Posts Tagged ‘home’

Howto Configure Linux shell Prompt / Setup custom Terminal show Prompt using default shell variables PS1, PS2, PS3, PS4

Tuesday, August 27th, 2019

how-to-configure-lunux-bsd-shell-prompt-ps1-howto-make-your-terminal-console-shell-nice-and-shiny-1

System Console, Command Operation Console  or Terminal is a Physical device for text (command) input from keyboard, getting the command output and monitoring the status of a shell or programs I/O operations generated traditionally with attached screen. With the development of Computers, physical consoles has become emulated and the input output is translated on the monitor usually via a data transfer  protocol historically mostly over TCP/IP connection to remote IP with telnet or rsh, but due to security limitations Consoles are now accessed over data (encrypted) network protocols with SHA2 / MD5 cryptography algorithm enabled such as over SSH (Secure Shell) network protocol..
The ancestors of physical consoles which in the past were just a Terminal (Monitoring / Monitor device attached to a MainFrame system computer).

Mainframe-physical-terminal-monitor-Old-Computer

What is Physical Console
A classical TTY (TeleTYpewriter) device looked like so and served the purpose of being just a communication and display deivce, whether in reality the actual computing and storage tape devices were in a separate room and communicating to Terminal.

mainframe-super-computer-computing-tape-machine
TTYs are still present in  modern UNIX like GNU / Linux distrubions OSes and the BSD berkley 4.4 code based FreeBSD / NetBSD / OpenBSD if you have installed the OS on a physical computer in FreeBSD and Solaris / SunOS there is also tty command. TTY utility in *nix writes the name of the terminal attached to standard input to standard output, in Linux there is a GNU remake of same program part called GNU tty of coreutils package (try man tty) for more.

The physical console is recognizable in Linux as it is indicated with other tree letters pts – (pseudo terminal device) standing for a terminal device which is emulated by an other program (example: xterm, screen, or ssh are such programs). A pts is the slave part of a pts is pseudo there is no separate binary program for it but it is dynamically allocated in memory.
PTS is also called Line consle in Cisco Switches / Router devices, VTY is the physical Serial Console connected on your Cisco device and the network connection emulation to network device is creates with a virtual console session VTL (Virtual Terminal Line). In freebsd the actual /dev/pts* /dev/tty* temporary devices on the OS are slightly different and have naming such as /dev/ttys001.
But the existence of tty and pts emulator is not enough for communicating interrupts to Kernel and UserLand binaries of the Linux / BSD OS, thus to send the commands on top of it is running a System Shell as CSH / TSH / TCSH or BASH which is usually the first program set to run after user logs in over ptty or pseudo tty virtual terminal.

linux-tty-terminal-explained-brief-intro-to-linux-device-drivers-20-638

 

Setting the Bash Prompt in Terminal / Console on GNU / Linux

Bash has system environments to control multiple of variables, which are usually visible with env command, one important variable to change in the past was for example USER / USERNAME which was red by IRC Chat clients  such as BitchX / irssi and could be displayed publicly so if not changed to a separate value, one could have known your Linux login username by simple /whois query to the Nickname in question (if no inetd / xinetd service was running on the Linux box and usually inetd was not running).

Below is my custom set USER / USERNAME to separate

hipo@pcfreak:~$ env|grep USER
USERNAME=Attitude
USER=Attitude

There is plenty of variables to  tune email such as MAIL store directory, terminal used TERM, EDITOR etc. but there are some
variables that are not visible with env query as they're not globally available for all users but just for the single user, to show this ones you need to use declare command instead, to get a full list of All Single and System Wide defined variables and functions type declare in the bash shell, for readability, below is last 10 returned results:

 

hipo@pcfreak:~$ declare | tail -10
{
    local quoted=${1//\'/\'\\\'\'};
    printf "'%s'" "$quoted"
}
quote_readline ()
{
    local quoted;
    _quote_readline_by_ref "$1" ret;
    printf %s "$ret"
}

 

PS1 is present there virtually on any modern Linux distribution and is installed through user home's directory $HOME/.bashrc , ~/.profile or .bash_profile or System Wide globally for all existing users in /etc/passwd (password database file) from /etc/bash.bashrc
In Debian / Ubuntu / Mint GNU / Linux this system variable is set in user home's .bashrc but in Fedora / RHEL Linux distro,
PS1 is configured from /home/username/.bash_profile to find out where PS1 is located for ur user:

cd ~
grep -Rli PS1 .bash*

Here is one more example:

hipo@pcfreak:~$ declare|grep -i PS1|head -1
PS1='\[\e]0;\u@\h: \w\a\]${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
 

hipo@pcfreak:~$ grep PS1 /etc/bash.bashrc
[ -z “$PS1” ] && return
# but only if not SUDOing and have SUDO_PS1 set; then assume smart user.
if ! [ -n “${SUDO_USER}” -a -n “${SUDO_PS1}” ]; then
  PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '


Getting current logged in user shell configured PS1 variable can be done with echo:

hipo@pcfreak:~$ echo $PS1
\[\e]0;\u@\h: \w\a\]${debian_chroot:+($debian_chroot)}\u@\h:\w\$

So lets observe a little bit the meaning of this obscure line of (code) instructions code which are understood by BASH when being red from PS1 var to do so, I'll give a list of meaning of main understood commands, each of which is defined with \.

The ${debian_chroot} shell variable is defined from /etc/bash.bashrc

Easiest way to change PS1 is to export the string you like with the arguments like so:

 

root@linux:/home/hipo# export PS1='My-Custom_Server-Name# '
My-Custom_Server-Name# echo $PS1
My-Custom_Server-Name#

 

  •     \a : an ASCII bell character (07)
  •     \d : the date in “Weekday Month Date” format (e.g., “Tue May 26”)
  •     \D{format} : the format is passed to strftime(3) and the result is inserted into the prompt string; an empty format results in a locale-specific time representation. The braces are required
  •     \e : an ASCII escape character (033)
  •     \h : the hostname up to the first ‘.’
  •     \H : the hostname
  •     \j : the number of jobs currently managed by the shell
  •     \l : the basename of the shell's terminal device name
  •     \n : newline
  •     \r : carriage return
  •     \s : the name of the shell, the basename of $0 (the portion following the final slash)
  •     \t : the current time in 24-hour HH:MM:SS format
  •     \T : the current time in 12-hour HH:MM:SS format
  •     \@ : the current time in 12-hour am/pm format
  •     \A : the current time in 24-hour HH:MM format
  •     \u : the username of the current user
  •     \v : the version of bash (e.g., 2.00)
  •     \V : the release of bash, version + patch level (e.g., 2.00.0)
  •     \w : the current working directory, with $HOME abbreviated with a tilde
  •     \W : the basename of the current working directory, with $HOME abbreviated with a tilde
  •     \! : the history number of this command
  •     \# : the command number of this command
  •     \$ : if the effective UID is 0, a #, otherwise a $
  •     \nnn : the character corresponding to the octal number nnn
  •     \\ : a backslash
  •     \[ : begin a sequence of non-printing characters, which could be used to embed a terminal control sequence into the prompt
  •     \] : end a sequence of non-printing characters

The default's PS1 set prompt on Debian Linux is:
 

echo $PS1
\[\e]0;\u@\h: \w\a\]${debian_chroot:+($debian_chroot)}\u@\h:\w\$


As you can see \u (print username) \h (print hostname)  and \W (basename of current working dir) or \w (print $HOME/current working dir)
are the most essential, the rest are bell character, escape character etc.

