add another simple example

Author: mikhailnov

examples/write-to-file.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+
+# https://github.com/mikhailnov/bashlib, https://abf.io/import/bashlib
+. bashlib ||{ echo "Failed to source bashlib!" ; exit 1 ;}
+
+readonly file="/var/www/r8168.list"
+readonly lock="/var/www/r8168.lock"
+readonly rev="$(safe_param rev)"
+readonly probe="$(safe_param probe)"
+
+# possible values: 0x15, 0x09
+if ! [[ "$rev" =~ ^0x..$ ]]; then
+	echo "Incorrect value of rev"
+	exit 1
+fi
+
+if [ ${#probe} -gt 20 ] || ! [[ "$probe" =~ ^[a-zA-Z0-9]+$ ]]; then
+	echo "Incorrect value of probe"
+	exit 1
+fi
+
+set -e
+echo "$rev;$probe" | flock "$lock" tee -a "$file" >/dev/null
+echo "Status: 200 OK"
+echo "Content-Type: text/plain; charset=utf-8"
+echo ""
+echo "OK"