Created SC2206 (markdown)

SC2206.md

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+## Quote to prevent word splitting, or split robustly with mapfile or read -a.
+
+### Problematic code:
+
+```sh
+array=( $var )
+```
+
+### Correct code:
+
+If the variable should be a single element:
+
+```sh
+array=( "$var" )
+```
+
+If it's multiple lines, each of which should be an element:
+
+```sh
+# For bash
+mapfile -t array <<< "$var"
+
+# For ksh
+printf '%s\n' "$var" | while IFS="" read -r line; do array+=("$line"); done
+```
+
+If it's a line with multiple words (separated by spaces, other delimiters can be chosen with IFS), each of which should be an element:
+
+```sh
+# For bash
+IFS=" " read -r -a array <<< "$var"
+
+# For ksh
+IFS=" " read -r -A array <<< "$var"
+```
+
+### Rationale:
+
+You are expanding a variable unquoted in an array. This will invoke the shell's sloppy word splitting and glob expansion.
+
+Instead, prefer explicitly splitting (or not splitting):
+
+* If the variable should become a single array element, quote it.
+* If you want to split into lines or words, use `mapfile`, `read -ra` and/or `while` loops appropriate.
+
+This prevents the shell from doing unwanted splitting and glob expansion, and therefore avoiding problems with data containing spaces or special characters.
+
+### Exceptions:
+
+If you have already taken care (through setting IFS and `set -f`) to have word splitting work the way you intend, you can ignore this warning.