From 5d10c4f9b945d3edc84e30de315ef4a34424e8bb Mon Sep 17 00:00:00 2001
From: Michael Raskin <7c6f434c@mail.ru>
Date: Sat, 5 Jun 2010 21:14:01 +0000
Subject: [PATCH] Hint at usage if called without parameters

svn path=/nixpkgs/trunk/; revision=22159
---
 pkgs/build-support/upstream-updater/update-upstream-data.sh | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/pkgs/build-support/upstream-updater/update-upstream-data.sh b/pkgs/build-support/upstream-updater/update-upstream-data.sh
index 61c062518026..006da112fdbe 100755
--- a/pkgs/build-support/upstream-updater/update-upstream-data.sh
+++ b/pkgs/build-support/upstream-updater/update-upstream-data.sh
@@ -6,6 +6,11 @@ own_dir="$(cd "$(dirname "$0")"; sh -c pwd)"
 
 source "$own_dir/snippets.sh"
 
+[ -z "$1" ] && {
+  echo "Specify main expression filename."
+  exit 1;
+}
+
 main_file="$1"
 main_dir="$(cd "$(dirname "$main_file")" ; sh -c pwd)"
 file_name="$(basename "$main_file")"