A very good way to make your life easier and learn the abbreviations / generate exactly the PS1 PROMPT you want to have is with Easy Bash PS1 Generator Web Utility
with which you can just click over buttons that are capable to produce all of the PS1 codes.
 

1. How to show current hour:minute:seconds / print full date in Prompt Shell (PS)


Here is an example with setting the Bash Shell prompt  to include also the current time in format hour:minute:seconds (very useful if you're executing commands on a critical servers and you run commands in some kind of virtual terminal like screen or tmux.
 

root@pcfreak:~# PS1="\n\t \u@\h:\w# "
14:03:51 root@pcfreak:/home#


PS1-how-to-setup-date-time-hour-minutes-and-seconds-in-bash-shell-prompt
 

 

export PS1='\u@\H \D{%Y-%m-%d %H:%M;%S%z}] \W ] \$ '

 


export-PS1-Linux-set-full-date-time-clock-prompt-screenshot-console


Make superuser appear in RED color (adding PS1 prompt custom color for a User)
 

root@pcfreak:~$  PS1="\\[$(tput setaf 1)\\]\\u@\\h:\\w #\\[$(tput sgr0)\\]"

 

how-to-change-colors-in-bash-prompt-shell-on-linux-shell-environment

In above example the Shell Prompt Color changed is changed for administrator (root) to shebang symbol # in red, green, yellow and blue for the sake to show you how it is done, however this example can be adapted for any user on the system. Setting different coloring for users is very handy if you have to administer Mail Server service like Qmail or other Application that consists of multiple small ones of multiple daemons such as qmail + vpopmail + clamd + mysql etc. Under such circumstances, coloring each of the users in different color like in the example for debugging is very useful.

Coloring the PS1 system prompt on Linux to different color has been a standard practice in Linux Server environments running Redhat Enterprise Linux (RHEL) and SuSE Enterprise Linux and some Desktop distributions such as Mint Linux.

To make The Root prompt Red colored only for system super user (root) on any Linux distribution
, add the following to /etc/bashrc, e.g.

vim /etc/bashrc
 


# If id command returns zero, you've root access.
if [ $(id -u) -eq 0 ];
then # you are root, set red colour prompt
  PS1="\\[$(tput setaf 1)\\]\\u@\\h:\\w #\\[$(tput sgr0)\\]"
else # normal
  PS1="[\\u@\\h:\\w] $"
fi

 

 

2. How to make the prompt of a System user appear Green


Add to ~/.bashrc  following line

 

 

PS1="\\[$(tput setaf 2)\\]\\u@\\h:\\w #\\[$(tput sgr0)\\]"
 

 

3. Print New line, username@hostname, base PTY, shell level, history (number), newline and full working directory $PWD

 

export PS1='\n[\u@\h \l:$SHLVL:\!]\n$PWD\$ '

 

4. Showing the numbert of jobs the shell is currently managing.


This is useful if you run and switch with fg / bg (foreground / background) commands
to switch between jobs and forget some old job.

 

export PS1='\u@\H \D{%Y-%m-%d %H:%M;%S%z}] \W \$]'

 

Multi Lines Prompt / Make very colorful Shell prompt full of stats info

PS1="\n\[\033[35m\]\$(/bin/date)\n\[\033[32m\]\w\n\[\033[1;31m\]\u@\h: \[\033[1;34m\]\$(/usr/bin/tty | /bin/sed -e ‘s:/dev/::’): \[\033[1;36m\]\$(/bin/ls -1 | /usr/bin/wc -l | /bin/sed ‘s: ::g’) files \[\033[1;33m\]\$(/bin/ls -lah | /bin/grep -m 1 total | /bin/sed ‘s/total //’)b\[\033[0m\] -> \[\033[0m\]"

 

 

prompt-show-how-many-files-and-virtual-pts-ps1-linux
 

5. Set color change on command failure


If you have a broken command or the command ended with non zero output with some kind of bad nasty message and you want to make, that more appearing making it red heighlighted, here is how:

 

PROMPT_COMMAND='PS1="\[\033[0;33m\][\!]\`if [[ \$? = “0” ]]; then echo “\\[\\033[32m\\]”; else echo “\\[\\033[31m\\]”; fi\`[\u.\h: \`if [[ `pwd|wc -c|tr -d ” “` > 18 ]]; then echo “\\W”; else echo “\\w”; fi\`]\$\[\033[0m\] “; echo -ne “\033]0;`hostname -s`:`pwd`\007"'

 

6. Other beautiful PS1 Color Prompts with statistics

 

PS1="\n\[\e[32;1m\](\[\e[37;1m\]\u\[\e[32;1m\])-(\[\e[37;1m\]jobs:\j\[\e[32;1m\])-(\[\e[37;1m\]\w\[\e[32;1m\])\n(\[\[\e[37;1m\]! \!\[\e[32;1m\])-> \[\e[0m\]"

 

 

another-very-beuatiful-bash-colorful-prompt

 

7. Add Muliple Colors to Same Shell prompt

 

function prompt { local BLUE="\[\033[0;34m\]” local DARK_BLUE=”\[\033[1;34m\]” local RED=”\[\033[0;31m\]” local DARK_RED=”\[\033[1;31m\]” local NO_COLOR=”\[\033[0m\]” case $TERM in xterm*|rxvt*) TITLEBAR=’\[\033]0;\u@\h:\w\007\]’ ;; *) TITLEBAR=”” ;; esac PS1=”\u@\h [\t]> ” PS1=”${TITLEBAR}\ $BLUE\u@\h $RED[\t]>$NO_COLOR " PS2='continue-> ' PS4='$0.$LINENO+ ' }

colorful-prompt-blue-and-red-linux-console-PS1
 

8. Setting / Change Shell background Color


changing-background-color-of-bash-shell-prompt-linux

 

export PS1="\[$(tput bold)$(tput setb 4)$(tput setaf 7)\]\u@\h:\w $ \[$(tput sgr0)\]"

 

tput Color Capabilities:

  • tput setab [1-7] – Set a background color using ANSI escape
  • tput setb [1-7] – Set a background color
  • tput setaf [1-7] – Set a foreground color using ANSI escape
  • tput setf [1-7] – Set a foreground color

tput Text Mode Capabilities:

  • tput bold – Set bold mode
  • tput dim – turn on half-bright mode
  • tput smul – begin underline mode
  • tput rmul – exit underline mode
  • tput rev – Turn on reverse mode
  • tput smso – Enter standout mode (bold on rxvt)
  • tput rmso – Exit standout mode
  • tput sgr0 – Turn off all attributes

Color Code for tput:

  • 0 – Black
  • 1 – Red
  • 2 – Green
  • 3 – Yellow
  • 4 – Blue
  • 5 – Magenta
  • 6 – Cyan
  • 7 – White

 

9. Howto Use bash shell function inside PS1 variable

If you administrate Apache or other HTTPD servers or any other server whose processes are forked and do raise drastically at times to keep an eye while actively working on the server.

