From 836b1874369fa47f37a71f2f04af18e7929567ce Mon Sep 17 00:00:00 2001
From: johannst <johannes.stoelp@gmail.com>
Date: Wed, 20 Jan 2021 20:11:01 +0100
Subject: bash/zsh: add notes for regex matching

---
 src/tools/zsh.md | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

(limited to 'src/tools/zsh.md')

diff --git a/src/tools/zsh.md b/src/tools/zsh.md
index 4d52ae0..e9aa8bf 100644
--- a/src/tools/zsh.md
+++ b/src/tools/zsh.md
@@ -162,6 +162,24 @@ echo ${(L)foo}        # aabb
 echo ${(U)foo}        # AABB
 ```
 
+## Regular Expressions
+
+Zsh supports regular expression matching with the binary operator `=~`.
+The match results can be accessed via the `$MATCH` variable and
+`$match` indexed array:
+- `$MATCH` contains the full match
+- `$match[1]` contains match of the first capture group
+
+```zsh
+INPUT='title foo : 1234'
+REGEX='^title (.+) : ([0-9]+)$'
+if [[ $INPUT =~ $REGEX ]]; then
+    echo "$MATCH"       # title foo : 1234
+    echo "$match[1]"    # foo
+    echo "$match[2]"    # 1234
+fi
+```
+
 ## Completion
 
 ### Installation
-- 
cgit v1.2.3