使用子进程和pkexec

Question

I'm trying to use run a command alongside with pkexec, but is says no such file is found.

process = subprocess.Popen(["pkexec cat", "/dev/input/event4"], stdout=subprocess.PIPE)
for line in iter(process.stdout.readline, ''):
  sys.stdout.write(line)

OSError: [Errno 2] No such file or directory

However, path is okay and the file is there.

Answer 1

You probably want to use:

subprocess.Popen(["pkexec", "cat", "/dev/input/event4"])

Since subprocess.Popen quotes each entry in the list; so your example is the same using this on the commandline:

$ "pkexec cat" /dev/input/event4

Instead of:

$ pkexec cat /dev/input/event4

From the documentation (emphasis mine):

args is required for all calls and should be a string, or a sequence of program arguments. Providing a sequence of arguments is generally preferred, as it allows the module to take care of any required escaping and quoting of arguments (eg to permit spaces in file names) . If passing a single string, either shell must be True (see below) or else the string must simply name the program to be executed without specifying any arguments.