Move under www to ease rsync

www/eps/hpr2669/hpr2669_bash12_ex5.sh

@@ -0,0 +1,35 @@
+#!/bin/bash
+
+#
+# An IP address looks like this:
+#       192.168.0.5
+# Four groups of 1-3 numbers in the range 0..255 separated by dots.
+#
+re='^([0-9]{1,3}\.){3}[0-9]{1,3}$'
+
+#
+# The address is expected as the only argument
+#
+if [[ $# -ne 1 ]]; then
+    echo "Usage: $0 IP_address"
+    exit 1
+fi
+
+#
+# Validate against the regex
+#
+if [[ $1 =~ $re ]]; then
+    #
+    # Look at the components and check they are all in range
+    #
+    for d in ${1//./ }; do
+        if [[ $d -lt 0 || $d -gt 255 ]]; then
+            echo "$1 is not a valid IP address (contains $d)"
+            exit 1
+        fi
+    done
+
+    echo "$1 is a valid IP address"
+else
+    echo "$1 is not a valid IP address"
+fi