 

function httpdcount { ps aux | grep apache2 | grep -v grep | wc -l } export PS1="\u@\h [`httpdcount`]> "

10. PS2, PS3, PS4 little known variables
 

I'll not get much into detail to PS2, PS3, PS4 but will mention them as perhaps many people are not even aware they exist.
They're rarely used in the daily system administrator's work but useful for Shell scripting purposes of Dev Ops and Shell Scripting Guru Programmers.

  • PS2 – Continuation interactive prompt

A very long unix command can be broken down to multiple line by giving \ at the end of the line. The default interactive prompt for a multi-line command is “> “.  Let us change this default behavior to display “continue->” by using PS2 environment variable as shown below.

hipo@db-host :~$ myisamchk –silent –force –fast –update-state \
> –key_buffer_size=512M –sort_buffer_size=512M \
> –read_buffer_size=4M –write_buffer_size=4M \
> /var/lib/mysql/bugs/*.MYI
[Note: This uses the default “>” for continuation prompt]

  • PS3 – Prompt used by “select” inside shell script (usefulif you write scripts with user prompts)

     

  • PS4 – Used by “set -x” to prefix tracing output
    The PS4 shell variable defines the prompt that gets displayed.

You can find  example with script demonstrating PS2, PS3, PS4 use via small shell scripts in thegeekstuff's article Take control of PS1, PS2, PS3, PS4 read it here

 

Summary


In this article, I've shortly reviewed on what is a TTY, how it evolved into Pseudo TTY and how it relates to current shells which are the interface communicating with the modern UNIX like Operating systems's userland and kernel.
Also it was reviewed shortly how the current definitions of shell variables could be viewed with declare cmd. Also I went through on how to display the PS1 variable and  on how to modify PS1 and make the prompt different statistics and monitoring parameters straight into the command shell. I've shown some common PS1 strings that report on current date hour, minute, seconds, modify the coloring of the bash prompt shell, show processes count, and some PS1 examples were given that combines beuatiful shell coloring as well as how the Prompt background color can be changed.
Finally was shown how a combination of commands can be executed by exporting to PS1 to update process counf of Apache on every shell prompt iteration.
Other shell goodies are mostly welcome

 

 

Howto create Linux Music Audio CD from MP3 files / Create playable WAV format Audio CD Albums from MP3s

Tuesday, July 16th, 2019

cdburning-audio-music-cd-from-mp3-on-linuxcomapct-disc-tux-linux-logo

Recently my Mother asked me to prepare a Music Audio CD for her from a popular musician accordionist Stefan Georgiev from Dobrudja who has a unique folklore Bulgarian music.

As some of older people who still remember the age of the CD and who had most likely been into the CD burning Copy / Piracy business so popular in the countries of the ex-USSR so popular in the years 1995-2000 audio ,  Old CD Player Devices were not able to play the MP3 file format due to missing codecs (as MP3 was a proprietary compression that can't be installed on every device without paying the patent to the MP3 compression rights holder.

The revolutionary MP3 compression used to be booming standard for transferring Music data due to its high compression which made an ordinary MP3 of 5 minutes of 5MB (10+ times more compression than an ordinary classic WAV Audio the CPU intensiveness of MP3 files that puts on the reading device, requiring the CD Player to have a more powerful CPU.

Hence  due to high licensing cost and requirement for more powerful CPU enabled Audio Player many procuders of Audio Players never introduced MP3 to their devices and MP3 Neve become a standard for the Audio CD that was the standard for music listening inside almost every car out there.

Nowdays it is very rare need to create a Audio CD as audio CDs seems to be almost dead (As I heard from a Richard Stallman lecture In USA nowadays there is only 1 shop in the country where you can still buy CD or DVD drives) and only in third world as Africa Audio CDs perhaps are still in circulation.

Nomatter that as we have an old Stereo CD player on my village and perhaps many others, still have some old retired CD reading devices being able to burn out a CD is a useful thing.

Thus to make mother happy and as a learning excercise, I decided to prepare the CD for her on my Linux notebook.
Here I'll shortly describe the takes I took to make it happen which hopefully will be useful for other people that need to Convert and burn Audio CD from MP3 Album.

 

1. First I downloaded the Album in Mp3 format from Torrent tracker

My homeland Bulgaria and specific birth place place the city of Dobrich has been famous its folklore:  Galina Durmushlijska and Stefan Georgiev are just 2 of the many names along with Оркестър Кристал (Orchestra Crystal) and the multitude of gifted singers. My mother has a santiment for Stefan Georgiev, as she listened to this gifted accordinist on her Uncle's marriage.

Thus In my case this was (Стефан Георгиев Хора и ръченици от Добруджа) the album full song list here If you're interested to listen the Album and Enjoy unique Folklore from Dobrudja (Dobrich) my home city, Stefan Georgiev's album Hora and Rachenica Dances is available here

 


Stefan_Georgiev-old-audio-Music-CD-Hora-i-Rychenici-ot-Dobrudja-Horos-and-Ruchenitsas-from-Dobrudja-CD_Cover
I've downloaded them from Bulgarian famous torrent tracker zamunda.net in MP3 format.
Of course you need to have a CD / DVD readed and write device on the PC which nowdays is not present on most modern notebooks and PCs but as a last resort you can buy some cheap External Optical CD / DVD drive for 25 to 30$ from Amazon / Ebay etc.

 

2. You will need to install a couple of programs on Linux host (if you don't have it already)


To be able to convert from command line from MP3 to WAV you will need as minimum ffmpeg and normalize-audio packages as well as some kind of command line burning tool like cdrskin  wodim which is
the fork of old good known cdrecord, so in case if you you're wondering what happened with it just
use instead wodim.

Below is a good list of tools (assuming you have enough HDD space) to install:

 

root@jeremiah:/ # apt-get install –yes dvd+rw-tools cdw cdrdao audiotools growisofs cdlabelgen dvd+rw-tools k3b brasero wodim ffmpeg lame normalize-audio libavcodec58

 

Note that some of above packages I've installed just for other Write / Read operations for DVD drives and you might not need that but it is good to have it as some day in future you will perhaps need to write out a DVD or something.
Also the k3b here is specific to KDE and if you're a GNOME user you could use Native GNOME Desktop app such brasero or if you're in a more minimalistic Linux desktop due to hardware contrains use XFCE's native xfburn program.

