udisk_watch.py

#!/usr/bin/env python
# encoding: utf-8
import os
import datetime
import shutil
from shutil import copytree, ignore_patterns
from shutil import copyfile
import time
import subprocess
import hashlib

'''
todo 使用watchdog来写
'''

#PI_CODETEST ="/home/pi/mylab/raspberrypi_lab/codetest.py" #todo 拷贝到home里，~/udist_codetest/ 或者 /home/pi/codetest.py
PI_CODETEST ="/home/pi/codetest.py" #todo 拷贝到home里，~/udist_codetest/ 或者 /home/pi/codetest.py

last_md5_udisk_codetest = ""

def generate_file_md5(file):
    md5 = hashlib.md5(open(file, 'rb').read()).hexdigest()
    print({"file_md5":md5})
    return md5
 
def run_it(filepath):
    # todo:重构为log
    global last_md5_udisk_codetest
    current_file_md5 = generate_file_md5(filepath)
    if current_file_md5 != last_md5_udisk_codetest:
        try:
            copyfile(filepath,PI_CODETEST)
            subprocess.Popen(["pkill","-f",'codetest'])
            print("running!")
            subprocess.call("/usr/bin/python {}".format(PI_CODETEST),shell=True) #会自己退出?
            print("run complate!")
        except Exception as e:
            print(e)
        finally:
            last_md5_udisk_codetest = current_file_md5
    else:
        return

def order_by_mtime(file):
    return time.ctime(os.stat(file).st_mtime)
 
def get_newest_codetest(u_root):
    '''
    在u盘第一层目录里找
    需要获取最新的文件的原因是，学生可能会拖动多个文件进去
    '''
    udisk_dir = '/media/pi/%s' % u_root
    codetestlist=[]
    for filename in os.listdir(udisk_dir):
        if filename.startswith("codetest"):
            codetestlist.append(os.path.join(udisk_dir,filename))
    if codetestlist:
        #max([time.ctime(os.stat(os.path.join(udisk_dir,codetest)).st_mtime) for codetest in codetestlist])
        #newest = sorted(codetestlist, key=order_by_mtime)
        newest = sorted(codetestlist, key=lambda file:time.ctime(os.stat(file).st_mtime))
        if newest:
            return newest[-1]
    else:
        return

while True:
 print('sleep 3s')
 time.sleep(3)
 print("watching /media/pi/ ...")
 udisk_exists = os.path.exists('/media/pi/')
 if not udisk_exists:
     print("can not find u disk")
     continue
 else:
    media_pi = os.listdir('/media/pi/')
    try :
        for u_root in media_pi:
          if u_root:
            #source = '/media/pi/%s' % u_root
            newest_codetest = get_newest_codetest(u_root)
            udisk_codetest = newest_codetest
            if not udisk_codetest:
                print("can not find the codetest(.*).py in the u disk")
                continue
            else:
                print("find  the codetest(.*).py in the u disk")
                run_it(udisk_codetest)

    except Exception as e:
        print(e)