grep and egrep with regular expression
| CTRL + H | [a-zA-Z0-9]|\p{Punct}|\n\r |
|---|---|
| [a-zA-Z0-9]|\p{Punct}|\n\r | |
| punctuation | \p{Punct}+ |
| number | [0-9]+ |
| start with number | ^[0-9]+ |
| remove all letters | [a-z]|[A-Z] |
| all letters ( including Chinese char ) | [[:alpha:]] [\u\l] |
Find: \p{Punct}+
