| head | See first n lines of file |
| tail | See last n lines of file |
| sort | Sort the output |
| less | A filter for paging through text one screenful at a time |
| su | Switch user |
| shred | Securely remove file by overwriting and removing |
| which | Shows the path of the command |
| ps | Process |
| rsync | scp but better for SSH access moving files |
| scp | Secure Copy Protocol |
| source | Source shell vars |
| ln | Link folders |
| top | Show process, memory etc |
| time | How long a process takes to run |
| cut | cut columns from a file |
| awk | Programming language built for text processing (Aho, Weinberger, Kernighan (authors)) |
| sed | Same as awk (Stream editor) |
| uniq | Filter unique |
| column | Remedy ugly output by spacing with columns |
| find | Find file (like want -name or -iname flag) |
| diff,comm | Diff or find commonality between two files |
| tr | Translate - also useful with "-d" flag to delete |
| split | Split a file up |
| nl | Numbered line |
| yes | Prints character "y" |
| crontab | Used to run cron jobs |
| apropos | Display related commands to arg. French "à propos" which means appropriate. |
| watch | Use to monitor |
| dig | DNS lookup utility |
| ifconfig | Network information |
