Learning Essays on Linux commands

getconf page_size//Get the size of the memory page
Alias vi= ' vim '//Temporary effect
Vi/root/.bashrc
Whereis ls
Output redirection
> >> 2> 2>>
cmd > File 2>&1 cmd >> file 2>&1
cmd &>> file cmd >> file1 2>> file2

; Command delimiter
CMD1&&CMD2//1 execution is successful. 2
cmd1| | CMD2//Execute only one of the commands (sequential execution)

Pipeline |
cmd1 | Cmd2
CMD1 must have correct output

Wildcard characters:
*
[]
[^0-9]
' GFHJASHJD '//special symbols have no special meaning
"Jsdsfjjas"//have special meaning
$ ()//first executed inside the parentheses, in return
$ reference Variable Value

Learning Essays on Linux commands