Good for normalizing input. declare -u upper-case declare -l
lower-case
| Format | Result |
|---|---|
| ${parameter,,pattern} | Expand the value of parameter into all |
| lowercase. pattern is optional. | |
| ${parameter,pattern} | Expand value of parameter, changing |
| only first character to lowercase. | |
| ${parameter^pattern} | Expand value of parameter into all uppercase |
| ${parameterpattern} | Expand value of parameter, changing only |
| first character to uppercase. |
Case Conversion Parameter Expansions