Globbing
????→ 4 chars*→ any number of chars[:upper:]⇔[A-Z]same for[:lower:]and[:digit:][:alpha:]⇔[a-zA-Z][:alnum:]⇔[a-zA-Z0-9]ls -l [a-d]→ part of a range^ and $ works like in regex
la a*.{doc,docx}→ ORls a*.(doc|docx)→ OR
???? → 4 chars
* → any number of chars
[:upper:] ⇔ [A-Z] same for [:lower:] and [:digit:]
[:alpha:] ⇔ [a-zA-Z]
[:alnum:] ⇔ [a-zA-Z0-9]
ls -l [a-d] → part of a range
^ and $ works like in regex
la a*.{doc,docx} → OR
ls a*.(doc|docx) → OR