102-400

102-400 practice questions, page 3 of 5, with answer review and explanations.

Question 11

What is the difference between the commands test -e path and test -f path?

  1. They are equivalent options with the same behaviour.
  2. The -f option tests for a regular file. The -e option tests for an empty file.
  3. Both options check the existence of the path. The -f option also confirms that it is a regular file.
  4. The -f option tests for a regular file. The -e option tests for an executable file.

Question 12

How can the existing environment variable FOOBAR be suppressed for the execution of the script./myscript only?

  1. unset -v FOOBAR;./myscript
  2. set -a FOOBAR="";./myscript
  3. env -u FOOBAR./myscript
  4. env -i FOOBAR./myscript

Question 13

When the command echo $ outputs 12942, what is the meaning of 12942?

  1. It is the process ID of the echo command.
  2. It is the process ID of the current shell.
  3. It is the process ID of the last command executed.
  4. It is the process ID of the last command which has been placed in the background.

Question 14

What output will the following command produce? seq 1 5 20

  1. 1
  2. 1
  3. 1
  4. 2
  5. 5

Question 15

Which of the following words is used to restrict the records that are returned from a SELECT SQL query based on a supplied criteria for the values in the records?

  1. CASE
  2. FROM
  3. WHERE
  4. IF