Add chargen

Author: mariadb-AndreyPiskunov

benchmarks/chargen.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+for (( VAR=1; VAR<=1000; VAR++ ))
+do
+    shuf -er -n3  {A..Z} {a..z} | tr -d '\n'
+    echo
+done

benchmarks/numgen.sh

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+seq 1 100000000