Unix Commands Extended

Question 1

What does the du command do?

Answer 1

Prints the number of disk blocks -512 byte units, being used by the contents of the current directory.

Question 2

What does the sort command do?

Answer 2

Sorts the input according to the given option.

Question 3

What does the cut command do?

Answer 3

Extracts columns out of text files.

Question 4

What does the tar command do?

Answer 4

Bundles files into an archive.

Question 5

What does the diff command do?

Answer 5

Finds the differences between 2 files.

Question 6

What does grep command do?

Answer 6

Search for information using regular expressions.

Question 7

What does date +%j print?

Answer 7

The number of days since January 1st.

Question 8

What does date +%s print?

Answer 8

The Unix timestamp.

Question 9

What does cal -j print?

Answer 9

Displaying the day numbers.

Question 10

What does du name print?

Answer 10

Prints the disk usage of the entered directory.

Question 11

What does du -h print?

Answer 11

Prints the disk usage in human readable form.

Question 12

What does du -s print?

Answer 12

Prints a grand summary of the disk space used.

Question 13

What does du -a do?

Answer 13

Prints the disk usage of all files and subdirectories in the current directory.

Question 14

What does du -c print?

Answer 14

Prints a grand total for each file.

Question 15

What was head -n _ print?

Answer 15

Prints the first blank number of lines instead of the first ten.

Question 16

What does head -c _ print?

Answer 16

Prints the first blank number of bytes.

Question 17

What does tail -h print?

Answer 17

Watches for changes in the file (for logging).

Question 18

What does the cut -c print?

Answer 18

Cuts each line of the file from start position to end position.

Question 19

What does cut -b print?

Answer 19

Cuts by bytes instead of characters.

Question 20

What does cut -f fieldNumbers -d delimiters print?

Answer 20

Separates the lines into fields based off the delimiters then prints the significant fields.

Question 21

What does cut [options] –complement filename print?

Answer 21

Prints the complement - the parts of the files that would have been left out in the original cut command.

Question 22

What does cut [options] –output-delimiter new di filename print?

Answer 22

Changes the output delimiter from space to the given delimiter.

Question 23

What does sort -r fileName print?

Answer 23

Sorts in reverse order.

Question 24

What does sort -n fileName print?

Answer 24

Sorts numerical content as numbers instead of lexicographical order.

Question 25

What does sort -f fileName print?

Answer 25

Ignores the case while sorting.

Question 26

What does sort -c fileName print?

Answer 26

Checks if a file is already sorted. Prints the lines that are not in order. The file is already sorted if there is no output.

Question 27

What does sort -u fileName print?

Answer 27

Sorts the file contents and removes the duplicates.

Question 28

What does tar -c print?

Answer 28

Insert files into a tar file?

Question 29

What does tar -f print?

Answer 29

Uses the name of the tar file that is specified.

Question 30

What does tar -v print?

Answer 30

Outputs the name of each file as it is inserted into or extracted from a tar file.

Question 31

What does tar -x print?

Answer 31

Extracts the files from a tar file.

Question 32

What does tar -t print?

Answer 32

Lists contents of an archive.

Question 33

What does tar -z print?

Answer 33

gzip/gunzip if necessary.

Question 34

What does the diff -b print?

Answer 34

Treat groups of spaces as one.

Question 35

What does diff -i print?

Answer 35

Ignores case.

Question 36

What does tar -r print?

Answer 36

Includes directories in comparison.

Question 37

What does diff -w do?

Answer 37

Ignores all spaces and tabs.

Question 38

What does grep -i do?

Answer 38

Ignores case.

Question 39

What does grep -n print?

Answer 39

Displays line numbers.

Question 40

What does grep -I print?

Answer 40

Displays only the names of the files and note the actual lines.

Question 41

What does grep -P do?

Answer 41

Pattern is a Perl regular expression, not a Unix regular expression.