linux心得--常用linux字元

- Single-dash 單破折號
$0 Command name
' ' Full quote (no expansion)
" " Partial quote (allows variable and command expansion)
$$ Process id
$* All arguments as a simple word
$n nth argument (n from 0 to 9)
$var Use avalue for variable
& Run process in background
() Execute in subshell
* wildcard (represents everything)
. Single Period (The current directory)
.. Double Period (Parent Directory)
; Separate commands on same line
? Single character wildcard
[] Match any characters enclosed
\ Quote the following character.Also used to break a command line to multiple lines
` ` back ticks (Substitute output of enclosed command)
| Pipe (Takes the stdout and it becomes the stdin for the command after the pipe)
< Redirect input
<< Uses a delimiter with text to pass as input a command
> Redirect output
>> Used to append data to another file