=== modified file 'linaro_image_tools/tests/fixtures.py'
--- linaro_image_tools/tests/fixtures.py	2012-06-07 13:22:47 +0000
+++ linaro_image_tools/tests/fixtures.py	2012-06-11 12:49:40 +0000
@@ -69,8 +69,9 @@
     # used in tests to make sure all callsites wait for their child.
     child_finished = True
 
-    def __init__(self, assert_child_finished=True):
+    def __init__(self, output_string='', assert_child_finished=True):
         self.assert_child_finished = assert_child_finished
+        self.output_string = output_string
 
     def __call__(self, cmd, *args, **kwargs):
         if self.assert_child_finished and not self.child_finished:
@@ -91,7 +92,7 @@
 
     def communicate(self, input=None):
         self.wait()
-        return '', ''
+        return self.output_string, ''
 
     def wait(self):
         self.child_finished = True
@@ -112,9 +113,9 @@
     If no mock is given, a MockCmdRunnerPopen instance is used.
     """
 
-    def __init__(self, assert_child_finished=True):
+    def __init__(self, output_string='', assert_child_finished=True):
         super(MockCmdRunnerPopenFixture, self).__init__(
-            cmd_runner, 'Popen', MockCmdRunnerPopen(assert_child_finished))
+            cmd_runner, 'Popen', MockCmdRunnerPopen(output_string, assert_child_finished))
 
     def tearDown(self):
         super(MockCmdRunnerPopenFixture, self).tearDown()

=== modified file 'linaro_image_tools/tests/test_utils.py'
--- linaro_image_tools/tests/test_utils.py	2012-06-06 13:59:32 +0000
+++ linaro_image_tools/tests/test_utils.py	2012-06-13 08:19:55 +0000
@@ -24,6 +24,7 @@
 import logging
 import tempfile
 import tarfile
+from StringIO import StringIO
 
 from linaro_image_tools import cmd_runner, utils
 from linaro_image_tools.testing import TestCaseWithFixtures
@@ -249,19 +250,45 @@
 
 class TestInstallPackageProviding(TestCaseWithFixtures):
 
-    def test_found_package(self):
-        self.useFixture(MockSomethingFixture(
-            sys, 'stdout', open('/dev/null', 'w')))
-        fixture = self.useFixture(MockCmdRunnerPopenFixture())
+    # This is the package we need to fake the installation of, it is a
+    # slightly changed version of 'apt-get -s install' output.
+    # It is used as an argument to MockCmdRunnerPopenFixture in order to
+    # pass a string that should be expected as output from the command that
+    # is being executed.
+    output_string = 'Inst dosfstools (3.0.12-1ubuntu1 Ubuntu:12.04)'
+
+    def test_package_installation_accepted(self):
+        self.useFixture(MockSomethingFixture(sys,
+                                             'stdout',
+                                             open('/dev/null', 'w')))
+        # We need this since we are getting user input via raw_input
+        # and we need a 'Y' to proceed with the operations.
+        self.useFixture(MockSomethingFixture(sys,
+                                             'stdin',
+                                             StringIO('Y')))
+        fixture = self.useFixture(MockCmdRunnerPopenFixture(self.output_string))
         install_package_providing('mkfs.vfat')
         self.assertEqual(
-            ['%s apt-get --yes install dosfstools' % sudo_args],
-            fixture.mock.commands_executed)
+                         ['apt-get -s install dosfstools',
+                          '%s apt-get --yes install dosfstools' %
+                          sudo_args],
+                         fixture.mock.commands_executed)
+
+    def test_package_installation_refused(self):
+        self.useFixture(MockSomethingFixture(sys,
+                                             'stdout',
+                                             open('/dev/null', 'w')))
+        # We need this since we are getting user input via raw_input
+        # and we need a 'n' to mimic a refused package installation.
+        self.useFixture(MockSomethingFixture(sys,
+                                             'stdin',
+                                             StringIO('n')))
+        self.useFixture(MockCmdRunnerPopenFixture(self.output_string))
+        self.assertRaises(SystemExit, install_package_providing, 'mkfs.vfat')
 
     def test_not_found_package(self):
-        self.assertRaises(
-            UnableToFindPackageProvidingCommand,
-            install_package_providing, 'mkfs.lean')
+        self.assertRaises(UnableToFindPackageProvidingCommand,
+                          install_package_providing, 'mkfs.lean')
 
 
 class Args():
@@ -288,7 +315,7 @@
                                               board="testboard")))
 
 
-class TestPrepMediaPath(TestCaseWithFixtures):
+class TestAdditionalOptionChecks(TestCaseWithFixtures):
 
     def test_additional_option_checks(self):
         self.useFixture(MockSomethingFixture(os.path, 'abspath', lambda x: x))

=== modified file 'linaro_image_tools/utils.py'
--- linaro_image_tools/utils.py	2012-06-06 13:59:32 +0000
+++ linaro_image_tools/utils.py	2012-06-13 08:19:55 +0000
@@ -171,7 +171,10 @@
 
     If we can't find any package which provides it, raise
     UnableToFindPackageProvidingCommand.
+
+    If the user denies installing the package, the program exits.
     """
+
     if CommandNotFound is None:
         raise UnableToFindPackageProvidingCommand(
             "Cannot lookup a package which provides %s" % command)
@@ -182,12 +185,35 @@
             "Unable to find any package providing %s" % command)
 
     # TODO: Ask the user to pick a package when there's more than one that
-    # provide the given command.
+    # provides the given command.
     package, _ = packages[0]
-    print ("Installing required command %s from package %s"
-           % (command, package))
-    cmd_runner.run(
-        ['apt-get', '--yes', 'install', package], as_root=True).wait()
+    output, _ = cmd_runner.run(['apt-get', '-s', 'install', package],
+                               stdout=subprocess.PIPE).communicate()
+    to_install = []
+    for line in output.splitlines():
+        if line.startswith("Inst"):
+            to_install.append(line.split()[1])
+    if not to_install:
+        raise UnableToFindPackageProvidingCommand(
+            "Unable to find any package to be installed.")
+
+    try:
+        print ("In order to use the '%s' command, the following package/s have "
+               "to be installed: %s" % (command, " ".join(to_install)))
+        resp = raw_input("Install? (Y/n) ")
+        if resp.lower() != 'y':
+            print "Package installation is necessary to continue. Exiting."
+            sys.exit(1)
+        print ("Installing required command '%s' from package '%s'..."
+                % (command, package))
+        cmd_runner.run(['apt-get', '--yes', 'install', package],
+                        as_root=True).wait()
+    except EOFError:
+        raise PackageInstallationRefused(
+                            "Package installation interrupted: input error.")
+    except KeyboardInterrupt:
+        raise PackageInstallationRefused(
+                            "Package installation interrupted by the user.")
 
 
 def has_command(command):
@@ -272,6 +298,10 @@
     """We can't find a package which provides the given command."""
 
 
+class PackageInstallationRefused(Exception):
+    """User has chosen not to install a package."""
+
+
 class InvalidHwpackFile(Exception):
     """The hwpack parameter is not a regular file."""
 