If you're a console / terminal geek like me you will definitely enjoy to use cdw
 

root@jeremiah:/ # apt-cache show cdw|grep -i description -A 1
Description-en: Tool for burning CD's – console version
 Ncurses-based frontend for wodim and genisoimage. It can handle audio and

Description-md5: 77dacb1e6c00dada63762b78b9a605d5
Homepage: http://cdw.sourceforge.net/

 

3. Selecting preferred CD / DVD / BD program to use to write out the CD from Linux console


cdw uses wodim (which is a successor of good old known console cdrecord command most of use used on Linux in the past to burn out new Redhat / Debian / different Linux OS distro versions for upgrade purposes on Desktop and Server machines.

To check whether your CD / DVD drive is detected and ready to burn on your old PC issue:

 

root@jeremiah:/# wodim -checkdrive
Device was not specified. Trying to find an appropriate drive…
Detected CD-R drive: /dev/cdrw
Using /dev/cdrom of unknown capabilities
Device type    : Removable CD-ROM
Version        : 5
Response Format: 2
Capabilities   :
Vendor_info    : 'HL-DT-ST'
Identification : 'DVDRAM GT50N    '
Revision       : 'LT20'
Device seems to be: Generic mmc2 DVD-R/DVD-RW.
Using generic SCSI-3/mmc   CD-R/CD-RW driver (mmc_cdr).
Driver flags   : MMC-3 SWABAUDIO BURNFREE
Supported modes: TAO PACKET SAO SAO/R96P SAO/R96R RAW/R16 RAW/R96P RAW/R96R

You can also use xorriso (whose added value compared to other console burn cd tools is is not using external program for ISO9660 formatting neither it use an external or an external burn program for CD, DVD or BD (Blue Ray) drive but it has its own libraries incorporated from libburnia-project.org libs.

Below output is from my Thinkpad T420 notebook. If the old computer CD drive is there and still functional in most cases you should not get issues to detect it.

cdw ncurses text based CD burner tool's interface is super intuitive as you can see from below screenshot:

cdw-burn-cds-from-console-terminal-on-GNU-Linux-and-FreeBSD-old-PC-computer

CDW has many advanced abilities such as “blanking” a disk or ripping an audio CD on a selected folder. To overcome the possible problem of CDW not automatically detecting the disk you have inserted you can go to the “Configuration” menu, press F5 to enter the Hardware options and then on the first entry press enter and choose your device (by pressing enter again). Save the setting with F9.
 

4. Convert MP3 / MP4 Files or whatever format to .WAV to be ready to burn to CD


Collect all the files you want to have collected from the CD album in .MP3 a certain directory and use a small one liner loop to convert files to WAV with ffmpeg:
 

cd /disk/Music/Mp3s/Singer-Album-directory-with-MP3/

for i in $( ls *.mp3); do ffmpeg -i $i $i.wav; done


If you don't have ffmpeg installed and have mpg123 you can also do the Mp3 to WAV conversion with mpg123 cmd like so:

 

for i in $( ls ); do mpg123 -w $i.wav $i.mp3; done


Another alternative for conversion is to use good old lame (used to create Mp3 audio files but abling to also) decode
mp3 to wav.

 

lame –decode somefile.mp3 somefile.wav


In the past there was a burn command tool that was able to easily convert MP3s to WAV but in up2date Linux modern releases it is no longer available most likely due to licensing issues, for those on older Debian Linux 7 / 8 / 9 / Ubuntu 8 to 12.XX / old Fedoras etc. if you have the command you can install burn and use it (and not bother with shell loops):

apt-get install burn

or

yum install burn


Once you have it to convert

 

$ burn -A -a *.mp3
 

 

5. Fix file naming to remove empty spaces such as " " and substitute to underscores as some Old CD Players are
unable to understand spaces in file naming with another short loop.

 

for f in *; do mv "$f" `echo $f | tr ' ' '_'`; done

 

6. Normalize audio produced .WAV files (set the music volume to a certain level)


In case if wondering why normalize audio is needed here is short extract from normalize-audio man page command description to shed some light.

"normalize-audio  is  used  to  adjust  the volume of WAV or MP3 audio files to a standard volume level.  This is useful for things like creating mp3 mixes, where different recording levels on different albums can cause the volume to  vary  greatly from song to song."
 

cd /disk/Music/Mp3s/Singer-Album-directory-with-MP3/

normalize-audio -m *.wav

 

7. Burn the produced normalized Audio WAV files to the the CD

 

wodim -v -fix -eject dev='/dev/sr0' -audio -pad *.wav


Alternatively you can conver all your MP3 files to .WAV with anything be it audacity
or another program or even use 
GNOME's CDBurn tool brasero (if gnome user) or KDE's CDBurn which in my opinion is
the best CD / DVD burning application for Linux K3B.

Burning Audio CD with K3b is up to few clicks and super easy and even k3b is going to handle the MP3 to WAV file Conversion itself. To burn audio with K3B just run it and click over 'New Audio CD Project'.

k3b-on-debian-gnu-linux-burn-audio-cd-screenshot

For those who want to learn a bit more on CD / DVD / Blue-Ray burning on GNU / Linux good readings are:
Linux CD Burning Mini Howto, is Linux's CD Writing Howto on ibiblio (though a bit obsolete) or Debian's official documentation on BurnCD.
 

8. What we learned here


Though the accent of this tutorial was how to Create Audio Music CD from MP3 on GNU / Linux, the same commands are available in most FreeBSD / NetBSD / OpenBSD ports tree so you can use the same method to build prepare Audio Music CD on *BSDs.

In this article, we went through few basic ways on how to prepare WAV files from MP3 normalize the new created WAV files on Linux, to prepare files for creation of Audio Music CD for the old mom or grandma's player or even just for fun to rewind some memories. For GUI users this is easily done with  k3b,  brasero or xfburn.

I've pointed you to cdw a super useful text ncurses tool that makes CD Burninng from plain text console (on servers) without a Xorg / WayLand  GUI installed super easy. It was shortly reviewed what has changed over the last few years and why and why cdrecord was substituted for wodim. A few examples were given on how to handle conversion through bash shell loops and you were pointed to some extra reading resources to learn a bit more on the topic.
There are plenty of custom scripts around for doing the same CD Burn / Covnersion tasks, so pointing me to any external / Shell / Perl scripts is mostly welcome.

