Math 300: Basic Linux Commands (back to Math 300 notes)

One does not need to know very many commands in order to get around on a connection to a remote machine pretty easily. Here we give a simple list of some of the most commonly used commands for Linux/Unix. Note that most commands can accept options that change their behavior. For example, ls provides a listing of the contents of the current directory, while ls -l gives that listing in long format, including many more details about each file in the directory. On the other hand, ls -a lists all the files in the directory, including the "hidden" ones. We can mix options simply by chaining them together; e.g. ls -la gives a listing of all files in a long format.

Remember that you can get a full description of the usage of any command by typing man <commandname> in a terminal.
CommandFunctionExample Formats
cdChange Directory cd
cd directory/path
chmodChange Mode - file permissions chmod u+w file_name
chmod 755 file_name
cpCopy files cp from_file to_file
exitExit the shell exit
lessList contents of a file less file_name
lsList filenames in a directory ls
ls -l
ls file_name
manManual pages man cp
man mv
mkdirMake a Directory mkdir directory_name
mvMove a file mv from_file to_file
nanoStart a primitive editor nano file_name
pwdPrint Working Directory pwd
rmRemove a file rm file_name
rmdirRemove a Directory rmdir directory_name

There are a few "wildcard" characters that can match many things. The question mark matches any single character. Thus, ls image?.jpg would list all of the files image1.jpg, image9.jpg, and imageA.jpg on a directory, but would not list image23.jpg The asterisk matches any number of characters, so that ls image*.jpg would list image1.jpg, image23.jpg and image49027.jpg.