Guide To Unix Chp. 5 Review Questions

Front 1

You have just finished a 25-page paper that you have written using Emacs. After your instructor has briefly looked at the paper, she recommends that you change all instances of the reference "data is" to "data are" before you submit it. Which command can you use to locate these references in the file for a quick assessment of how much you have to change?

Back 1

grep "data is" /assignments/data_sources

Front 2

You are interested in determining the number of words in your /assignments/
data_sources file mentioned in Question 1.Which of the following commands should
you use?

Back 2

wc -w /assignments/data_sources

Front 3

Which of the following are examples of manipulation and transformation
commands?

Back 3

sed
pr
join
paste

Front 4

Which of the following is true of the pipe operator?

Back 4

It redirects the output of one command to the input of another command.

Front 5

Because the data was formatted the same in two inventory files, you decided to combine their contents into one file. Now you want to determine if there are duplicate entries on consecutive lines in the new file. Which command enables you to find the duplicate entries?

Back 5

uniq

Front 6

Your friend is using the command comm entryfile, but is getting an error message.
What is the problem?

Back 6

It is necessary to specify two files when you use the comm command.

Front 7

Your boss is trying to import the customers file into her spreadsheet program, but
the data goes into the spreadsheet incorrectly.This is because the fields are separated
by dashes (-) and the spreadsheet program requires the fields to be separated by
colons (:).Which of the following commands can you use to convert the
customers file?

Back 7

tr "-" ":" < customers

Front 8

How can you link multiple files to manipulate the data in those files?

Back 8

with a common or key field

Front 9

While in the Bash shell, you have written a simple script file and now want to
execute the script.Which of the following commands enables you to run the script?

Back 9

sh

Front 10

You are using the grep command, but it is only searching through files in your immediate home directory. What option enables you to search through subdirectories
below your home directory?

Back 10

-r

Front 11

Your software has a bug in that it enables you to create a vendors file in which there
are duplicate entries of vendors.Which of the following methods enables you to
remove the duplicate vendors in this text file?

Back 11

Sort the file and then use the uniq command to remove the duplicates, inputting the
result in a new file.

Front 12

Each time you list the files in your home directory, the output scrolls by so fast you
can’t read it.Which of the following enables you to view the output one screen at
a time?

Back 12

ls -l | more

Front 13

You are creating a file to send over the Internet via a satellite connection that only
allows you to send files under 250 KB.Which of the following commands enables
you to determine the number of bytes in the file before you try to send it?

Back 13

wc -c

Front 14

In the command sed -f fixit notes > instructions, what is “fixit”?

Back 14

a script file

Front 15

When you design a record layout, you should do which of the following?

Back 15

identify each field by data type
identify each field by name
store only fields relevant to the record’s purpose

Front 16

What sed command option enables you to append new text to a file?

Back 16

a\

Front 17

Your boss has two salary scale files, salary and salary1, and wants to compare their contents side by side to see if there are any differences in the files. Which of the following commands should he use?

Back 17

comm salary salary1

Front 18

When you use the pr command how can you limit the output to only a screen full
of text to view

Back 18

Use the -l 23 option

Front 19

When you use the Awk printf capability, what does the dollar sign ($) represent?

Back 19

a data field

Front 20

Your boss is trying to delete the word “difficult” as it appears in a text file containing
his speech about motivation.The name of the file is motivate.When he decides to
use the tr command to delete this word, it instead deletes characters throughout the
text.Which of the following commands is he likely to have used?

Back 20

tr -d "difficult" < motivate

Front 21

When you enter the command grep Linux /info/Linux_ features | head, what is the
maximum number of lines that will be displayed?

Back 21

10 lines

Front 22

List four examples of selection commands

Back 22

Comm: compares sorted files and shows differences;
cut: selects columns (fields);
diff: compares and selects differences in two files;
grep: selects lines or rows

Front 23

What is the general format for using the pipe operator?

Back 23

First_command | second_command

Front 24

Briefly explain what you can accomplish with the sed command

Back 24

Sed can make large changes to large files

Front 25

You want to create a file of your friends’ and relatives’ names, addresses, telephone
numbers, and other information.When you mention this to your sister-in-law, she
recommends having separate fields for the first, middle, and last names. Briefly
explain why this is a good idea.

Back 25

When you divide the name into three fields, you can use many more data sorting techniques, like sorting by last name, or using all three fields to identify duplicate data