Hope this learned you something new, Enjoy ! 🙂

Virtualbox Shared folder set up on Linux between Host and Guest OS – Set up Virtualbox shared folder to Copy files from PC Host to Guest

Wednesday, September 12th, 2018

mount-shares-between-host-OS-and-guest-virtual-machine-howto-virtualbox-vbox-logo

How to set-up Virtualbox shared folder to Copy files from PC Host  and Guest Virtualized OS?

Running VirtualBox Host is an easy thing to set-up across all Operating Systems.  Once you have it sooner or later you will need to copy files from the VM Host OS (that in my case is GNU / Linux) to the virtualized Guest operating system (again in my case that's again another Linux ISO running indide the Virtual Machine).

Below are steps to follow To use Virtualbox Shared Folder functionality to copy files between VBox and your Desktop / server Linux install.

1. Install Virtualbox Guest Additions CD Image ISO

I've explained how to add the Guest Additions CD image thoroughfully in my previous article Howto enable Copy / Paste Virtualbox betwen Linux guest and Host OS
Anyways I'll repeat myself below for sake of clarity:

To do so use Oracle VBox menus (on the booted virtualized OS VBox window):

 

Devices -> Insert Guest additions CD Image

 

Mount the ISO inside the Linux Virtual Machine:

root@debian:~# mount /media/cdrom1/
 

If the mount fails and there are no files inside the mount point it might be because the virtualbox-dkms and virtualbox-guest-dkms packages might be missing on the Host OS.

To install them (on Debian GNU / Linux) assuming that you're using virtualbox default distro packages /etc/apt/sources.list :
 

apt-get install –yes -qq virtualbox-dkms virtualbox-guest-dkms


and run:

 

root@debian:/media/cdrom1# cd /media/cdrom1; sh VBoxLinuxAdditions.run


2. Create directory for Shared Folder that will be used to access Host / OS files from the Guest Virtualized OS
 

root@debian:~# mkdir /mnt/shared_folder

 

3. Map from VBox program interface Shared folder settings and Mount /mnt/shared_folder location

virtualbox-virtual-machine-devices-shared-folders-shared-folder-settings-linux-screenshot

 

Devices -> Shared Folder -> Shared Folder settings -> Transient Folders (click blue folder add small button right)

 

From Transient Folders add whatever directory you want to be shared from your local notebook / PC to the VM.

virtualbox-devices-Shared-Folder-Add-Shared-Folder-add-share-linux-screenshotDepending on whether you would like to mount the shared folder only for reading files (choose Read Only) to make it a permanent shared folder (and not just for the one session of current running Virtual Machine until its killed use Make Permanent) or check Auto-Mount tick if you want the shared_folder mapping to be mounted on every VM boot.

Once the shared_folder directory location is set-up from GUI menu click OK and in order for the settings to take effect, you'll need to restart the VM Guest with Linux (use halt command from terminal) or Power Off the Machine via the VBox menus.

To mount use command like:

mount -t vboxsf name_of_folder_linked_from_vbox  /mnt/name_folder_guest_os/


mount-vboxsf-shared-folder-mnt-shared-linux-guest-screenshot

In my case I wanted to share home folder /home so the command I used is:

root@debian:~# mount -t vboxsf  shared_folder /mnt/shared_folder


If everything is fine your Host OS file content from /home will be visible (for read and write if you Mapped it so) 
under /mnt/shared_folder …

And as Turtles Ninja used to heavily say Cowabunga !!! 🙂
You have it mounted and ready for file share between Desktop -> Virtualized OS.

 

Bear in mind that above mount command has to run as root (superuser) to succeed.

You now could copy files from your Host OS (running the Virtual Machine) and the Guest OS (Virtualized OS) using /mnt/shared_folder mount point without problems.

The example is if you want to share files between VirtualBox installed Linux and the Guest (Desktop / server) OS, however at many cases mounting your Host OS directory for root users might be not very practical but, instead you might prefer to do the mount for specific non admin user, for example I prefer to do the shared folder mount with my pointed non-root username hipo.

Here is how to do above VM shared_folder mount for non-root user:

First you need to know the exact UID / GID (User ID / Group ID) of user, you can get that with id command:

 

hipo@linux:~$  id
uid=1000(hipo) gid=1000(hipo) groups=1000(hipo),24(cdrom),25(floppy),29(audio),30(dip),44(video),46(plugdev),108(netdev),114(bluetooth),115(lpadmin),119(scanner)

 

As you see UID / GID in my case are 1000 / 1000

hipo@linux:~$ sudo mount -t vboxsf -o rw,uid=1000,gid=1000 shared_folder /mnt/shared_folder

 

mount-virtual-box-shared_folder-with-non-administration-permissions-non-root-permissions-id-and-mount-command-screenshot-linux


4. Mounting configured shared_folder to automatically mount into the Guest OS Linux on every boot

a) Configuring shared_folder auto-mount using /etc/rc.local

If you need the shared_folder to automatically mount next-time you boot the virtual machine quickest way is to add the mount command to /etc/rc.local (on Debian 8 and Debian 9 and newer Ubuntu Linuxes rc.local is missing by default to enable it to work like it worked before read follow my previous article ).

b) Configuring auto-mount for shared_folder through /etc/fstab

The more professional way to auto-mount on emulated OS VM boot time,  you could add the vboxsf mount definitions to /etc/fstab with your favourite text-editor mcedit, nano, joe etc. … (for me that's vim).

Syntax of /etc/fstab is as follows:
 

<Device> <Mount Point> <Type> <Options> <Dump> <Pass>

root@linux:~# vim /etc/fstab

 

shared_folder /mnt/shared_folder                                vboxsf rw,uid=1000,gid=1000 0 0

Note that you will want to change 1000 / 1000, id / gid with the ones of the non-admin user you would like to add to mount it for.

A quick way to add it to /etc/fstab with a shell one-liner is with command
 

root@linux:~# echo 'shared_folder /mnt/shared_folder                                vboxsf rw,uid=1000,gid=1000 0  0' >> /etc/fstab

An alternative way to add a user to have permissions for vboxsf file system (without specifying the long -o uid=1000,gid=1000 options is to simply add the username in question to group vboxsf like so:

c) Adding non super user username to vboxsf group

root@linux:~# usermod -G vboxsf hipo
root@linux:~# grep -i vboxsf /etc/group
vboxsf:x:999:hipo

 

hipo@linux:~$ sudo mount -t vboxsf  shared_folder /mnt/shared_folder

 

without the extra arguments and the options to pass to /etc/fstab (for eventual requirement to auto mount the shared_folder) would be more simple e.g.:

 

echo 'shared_folder /mnt/shared_folder                                vboxsf ' >> /etc/fstab

 

One note to make here is if the uesr is added to vboxsf the line for /etc/fstab to auto mount to mount for root user and non-root will be identical.

