LPI 101-500 Dumps Questions Answers

 The command kill -TERM 123 kills the process with the PID 123 but allows the process to “clean up” before exiting. The option -TERM specifies the signal to be sent to the process, which is the termination signal (SIGTERM). This signal requests the process to terminate gracefully, which means that the process can perform any necessary actions before exiting, such as closing files, releasing resources, or saving data. The process can also catch the signal and ignore it or handle it in a different way, if it is programmed to do so. The syntax is: kill -TERM pid. For example, kill -TERM 123 will send the SIGTERM signal to the process with the PID 123, asking it to terminate nicely. The other options are not correct because:

A. kill -PIPE 123: This command sends the broken pipe signal (SIGPIPE) to the process, which is not used to kill the process, but to notify it that the other end of a pipe has been closed. This signal is usually ignored by the process, unless it is writing to the pipe, in which case it will cause the process to terminate1.

B. kill -KILL 123: This command sends the kill signal (SIGKILL) to the process, which is the most powerful way to kill the process, but it does not allow the process to “clean up” before exiting. The SIGKILL signal cannot be caught, blocked, or ignored by the process, and it forces the process to terminate immediately, without performing any actions. This command should be used as a last resort, when the process is unresponsive or causing harm to the system2.

C. kill -STOP 123: This command sends the stop signal (SIGSTOP) to the process, which is not used to kill the process, but to pause it. The SIGSTOP signal cannot be caught, blocked, or ignored by the process, and it suspends the execution of the process until it receives a continue signal (SIGCONT). This command can be used to temporarily stop a process from running, without terminating it3. References:

What is the purpose of the SIGPIPE signal? - Stack Overflow

How to kill a process in Linux - LinuxConfig.org

Linux Signals - GeeksforGeeks

The nice command is used to start a process with a modified scheduling priority. The scheduling priority is a value that determines how much CPU time a process will receive from the kernel. The lower the priority, the more CPU time a process will get. The priority is also known as the nice value, because a process with a high nice value is being nice to other processes by giving up CPU time. The nice value ranges from -20 to 19, with -20 being the highest priority and 19 being the lowest. By default, processes are started with a nice value of 0, which means normal priority.

The nice command takes an optional argument -n followed by a number, which specifies the increment or decrement of the nice value from the default value of 0. For example, the command:

nice -n 5 /usr/bin/prog

will start the /usr/bin/prog process with a nice value of 5, which means a lower priority than the default. Similarly, the command:

nice -n -5 /usr/bin/prog

will start the /usr/bin/prog process with a nice value of -5, which means a higher priority than the default. If the -n argument is omitted, the nice command will assume a default increment of 10. For example, the command:

nice /usr/bin/prog

will start the /usr/bin/prog process with a nice value of 10, which means a very low priority. Note that only the root user can start a process with a negative nice value, as this requires special privileges.

Therefore, the command:

nice -5 /usr/bin/prog

is equivalent to:

nice -n -5 /usr/bin/prog

and will start the /usr/bin/prog process with a nice value of -5, which means a higher priority than the default. This means that the correct answer is B. /usr/bin/prog is executed with a nice level of 5.

A hard link is a directory entry that refers to the same inode as another file. An inode is a data structure that stores the metadata and the location of the data blocks of a file. A hard link allows multiple names to refer to the same file content, as long as they are on the same filesystem. However, if the source and the target of the hard link are on different filesystems, the ln command will return an error, because the inode numbers are not consistent across different filesystems. Therefore, the ln command cannot create a hard link that crosses filesystem boundaries. The other options are either incorrect or not applicable. The source file being hidden, read-only, a shell script, or not owned by the user does not prevent the creation of a hard link, as long as the user has the permission to write to the target directory and the source and the target are on the same filesystem. References:

LPIC-1 Exam 101 Objectives, Topic 103: GNU and Unix Commands, 103.3 Perform basic file management

LPIC-1 Linux Administrator 101-500 Exam FAQ, LPIC-1 Exam 101 Objectives, GNU and Unix Commands (Total Weight: 25)