Linux Text Processing & Editors 3

Question 1

What does `grep -v "error" logfile` display?

Accepted Answer

Lines that do NOT contain the word 'error'

Answer

The -v flag inverts the match, so grep -v displays only the lines that do not contain the specified pattern.

Question 2

In vim's normal mode, which key switches to insert mode placing the cursor before the current character?

Accepted Answer

i

Answer

Pressing 'i' in vim's normal mode enters insert mode, positioning the cursor to insert text just before the current character.

Question 3

What does `awk 'NR==3 {print}' file` do?

Accepted Answer

Prints only the third line of the file

Answer

NR is awk's built-in variable for the current record number; NR==3 is true only when processing the third line.

Question 4

What does `sed -i 's/old/new/g' file` do?

Accepted Answer

Modifies the file in-place, replacing all occurrences

Answer

The -i flag tells sed to edit the file in-place, making changes directly to the file rather than writing to stdout.

Question 5

What does `grep -c "pattern" file` return?

Accepted Answer

The count of lines that match the pattern

Answer

grep -c suppresses normal output and prints only the total number of lines that match the given pattern.

Linux Practice Test