Then you can get the /etc/fstab auto-mount configured tested by running:

c) Checking auto-mount is working

hipo@linux:~# mount -a
hipo@linux:~# mount |grep -i vboxsf
shared_folder on /mnt/shared_folder type vboxsf (rw,nodev,relatime)


5. What if you end up with mounting failed errors ? – What might be causing the mounting failed Protocol error (a few things to check to solve)


In case of troubles with the mount you might get an error like:

hipo@linux:~# mount -t vboxsf  share_folder /mnt/shared_folder

/sbin/mount.vboxsf: mounting failed with the error: Protocol error


This error might be caused because of Insert Guest Additions CD Image might be not properly enabled and installed using the ISO provided VBoxLinuxAdditions.sh shell script.
Other common reason you might get this error if you have mistyped the Folder name: given in Shared Folders -> Folder Path -> Add Share for example I have given shared_folder as a Map name but as you can see in above mount -t vboxsf, I've mistyped share_folder instead of the correct one shared_folder inserted.
In some VBox releases this error was caused by bugs in the Virtual Machine.
 

virtualbox-virtual-machine-shared-folder-transient-folder-add-folder-linux-VM-guest-linux

One useful tip is to be able to check whether a Virtualbox Virtual Machine has a configured shared_folder (if you're logging to manage the machine on remote server – nomatter whether you have logged in with VNC / Teamviewer / Citrix etc. or via SSH session.

To do so use VBoxControl as of time of writting usually located on most distributions under (/usr/bin/VBoxControl)
 

 

hipo@linux:~# VBoxControl sharedfolder list -automount
Oracle VM VirtualBox Guest Additions Command Line Management Interface Version 5.2.18
(C) 2008-2018 Oracle Corporation
All rights reserved.

 

Auto-mounted Shared Folder mappings (0):

No Shared Folders available.

You can use VBoxControl command to get set and list a number of settings on the VBox VM, here is an useful example with it where you get information about numerous VBox info values:

 

root@linux:~# VBoxControl guestproperty enumerate
Oracle VM VirtualBox Guest Additions Command Line Management Interface Version 5.2.18
(C) 2008-2018 Oracle Corporation
All rights reserved.

 

Name: /VirtualBox/GuestInfo/OS/Product, value: Linux, timestamp: 1536681633430852000, flags: <NULL>
Name: /VirtualBox/GuestInfo/Net/0/V4/IP, value: 10.0.2.15, timestamp: 1536681633438717000, flags: <NULL>
Name: /VirtualBox/HostInfo/GUI/LanguageID, value: en_US, timestamp: 1536697521395621000, flags: RDONLYGUEST
Name: /VirtualBox/GuestInfo/Net/0/MAC, value: 08002762FA1C, timestamp: 1536681633442120000, flags: <NULL>
Name: /VirtualBox/GuestInfo/OS/ServicePack, value: <NULL>, timestamp: 1536681633431259000, flags: <NULL>
Name: /VirtualBox/HostInfo/VBoxVerExt, value: 5.2.18, timestamp: 1536681619002646000, flags: TRANSIENT, RDONLYGUEST
Name: /VirtualBox/GuestInfo/Net/0/V4/Netmask, value: 255.255.255.0, timestamp: 1536681633440157000, flags: <NULL>
Name: /VirtualBox/GuestInfo/OS/Version, value: #1 SMP Debian 4.9.110-3+deb9u2 (2018-08-13), timestamp: 1536681633431125000, flags: <NULL>
Name: /VirtualBox/GuestAdd/VersionExt, value: 5.2.18, timestamp: 1536681633431582000, flags: <NULL>
Name: /VirtualBox/GuestAdd/Revision, value: 124319, timestamp: 1536681633432515000, flags: <NULL>
Name: /VirtualBox/HostGuest/SysprepExec, value: <NULL>, timestamp: 1536681619002355000, flags: TRANSIENT, RDONLYGUEST
Name: /VirtualBox/GuestInfo/OS/LoggedInUsers, value: 1, timestamp: 1536681673447293000, flags: TRANSIENT, TRANSRESET
Name: /VirtualBox/GuestInfo/Net/0/Status, value: Up, timestamp: 1536681633443911000, flags: <NULL>
Name: /VirtualBox/GuestInfo/Net/0/Name, value: enp0s3, timestamp: 1536681633445302000, flags: <NULL>
Name: /VirtualBox/HostGuest/SysprepArgs, value: <NULL>, timestamp: 1536681619002387000, flags: TRANSIENT, RDONLYGUEST
Name: /VirtualBox/GuestAdd/Version, value: 5.2.18, timestamp: 1536681633431419000, flags: <NULL>
Name: /VirtualBox/HostInfo/VBoxRev, value: 124319, timestamp: 1536681619002668000, flags: TRANSIENT, RDONLYGUEST
Name: /VirtualBox/GuestInfo/Net/0/V4/Broadcast, value: 10.0.2.255, timestamp: 1536681633439531000, flags: <NULL>
Name: /VirtualBox/HostInfo/VBoxVer, value: 5.2.18, timestamp: 1536681619002613000, flags: TRANSIENT, RDONLYGUEST
Name: /VirtualBox/GuestInfo/OS/LoggedInUsersList, value: hipo, timestamp: 1536681673446498000, flags: TRANSIENT, TRANSRESET
Name: /VirtualBox/GuestInfo/Net/Count, value: 1, timestamp: 1536698949773993000, flags: <NULL>
Name: /VirtualBox/GuestInfo/OS/Release, value: 4.9.0-7-amd64, timestamp: 1536681633431001000, flags: <NULL>
Name: /VirtualBox/GuestInfo/OS/NoLoggedInUsers, value: false, timestamp: 1536681673447965000, flags: TRANSIENT, TRANSRESET
Name: /VirtualBox/GuestAdd/HostVerLastChecked, value: 5.2.18, timestamp: 1536681702832389000, flags: <NULL>

Hope you enjoyed ! Have phun! 🙂

Why don’t you use Window Maker GNU Step to improve your computer interaction performance

Monday, October 30th, 2017

Why-dont-you-use-Window-Maker-graphical-environment-for-your-GNU_Linux-FreeBSD-desktop

If you're pissed off too already of GNOME 3 Unity / GNOME 3 Flashback and KDE Plasma  as I am you perhaps are looking for something more light weigth but you're not okay with default Debian Cinnanom GUI environment or you don't feel confortable for system administration jobs and programming with XFCE then perhaps you would like to give a try to something more old school but build with good design in Mind.

Those who are fans of the evil genius Steve Jobs (as Richard Stallman use to call him), definitely Remember NeXT company and the revolutionary Graphic Environment they tried to develop NeXT Step then you'll be happy to hear about GNUStep  which historically was called AfterStep and is a Free Software remake of NextStep graphical environment for Free and Open Source operating systems (FOSS) such as GNU / Linux and FreeBSD / OpenBSD / NetBSD etc.

Amanda_the_panda_mascot_of_window_maker-graphical-environment-system

Amanda the Panda is the mascot of Window Maker. She was designed by Agnieszka Czajkowska.

