check uid before executing netcat

shellgopher.sh

@@ -11,6 +11,15 @@ createsrv () {
 
   nc -l "$1" <"$2" >>"$3" & exec 3>"$2"
 }
+die () {
+  # $1 - error message
+  printf "%s\n" $1
+  exit 1
+}
+checkuid () {
+  [ $(whoami) = "root" ] && \
+    die "You must execute shellgopher as root."
+}
 writefile () {
   # $1 - file
   foo cat "$1" >&3
@@ -34,6 +43,7 @@ tmplocation=$(mktmp)
 writelocation="${tmplocation}/write"
 readlocation="${tmplocation}/read"
 
+checkuid
 createsrv 70 "${writelocation}" "${readlocation}"
 printf "server created\n"
 while true; do