AMP program No.7

Write an assignment on directory functions 39H (Create directory), 3AH (Delete directory) of DOS  INT  21H  and  program  to  simulate  MD  (Make  directory),  RD  (Remove  Directory) commands.

theory:

A directory is actually a folder which we create in our drives

A hierarchical structure is a one which consists of sub directories within directories

The root directory (main directory) contains files and other directories.

The work directory further contains directories and files.

Hence to access any file or sub directory we need to specify the particular path.

Function 39H: Create directory

This function is used to create a subdirectory in the current directory or a root directory in the particular drive.

Eg: when we give the path in the program as \ubaid, it will create a root directory in drive C.

Eg: when we give the path in the program C :\tasm\bin\ubaid, it will create a subdirectory in directory bin

For its occurrence AH must be loaded with 39H

The path must be pointed by DS : DX

Function 3AH : Delete directory

This function is used to delete a directory (root or subdirectory)

For its occurrence AH must be loaded with value 3AH

The directory name must be pointed with DS : DX

The directory must be empty for this function to complete successfully

If deleted successfully:

Carry flag = clear ; else

Carry flag = set ; AX = error code