Common Linux Command Cheatsheet (Updating...)

Manual

To check the manual for a command, you can use the man command

man ls
man rm
...

File/Folder

Basic Operations

# list files and directories
ls -l # show detailed information
ls -a # show hidden files
ls -lh # display human-redable file sizes
 
# remove
rm -r directory # remove directory recursively
rm -f file.txt # force removal
rm -rf directory # delete forcefully and recursively
rm -rf ./* # remove all contents 
 
# copy
cp -r directory destination 
# if destination exists, the new directory will be placed 
# under the extsting folder. else if destination and the 
# destination only has more than 1 segment doesn't exist, 
# error occurs. 
cp file.txt directory 
 
# move
mv old.txt new.txt # rename
mv file.txt directory
 
# create
touch file.txt
 
# show the start of a file
head -n 5 file.txt # show top 5 lines
 
# show the end of a file
tail -n 100 file.txt # show last 100 lines
 
# find
find /path/to/search -name "*.txt"
 
# move file from server to local
scp /path/to/local/file username@remote_host:/path/to/remote/directory
 
# move file from local to server
scp username@remote_host:/path/to/remote/file /path/to/local/directory

File Permission Commands

drwxr-xr-x

1. d: The first character represents the file type. In this case, d means it's a directory. If it was a file, this character would be -.

2. rwxr-xr-x: The next nine characters represent the file permissions, divided into three groups of three:

   • rwx: The first group of three characters (after the d) shows the permissions for the owner

     (the user who owns the directory or file).

     • r means the owner has read permission.
     • w means the owner has write permission.
     • x means the owner has execute permission (for a directory, this means the owner can list its contents).

   • r-x: The second group represents the permissions for the group

     (other users who are part of the file’s group).

     • r means group members can read the file/directory.
     • - means group members cannot write to the file/directory.
     • x means group members can execute the file or access the directory.

   • r-x: The third group shows the permissions for others

     (everyone else).

     • r means others can read the file/directory.
     • - means others cannot write to the file/directory.
     • x means others can execute the file or access the directory.

chmod 755 myfile
# 7: rwx (owner)
# 5: r-x (group)
# 5: r-x (others)
 
# check which group I belong to
groups
# The id command provides more detailed information about your user ID 
# and group memberships:
id

Vim

:w - Save the file (write changes to disk).

:q - Quit Vim.

:wq - Save the file and quit Vim.

:q! - Quit without saving changes.

0 (zero) - Move to the beginning of the current line.

$ - Move to the end of the current line.

dd - Delete the current line.