In this section, we will explore the different file types and attributes in the OpenVMS operating system. Understanding these concepts is crucial for effective file management and system administration.

OpenVMS supports various file types, each serving different purposes. Here are some of the most common file types:

1. Text Files:

   • Description: Files containing plain text, often used for scripts, configuration files, and documentation.
   • Example: .TXT, .LOG

2. Executable Files:

   • Description: Binary files that can be executed by the system.
   • Example: .EXE

3. Object Files:

   • Description: Intermediate files generated by compilers, containing machine code that is not yet linked.
   • Example: .OBJ

4. Library Files:

   • Description: Collections of object files that can be linked into executables.
   • Example: .OLB (Object Library), .TLB (Text Library)

5. Data Files:

   • Description: Files used to store data, often in binary format.
   • Example: .DAT

6. Command Procedures:

   • Description: Scripts written in DCL (Digital Command Language) to automate tasks.
   • Example: .COM

7. Backup Files:

   • Description: Files created by the backup utility to store copies of other files.
   • Example: .BCK

File attributes provide metadata about files, such as their size, creation date, and access permissions. Here are some key file attributes in OpenVMS:

1. File Name:

   • Description: The name of the file, which can include a file type extension.
   • Example: REPORT.TXT

2. File Size:

   • Description: The size of the file in blocks or bytes.
   • Example: 1024 blocks

3. Creation Date:

   • Description: The date and time when the file was created.
   • Example: 1-JAN-2023 12:00:00.00

4. Modification Date:

   • Description: The date and time when the file was last modified.
   • Example: 2-JAN-2023 14:30:00.00

5. Owner:

   • Description: The user who owns the file.
   • Example: SYSTEM

6. Protection:

   • Description: Access control settings that determine who can read, write, execute, or delete the file.
   • Example: (S:RWED, O:RWED, G:RE, W:RE)

7. Record Format:

   • Description: The format of the records within the file, such as fixed-length or variable-length.
   • Example: Fixed-length 512 bytes

8. Record Attributes:

   • Description: Additional attributes related to the records, such as carriage control.
   • Example: Carriage return

To view the attributes of a file in OpenVMS, you can use the DIR command with the /FULL qualifier:

This command will display detailed information about the file REPORT.TXT, including its size, creation date, modification date, owner, protection settings, and more.

To change the protection settings of a file, you can use the SET FILE/PROTECTION command:

This command sets the protection of REPORT.TXT so that the system and owner have read, write, execute, and delete permissions, while the group and world have read and execute permissions.

1. Create a text file named EXAMPLE.TXT.
2. Use the DIR/FULL command to view the attributes of EXAMPLE.TXT.
3. Note down the file size, creation date, and protection settings.

Solution:

1. Change the protection settings of EXAMPLE.TXT so that only the owner has read and write permissions.
2. Verify the new protection settings using the DIR/FULL command.

Solution:

In this section, we covered the different file types and attributes in OpenVMS. We learned about common file types such as text files, executable files, and data files. We also explored various file attributes, including file size, creation date, and protection settings. Practical examples and exercises helped reinforce these concepts. Understanding file types and attributes is essential for effective file management and system administration in OpenVMS.