Linux Tools for Developers

1.Which command will list all files under the current directory with a .cfg extension, and then delete them?

• find . -exec rm {} ';' -name "*.cfg"

• find . -name "*.cfg" -exec rm {} ';'

• find -exec rm {} ';' -name "*.cfg" .

• find -name "*.cfg" . -exec rm {} ';'

2.Which command will list all files and directories on the system with cfg in their name?

• ls -l $(locate cfg)

• find cfg

• locate

• locate cfg -exec ls -l {} ';'

3.Which command will find all files and directories in the system whose name ends with cfg?

• locate -r "^cfg"

• locate cfg$

• locate cfg

• locate -r "cfg$"

4.Which commands can change all occurrences within a file of the string boris to natasha (Select all answers that apply)?

• sed -e s:boris:natasha:g file

• sed -e s/boris:natasha/g file

• sed -e s\boris\natasha\g file

• sed -e s/boris/natasha/g file

5.Which command will print out all lines beginning with "X" in all files in the current directory?

• grep $X *

• grep "X$" *

• grep "^X" *

6. Which command is used to combine three files into a fourth file?

• cat file1 file2 file3 > file4

• cp file1 file2 file3 > file4

• cat file1 > file2 > file3 | file4

• cat file1 > file2 > file3 > file4

7.Which of the following commands can be used to view the last 15 lines of a file (Select all answers that apply)?

• tail=15 some_file

• tail +15 some_file

• tail -n15 some_file

• tail -15 some_file

8.Which of the following commands will replace all instances of the word "dog" with "pig" in the file named some_file and send the output to stdout (Select all answers that apply)?

• sed -e s/dog/pig/ some_file

• cat some_file | sed -e s/dog/pig/g

• sed -e s:dog:pig:g some_file

• sed -e s/dog/pig/g some_file

9.Which commands can be used to print the lines that contain the numbers 0–5 in a file (Select all answers that apply)?

• grep [0,1,2,3,4,5] filenamegrep [0,1,2,3,4,5] filename

• grep {0-5} filenamegrep {0-5} filename

• grep [0-5] filenamegrep [0-5] filename

• grep [-e0 -e1 -e2 -e3 -e4 -e5] filenamegrep [-e0 -e1 -e2 -e3 -e4 -e5] filename

10.Which command is used to extract columns from a file to work on them later?

• wc

• cut

• tr

• tee