CompTIA Linux+ Linux GNU and Unix Commands Flashcards

Which command displays currently logged-in users along with what they are doing?

Answer: w

The w command shows who is logged in and their current activity including load averages.

A technician needs to compare two files line by line. Which command should be used?

Answer: diff file1 file2

diff compares two files line by line and shows the differences with context markers.

What does 'chown alice:developers report.txt' do?

Answer: Sets owner to alice and group to developers

chown user:group sets the file's owner to alice and its group to developers.

Which command creates a symbolic link named 'link.txt' pointing to 'original.txt'?

Answer: ln -s original.txt link.txt

ln -s creates a symbolic (soft) link; without -s it creates a hard link.

Which pipeline counts the number of lines in a file named 'data.txt'?

Answer: cat data.txt | wc -l

wc -l counts lines; piping cat output through wc -l gives the total line count.

What does the 'umask 022' setting mean for newly created files?

Answer: Files are created with permissions 644

umask 022 subtracts from 666 (default file perms), yielding 644 (rw-r--r--).

Which command searches for the string 'ERROR' in all .log files recursively?

Answer: grep -rE 'ERROR' --include='*.log' .

grep -rE with --include='*.log' recursively searches only .log files for the pattern.