Add grep -c flag playground

grep_c/file.txt

@@ -0,0 +1 @@
+pattern

grep_c/grep_c.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+set -e
+
+timeout 10 bash -c '
+  until [ $(grep -c "pattern" file.txt) -gt 0 ]; do
+    echo "pattern not found, sleeping for 2 secs..."
+    sleep 2
+  done
+'
+echo "pattern found! Exiting"