| Command | Meaning | 
|---|---|
| command > file | redirect standard output to a file | 
| command >> file | append standard output to a file | 
| command < file | redirect standard input from a file | 
| command1 pipe command2 | pipe the output of command1 to the input of command2 | 
| cat file1 file2 > file0 | concatenate file1 and file2 to file0 | 
| sort | sort data | 
| who | list users currently logged in |