'''Run a command and capture what it writes to stdout.

If the command fails or writes something to stderr, that is logged.

Returns the captured string, or None if the command failed.

'''

# TODO: This is a modified copy-paste from compilers._Command.

commandParts = shsplit(commandLine)

env = dict(environ)

env['LC_ALL'] = 'C.UTF-8'

while commandParts:

if '=' in commandParts[0]:

name, value = commandParts[0].split('=', 1)

del commandParts[0]

env[name] = value

else:

break

else:

raise ValueError(

'No command specified in "%s"' % commandLine

)

if msysActive() and commandParts[0] != 'sh':

commandParts = [

msysShell(), '-c', shjoin(commandParts)

]

try:

proc = Popen(

commandParts, bufsize = -1, env = env,

stdin = None, stdout = PIPE, stderr = PIPE,

)

except OSError as ex:

print('Failed to execute "%s": %s' % (commandLine, ex), file=log)

return None

stdoutdata, stderrdata = proc.communicate()

if stderrdata:

severity = 'warning' if proc.returncode == 0 else 'error'

log.write('%s executing "%s"\n' % (severity.capitalize(), commandLine))

# pylint 0.18.0 somehow thinks stderrdata is a list, not a string.

# pylint: disable-msg=E1103

stderrdata = stderrdata.decode('utf-8').replace('\r', '')

log.write(stderrdata)

if not stderrdata.endswith('\n'):

log.write('\n')

if proc.returncode == 0:

return stdoutdata.decode('utf-8')

else:

print('Execution failed with exit code %d' % proc.returncode, file=log)

'''Joins the given sequence into a single string with space as a separator.

Characters that have a special meaning for the shell are escaped.

This is the counterpart of shlex.split().

'''

def escape(part):

return ''.join(

'\\' ch if ch in '\\ \'"$()[]' else ch

for ch in part

)