LPI 010-160 Exam Practice Questions (P. 3)

GPT-4o - Answer

The correct permissions set by 'chmod 654 file.txt' result in '-rw-r-xr--'. This means the owner has read and write permissions (6), the group has read and execute permissions (5), and others have read permission (4). It’s essential to remember that the initial '-' in the permissions string represents a regular file, and this directly aligns with the given command outcome. This set of permissions satisfies typical needs where the owner can modify the file, the group can view and execute, and others can only view it. Always ensure the numeric mode accurately reflects desired permission levels.

GPT-4o - Answer

Each file in Unix-like systems is uniquely owned by one user and one group. This clear ownership structure aids in permission management and resource tracking within the system. It’s essential to understand that although a file may only have one primary group explicitly assigned, additional permissions can be configured using Access Control Lists (ACLs), which allow for more detailed permissions for various users and groups. However, the basic understanding that each file has one user and one group owner remains fundamentally correct and integral to file permission concepts.

GPT-4o - Answer

The correct permissions for the /tmp/ directory, rwxrwxrwt, incorporate a sticky bit (denoted by the 't' at the end), which is essential for shared directories like /tmp/. This sticky bit restricts file deletion so that only the file's owner, the directory's owner, or the root user can remove files from the directory. This attribute is crucial for maintaining the security and proper function of temporary storage areas in multi-user environments, preventing users from deleting or altering each other's temporary files.

GPT-4o - Answer

Indeed, the command 'useradd -m tux' is the correct choice for adding a new user named tux while simultaneously creating the user's home directory. The '-m' option is crucial as it instructs the system to create a home directory for the user, which will be populated with default configuration files. This command thus effectively sets up a new user with their own space on the system, making it ready for immediate use.

GPT-4o - Answer

The /etc/passwd file on Linux systems contains key user information, including the username, numerical user ID, and the user's default shell. It's essential to remember that while this file used to store encrypted passwords, for increased security, these are now stored in the /etc/shadow file, accessible only to the root user or commands with suid bit. This separation enhances system security by limiting exposure of sensitive data.