Using libproc from Python with ctypes

proc.py

import ctypes

libproc = ctypes.cdll.LoadLibrary('/usr/lib/libproc.dylib')

# int proc_listallpids(void * buffer, int buffersize)
libproc.proc_listallpids.res_type = ctypes.c_int
libproc.proc_listallpids.arg_types = [ctypes.c_void_p, ctypes.c_int]

# int proc_pidpath(int pid, void * buffer, uint32_t buffersize)
libproc.proc_pidpath.res_type = ctypes.c_int
libproc.proc_pidpath.arg_types = [ctypes.c_int, ctypes.c_void_p, ctypes.c_int]

# Defined in sys/proc_info.h
PROC_PIDPATHINFO_MAXSIZE = 4096

def get_all_pids():
    n = libproc.proc_listallpids(None, 0) 
    pids = (ctypes.c_int * n)()
    count = libproc.proc_listallpids(pids, ctypes.sizeof(pids))
    return [pids[i] for i in xrange(count)]

def get_pid_path(pid):
    buf = ctypes.create_string_buffer(PROC_PIDPATHINFO_MAXSIZE)
    if libproc.proc_pidpath(pid, buf, ctypes.sizeof(buf)) > 0:
        return buf.value
    return None

if __name__ == '__main__':
    for pid in get_all_pids():
        print pid, get_pid_path(pid) or ''