comment on

Hello everyone.

I wrote a script which backs up certain files and folders which get modified often. Some of the files or files within folders do not get modified as often as I back them up. I was wondering if checking the last modified time and ignoring those which have the same last modified time, would be faster than just overwriting.

Original script which overwrites

#!/usr/bin/perl
use strict;
use warnings;

use File::Copy qw(copy);
use File::Mirror qw(mirror);
use Try::Tiny;

local $\ = "\n";

if (-e "J:/") {
  while (<DATA>) {
    my ($source,$destination) = split(/\|/,$_);
    chomp($source,$destination);
    print "Copying $source to $destination";
    
    # I guess at one time the copy failed and made the script die, so 
+I added
    # Tiny::Try to keep the script from dying.
    
    try {
      if (-f $source) {
        copy($source,$destination);
      }
      elsif (-d $source) {
        mirror($source,$destination);
      }
      else {
        print "What did you do wrong?";
      }
    }
    catch {
      print "Couldn't copy $source to $destination";
    }
  }
}
else {
  print "Insert the thumb drive!";
}

__DATA__
C:/Documents and Settings/me/My Documents/home/checkbook2.xls|J:/My Do
+cuments/home/checkbook2.xls
C:/Documents and Settings/me/Local Settings/Application Data/Microsoft
+/Outlook/Outlook.pst|J:/application data/Outlook/Outlook.pst
C:/Documents and Settings/me/My Documents/gaming|J:/My Documents/gamin
+g
C:/Documents and Settings/me/My Documents/fantasy|J:/My Documents/fant
+asy
C:/Documents and Settings/me/Application Data/Notepad++/stylers.xml|J:
+/application data/Notepad++/stylers.xml
C:/Documents and Settings/me/Application Data/HexChat|J:/application d
+ata/HexChat
[download]

Script which checks last modified time (untested)

#!/usr/bin/perl
use strict;
use warnings;

use File::Copy qw(copy);
use File::Mirror qw(mirror recursive);
use Try::Tiny;

# return the last modified time
sub get_mod_time {
  my $file = shift;
  
  my @stats = stat($file);
  my $mod = $stats[9];
  
  return $mod;
}

# compare the two files' last modified times and return false or true
sub same_mod_time {
  my ($src_file,$dst_file) = @_;
  
  my $same_mod = get_mod_time($src_file) != get_mod_time($dst_file) ? 
+0 : 1;
  
  return $same_mod;
}

local $\ = "\n";

if (-e "J:/") {
  while (<DATA>) {
    my ($source,$destination) = split(/\|/,$_);
    chomp($source,$destination);
    print "Copying $source to $destination";
    
    # I guess at one time the copy failed and made the script die, so 
+I added
    # Tiny::Try to keep the script from dying.
    
    try {
      if (-f $source) {
        copy($source,$destination) if same_mod_time($source,$destinati
+on) == 0;
      }
      elsif (-d $source) {

        # I had to change "mirror" to "recursive" to check for the sam
+e mod time.

        recursive {
          copy($_[0],$_[1]) if same_mod_time($_[0],$_[1]) == 0;
        } $source, $destination;
      }
      else {
        print "What did you do wrong?";
      }
    }
    catch {
      print "Couldn't copy $source to $destination";
    }
  }
}
else {
  print "Insert the thumb drive!";
}

__DATA__
C:/Documents and Settings/me/My Documents/home/checkbook2.xls|J:/My Do
+cuments/home/checkbook2.xls
C:/Documents and Settings/me/Local Settings/Application Data/Microsoft
+/Outlook/Outlook.pst|J:/application data/Outlook/Outlook.pst
C:/Documents and Settings/me/My Documents/gaming|J:/My Documents/gamin
+g
C:/Documents and Settings/me/My Documents/fantasy|J:/My Documents/fant
+asy
C:/Documents and Settings/me/Application Data/Notepad++/stylers.xml|J:
+/application data/Notepad++/stylers.xml
C:/Documents and Settings/me/Application Data/HexChat|J:/application d
+ata/HexChat
[download]

So my question is, which is the better way to back up my files? If you have any other suggestions, I would like to know.

(I still need to figure out how to clean out files I deleted in the source which are still in my backups.)

Have a cookie and a very nice day!

Lady Aleena

In reply to Will checking last modified date take more time than just overwriting? by Lady_Aleena

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