From 091fd0244ad78da9e4ae1ef87361d4ecc41bf3c7 Mon Sep 17 00:00:00 2001
From: Vidar Holen <vidar@vidarholen.net>
Date: Tue, 17 Aug 2021 22:08:13 -0700
Subject: [PATCH] Created SC3015 (markdown)

---
 SC3015.md | 29 +++++++++++++++++++++++++++++
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+## In POSIX sh, =~ regex matching is undefined.
+
+### Problematic code:
+
+```sh
+[ "$var" =~ .*foo[0-9]* ]
+```
+
+### Correct code:
+
+```sh
+expr "$var" : ".*foo[0-9]*" > /dev/null
+```
+
+### Rationale:
+
+You are using `=~` in a script declared to be compatible with POSIX sh or Dash.
+
+`=~` is not a POSIX operator and is unlikely to outside `[[ ]]` in Bash and Ksh.
+
+Use `expr`'s `:` operator instead.
+
+### Exceptions:
+
+None
+
+### Related resources:
+
+* Help by adding links to BashFAQ, StackOverflow, man pages, POSIX, etc!
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