Chapter 5. GNU and Unix Commands (Topic 1.103)

This Topic covers the essential aspect of working interactively with Linux command-line utilities. While it's true that GUI tools are available to manage just about everything on a Linux system, a firm understanding of command-line utilities is required to better prepare you to work on any LSB-compliant Linux distribution.

The family of commands that are part of Linux and Unix systems has a long history. Individuals or groups that needed specific tools contributed many of the commands in the early days of Unix development. Those that were popular became part of the system and accepted as default tools under the Unix umbrella. Today, Linux systems carry new, often more powerful GNU versions of these historical commands, which are covered in LPI Topic 1.103.

This LPI Topic has eight Objectives :

Objective 1: Work on the Command Line

This Objective states that a candidate should be able to interact with shells and commands using the command line. This includes typing valid commands and command sequences, defining, referencing and exporting environment variables, using command history and editing facilities, invoking commands in the path and outside the path, using command substitution, applying commands recursively through a directory tree and using man to find out about commands. Weight: 5.

Objective 2: Process Text Streams Using Filters

This Objective states that a candidate should be able to apply filters to text streams. Tasks include sending text files and output streams through text utility filters to modify the output, and using standard Unix commands found in the GNU textutils package. Weight: 6.

Objective 3: Perform Basic File Management

This Objective states that candidates should be able to use the basic Unix commands to copy, move, and remove files and directories. Tasks include advanced file management operations such as copying multiple files recursively, removing directories recursively, and moving files that meet a wildcard pattern. This includes using simple and advanced wildcard specifications to refer to files, as well as using find to locate and act on files based on type, size, or time. Weight: 5.

Objective 4: Use Unix Streams, Pipes, and Redirects

This Objective describes that a candidate should be able to redirect streams and connect them to efficiently process textual data. Tasks include redirecting standard input, standard output, and standard error. Also included is piping the output of one command to the input of another, using the output of one command as arguments to another command, and sending output to both stdout and a file. Weight: 5.

Objective 5: Create, Monitor, and Kill Processes

An LPI 101 candidate should be able to manage processes. This includes knowing how to run jobs in the foreground and background, bring a job from the background to the foreground and vice versa, start a process that will run without being connected to a terminal, and signal a program to continue running after logout. Tasks also include monitoring active processes, selecting and sorting processes for display, sending signals to processes, killing processes and identifying and killing X applications that did not terminate after the X sessions were closed. Weight: 5.

Objective 6: Modify Process Execution Priorities

This Objective states that a candidate should be able to manage process execution priorities . The tasks include running a program with higher or lower priority, determining the priority of a process and changing the priority of a running process. Weight: 3.

Objective 7: Search Text Files Using Regular Expressions

This Objective states you should be able to manipulate files and text data using regular expressions. This Objective includes creating simple regular expressions containing several notational elements. It also includes using regular expression tools to perform searches through a filesystem or file content. Weight: 3.

Objective 8: Perform Basic File Editing Operations Using vi

This Objective states a candidate should be able to edit files using vi. This Objective includes vi navigation, basic vi nodes, inserting, editing, deleting, copying, and finding text. Weight: 1.

The tools and concepts discussed here represent important and fundamental aspects of working with Linux and are essential for your success on Exam 101.