Bash: named character classes
12 December 2025 (Updated 12 December 2025)
[:alpha:]- Matches letters A-Z or a-z
[:alnum:]- Matches letters (A-Z,a-z) or numbers (0-9)
[:digit:]- Matches numbers 0-9
[:upper:]- Matches uppercase letters (A-Z)
[:lower:]- Matches lowercase letters (a-z)
[:space:]- Matches whitespace (including space, tabs, and newline characters).
Tagged:
Bash