1# Copyright 2014 The Chromium OS Authors. All rights reserved. 2# Use of this source code is governed by a BSD-style license that can be 3# found in the LICENSE file. 4 5import os 6 7from autotest_lib.client.bin import utils 8from autotest_lib.client.common_lib import error 9 10 11def get_install_path(filename, host=None): 12 """ 13 Checks if a file exists on a remote machine in one of several paths. 14 15 @param filename String name of the file to check for existence. 16 @param host Host object representing the remote machine. 17 @return String full path of installed file, or None if not found. 18 19 """ 20 run = utils.run 21 if host is not None: 22 run = host.run 23 PATHS = ['/bin', 24 '/sbin', 25 '/system/bin', 26 '/usr/bin', 27 '/usr/sbin', 28 '/usr/local/bin', 29 '/usr/local/sbin'] 30 glob_list = [os.path.join(path, filename) for path in PATHS] 31 # Some hosts have poor support for which. Sometimes none. 32 # Others have shells that can't perform advanced globbing. 33 result = host.run('ls %s 2> /dev/null' % ' '.join(glob_list), 34 ignore_status=True) 35 found_path = result.stdout.split('\n')[0].strip() 36 return found_path or None 37 38 39def must_be_installed(cmd, host=None): 40 """ 41 Asserts that cmd is installed on a remote machine at some path and raises 42 an exception if this is not the case. 43 44 @param cmd String name of the command to check for existence. 45 @param host Host object representing the remote machine. 46 @return String full path of cmd on success. Error raised on failure. 47 48 """ 49 run = utils.run 50 if host is not None: 51 run = host.run 52 if run('ls %s >/dev/null 2>&1' % cmd, 53 ignore_status=True).exit_status == 0: 54 return cmd 55 56 # Hunt for the equivalent file in a bunch of places. 57 cmd_base = os.path.basename(cmd) 58 alternate_path = get_install_path(cmd_base, host=host) 59 if alternate_path: 60 return alternate_path 61 62 error_msg = 'Unable to find %s' % cmd 63 if host is not None: 64 error_msg += ' on %s' % host.hostname 65 raise error.TestError(error_msg) 66