Skipping Ad while playing video using Mplayer

To skip Advertisements/unwanted scenes, or to mute certain parts of a movie, the Edit Decision Lists (EDL) are very helpful.

Please read the following link for more details:-
http://www.mplayerhq.hu/DOCS/HTML/en/edl.html

Mounting Debian ISO files as Offline Software Repository

If you are not connected to internet, then still you can install packages from Debian Installer ISOs. For example, if Debian 7.0 (Wheezy) ISOs are in directory /media/FreeAgent GoFlex Drive/Softwares/Debian_7.0_Wheezy directory and we want to mount these iso in /mnt/Debian/ directory. The following command can be used:

$ sudo $(which mount_debian.pl) -d /mnt/Debian -g -r "/media/FreeAgent GoFlex Drive/Softwares/Debian_7.0_Wheezy"
Using iso(s) dir '/media/FreeAgent GoFlex Drive/Softwares/Debian_7.0_Wheezy'
Using mount point dir '/mnt/Debian'
...
Total 11 iso(s) mounted successfully.

Unmounting of the iso(s) can be achieved by the following command:

$ sudo $(which mount_debian.pl) -d /mnt/Debian -u -g -r
Running: umount "/mnt/Debian"/*.iso
Running: rmdir "/mnt/Debian"/*.iso
Running: cp "/etc/apt/sources.list.net" "/etc/apt/sources.list"
Running: apt-get update
...

Usage of the command:

$ sudo $(which mount_debian.pl)
/home/mitesh/Perl/mount_debian.pl: Please provide Dir where Debian installer iso(s) are present.
USAGE: /home/mitesh/Perl/mount_debian.pl [options] iso_dir
          -a apt_sources_dir        default  /etc/apt
          -d mount_base_dir         default  /mnt/Debian
          -g                        debug on 
          -r                        apt-get update 
          -u                        unmount 
          iso_dir                   Dir where Debian installer iso(s) are present.

PS: iso_dir is not required with -u command

The mount_debian.sh perl script is given as follows:

#!/usr/bin/perl -w
#===============================================================================
#
#         FILE:  mount_debian.pl
#
#        USAGE:  ./mount_debian.pl 
#
#  DESCRIPTION:  
#
#      OPTIONS:  ---
# REQUIREMENTS:  ---
#         BUGS:  ---
#        NOTES:  ---
#       AUTHOR:  Mitesh Singh Jat (mitesh)
#      COMPANY:  
#      VERSION:  1.0
#      CREATED:  11/07/2013 10:30:04 PM IST
#     REVISION:  ---
#===============================================================================

use strict;
use warnings;

use Getopt::Std;
my $apt_sources_dir = "/etc/apt";
my $mount_point_base = "/mnt/Debian";
my $umount = 0;
my $reload = 0;
my $debug = 0;

sub usage()
{
    print STDERR "USAGE: $0 [options] <iso_dir>\n";
    print STDERR "          -a <apt_sources_dir>    apt sources dir: default  $apt_sources_dir\n";
    print STDERR "          -d <mount_base_dir>     mount point dir: default  $mount_point_base\n";
    print STDERR "          -g                      debug on \n";
    print STDERR "          -r                      apt-get update \n";
    print STDERR "          -u                      unmount \n";
    print STDERR "          <iso_dir>               Dir where Debian installer iso(s) are present.\n";
}

sub run_cmd()
{
    my $cmd = $_[0];
    print "Running: $cmd\n" if $debug;
    system("$cmd");
    my $retval = $?; 
    if ($retval != 0)
    {   
        print STDERR "Error in running: $cmd\nExit code = $retval\n";
    }   
    return ($retval);
}

sub run_cmd_get()
{
    my $cmd = $_[0];
    print "Running: $cmd\n" if $debug;
    my @outs = `$cmd`;
    my $retval = $?;
    if ($retval < 0)
    {
        print STDERR "Error in running: $cmd\nExit code = $retval\n";
        exit($retval);
    }
    chomp(@outs);
    return (@outs);
}
sub take_backup() 
{
    my $file1 = $_[0];
    my $file2 = $_[1];
    my $cmd = "cp \"$file1\" \"$file2\"";
    my $retval = &run_cmd("$cmd");
    if ($retval != 0)
    {
        print STDERR "$0: Cannot copy \"$file1\" to \"$file2\"\n";
        exit(-1);
    }
    return 1;
}
sub reload_repo()
{
    my $file1 = $_[0];
    my $file2 = $_[1];

    my $cmd = "cp \"$file1\" \"$file2\"";
    my $retval = &run_cmd($cmd);
    exit(-1) if ($retval != 0);

