ENH: automatic creation of the SuperBuild source archive

Utilities/Maintenance/SuperbuildDownloadList.sh

 #/bin/bash
-grep -h -E "^[^#]*\"https?://.*(\.tar\.gz|\.tar\.bz2|\.tgz|\.tar\.xz|\.zip|export=download).*\"" ../../SuperBuild/CMake/*.cmake | grep -o -E "https?://[^\"]*" | sed "s/\/download$//" | sort | uniq
+
+if [ $# -eq 2 ]; then
+DOWNLOAD_DIR=$(readlink -f $1)
+OUTPUT_DIR=$(readlink -f $2)
+else
+echo 'Usage: '$0' <download_directory> <archive_output_directory>'
+exit 1
+fi
+
+SB_CMAKE_DIR_REL=$(dirname $0)/../../SuperBuild/CMake
+SB_CMAKE_DIR=$(readlink -f ${SB_CMAKE_DIR_REL})
+
+DOWNLOAD_LIST=$(grep -h -E "^[^#]*\"https?://.*(\.tar\.gz|\.tar\.bz2|\.tgz|\.tar\.xz|\.zip|export=download).*\"" ${SB_CMAKE_DIR}/*.cmake | grep -o -E "https?://[^\"]*" | sed "s/\/\(download\)\?$//" | sort | uniq)
+
+DOWNLOAD_NAMES=
+
+mkdir -p ${DOWNLOAD_DIR}
+cd ${DOWNLOAD_DIR}
+
+echo "Start downloads..."
+
+for url in ${DOWNLOAD_LIST}; do
+  # clean log file
+  echo "" >download.log
+
+  file_name=$(echo "${url}" | grep -o -E "[^\/]+$")
+  docs_google=$(echo "${file_name}" | grep -F "export=download")
+  if [ "${docs_google}" = "" ]; then
+    echo "Download ${file_name}..."
+    wget -N ${url} -o download.log
+  else
+    # look into the original file for a valid download name
+    file_name=$(grep -h -A 3 -B 3 -F "${url}" ${SB_CMAKE_DIR}/*.cmake | grep -E "^[^#]*DOWNLOAD_NAME" | grep -o -E "[^ ]*\.(tar\.gz|tar\.bz2|tar\.xz|zip)" | uniq)
+    if [ -z "$file_name" ]; then
+      echo "Can't find correct filename for url ${url} : skip download"
+    else
+      echo "Download ${file_name}..."
+      wget -O ${file_name} ${url} -o download.log
+    fi
+  fi
+
+  download_errors=$(grep "ERROR" download.log)
+  if [ "$download_errors" != "" ]; then
+    echo "=== Error downloading ${file_name} ==="
+    cat download.log
+  else
+    if [ "$file_name" != "" ]; then
+      DOWNLOAD_NAMES="${DOWNLOAD_NAMES} ${file_name}"
+    fi
+  fi
+done
+
+rm download.log
+
+echo "Create archive..."
+
+cd ${OUTPUT_DIR}
+tar -cjf SuperBuild-archives.tar.bz2 -C ${DOWNLOAD_DIR} ${DOWNLOAD_NAMES}