = redirection list index
ES: DI = segment: offset of buffer to receive
setup string
Returns: If function successful
Carry flag = clear
CX = length of printer setup string
ES: DI = segment: offset of buffer to receive
setup string
If function unsuccessful
Carry flag = set
AX = error code
Comments:
This function is used to obtain the printer setup string for a particular network printer.
INT 21H (0x21)
Function 5FH (0x5F or 95), sub function 02H (0x02)
--> Get redirection list entry
Call with: AH = 5FH
AL = 02H
BX = redirection list index
DS: SI = segment: offset of 16-byte buffer to
receive local device name
ES: DI = segment: offset of 128-byte buffer to
receive network name
Returns: If function successful
Carry flag = clear
BH = device status flag
Bit 0 = 0 if device valid
= 1 if not valid
BL = device type
03H, if printer
04H, if drive
CX = stored parameter value
DX = destroyed
BP = destroyed
DS: SI = segment: offset of ASCIIZ local
device name
ES: DI = segment: offset of ASCIIZ network
name
If function unsuccessful
Carry flag = set
AX = error code
Comments:
This sub function allows inspection of the system redirection list, which associates local logical names with network files, directories, or printers. This function call is only available when Microsoft Networks is running and the file-sharing module has been loaded.
| Sample Chapters from book DATA RECOVERY WITH AND WITHOUT PROGRAMMING by Author Tarun Tyagi |
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Publishers of the Book
Number of Pages
ISBN
Price of the Book
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BPB Publications, New Delhi, India
540
81-7656-922-4
$69.00 (Including Shipping Charges, Cost of Book and Other expenses, Free Source Code CD included with the Book)
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