This Is Your Brain On Informatics: Linux Commands

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General Linux Command Info

  • Almost every single command should have an argument (an input for a function)
  • A filename in Linux refers to both a file's name and a directory's name

Common Linux Commands

Command Syntax Description
cat cat filename Display file’s contents to the standard output device (usually your monitor)
cd cd /pathname Change to the given directory
chmod* chmod options mode filename Changes a file's permissions.
chown chown private_owner:group_owner filename Changes ownership of the file
clear clear Clears the screen by scrolling (does not delete anything)
cp cp options source destination Copies a file from the source to the destination
find find /pathname string Starts at the indicated directory and searches for the string in a filename
grep grep options pattern filename Searches for the pattern in the file
ifconfig ifconfig Displays the current networks available and various information about them
ll ll /pathname List Long: lists the details of the entire directory or file indicated
ln ln options source destination Link: creates a shortcut. Use -s for the options to create a soft link (more capabilities)
ls ls /pathname Lists the files and directories in a given directory
man man command Opens the manual page for the given command
mkdir mkdir options filename Makes a directory at the given location with the given name
mv mv options source destination Moves a file or directory from the source to the destination
pico pico filename Opens the given file in the pico text editor
pwd pwd Displays the pathname for the current directory
rm rm options filename Removes the given file. If -rf is used for the options, a directory and its roots will be removed as well
ssh ssh options user@machine Remotely logs into the given machine with the given user name
sudo sudo command Allows super user privileges for the given command (requires root password). sudo su allows login to root
tar tar -xzvf filename Extracts files with the extension *.tar.gz or *.tgz
touch touch filename Creates an empty file with given name
wget wget internet address Downloads a file from a given internet address

*Notes on chmod

chmod has several input options. Using a "+" and an "r", "w", and/or "x" will add read, write, or execute permissions respectively to the given file. A "-" will take these away. The other system is a binary system in which there are permissions for the private user, the group, and the public (other) given as 000 000 000 where each set of three 0's equals the private user, group, or public respectively. The first 0 in each set of 0's is for reading permission, the second for writing, and the third for executing. Because it is binary 100 000 000 (permission for the private user to read only) will be written as 400 in the command line (after translating the binary to decimal where 100 = 4)