The good thing about Window Maker and the complete bunch of desktop environment GNUStep is it much lighter and less complex than the more and more becoming bloated modern Free Software graphical environments, it definitely easifies the way the user interacts with basic browsing with Firefox / Opera, terminal code writting or command system administration and basic chat functionalities such as with Gajim or Pidgin and basic email writting operatins be it with some text email client such as Mutt or with Thunderbird. Its great also to reduce the overall load the Operating System puts on your brain so you can have more time to invest in more useful stuff like programming.

windows-maker-increase-performance-of-work-with-your-computer-howto-wmaker-screenshot

After all simplicity in Operating System is a key for an increased productivity with your computer.
Besides that stability of Window Maker is much better when compared to GNOME and GNOME 2 fork MATE graphical environment which nowadays in my opinion is becoming even more buggy than it used to be some years ago.

Below is how Window Makers site describes Window Maker:

"Window Maker is an X11 window manager originally designed to provide integration support for the GNUstep Desktop Environment. In every way possible, it reproduces the elegant look and feel of the NEXTSTEP user interface. It is fast, feature rich, easy to configure, and easy to use. It is also free software, with contributions being made by programmers from around the world.

Window Maker has a stable user interface since many years and comes with a powerful GUI configuration editor called WPrefs, which removes the need to edit text-based config files by hand. It supports running dockapps which make everyday tasks such as monitoring system performance and battery usage, mounting devices or connecting to the internet very easy. Please see the features section for more specifics on what Window Maker can do, and how it compares with other popular window managers."

Window Maker is bundled with a number of useful applications which gives ability to put Dock applets easily for easily intearcive desktop update of current Weather Report, Monitoring Network Traffic, TV Player (video4linux), laptop battery info dock, CD player and Volume control management app, text editor, pdf viewer, integrated Mail application, Calculator, RSS Reader, GNUStep games and much useful things to customize from the desktop resembling many of the basic features any other graphical environment such as GNOME / KDE Provides.

The User Interface (UI) of Window Maker is highly configurable with an integrated WMaker tool called

WPrefs

Why-dont-you-use-Wmaker-for-better-desktop-performance-Windowmaker_colour_preferences

All generated settings from WPrefs (Window Maker Prefernces) GUI tool are to be stored in a plaintext file:
 

~/GNUstep/Defaults/WMRootMenu

All Wmaker configurations are stored inside ~/GNUstep/ (Your user home GNUStep), so if you're to become its user sooner or later you will have to get acquired to it.

Wmaker is very minimalist and the performance is killing so Window Maker is perhaps the number one choice Graphical Environment to use on Old Computers with Linux and BSD.

Below is a full list of all packages installed on my Debian GNU / Linux that provides WMaker / GNUStep great functionalities:

root@jericho:/home/hipo# dpkg -l |grep -i wmaker; dpkg -l |grep -i gnustep
ii  wmaker                                        0.95.8-2                             amd64        NeXTSTEP-like window manager for X
ii  wmaker-common                                 0.95.8-2                             all          Window Maker – Architecture independent files
ii  wmbattery                                     2.50-1+b1                            amd64        display laptop battery info, dockable in WindowMaker
ii  wmcdplay                                      1.1-2+b1                             amd64        CD player based on ascd designed for WindowMaker
ii  wmifs                                         1.8-1                                amd64        WindowMaker dock app for monitoring network traffic
ii  wmnut                                         0.66-1                               amd64        WindowMaker dock app that displays UPS statistics from NUT's upsd
ii  wmpuzzle                                      0.5.2-2+b1                           amd64        WindowMaker dock app 4×4 puzzle
ii  wmrack                                        1.4-5+b1                             amd64        Combined CD Player + Mixer designed for WindowMaker
ii  wmtv                                          0.6.6-1                              amd64        Dockable video4linux TV player for WindowMaker
ii  wmweather                                     2.4.6-2+b1                           amd64        WindowMaker dockapp that shows your current weather
ii  wmweather+                                    2.15-1.1+b2                          amd64        WindowMaker dock app that shows your current weather
ii  addressmanager.app                            0.4.8-2+b2                           amd64        Personal Address Manager for GNUstep
ii  agenda.app                                    0.42.2-1+b7                          amd64        Calendar manager for GNUstep
ii  charmap.app                                   0.3~rc1-3                            amd64        Character map for GNUstep
ii  charmap.app-common                            0.3~rc1-3                            all          Character map for GNUstep (arch-independent files)
ii  cynthiune.app                                 1.0.0-1+b4                           amd64        Music player for GNUstep
ii  dictionaryreader.app                          0+20080616+dfsg-2+b6                 amd64        Dict client for GNUstep
ii  edenmath.app                                  1.1.1a-7.1+b1                        amd64        Scientific calculator for GNUstep
ii  gnumail.app                                   1.2.2-1.1                            amd64        Mail client for GNUstep
ii  gnumail.app-common                            1.2.2-1.1                            all          Mail client for GNUstep (common files)
ii  gnustep                                       7.8                                  all          User applications for the GNUstep Environment
ii  gnustep-back-common                           0.25.0-2                             amd64        GNUstep GUI Backend – common files
ii  gnustep-back0.25                              0.25.0-2                             all          GNUstep GUI Backend
ii  gnustep-back0.25-cairo                        0.25.0-2                             amd64        GNUstep GUI Backend (cairo)
ii  gnustep-base-common                           1.24.9-3.1                           all          GNUstep Base library – common files
ii  gnustep-base-doc                              1.24.9-3.1                           all          Documentation for the GNUstep Base Library
ii  gnustep-base-runtime                          1.24.9-3.1                           amd64        GNUstep Base library – daemons and tools
ii  gnustep-common                                2.7.0-1                              amd64        Common files for the core GNUstep environment
ii  gnustep-core-devel                            7.8                                  all          GNUstep Development Environment — core libraries
ii  gnustep-core-doc                              7.8                                  all          GNUstep Development Environment — core documentation
ii  gnustep-devel                                 7.8                                  all          GNUstep Development Environment — development tools
ii  gnustep-games                                 7.8                                  all          GNUstep games
ii  gnustep-gui-common                            0.25.0-4                             all          GNUstep GUI Library – common files
ii  gnustep-gui-doc                               0.25.0-4                             all          Documentation for the GNUstep GUI Library
ii  gnustep-gui-runtime                           0.25.0-4+b1                          amd64        GNUstep GUI Library – runtime files
ii  gnustep-icons                                 1.0-5                                all          Several free icons for use with GNUstep and others
ii  gnustep-make                                  2.7.0-1                              all          GNUstep build system
ii  gnustep-make-doc                              2.7.0-1                              all          Documentation for GNUstep Make
ii  gomoku.app                                    1.2.9-2+b2                           amd64        Extended TicTacToe game for GNUstep
ii  gorm.app                                      1.2.23-1                             amd64        Visual Interface Builder for GNUstep
ii  gridlock.app                                  1.10-4+b2                            amd64        Collection of grid-based board games for GNUstep
ii  grr.app                                       1.0-1+b2                             amd64        RSS reader for GNUstep
ii  gworkspace-common                             0.9.3-1                              all          GNUstep Workspace Manager – common files
ii  gworkspace.app                                0.9.3-1+b2                           amd64        GNUstep Workspace Manager
ii  helpviewer.app                                0.3-8+b3                             amd64        Online help viewer for GNUstep programs
ii  libaddresses0                                 0.4.8-2+b2                           amd64        Database API backend framework for GNUstep (library files)
ii  libaddressview0                               0.4.8-2+b2                           amd64        Address display/edit framework for GNUstep (library files)
ii  libgnustep-base-dev                           1.24.9-3.1                           amd64        GNUstep Base header files and development libraries
ii  libgnustep-base1.24                           1.24.9-3.1                           amd64        GNUstep Base library
ii  libgnustep-gui-dev                            0.25.0-4+b1                          amd64        GNUstep GUI header files and static libraries
ii  libgnustep-gui0.25                            0.25.0-4+b1                          amd64        GNUstep GUI Library
ii  libpantomime1.2                               1.2.2+dfsg1-1                        amd64        GNUstep framework for mail handling (runtime library)
ii  libpopplerkit0                                0.0.20051227svn-7.1+b9               amd64        GNUstep framework for rendering PDF content (library files)
ii  libpreferencepanes1                           1.2.0-2+b2                           amd64        GNUstep preferences library – runtime library
ii  librenaissance0                               0.9.0-4+b6                           amd64        GNUstep GUI Framework – library files
ii  librenaissance0-dev                           0.9.0-4+b6                           amd64        GNUstep GUI Framework – development files
ii  librsskit0d                                   0.4-1                                amd64        GNUstep RSS framework (runtime library)
ii  mknfonts.tool                                 0.5-11+b5                            amd64        Create nfont packages for GNUstep
ii  price.app                                     1.3.0-1                              amd64        Image filtering and manipulation using GNUstep
ii  projectcenter.app                             0.6.2-1                              amd64        IDE for GNUstep Development
ii  renaissance-doc                               0.9.0-4                              all          GNUstep GUI Framework – documentation
ii  systempreferences.app                         1.2.0-2+b2                           amd64        GNUstep preferences application
ii  terminal.app                                  0.9.8.1-1                            amd64        Terminal Emulator for GNUstep
ii  textedit.app                                  4.0+20061029-3.5+b1                  amd64        Text editor for GNUstep
ii  viewpdf.app                                   1:0.2dfsg1-5+b2                      amd64        Portable Document Format (PDF) viewer for GNUstep
ii  zipper.app                                    1.5-1+b2                             amd64        Archive manager for GNUstep

