Source code for obci.utils.filesystem

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import os
import os.path
import psutil


def which_binary(program):
    binary = which(program)
    if binary:
        return binary
    binary = os.path.split(program)[-1]
    if os.environ.get('OBCI_INSTALL_DIR'):
        amplifiers = os.path.join(os.getenv('OBCI_INSTALL_DIR'), 'drivers', 'eeg', 'cpp_amplifiers')
        if binary == 'obci_broker':
            if is_exe(binary):
                return binary
        elif (binary == 'tmsi_amplifier'
              or binary == 'file_amplifier'
              or binary == 'dummy_amplifier'
              or binary == 'gtec_amplifier'):
            path = os.path.join(amplifiers, binary)
            if is_exe(path):
                return path
    return which(binary)


def is_exe(fpath):
    return os.path.exists(fpath) and os.access(fpath, os.X_OK)


def which(program):

    def ext_candidates(fpath):
        yield fpath
        for ext in os.environ.get('PATHEXT', '').split(os.pathsep):
            yield fpath + ext

    fpath, fname = os.path.split(program)
    if fpath:
        if is_exe(program):
            return program
    else:
        for path in os.environ["PATH"].split(os.pathsep):
            exe_file = os.path.join(path, program)
            for candidate in ext_candidates(exe_file):
                if is_exe(candidate):
                    return candidate
    return False


def checkpidfile(file):
    lockfile = getpidfile(file)

    if os.access(os.path.expanduser(lockfile), os.F_OK):
        pidfile = open(os.path.expanduser(lockfile), "r")
        pidfile.seek(0)
        try:
            old_pd = int(pidfile.readline())
        except:  # assumed error in pidfile
            pidfile.close()
            os.remove(os.path.expanduser(lockfile))
        else:
            if psutil.pid_exists(old_pd) == 1:
                print("You already have an instance of the program running")
                print("It is running as process %s," % str(old_pd))
                return True
            else:
                pidfile.close()
                os.remove(os.path.expanduser(lockfile))

    with open(os.path.expanduser(lockfile), 'w') as pidfile:
        pidfile.write("%s" % os.getpid())

    return False


def getpidfile(file):
    obci_home_dir = os.path.join(os.path.expanduser('~'), '.obci')
    lockfile = os.path.join(obci_home_dir, file)

    try:
        if not os.path.isdir(obci_home_dir):
            os.makedirs(obci_home_dir)
    except Exception:
        pass

    return lockfile


def removepidfile(file):
    lockfile = getpidfile(file)
    try:
        os.remove(lockfile)
    except OSError:
        print("Attempted to remove pid file: " + lockfile + " but couldn't find the file. Ignore!")