Add a --no-prompt flag to install quietly.

build/install-build-deps.sh

Index: build/install-build-deps.sh
===================================================================
--- build/install-build-deps.sh	(revision 133398)
+++ build/install-build-deps.sh	(working copy)
@@ -13,6 +13,7 @@
   echo "Options:"
   echo "--[no-]syms: enable or disable installation of debugging symbols"
   echo "--[no-]lib32: enable or disable installation of 32 bit libraries"
+  echo "--no-prompt: silently select standard options/defaults"
   echo "Script will prompt interactively if options not given."
   exit 1
 }
@@ -24,6 +25,9 @@
   --no-syms)                do_inst_syms=0;;
   --lib32)                  do_inst_lib32=1;;
   --no-lib32)               do_inst_lib32=0;;
+  --no-prompt)              do_default=1
+                            do_quietly="-qq --assume-yes"
+    ;;
   *) usage;;
   esac
   shift
@@ -122,6 +126,9 @@
 # The function will echo the user's selection followed by a newline character.
 # Users can abort the function by pressing CTRL-C. This will call "exit 1".
 yes_no() {
+  if [ 0 -ne "${do_default-0}" ] ; then
+    return $1
+  fi
   local c
   while :; do
     c="$(trap 'stty echo -iuclc icanon 2>/dev/null' EXIT INT TERM QUIT
@@ -194,7 +201,7 @@
     echo "No missing packages, and the packages are up-to-date."
   else
     echo "Installing missing packages: $new_list."
-    sudo apt-get install ${new_list}
+    sudo apt-get install ${do_quietly-} ${new_list}
   fi
   echo
 else