如何正确比较ctime？

Question

我有一个程序，可以获取目录和文件的修改日期/时间。然后，我想获取30秒前的日期/时间，并将其与修改后的日期/时间进行比较。

如果修改时间小于30秒，我想触发一个警报。即使修改时间超过30秒，我的代码也会触发警报。

有没有办法，如果修改发生在30秒内，我才能触发警报？

import os.path
import time, stat
import sys

share_dir = 'C:/mydir'
source_dir  = r'' + share_dir + '/'

def trigger():
    print("Triggered")

def check_dir():
    while True:
        for currentdir, dirs, files in os.walk(source_dir):
            for file in files:
                currentfile = os.path.join(currentdir, file)

                # get modified time for files
                ftime = os.stat(currentfile )[stat.ST_MTIME]
                past = time.time() - 30  # last 30 seconds
                if time.ctime(ftime) >= time.ctime(past):
                    print(time.ctime(ftime) + " > " + time.ctime(past))
                    print("Found modification in last 30 seconds for file =>", currentfile, time.ctime(ftime))
                    trigger()
                    sys.exit()
                else:
                    print('No recent modifications.' + currentfile)
            for folder in dirs:
                currentfolder = os.path.join(currentdir, folder)

                # get modified time for directories
                dtime = os.stat(currentfolder)[stat.ST_MTIME]
                past = time.time() - 30  # last 30 seconds
                if time.ctime(dtime) >= time.ctime(past):
                    print(time.ctime(dtime) + " > " + time.ctime(past))
                    print("Found modification in last 30 seconds for folder =>", currentfolder, time.ctime(dtime))            
                    trigger()
                    sys.exit()
                else:
                    print('No recent modifications: ' + currentfolder)
        time.sleep(4)

if __name__ == "__main__":
    check_dir()

Answer 1

我是在一个大规模的文件系统上这样做的。我个人使用SQLite3并对文件的mtime进行循环(我使用任何其他类型的操作都会发生奇怪的事情，而且更加一致)。

我也不确定为什么你不做一个纯粹的数学解决方案。取当前时间，取文件的mtime，找出它们之间的差异，如果它小于或等于30，就会得到匹配。

我重做了一些代码。我推荐你试试这个：

import os.path
import time, stat
import sys 

def trigger():
    print("Triggered")

def check_dir(source_dir):
    for currentdir, dirs, files in os.walk(source_dir):
        for file in files:
            currentfile = os.path.join(currentdir, file)

            # get modified time for files
            ftime = os.path.getmtime(currentfile)
            if time.time() - ftime <= 30: 
                print("Found modification in last 30 seconds for file =>", currentfile, time.ctime(ftime))
                trigger()
                exit(0)

            else:
                print('No recent modifications.' + currentfile)

        for folder in dirs:
            currentfolder = os.path.join(currentdir, folder)

            # get modified time for directories
            dtime = os.stat(currentfolder)[stat.ST_MTIME]
            if time.time() - dtime <= 30: 
                print("Found modification in last 30 seconds for folder =>", currentfolder, time.ctime(dtime))
                trigger()
                exit(0)

            else:
                print('No recent modifications: ' + currentfolder)

if __name__ == "__main__":
    check_dir('yourdirectoryhere')

在我自己的系统上做了一些轻量级的测试，它似乎工作得很好。可能想要添加回while循环，但它应该可以工作。