Sec. 7: Searching and Extracting Data from Files and Archiving

Pipes or command-pipelines help users mash-up two or more commands at the same time and run them consecutively.

• True

• False

Answer explanation

True, by using a command pipe (|), a user can enter two or more commands in a series or chain.

The grep command allows you to:

• Rename a file or directory

• Search for files that contain a specified string

• Repeat the previous command

Answer explanation

Grep is used to search for a specific string or regular expression within a file.

Which redirection operator accepts text on the following lines as standard input

• <>

• >>

• <<

Answer explanation

The << operator allows the user to accept text on the following lines as standard input.

The two forms of commonly used regular expressions: basic and complicated.

• True

• False

Answer explanation

There are also two types of regular expressions: basic and extended.

The regular expression b[aeiou]g will match the words:

• bag, beg, big

• bag, beg, big, bog, bug

• baeioug

Answer explanation

The regular expression b[aeiou]g will search for any three letter words that begin with b, end with g, and have a vowel as the second letter.

What does the redirection operator <> do?

• Accepts text on the following lines as standard input.

• Causes the specified file to be used for both standard input and standard output.

• Sends the contents of the specified file to be used as standard input.

Answer explanation

The <> redirection operator will let the file be used for input and output.

Two types of output messages

• Manual and Automatic messages

• Standard Output and Input messages

• Standard Output and Standard Error messages

Answer explanation

Standard Output and Standard Error messages are the two different types of output messages within Linux.

The ____ represents the start of a line, and the _____ denotes the end of a line.

• ^ and $

• \ and .

• # and *

Answer explanation

The ^ represents the start of a line, and the $ represents the end of a line within a regular expression search.

The tar can be used to back up or archive data, which stands for

• Transfer tool

• Target archive

• Tape archive

Answer explanation

The tar command stands for the “tape archive”, since that was the original use of this tool.

To use a file that’s been compressed, it must first be uncompressed with a matching program.

• True

• False

Answer explanation

True, a compressed file must be uncompressed prior to be read by a program.