From 1aea36ac900fa1b07fe0c5e324bd9390f6cbe6f4 Mon Sep 17 00:00:00 2001
From: Dylan Araps <dylan.araps@gmail.com>
Date: Fri, 15 Jun 2018 15:57:17 +1000
Subject: [PATCH] Added another entry

---
 README.md | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/README.md b/README.md
index bc311d6..a5829b5 100644
--- a/README.md
+++ b/README.md
@@ -52,6 +52,7 @@ scripts and not full blown utilities.
     * [Strip first occurrence of pattern from string.](#strip-first-occurrence-of-pattern-from-string)
     * [Strip pattern from start of string.](#strip-pattern-from-start-of-string)
     * [Strip pattern from end of string.](#strip-pattern-from-end-of-string)
+    * [Check if string contains a substring.](#check-if-string-contains-a-substring)
 * [Variables](#variables)
     * [Assign and access a variable using a variable.](#assign-and-access-a-variable-using-a-variable)
 * [Arrays](#arrays)
@@ -390,6 +391,25 @@ $ rstrip "The Quick Brown Fox" " Fox"
 The Quick Brown
 ```
 
+## Check if string contains a substring.
+
+```shell
+# Normal
+if [[ "$var" == *sub_string* ]]; then
+    printf '%s\n' "sub_string is in var"
+fi
+
+# Inverse (substring not in string).
+if [[ "$var" != *sub_string* ]]; then
+    printf '%s\n' "sub_string is not in var"
+fi
+
+# This works for arrays too!
+if [[ "${arr[*]}" == *sub_string* ]]; then
+    printf '%s\n' "sub_string is in array."
+fi
+```
+
 # Variables
 
 ## Assign and access a variable using a variable.