Unix commands

list files in current directory:          ls   (ls -a,   ls -l)

check the disk space (in kbtyes):         df -k

check the present working directory:      pwd

make a new directory dir1:                mkdir dir1

change to directory dir1:                 cd dir1

change back one directory:                cd ../

change to the home directory:             cd

remove a file called file1:               rm file1

remove all files in current directory:    rm *

remove all files starting with z:         rm z*

remove all file ending with a:            rm *a

remove a directory called data:           rmdir data

make a duplicate copy of file dog:        cp dog dog2

change the name of dog2 to dog1:          mv dog2 dog1   (mv dog ../dog
                                                          mv dog dir1/dog
                                                          mv dog ~/dog)
print the file dog on the screen:         cat dog

print the first ten lines of file dog:    head -l10 dog

print the last twenty lines of file dog:  tail -l20 dog

print any lines in file dog that have the specified pattern:  grep 'hello world' dog

compare two files line by line:           diff file1 file2

Delete text with backspace.

Highlight text with left clicker on mouse and paste it at
the cursor with the middle clicker.

Use up and down arrow keys to scroll through your previous commands.

Use the tab key to finish typing the name of a file.