| exit | Exit actual session, exit from the program |
| whatis [command] | Show a one-line description of the command |
| clear | clear terminal window |
| man [command] | show manual page for command |
| less [file] | allow you to view, search in many ways in text files |
| pwd | print current working directory |
| ls | list files/folders in the directory |
| cd | change directory |
| cat | send input to output, for example, take the content of the file and send it to another program |
| type [command] | show command type for example type ls -> ls is aliased to `ls –color=auto’ |
| alias | allows you to create command aliases, without params show actual aliases |
| whoami | display current username |
| whereis | allows you to locate binaries, manuals etc. (show all important files) |
| date | show the current system date and time |
| touch | allows you to update file timestamp or create the file |
| file | determine file type |
| which | similar to whereis. Whereis show all “possibly useful” files, which show the only path to the binary |
| echo | allows you to display text and variables |
| nano | popular text editor alternative to vim, not available in all distro as build-in and you need to install it |
| ln | allows you to make file or directory links |
| mkdir | allows you to make directories |
| cp | allows you to copy files and directories |
| mv | allows you to move files/rename/files and directories |
| rm | allows you to remove files or directories |
| wc | allows you to count lines, words and bytes |
| head | allows you to print the first lines of a file |
| tail | allows you to print the last lines of a file |
| apropos | allows you to search manual titles and descriptions |
| find | allows you to search for files within directories |
| sort | allows you to sort lines within the text files |
| uniq | allows you to find repeating consecutive lines |
| cut | allows you to cut part of text from lines |
| diff | allows you to compare lines of text files |
| comm | allows you to simply compare two files |
| sdiff | allows you to compare and merge two files |
| paste | allows you to combine lines from two files |
| join | allows you to join lines from two files |
| grep | allows you to search for text patterns in a file |
| sed | allows you to edit a stream of text for example replace text in the file |
| calendar | reminder service, show upcoming events and allow you to make reminders – requires cpp installed |
| cal | allows you to show a visual calendar in terminal |
| sleep | allows you to pause for a specified amount of time |
| crontab | allows you to create and schedule automated jobs |
| ps | allows you to print a snapshot of current processes |
| printenv | allows you to print environment variables |
| export | allows you to pass environment variables to other processes |
| set | allows you to display or set shell and environment variables |
| unset | allows you to unset variables or function |
| stat | allows you to show file or file system status |
| df | allows you to display file or file system space |
| du | allows you to show disk utilization for files and directories similar to df but for files and folders |
| free | allows you to display memory in system RAM |
| pg | allows you to view text files page by page |
| more | allows you to view text files |
| vim | basic text editor |
| history | show history of your commands |
| kill | kill process |
| bg | allows you to move a process to the background |
| uname | allows you to display system information, uname -a show all info about the system |
| jobs | allows you to show jobs in the terminal |
| apt-get | package manager used in ubuntu etc. apt-cache – allows you to search for packages |
| gzip | allows you to compress and decompress files |
| tar | allows you to archive files and directories |
| chmod | allows you to change file permissions |
| chown | allows you to change file owner and group |
| id | allows you to show user and group information |
| su | allows you to temporarily substitute user |
| sudo | allows you to run a command as superuser |
| passwd | allows you to change user password |
| adduser | allows you to add users and groups |
| wget | download files non-interactively |
| ssh | remotely access a server |
| source | read and execute commands from a file |
| tree | read from standard input and write to standard output and files |
| printf | create formatted output |