    $cmd = "apt-get update";
    $retval = &run_cmd($cmd);
    exit(-1) if ($retval != 0);
}

my %opts;
getopt('a:d:', \%opts);

foreach my $opt (sort keys %opts)
{
    if (!defined($opts{$opt}))
    {
        print STDERR "$0: Requires value for option '$opt'\n";
        &usage();
        exit(-1);
    }
    else 
    {
        if ($opts{$opt} =~ m/^-/) 
        {
            print STDERR "$0: Requires value for option '$opt'\n";
            &usage();
            exit(-1);
        }
    }
}
$apt_sources_dir = $opts{"a"} if (defined($opts{"a"}));
$mount_point_base = $opts{"d"} if (defined($opts{"d"}));
$debug = 1 if (defined($opts{"g"}));
$reload = 1 if (defined($opts{"r"}));
$umount = 1 if (defined($opts{"u"}));

my $apt_dvd = "$apt_sources_dir/sources.list.dvd";
my $apt_net = "$apt_sources_dir/sources.list.net";
my $apt_orig = "$apt_sources_dir/sources.list";

my $retval = 0;
my $cmd;
$retval = `whoami`;
chomp($retval);
unless ($retval eq "root")
{
    print STDERR "$0: Please run this script as 'root' user.\n";
    &usage();
    exit(-1);
}

unless ($umount)
{

if (@ARGV != 1) 
{
    print STDERR "$0: Please provide Dir where Debian installer iso(s) are present.\n";
    &usage();
    exit(-1);
}
my $iso_dir = "$ARGV[0]";
## Check for iso dir presence
unless (-d "$iso_dir") 
{
    print STDERR "$0: Please make sure the iso(s) dir '$iso_dir' is present\n";
    exit(-1);
}
print "Using iso(s) dir '$iso_dir'\n" if ($debug);

## Check for destination dir
unless (-d "$mount_point_base") 
{
    $cmd = "mkdir -p \"$mount_point_base\"";
    $retval = &run_cmd("$cmd");
    if ($retval != 0) 
    {
        print STDERR "$0: Cannot create dir '$mount_point_base'\n";
        exit(-1);
    }
}
print "Using mount point dir '$mount_point_base'\n" if ($debug);

## Taking backup of ftp/http line sources.list
my $is_backed_up = 0;
if (-f "$apt_net") 
{
    ## Take backup only when ftp / http (internet)
    $cmd = "grep -v -e \"^#\" -e \"^\$\" \"$apt_orig\" | egrep -c \"(ftp|http)://\"";
    my @nets = &run_cmd_get($cmd);
    if ($nets[0] > 0) 
    {
        $is_backed_up = &take_backup("$apt_orig", "$apt_net");
    }
}
else
{
    $is_backed_up = &take_backup("$apt_orig", "$apt_net");
}

## Get loop devices
$cmd = "ls /dev/loop[0-9]*";
my @temps = &run_cmd_get($cmd);
my %loop_devices;
my $nloop_devices = @temps;
foreach my $temp (@temps) 
{
    $loop_devices{$temp} = 1;
}
$cmd = "ls \"$iso_dir\" | grep -i \"\.iso\$\"";
@temps = &run_cmd_get($cmd);
my %iso_images;
my $niso_images = @temps;
foreach my $temp (@temps) 
{
    $iso_images{$temp} = 1;
}
$cmd = "df | awk '{print \$1}' | grep \"/dev/loop\"";
@temps = &run_cmd_get($cmd);
my %mounted_loop_devices;
my $nmounted_loop_devices = @temps;
foreach my $temp (@temps) 
{
    $mounted_loop_devices{$temp} = 1;
}

