The install command in Linux is a versatile utility primarily used for copying files and directories, but it also offers powerful options for creating directories with specific ownership and permissions. This guide focuses on using install for directory creation.

Creating Directories with Specific Permissions

To create a directory with specific ownership and permissions, you can utilize the -o (owner), -g (group), and -m (mode/permissions) flags with the -d flag to indicate directory creation.

# To create a directory for a user with a group with permission 700
install -o <username> -g <groupname> -m 700 -d /home/<username>/<directoryname>

In this example:

• -o <username>: Sets the owner of the new directory to the specified username.
• -g <groupname>: Sets the group ownership of the new directory to the specified group name.
• -m 700: Sets the permissions for the directory. 700 means the owner has read, write, and execute permissions, while the group and others have no permissions.
• -d: Specifies that the operation is to create a directory.
• /home/<username>/<directoryname>: The path and name of the directory to be created.

Understanding Directory Permissions

File permissions in Linux are represented by three sets of octal digits, each corresponding to the owner, group, and others. The digits represent:

• 4: Read permission
• 2: Write permission
• 1: Execute permission

For example, 700 is calculated as 4 (read) + 2 (write) + 1 (execute) for the owner, and 0 for the group and others.

Common Use Cases

This command is particularly useful in shell scripting for setting up specific directory structures with appropriate security settings before deploying applications or running certain processes. It ensures that directories are created with the intended access controls from the outset.

Further Reading

• Linux install command man page
• Understanding Linux File Permissions