Top Tips for Passing the LPI 010-160 Exam on Your First Try

 The correct command to extract the contents of the compressed archive file1.tar.gz is tar -xzf file1.tar.gz. This command uses the following options:

• -x means extract files from an archive.
• -z means filter the archive through gzip, which is a compression program that reduces the size of files.
• -f means use the following archive file name, which is file1.tar.gz in this case.

The other commands are incorrect for the following reasons:

• tar -czf file1.tar.gz creates a compressed archive file1.tar.gz from the files specified after the command, not extract it.
• ztar file1.tar.gz is not a valid command, as ztar is not a standard program or option for tar.
• tar --extract file1.tar.gz is missing the -z option to handle the gzip compression, and also the -f option to specify the file name.
• detar file1.tar.gz is not a valid command, as detar is not a standard program or option for tar.

References:

• Linux Essentials - Topic 106: The Linux Operating System, section 106.2 Use single shell commands and one line command sequences to perform basic tasks on the command line.
• LPI Linux Essentials Study Guide: Exam 010 v1.6, 3rd Edition, Chapter 5: Working with Files and Directories, section Compressing and Archiving Files.

 A bus is a communication system that transfers data between components inside a computer or between computers. There are different types of buses that serve different purposes. The RAM bus connects the CPU with the main memory, the NUMA bus connects multiple processors in a multiprocessor system, the CPU bus connects the CPU with other components on the motherboard, and the Auto bus is a fictional bus that can transform into a robot. The SATA bus is the correct answer because it is a type of bus that can connect hard disk drives with the motherboard. SATA stands for Serial Advanced Technology Attachment and it is a standard interface for connecting storage devices such as hard disk drives, solid state drives, and optical drives. SATA offers faster data transfer rates, lower power consumption, and improved cable management compared to older interfaces such as IDE and SCSI. References: : [Bus (computing)] : [Transformers: Robots in Disguise (2015 TV series)] : [Serial ATA]3) : [SATA vs. IDE: What’s the Difference?]

The operator that matches the preceding character either zero or one time in a regular expression is the question mark (?). This operator is also known as the optional quantifier, because it makes the preceding character or group of characters optional. For example, the regular expression colou?r matches both color and colour, because the u is optional. The question mark can also be used to modify other quantifiers, such as * (zero or more), + (one or more), or {m,n} (between m and n times), to make them non-greedy, meaning they will match the shortest possible string instead of the longest. For example, the regular expression .*? matches any character zero or more times, but as few as possible. The question mark is one of the basic regular expression operators covered in the Linux Essentials certification program from the Linux Professional Institute (LPI). References:

• Linux Essentials - Linux Professional Institute (LPI)
• Regular Expressions:Difference between ‘optional occurrence’ and 'zero …

When a user account is deleted, the files owned by that user are not automatically deleted from the file system, unless they are in the user’s home directory. The files residing outside the home directory will remain unchanged, but they will have an invalid owner. The owner of a file is identified by a numeric user ID (UID), which is mapped to a user name by the /etc/passwd file. When a user is deleted, the corresponding entry in the /etc/passwd file is removed, but the UID of the file is not changed. Therefore, when listing the file’s details, the UID of the former owner is shown instead of the user name. For example, if the user alice with UID 1001 is deleted, and she owns a file named report.txt in the /tmp directory, the output of ls -l /tmp/report.txt will look something like this:

-rw-r–r-- 1 1001 users 1024 Nov 20 14:11 /tmp/report.txt

The user root is not set as the new owner of the file, nor is the file moved to /lost+found or removed from the file system. The /lost+found directory is used to store files that are recovered from a corrupted file system after running the fsck command, not from deleted user accounts. The file system check does not affect the ownership or permissions of the files, unless there is a serious inconsistency that needs to be fixed. References:

• Linux Essentials - Linux Professional Institute (LPI), section 5.2.1
• 5.2 Lesson 1 - Linux Professional Institute Certification Programs, slide 6.