*: wildcard, matches any character, such as LS *.txt to see all files ending in. txt
?: matches any one character
#: annotation characters
\: escape character for converting special symbols to normal characters, such as Touch \#.txt to create a file named #.txt
|: pipe break, throw a command execution result to the command following the pipe character, such as CAT/ETC/PASSWD | Wc-l
$:① represents a prefix for a variable, such as Echo $HOSTNAME ② for "End", which is used more in regular expressions
;: semicolons are used to execute multiple commands sequentially, such as touch 1.txt; Touch 2.txt; Touch 3.txt
~: represents the user's home directory, such as LS ~/.BASHRC
&: placed behind the execution command, indicating that the command is executed in the background, such as sleep & indicates that sleep 80 is running in the background
[]: Used to match any one of the characters in brackets, such as LS [123].txt will match 1.txt, 2.txt, 3.txt
Shell Special Symbols