## Check for free loop devices
my $nfree_loops = $nloop_devices - $nmounted_loop_devices;
if ($niso_images > $nfree_loops)
{
    print "Less available loop devices $nfree_loops than isos $niso_images\n" if ($debug);
    my $req_loops = $niso_images - $nfree_loops; 
    if ($nmounted_loop_devices == 0) 
    {
        print "Reloading loop kernel module with extra $req_loops loop devices\n" if $debug;
        $cmd = "rmmod loop";
        $retval = &run_cmd($cmd);
        print "$retval\n";
        exit(-1) if ($retval != 0);
        $cmd = "modprobe loop max_loop=$niso_images";
        $retval = &run_cmd($cmd);
        exit(-1) if ($retval != 0);
    }
    else 
    {
        print STDERR "Please reload 'loop' kernel module. After unloading following loop devices...\n";
        foreach my $temp (sort keys %mounted_loop_devices)
        {
            print STDERR "$temp\n";
        }
        print STDERR "\nrmmod loop\n";
        my $temp = $nmounted_loop_devices + $req_loops;
        print STDERR "\nmodprobe loop max_loop=$temp\n\n";
        exit(-2);
    }
}

## Create entries in sources.list file
open(SFH, ">$apt_orig") or die("$0: Cannot write in file '$apt_orig'\n");
foreach my $iso (sort keys %iso_images)
{
    print "Mounting iso $iso ...\n" if $debug;
    my $dest_dir = "$mount_point_base/$iso";
    unless (-d "$dest_dir") 
    {
        $cmd = "mkdir -p \"$dest_dir\"";
        $retval = &run_cmd($cmd);
        exit(-1) if ($retval != 0);
    }
    $cmd = "df \"$dest_dir\" | grep -c \"^/dev/loop.*\.iso\$\"";
    my @mounts = &run_cmd_get($cmd); 
    if ($mounts[0] == 0) ## Mount only if not mounted
    {
        $cmd = "mount -o loop,ro \"$iso_dir/$iso\" \"$dest_dir\"";
        $retval = &run_cmd($cmd);
        exit(-1) if ($retval != 0);

        ## read distro version dir in dists/
        $cmd = "ls -l \"$dest_dir/dists\" | grep \"^d\" | awk '{print \$(NF)}' | head -1";
        my $version = `$cmd`;
        if (defined($version) and ($version ne ""))
        {
            $cmd = "ls -l \"$dest_dir/dists\"/*/ | grep \"^d\" | sort -u | awk '{print \$(NF)}' | awk '{sec=sec\" \"\$1} END{print sec}'";
            my $sections = `$cmd`;
            if (defined($sections))
            {
                chomp($sections);
                chomp($version);
                print SFH "deb file://$dest_dir $version $sections\n";
            }
        }
    }
}
print SFH "\n## Automatically generated by $0 ##\n";
close(SFH);
print "Total $niso_images iso(s) mounted successfully.\n" if $debug;

## Reload repository if sources.list is updated
if ($is_backed_up and $reload)
{
    &reload_repo("$apt_orig", "$apt_dvd");
}
exit(0);
}
#######################################
## umount code                       ##
#######################################

$cmd = "umount \"$mount_point_base\"/*.iso";
$retval = &run_cmd($cmd);
exit(-1) if ($retval != 0);
$cmd = "rmdir \"$mount_point_base\"/*.iso";
$retval = &run_cmd($cmd);
exit(-1) if ($retval != 0);
if ($reload)
{
    &reload_repo("$apt_net", "$apt_orig");
}
exit(0);

PS: The above script can be used with any Debian Package Management related distros like Ubuntu, Linux Mint, etc.

Pidgin: Keyboard becomes unresponsive after Status change

In Fedora 17 (i386), after changing status in pidgin 2.10.x, it is not possible to use keyboard in chat window. Keyboard becomes unresponsive. Even, I tried to compile and install newer pidgin 2.10.7, the issue remains same.

Then, after searching, I came across this bug https://developer.pidgin.im/ticket/15220 in Pidgin (actually GTK+), which suggests to

Right Click inside typing input box of Chat window > Input Methods > (Select any input method)

After this, input from keyboard is again possible.

Emacs in Daemon mode

When I started to use emacs as Java IDE, I have installed CEDET and JDEE. This make start time of emacs longer, even when I am not opening any Java file. Therefore, it is required to start Emacs in daemon mode. So that only one time startup is longer, and subsequent startup of emacs (emacs client to be precise) will be much faster.

I have written the following shell script (em, please place it in your $PATH), which starts the emacs daemon on first time only, and connects emacsclient to it.

