gistfile1.sh

#!/bin/bash

# Usage:
# ./download.sh allmodules.txt
#
# Assumes allmodules.txt is a newline-separated list of projects you want to
# download.
# @todo Error handling of any kind. :P I'm so optimistic. :P

# Versions to attempt to download, in order of preference.
# @todo Maybe someday parameterize this.
versions=(7 6 8)

# Files are called "allsomething.txt"; strip the extension off and make it the
# download destination directory.
# @todo Maybe someday parameterize this.
filename=$1
dir=${filename%%.*}

# If directory doesn't already exist, create it.
`mkdir -p $dir`

# Read in the contents of the file, line by line. Each one is a project name.
while read -r project
do
  # Loop through each version.
  for version in ${versions[@]} 
  do
    # Attempt to download the project.
    # That funny 2>&1 business at the end will ensure that the output from
    # Drush can be inspected below.
    output=$(drush dl --dev -y --destination=$dir --default-major=$version --package-handler=git_drupalorg $project 2>&1)

    # If there is no development release for the project, let's grab the latest
    # stable version release.
    if [[ $output == *no*development* ]]
    then
      output=$(drush dl -y --destination=$dir --default-major=$version --package-handler=git_drupalorg $project 2>&1)
    fi

    # Unfortuantely, Drush commands return a success error code (0), even when
    # they don't work. :P Only way to see if this command failed is to check
    # the output of the script.
    # @todo Re-work this when http://drupal.org/node/1735230 is fixed.
    if [[ "$output" != *warning* ]];
    then
      # No problems? Move onto the next project!
      break
    fi
  done
done < $1