Initial commit

snippets/is_valid_ipv4.sh

@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+
+## - Test of valid IPv4 Address
+## -
+## -    Returns 0 if valid, > 0 otherwise
+## -
+is_valid_ipv4() {
+  local -a octets=( ${1//\./ } )
+  local RETURNVALUE=0
+ 
+  # return an error if the IP doesn't have exactly 4 octets
+  [[ ${#octets[@]} -ne 4 ]] && return 1
+ 
+  for octet in ${octets[@]}
+  do
+    if [[ ${octet} =~ ^[0-9]{1,3}$ ]]
+    then # shift number by 8 bits, anything larger than 255 will be > 0
+      ((RETURNVALUE += octet>>8 ))
+    else # octet wasn't numeric, return error
+      return 1
+    fi
+  done
+  return ${RETURNVALUE}
+}
+
+if [ "X$@" = "X" ]; then
+   echo -e "\n\t\033[33m\033[1mNo argumnet given!\033[m\n"
+   exit 1
+fi
+
+if is_valid_ipv4 $@ ; then
+   echo -e "\n\t\033[32m\033[1m$@ is a valid IPv4 Address\033[m\n"
+else
+   echo -e "\n\t\033[31m\033[1m$@ is NOT a valid IPv4 Address\033[m\n"
+fi
+
+exit