Last Updated on October 17, 2019 by Admin
NDG Linux Essentials 2.0 Chapter 11 Exam Answers
A file begins with
#!/bin/csh. This means:
- This is a Perl script
- The operator should not be using /bin/csh
- C Shell compatibility mode is enabled
- Running the script will invoke /bin/csh to interpret the rest of the file
- Nothing, this is a comment
Which are appropriate editors for writing shell scripts?
- LibreOffice Writer
nano’s commands take the form of:
- Mouse clicks
- Escape followed by another character
- Control and another character
- The F1 through F12 function keys
- Alt and another character
What does this shell script do?
FOO=/tmp/foo if [ ! –d $FOO ]; then mkdir $FOO fi
- Creates /tmp/foo if it does not exist
- Outputs a message to the screen
- Creates /tmp/foo and raises an error if there is a problem
- Nothing, since there is a problem with the conditions in the if statement
- Makes the /tmp/foo directory if a file by that name exists
Which of the following are correct about for and while loops?
- for loops have a test each cycle to determine if it should run again
- for loops operate over a fixed list of items
- for loops require a variable over which to iterate
- while loops operate over a fixed list of items
- while loops have a test each cycle to determine if it should run again
Given the following part of a script:
if [ -f $1 ]; then echo “I am here” fi
What is the meaning of $1?
- It is a parameter to -f, indicating the size of the file
- It is the first argument passed to the script
- It is a special variable that indicates the exit code of the command before it
- It is a file called $1
- It is a list of files that gets interpolated
Given the following script that is run through
./test.sh hello goodbye:
if [ -f $2 ]; then echo "I am here" fi
When will “I am here” be printed?
- If a file called “goodbye” exists in the current directory
- The script will always print “I am here”
- If there are two files in the current directory
- If a file called “hello” exists in the current directory
What is the correct way to assign the word “Hello” to a variable?
- A = “Hello”
- echo “Hello” > A
- echo $A “Hello”
What is the correct way to save the current directory to a variable?
- pwd | $A
- pwd $A
Which shell command accepts input from the user’s keyboard?
What information is held inside
- The name of the command run
- The previous command’s exit code
- The number of arguments passed to the script
- The current process id
- The current user ID
How would you finish your script with an exit code of 42?
- return 42
- break 42
- exit 42
ifcommand looks for what exit code to consider a condition to be true?
The number of users logged in is in a variable called USERS. How would you test to see if 5 users are logged in?
- test $USERS –eq 5
- test –f USERS=5
- test $USERS = 5
- test $USERS,5
- test $USERS –a 5
Given the following script:
while [ ! –f /tmp/foo ]; do echo –n “.” process_data > /tmp/foo done
Which of the following are true?
- The screen will fill with dots.
- If a file called /tmp/foo exists, process_data won’t be run
- process_data will be called at most once
- process_data will never be run
- /tmp/foo will be removed if it exists
A conditional that lets you make multiple comparisons with a pattern is called:
What is the meaning of
$(( $i + 1))?
- 1 will be added to the i variable
- If i is 0, the loop will stop
- This will return the value of the next argument to the script
- This will return the value of the first argument to the script
- This runs the command stored in variable i
How would you write a test that says “if /tmp/foo is a directory or USERS is greater than 5”?
- test –d /tmp/foo –o $USERS –gt 5
- test –d /tmp/foo | $USERS > 5
- test /tmp/foo || $USERS > 5
- test /tmp/foo –d –o $USERS -gt 5