Automatically rename files when they are placed in a specific directory

Question

Is it possible to automatically rename a file when it's placed in a specific directory?

For example I have a directory named "dir0".I move or copy a file named "file1" to "dir0".then "file1" should rename to "file1_{current timestamp}"

Answer 1

Usually you would do this programatically at the time you create or move the file, but it is possible to trigger a script whenever a file gets created or moved to a folder using incron. Set up your tab file using incrontab -e with a line like this, but with your paths of course:

/path/to/dir0 IN_MOVED_TO,IN_CREATE /path/to/script $@/$#

Then in /path/to/script write a quick rename action. Be aware that the script will also get called for the new file that you create, so it has to test whether the file has been appropriately named already or not. In this example it checks to see if the file has a ten-digit number for seconds from epoch as the last part of the file name, and if it doesn't, it adds it:

#!/bin/bash
echo $1 | grep -qx '.*_[0-9]\{10\}' || mv "$1" "$1_$(date +%s)"

Edit: When I first wrote this up I was short on time and couldn't figure out how to make bash do the pattern matching here. Gilles pointed out how to do this without invoking grep using ERE matching in bash:

#!/bin/bash
[[ ! ( $1 =~ _[0-9]{10}$ ) ]] && mv "$1" "$1_$(date +%s)"

Answer 2

I think that inotify is tool that coul be used in this case. In Debian there is tool inoticoming for executing action on file creation:

 inoticoming --foreground /path/to/directory mv {} {}-"`date`" \;

{} will be replaced with the filename.

The command that I provided isn't complete - it cause a loop because when the file will be renamed it will be recognized as new so it will get mved AGAIN and so on. To avoid this you could use --suffix option if you know what suffix will be in file before rename.

Answer 3

You could just take a script like this and have it running... I'll leave it as an exercise for the reader to add the extra bits to have it start as a service and prevent multiple copies running at once.

#!/usr/bin/perl
use strict;
use warnings;
use File::Slurp;
use POSIX qw(strftime);

chdir($ENV{STAMP_DIR} || '/home/me/dir0')
    or die "Cannot get to stamp dir: $!\n";

while (1) {
    my $stamp = strftime("_%Y%m%d%H%M%S", localtime);
    for my $orig ( grep { $_ !~ /_\d{14}$/ } read_dir('.') ) {
        rename $orig, "$orig$stamp"
            or warn "Failed to rename $orig to $orig$stamp: $!\n";
    }
    sleep($ENV{STAMP_DELAY} || 10);
}

And here's it working:

$ STAMP_DIR=/home/me/stamps STAMP_DELAY=1 ./t.pl &
[1] 6989
$ cd stamps/
$ ls
$ touch hello
$ ls
hello_20110704033253
$ touch world
$ ls
hello_20110704033253
world_20110704033258
$ touch hello
$ ls
hello_20110704033253
hello_20110704033302
world_20110704033258