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     pb_fg 0-254  set foreground colour
     pb_bg 0-254  set background colour
     pb_nc        remove coulours
+
+## Bash string manipulation cheatsheet 
+### https://gist.github.com/magnetikonline/90d6fe30fc247ef110a1
+
+| Assignment |     |
+| --- | --- |
+| Assign `value` to `variable` if `variable` is not already set, `value` is returned.  <br>  <br>Combine with a `:` no-op to discard/ignore return `value`. | `${variable="value"}`  <br>`: ${variable="value"}` |
+| Removal |     |
+| Delete shortest match of `needle` from front of `haystack`. | `${haystack#needle}` |
+| Delete longest match of `needle` from front of `haystack`. | `${haystack##needle}` |
+| Delete shortest match of `needle` from back of `haystack`. | `${haystack%needle}` |
+| Delete longest match of `needle` from back of `haystack`. | `${haystack%%needle}` |
+| Replacement |     |
+| Replace first match of `needle` with `replacement` from `haystack`. | `${haystack/needle/replacement}` |
+| Replace all matches of `needle` with `replacement` from `haystack`. | `${haystack//needle/replacement}` |
+| If `needle` matches front of `haystack` replace with `replacement`. | `${haystack/#needle/replacement}` |
+| If `needle` matches back of `haystack` replace with `replacement`. | `${haystack/%needle/replacement}` |
+| Substitution |     |
+| If `variable` not set, return `value`, else `variable`. | `${variable-value}` |
+| If `variable` not set _or_ empty, return `value`, else `variable`. | `${variable:-value}` |
+| If `variable` set, return `value`, else null string. | `${variable+value}` |
+| If `variable` set _and_ not empty, return `value`, else null string. | `${variable:+value}` |
+| Extraction |     |
+| Extract `length` characters from `variable` starting at `position`. | `${variable:position:length}` |
+| Return string length of `variable`. | `${#variable}` |
+| Escaping |     |
+| Single quotes inside a single quoted string. | `echo 'Don'\''t break my escape!'` |
+| Indirection |     |
+| Return value of variable name held in `indirect`, else `value`. | `indirect="apple"`  <br>`apple="fruit"`  <br>`${!indirect-value}` |
+