This page provides descriptions for using basic Linux commands.
Command Descriptions
Note: You can use these commands at the Linux system prompt.
| Command | Description |
| | more | the pipe symbol (|), located above the backward slash (\) key, and the word more can be used after Unix listing commands (such as ls or cat filename) to display information one screen at a time (ls |more or cat filename |more). Press Enter or the Spacebar to scroll forward. |
| cat filename | displays the contents of a file |
| cat filename filename > new file | copies one or more files to a newly created file |
| cat filename >> destination file | adds one file to another file |
| cd | moves back to your home directory |
| cd directory | changes the current or working directory to another directory |
| cd .. | moves back one directory |
| cp filename newfilename | makes a copy of a file with a new name. To copy the file to another directory, use the command: cp filename directoryname or cp filename directoryname/newfilename |
| chmod | changes the read, write, and execute permissions of specified files and the search permissions of specified directories. For example, the command chmod 711 directorypath gives public access to that directory. The command chmod 644 filename also gives public access to the listed file. You must be in the directory where the file is stored. |
| history | more | displays of list of the last forty commands issued at the Unix prompt |
| kill -9 process# | kills a process. (Use ps command to list current processes.) |
| ls | lists directory contents and file information |
| ls -a | lists all files including hidden files |
| ls -F | lists files and subdirectories |
| ls -R | lists the chain of directories starting from the current directory |
| ls -s | lists the name and size of each file in a directory |
| man command | displays information from the online Unix reference manual about a specific command. For example, the command man cd displays information about changing directories. |
| man -k keyword | displays the commands relevant to a keyword. For example, the command man -k directory displays the commands for working with directories. |
| mkdir directoryname | adds a new directory |
| more filename | displays a file--one screen at a time |
| mv oldfilename newfilename | changes the name of a file |
| mv "filenamewithspace"newfilename | renames a file that has a space or unacceptable character in the filename. For example, the command mv "new budget" newbudget changes the name of the file from new budget to newbudget. |
| mv filename directoryname/ | moves a file to another directory. Directoryname is the destination directory for the file. |
|
nano filename (Compute and HPC) |
creates a file using the nano editor |
|
pico filename (Astro) |
creates a file using the pico editor |
| ps | lists the active processes running in your account. (See the kill command to end a process.) |
| pwd | displays the current working directory |
| rm filename | deletes a file in a directory |
| rm filename1 filename2 | deletes more than one file at a time |
| rmdir directoryname | deletes an empty directory |
| rm -r directoryname | deletes a directory and the subdirectories and files in the directory |
| vi filename |
creates a file using the vi editor |