How to free RAM Memory

STEP1:

    i) sudo sync

  ii)sudo sysctl -w vm.drop_caches=3

  iii) sudo sync




STEP2:


  i) echo 1 > /proc/sys/vm/drop_caches

  ii) echo 2 > /proc/sys/vm/drop_caches

  iii) echo 3 > /proc/sys/vm/drop_caches

perl: warning: Please check that your locale settings

Problem: perl: warning: Please check that your locale settings:     LANGUAGE = (unset),     LC_ALL = (unset),     LC_TIME = "en_IN.UTF-8",     LC_MONETARY = "en_IN.UTF-8",     LC_ADDRESS = "en_IN.UTF-8",     LC_TELEPHONE = "en_IN.UTF-8",     LC_NAME = "en_IN.UTF-8",     LC_MEASUREMENT = "en_IN.UTF-8",     LC_IDENTIFICATION = "en_IN.UTF-8",     LC_NUMERIC = "en_IN.UTF-8",     LC_PAPER = "en_IN.UTF-8",     LANG = "en_US.UTF-8"     are supported and installed on your system.

Solution:

$ locale  locale: Cannot set LC_ALL to default locale: No such file or directory  LANG=en_US.UTF-8  LANGUAGE=  LC_CTYPE=en_US.UTF-8  LC_NUMERIC=ru_RU.UTF-8  LC_TIME=ru_RU.UTF-8  LC_COLLATE="en_US.UTF-8"  LC_MONETARY=ru_RU.UTF-8  LC_MESSAGES="en_US.UTF-8"  LC_PAPER=ru_RU.UTF-8  LC_NAME=ru_RU.UTF-8  LC_ADDRESS=ru_RU.UTF-8  LC_TELEPHONE=ru_RU.UTF-8  LC_MEASUREMENT=ru_RU.UTF-8  LC_IDENTIFICATION=ru_RU.UTF-8  LC_ALL=    $ sudo su    # export LANGUAGE=en_US.UTF-8  # export LANG=en_US.UTF-8  # export LC_ALL=en_US.UTF-8    # locale-gen en_US.UTF-8  Generating locales...    en_US.UTF-8... up-to-date  Generation complete.    # dpkg-reconfigure locales  Generating locales...    en_AG.UTF-8... done    en_AU.UTF-8... done    en_BW.UTF-8... done    en_CA.UTF-8... done    en_DK.UTF-8... done    en_GB.UTF-8... done    en_HK.UTF-8... done    en_IE.UTF-8... done    en_IN.UTF-8... done    en_NG.UTF-8... done    en_NZ.UTF-8... done    en_PH.UTF-8... done    en_SG.UTF-8... done    en_US.UTF-8... up-to-date    en_ZA.UTF-8... done    en_ZM.UTF-8... done    en_ZW.UTF-8... done  Generation complete.    # exit    $ locale  LANG=en_US.UTF-8  LANGUAGE=en_US.UTF-8  LC_CTYPE="en_US.UTF-8"  LC_NUMERIC="en_US.UTF-8"  LC_TIME="en_US.UTF-8"  LC_COLLATE="en_US.UTF-8"  LC_MONETARY="en_US.UTF-8"  LC_MESSAGES="en_US.UTF-8"  LC_PAPER="en_US.UTF-8"  LC_NAME="en_US.UTF-8"  LC_ADDRESS="en_US.UTF-8"  LC_TELEPHONE="en_US.UTF-8"  LC_MEASUREMENT="en_US.UTF-8"  LC_IDENTIFICATION="en_US.UTF-8"  LC_ALL=en_US.UTF-8

How to install flash player in Ubuntu

sudo apt-get update    sudo apt-get purge adobe-flash{plugin,-properties-gtk}    sudo apt-get install flashplugin-installer

grub rescue

if get error as follows at the of boot:

No Such partition..

grub rescue>

or unknown file system

grub rescue>

follow the following steps:

1. run ls command

2. you will get list of partitions

3. apply ls comman on each

4. ls (hd0)

 you will get 'not found' or unknown file system message

apply ls on next partition eg

ls (hd0,msdos8)

again  you will get 'not found' or unknown file system message

apply ls on next partition eg
ls (hd0,msdos7)
now suppose here you gets some list of files and folder. THis indicates that your ubuntu/linux is installed here

now apply ls (hd0.msdos7)/boot/grub

you should get list of mod files

5. Now use following commands

set root=(hd0,msdos7)

set prefix=(hd0,msdos7)/boot/grub

insmod normal

normal

Your system to start...

6. Once you started the system in Linux

   Re-install the grub

    sudo grub-install /dev/sda

do not put partition number like sda1 or sda2

Update the grub:
 sudo update-grub

how to remove crossplatformui

1. Enter /var/lib/dpkg/info

   cd /var/lib/dpkg/info  

2. Delete all entry related to crossplatformui

   sudo rm crossplatformui.*  

3. Force remove crossplatformui

   sudo dpkg --remove --force-remove-reinstreq crossplatformui    (Reading database ...   dpkg: warning: files list file for package `crossplatformui' missing, assuming package has no files currently installed.    (Reading database ... 159448 files and directories currently installed.)    Removing crossplatformui ... 
   

Source: http://askubuntu.com/questions/136423/crossplatformui-error

Can't locate Audio/Wav.pm

Error: Can't locate Audio/Wav.pm

Solution: install the missing Audio::Wav dependency module by following command:
sudo cpan Audio::Wav

Resampling audio data

Method1:

Using ch_wav  command

Example: Converting 16 Khz wave file into 8 Khz

ch_wave   -f    16000   -F    8000 -o   wav_8KHz/text001.wav     ../wav_16KHz/text001.wav

Method2:

Using sox command

sox input.wav -r 44000 output.wav resample

Here 44000 is the sampling rate of output file

Example: Converting 16 Khz wave file into 8 Khz

sox   text0001.wav   -r    8000   wav_8KHz/text001.wav   resample

Resampling all files of a directory

write following code in a file suppose down_sample.pl
chomp(@ARGV = <STDIN>) unless @ARGV;
for ( @ARGV )
{
  $was = $_;
  print "was=$was";
  #print "op =$op";

   
 
 $now="./output/".$was;
print "now1=$now\n";
   # @args= ( "ch_wave", "-f", "48000", "-F", "16000", "-o", "$now", "$was");
 @args= ( "sox", "$was", "-r", "16000", "$now", "resample" );
  
                            system(@args);


}

Suppose you are having 48 Khz wav files i directory wav_48khz:

1. Copy the down_sample.pl file having above code into wav_48khz directory

2. Create directory output inside wav_48khz directory

3. Open terminal and go to the wav_48khz directory

4. run following command

    perl down_sample.pl *.wav

5. 16 Khz wav files will be inside output directory

7. You may use either sox or ch_wav command. Some times ch_wav command does not recognise wave files then we should use sox.