#!/bin/bash

usr=$(whoami)
emacs_daemon="emacs --daemon"
cmd="ps auxww | grep \"$usr.*$emacs_daemon\" | grep -v grep"
#echo "$cmd"
is_running=$(eval "$cmd")
if [ -z "$is_running" ]
then
    echo "Starting emacs daemon"
    eval "$emacs_daemon"
    if [ $? -ne 0 ]
    then
        echo "$0: Cannot start $emacs_daemon" >&2
        exit
    fi
fi
emacsclient -a "" -t "$@"
exit $?

First Run:

$ em Hello.java
Starting emacs daemon

Warning: due to a long standing Gtk+ bug
http://bugzilla.gnome.org/show_bug.cgi?id=85715
Emacs might crash when run in daemon mode and the X11 connection is unexpectedly lost.
Using an Emacs configured with --with-x-toolkit=lucid does not have this problem.
("emacs")
Loading /usr/share/emacs/site-lisp/site-start.d/auto-complete-init.el (source)...
Loading /usr/share/emacs/site-lisp/site-start.d/auto-complete-init.el (source)...done
Loading /usr/share/emacs/site-lisp/site-start.d/emacs-color-theme-init.el (source)...
Loading /usr/share/emacs/site-lisp/site-start.d/emacs-color-theme-init.el (source)...done
Loading /usr/share/emacs/site-lisp/site-start.d/emacs-goodies-loaddefs.el (source)...
Loading /usr/share/emacs/site-lisp/site-start.d/emacs-goodies-loaddefs.el (source)...done
Loading /usr/share/emacs/site-lisp/site-start.d/focus-init.el (source)...
Loading /usr/share/emacs/site-lisp/site-start.d/focus-init.el (source)...done
Loading /usr/share/emacs/site-lisp/site-start.d/gnuplot-init.el (source)...
Loading /usr/share/emacs/site-lisp/site-start.d/gnuplot-init.el (source)...done
Loading /usr/share/emacs/site-lisp/site-start.d/gnus-bonus-init.el (source)...
Loading /usr/share/emacs/site-lisp/site-start.d/gnus-bonus-init.el (source)...done
Loading /usr/share/emacs/site-lisp/site-start.d/php-mode-init.el (source)...
Loading /usr/share/emacs/site-lisp/site-start.d/php-mode-init.el (source)...done
Loading /usr/share/emacs/site-lisp/site-start.d/rpm-spec-mode-init.el (source)...
Loading /usr/share/emacs/site-lisp/site-start.d/rpm-spec-mode-init.el (source)...done
Loading /usr/share/emacs/site-lisp/site-start.d/rpmdev-init.el (source)...
Loading /usr/share/emacs/site-lisp/site-start.d/rpmdev-init.el (source)...done
Loading /usr/share/emacs/site-lisp/cedet-1.1/common/cedet.el (source)...
Setting up CEDET packages...
Warning: cedet-called-interactively-p called with 0 arguments, but requires 1
Warning: cedet-called-interactively-p called with 0 arguments, but requires 1
Setting up CEDET packages...done
Loading /usr/share/emacs/site-lisp/cedet-1.1/common/cedet.el (source)...done
Warning: cedet-called-interactively-p called with 0 arguments, but requires 1
Warning: cedet-called-interactively-p called with 0 arguments, but requires 1
Warning: cedet-called-interactively-p called with 0 arguments, but requires 1
Warning: cedet-called-interactively-p called with 0 arguments, but requires 1                                                                                                  
Warning: cedet-called-interactively-p called with 0 arguments, but requires 1                                                                                                  
Warning: cedet-called-interactively-p called with 0 arguments, but requires 1
Warning: cedet-called-interactively-p called with 0 arguments, but requires 1
jde-java-font-lock: building names cache...
jde-java-font-lock: building names cache...empty
Warning: cedet-called-interactively-p called with 0 arguments, but requires 1
Warning: cedet-called-interactively-p called with 0 arguments, but requires 1
Warning: cedet-called-interactively-p called with 0 arguments, but requires 1
Warning: cedet-called-interactively-p called with 0 arguments, but requires 1
Starting Emacs daemon.

Second and Subsequent Runs:

$ em Hello.java

Removing Empty Directories

We can remove empty directories inside a directory by using following command

$ ls -l * | grep -B1 "^total 0K" | grep -v -e "total 0K" -e "--" | cut -d: -f1 | xargs rmdir -v

The above command cannot delete recursively. Hence, using find command to delete recursively.

$ find . -type d -empty -delete