in reply to Perl process to constantly detect the time change of a file?

You could cut out a lot of code by using stat - specifically "mtime", which is the "last modify time in seconds since the epoch". I would suggest putting a small sleep time in the loop as well, just so you're not constantly hitting your machine - unless it's absolutely crucial that you know the second when this file has changed. 

my $file = "somefile.txt";

# Establish a base "last accessed time"
my $lastaccessed = (stat($file))[9]; 

while(1) {
  if ((stat($file))[9] == $lastaccessed) {
    # The file is the same
  } else {
    # File is different
  }
  sleep 5;
}

[download]

Check the docs for stat - it provides a lot of useful info about files.


Rich36
There's more than one way to screw it up...

Replies are listed 'Best First'.
Re: Re: Perl process to constantly detect the time change of a file?
by graff (Chancellor) on May 03, 2002 at 21:33 UTC
    Right -- of course one would usually want to make sure it goes like this (Rich36 assumes this goes without saying): 
    while(1) {
    my $modtime = (stat($file))[9];
    if ($modtime == $lastaccessed) {
      # The file is the same
    } else {
      # File is different; do whatever, and also:
      $lastaccessed = $modtime;
    }
    sleep 5;
}

    [download]
[reply]
[d/l]

In Section Seekers of Perl Wisdom