#!/usr/bin/perl -T

use warnings;
use strict;
use Sys::Syslog qw(:DEFAULT setlogsock);
use File::Tail;
use File::Copy 'mv';
use Proc::Daemon;
use POSIX qw/setuid setgid/;

my $kernlogfile = '/var/log/big_fat_file';
my $mntpath = '/media/nikon';
my $re = qr/kernel:\s+ Vendor:\s+ NIKON\s+ Model:\s+ NIKON\s+ DSC\s+ E
+2100\s+/x;
my $srcdir = "$mntpath/dcim/100nikon";
my $pixprefix = 'dscn';
my $destdir = '/home/hue/ftp/pix/priv/nikon';
my $user = 'hue';
$SIG{CHLD} = 'IGNORE';
$SIG{TERM} = \&sigterm_handler;
$ENV{PATH} = '/bin:/usr/bin';

sub sigterm_handler {
    closelog;
    exit 0;
}

sub do_log {
    my $logstring = shift;
    syslog 'LOG_DEBUG', '%s', $logstring;
}

sub move_files {
    system '/bin/mount', $mntpath  or do_log "Error mounting $mntpath:
+ $!", exit 1;
    chdir $mntpath;  # prevent fs from being unmounted under our feet
    while (glob "$srcdir/$pixprefix*") {
        $_ =~ m#^($srcdir/$pixprefix[0-9]{4}\.(?:jpg|mov))$#;
        my $unt = $1;
        do_log "Unexpected file name $_", next unless defined $unt;
        do_log "Moving $unt";
        mv $unt, $destdir          or do_log "Error moving $_: $!"; #,
+ next;
    }
    chdir '/';
    system '/bin/umount', $mntpath or do_log "Error unmounting $mntpat
+h: $!";
    do_log "Finished moving";
    exit 0;
}

Proc::Daemon::Init;
my (undef, undef, $uid, $gid) = getpwnam $user or do_log "User $user u
+nknown", exit 1;
setlogsock 'unix';
openlog 'nikon.pl', 'pid', 'LOG_LOCAL0';
my $tailfile = File::Tail->new (
    name        => $kernlogfile,
    maxinterval => 5,
    adjustafter => 10
);

while (defined (my $line = $tailfile->read)) {
    next if $line !~ $re;
    do_log "Camera detected";
    defined (my $pid = fork) or do_log "Error forking: $!", next;
    unless ($pid) {
        setgid $gid;
        do_log "Error setting gid $gid", exit 1 if $!;
        ## /bin/mount needs both uid and euid to be set
        setuid $uid;
        do_log "Error setting uid $uid", exit 1 if $!;
        move_files;
    }
}

do_log "Something wicked happened reading $kernlogfile. Exiting...";
$SIG{TERM}->();