11
The if command looks for what exit code to consider a condition to be true? 1 0 2 10 255
0
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
1 will be added to the i variable
What is the correct way to assign the word "Hello" to a variable? A = "Hello" echo "Hello" > A echo $A "Hello" $A="Hello" A="Hello"
A="Hello"
What is the correct way to save the current directory to a variable? A=`pwd` pwd | $A A=cwd A=pwd pwd $A
A=`pwd`
Most of 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
Control 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
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 Never 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
If a file called "goodbye" exists in the current directory
Given the following script: while [ ! -f /tmp/foo ]; do echo -n "." process_data > /tmp/foo done Which of the following are true? (choose two) 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
If a file called /tmp/foo exists, process_data won't be run process_data will be called at most once
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
It is the first argument passed to the script
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
Running the script will invoke /bin/csh to interpret the rest of the file
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
The previous command's exit code
A conditional that lets you make multiple comparisons with a pattern is called: fanout case if branch test
case
How would you finish your script with an exit code of 42? return 42 break 42 CODE=42 exit 42 $?=42
exit 42
Which of the following are correct about for and while loops? (choose two) 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
for loops operate over a fixed list of items while loops have a test each cycle to determine if it should run again
Which shell command accepts input from the user's keyboard? echo read gets input $1
read
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
test $USERS -eq 5
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
test -d /tmp/foo -o $USERS -gt 5
Which are appropriate editors for writing shell scripts?(choose two) Firefox /bin/bash LibreOffice Writer vi nano
vi nano
