File Operations

Question 1

ls

Answer 1

Lists files and directories in current directory (ls - list).

Question 2

ls -a

Answer 2

Lists files, dot files and directories in current directory (-a - all.

Question 3

ls dir1 dir2

Answer 3

Lists files in directory1 and directory2.

Question 4

ls -l

Answer 4

Lists a long list (-l - long). permissions, number of hard links, owner, group, size, last modified and filename.

Question 5

What does drwxrwxr-x means?

Answer 5

Position 1: - = file, d = directory, l = symbolic link, p = named pipe, c = character device, b = block device. 2-4: Read, write and execute permissions for the owner. 5-7: Group. 8-10: Other users.

Question 6

ls -ld dir1

Answer 6

Information about directory but not about what is in the directory.

Question 7

ls -lh

Answer 7

Prints size in a more readable format.

Question 8

ls -s

Answer 8

Prepend the size of files.

Question 9

Sort files by size.

Answer 9

ls -s | sort -n

Question 10

ls -R

Answer 10

List contents in directories recursively.

Question 11

cp [options] files (file|directory)

Answer 11

Copy one or several files.

Question 12

cp -a

Answer 12

Copy directories recursively. Same as cp -r but preserve file attributes.

Question 13

cp -r

Answer 13

Copy directories recursively. Same as cp -a but does not preserve file attributes.

Question 14

mv [options] source target

Answer 14

Move. Can also be used to rename a file.

Question 15

mv file1 file2

Answer 15

Rename file1 to file2.

Question 16

mv file1 file2 dir2

Answer 16

Move file1 and file2 to dir2.

Question 17

rm [options] files | directories

Answer 17

Remove.

Question 18

rm -r dir1 dir2

Answer 18

Recursively remove dir1 and dir2.

Question 19

rm -rf /

Answer 19

Probably you don’t want to do this.

Question 20

ln [options] source target

Answer 20

Create symbolic (also soft or sym) and hard links. The default is a hard link.

Question 21

ln -s

Answer 21

Create a symbolic link.

Question 22

ln -d

Answer 22

Create a hard link to a directory.

Question 23

cd

Answer 23

Change directory.

Question 24

pwd

Answer 24

Prints current directory.

Question 25

mkdir

Answer 25

Make directory.

Question 26

mkdir -p

Answer 26

Make a directory path, e.g. mkdir -p ./dir1/dir2, now both dir1 and dir2 will be created.