+ c="$(printf '%s\n' "$b" | sed '
+ # POSIX BRE metacharacters -> .
+ s/[\\.*^$]\|\[\|]/./g
+
+ # Escape the apostrophe the same way than `listfull.sh`,
+ # then re-escape in POSIX BRE.
+ # x -> x\\xx (where `x` is the apostrophe)
+ s/'\''/'\''\\\\'\'\''/g
+ ')"
+