Linux Final NOS 120 Questions and Answers
Because Standard Error and Standard Output represent the results of command
and Standard Input represents the input required for a command, only Standard
Error and Standard Output can be redirected to/from a file. True or False?
✔✔False
Before a user-defined variable can be used by processes that run in subshells, that
variable must be . ✔✔exported
The alias command can be used to make a shortcut to a single command. True or
False? ✔✔True
Which of the following files is always executed immediately after any user logs in
to a Linux system and receives a BASH shell? ✔✔/etc/profile
Which command could you use to see a list of all environment and user-defined
shell variables as well as their current values? ✔✔set
Every if construct begins with if and must be terminated with? ✔✔fi
Which of the following will display the message welcome home if the cd
/home/user1 command is successfully executed? ✔✔cd /home/user1 && echo
"welcome home"
,The current value for the HOME variable is displayed by which of the following
commands? (Choose all that apply.) ✔✔echo ~
echo $HOME
Which of the following file descriptor numbers represents stdout? ✔✔1
Which of the following operators reverses the meaning of a test statement? ✔✔!
What would be the effect of using the alias command to make an alias for the
date command named cat in honor of your favorite pet? ✔✔When you use the
cat command at the command prompt with the intention of viewing a text file,
the date appears instead.
How do you indicate a comment line in a shell script? ✔✔Begin the line with #.
You have redirected Standard Error to a file called Errors. You view the contents of
this file afterward and notice that there are six error messages. After repeating the
procedure, you notice that there are only two error messages in this file. Why?
✔✔You did not append the Standard Error to the Error file and as a result, it was
overwritten when the command was run a second time.
The sed and awk commands are filter commands commonly used to format data
within a pipe. True or False? ✔✔True
, What is wrong with the following command string ls /etc/hosts >listofhostfile?
✔✔Nothing is wrong with the command.
Which of the following is not necessarily generated by every command on the
system? (Choose all that apply.) ✔✔Standard Input
Standard Deviation
Which construct can be used in a shell script to read Standard Input and place it in
a variable? ✔✔read
A for construct is a loop construct that processes a specified list of objects. As a
result, it is executed as long as there are remaining objects to process. True or
False? ✔✔True
What does >> accomplish when entered on the command line after a command?
✔✔It appends Standard Ouput to a file.
Consider the following shell script:
echo -e "What is your favorite color?--> \c"
Because Standard Error and Standard Output represent the results of command
and Standard Input represents the input required for a command, only Standard
Error and Standard Output can be redirected to/from a file. True or False?
✔✔False
Before a user-defined variable can be used by processes that run in subshells, that
variable must be . ✔✔exported
The alias command can be used to make a shortcut to a single command. True or
False? ✔✔True
Which of the following files is always executed immediately after any user logs in
to a Linux system and receives a BASH shell? ✔✔/etc/profile
Which command could you use to see a list of all environment and user-defined
shell variables as well as their current values? ✔✔set
Every if construct begins with if and must be terminated with? ✔✔fi
Which of the following will display the message welcome home if the cd
/home/user1 command is successfully executed? ✔✔cd /home/user1 && echo
"welcome home"
,The current value for the HOME variable is displayed by which of the following
commands? (Choose all that apply.) ✔✔echo ~
echo $HOME
Which of the following file descriptor numbers represents stdout? ✔✔1
Which of the following operators reverses the meaning of a test statement? ✔✔!
What would be the effect of using the alias command to make an alias for the
date command named cat in honor of your favorite pet? ✔✔When you use the
cat command at the command prompt with the intention of viewing a text file,
the date appears instead.
How do you indicate a comment line in a shell script? ✔✔Begin the line with #.
You have redirected Standard Error to a file called Errors. You view the contents of
this file afterward and notice that there are six error messages. After repeating the
procedure, you notice that there are only two error messages in this file. Why?
✔✔You did not append the Standard Error to the Error file and as a result, it was
overwritten when the command was run a second time.
The sed and awk commands are filter commands commonly used to format data
within a pipe. True or False? ✔✔True
, What is wrong with the following command string ls /etc/hosts >listofhostfile?
✔✔Nothing is wrong with the command.
Which of the following is not necessarily generated by every command on the
system? (Choose all that apply.) ✔✔Standard Input
Standard Deviation
Which construct can be used in a shell script to read Standard Input and place it in
a variable? ✔✔read
A for construct is a loop construct that processes a specified list of objects. As a
result, it is executed as long as there are remaining objects to process. True or
False? ✔✔True
What does >> accomplish when entered on the command line after a command?
✔✔It appends Standard Ouput to a file.
Consider the following shell script:
echo -e "What is your favorite color?--> \c"
