OS Cheat Sheet by tteengx

i - insert at cursor (goes into insert mode)

ESC - Terminate insert mode

A - Write at the end of line (goes into insert mode)

U - undo all changes to the entire line

3dd - delete 3 lines

C - delete contents of a line after the cursor and insert new text

4dw - delete 4 words

R - overwrite characters from cursor onward

x - delete character at the cursor

S - Substitute entire line and begin to insert at the beginning of the line

k - move cursor up

h - move cursor left

Shift+zz: save the file and quit

:q - quit without saving

> : send output to file or another device

>> : appends new file to an existing file

!! : current history

wc : word count

Ctrl-c: stop current command

Ctrl-a: go to start of line

Ctrl-u: cut from start of line

Ctrl-k: cut to end of line

Alt-A; start marking text

Ctrl-X: close file

ALT-/ End of file

CTRL-E: End of line

CTRL-W: Find

ALT-W: Find next

# Display the user and group ids of your current user.

# Display the last users who have logged onto the system.

# Show who is logged into the system.

# Show who is logged in and what they are doing.

# Create a group named "­tes­t".

# Create an account named john, with a comment of "John Smith" and create the user's home directory.

# Delete the john account.

# Add the john account to the sales group

#Display Linux system inform­ation

#Show system host name

#Display kernel release inform­ation

# Display the IP addresses of the host

# Show which version of redhat installed

#Show the current date and time date

# Who you are logged in as

# Display who is online

# Show this month's calendar

# Show system host name

#Search for pattern in file: grep pattern file

# Search recurs­ively for pattern in directory: grep -r pattern directory

# Find files larger than 100MB in /home: find /home -size +100M

# Connect to host as your local username: ssh host

grep 'word' filename – Search any line that contains the word in filename on Linux

grep -i 'bar' file1 – A case-i­nse­nsitive search for the word ‘bar’ in Linux and Unix

# List all files in a long listing (detailed) format

# Display the present working directory

# Create a directory

# Remove (delete) file

# Remove the directory and its contents recurs­ively

# Force removal of file without prompting for confir­mation

# Forcefully remove directory recurs­ively

#Copy file1 to file2

# Copy source­_di­rectory recurs­ively to destin­ation. If destin­ation exists, copy source­_di­rectory into destin­ation, otherwise create destin­ation with the contents of source­_di­rec­tory.

# Rename or move file1 to file2. If file2 is an existing directory, move file1 into directory file2

# Create symbolic link to linkname

# Create an empty file or update the access and modifi­cation times of file.

# Display the first/last 10 lines of file

#View/­browse the contents of file

# Display the last 10 lines of file and "­fol­low­" the file as it grows.

tail -f file

user group/­other permis­sions - link account - user - group - filesize - date - filename

r : read, w : write, x - excute

/ to find

\> : searches for the next word that ends with a specific string

$: searches for the line that ends with a specific character

:! - leave vi tempo

ZZ: in command mode, save changes and exit vi

u : undo most recent change

/ to find

\> : searches for the next word that ends with a specific string

/ to find

\> : searches for the next word that ends with a specific string