1. Wildcard characters in the shell environment
* 0 to multiple arbitrary characters
? An arbitrary character
[] a character in parentheses
[-] All characters in the sequence
[^] a character, and a character that is not in parentheses
2. Special symbols
# comment Symbols
\ Escape Symbol
| Pipeline
; Continuous command delimiter
~ User home Folder
$ variable Leader
& Operation Control. Background work
! Logical operation "NON"
/directory symbol, PATH delimited
>> output data stream Redirect, replace, accumulate
<, << input data flow redirection
' Single quotation marks. Do not make variable substitution
"" double quotation marks. Variable substitution possible
"Two" ' is the middle of a command that can be executed first. function with $ ()
() "(" and ")" for the beginning and end of the shell
A command block combination between {} ' {' and '} '
Shell (vii) wildcard characters and special symbols