From 35d37a79c1d4807b6b30f3bddae867ef16947f7a Mon Sep 17 00:00:00 2001
From: Philip Wittamore <philip@wittamore.com>
Date: Sat, 17 May 2025 09:25:17 +0200
Subject: update

---
 README.md | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

(limited to 'README.md')

diff --git a/README.md b/README.md
index 4afebe0..ab01731 100644
--- a/README.md
+++ b/README.md
@@ -4,3 +4,33 @@
     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}` |
+
-- 
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