Well yes it is true Window Maker is not a spoon for every mouth, those who want to have more confortable desktop environment better look out at other options as Window Maker is Unix / Linux graphical environment that fits better hackers, computer developers and system administrators.

Anyhow if you have some old family member that has to use an old computer architecture and the person is only to use mainly just browser to check email, youtube and basic surfing then Wmaker will be a great choice as it will consume little CPU and Memory much less than the heavy and computer resources sucking GNOME and KDE.

I've historically used Wmaker also with its teminal emulator rxvt (VT102 terminal emulator for the X Windows System) which is a kinda of improved version of xterm (the default terminal program bundled with Xorg server), but for those who are already used to Gnome Terminal nice tabs perhaps that would be not the terminal of choice.

rxvt was build to match well the look and feel of AfterStep and consequently Wmaker, its scrollbar was aiming to very much resemble NeXTStep style scrollbar

windowmaker-bind-run-application-to-make-alt-f2-work-like-in-gnome

Most "custom" shortcuts are used to launch specific applications. To add your own keyboard shortcut for an application, go to the "Applications Menu Definition" panel in the Preferences app.  Select the application item in the menu for which you want to create a shortcut, then use the "capture" button to capture the keystrokes you want to assign to that item.  In the screenshot, I've assigned Mod1 + W to open Firefox.

Above  screenshot shows how to map the Run Application keyboard bind to behave like GNOME Run application ALT + F2

window-maker-run-command-like-gnome-run-screenshot-gnu-linux-unix-freebsd

Customizing background of Window Maker

Because WMaker is so simple made and targetting more of a developer audience for use it doesn't have a special graphical interaface to set a Background if you like so, but instead you need to use a wmsetbg command to do so:
 

wmsetbg -s -u filename.jpg

 

WMSetBG command stands for WindowMaker Set Background


If you're too lazy to install and start configuring wmaker, there is a Window Maker LiveCD, you can run Window Maker through LiveCD in Virtual Machine such as VirtualBox to get feeling what you're about to get if you install and start using Wmaker on your Computer.

window-maker-livecd-screenshot-synaptic+wprefs
 

Well at first with Window Maker you might feel confused and quickly irritating missing the already established way to work with your computer, but that's just for a starter sooner you will realize, that for using a limited number of applications for work wmaker, makes you much more efficient. Moreover using your computer with Wmaker can rewire your brain circuits to think a little bit different.

Once you switched to Window Maker you will likely want to have a graphical option to connect to Wireless Networks especially if you're using Wmaker on a notebook it is convenient to not always manually do scan for networks with
 

Iwlscan


commad and use wpasupplicant command to connect instead you can just install wicd and stop default Gnome Network Manager (called Network Manager), you can do so by running as root:
 

service network-manager stop
apt-get install wicd wicd-gtk
service wicd start
wicd-gtk &

 

How to turn keyboard backlight on GNU / Linux, keyboard no backlight solution

Friday, October 20th, 2017

how-to-make-CM_Storm_Devastator-keyboard_backlight-work-on-linux-enabled-disable-keyboard-glowing-gnu-linux

If you're a GNU / Linux user and you happen to buy a backlighted keyboard, some nice new laptop whose keyboard supports the more and more modern keyboard growing or if you happen to install a GNU / Linux for a Gamer friend no matter the Linux distribution, you might encounter sometimes  problem even in major Linux distributions Debian / Ubuntu / Mint / Fedora with keyboard backlight not working.

Lets say you buy a Devastator II backlighted keyboard or any other modern keyboard you plug it into the Linux machine and there is no nice blinking light coming out of the keyboard, all the joy is gone yes I know. The free software coolness would have been even more grandiose if your keyboard was shiny and glowing in color / colors 🙂

But wait, there is hope for your joy to be made complete.

To make the keyboard backlight switch on Just issue commands:

 

xmodmap -e 'add mod3 = Screen_Lock'

 

# Turn on the keyboard bright lamps
xset led on

# Turns off the keyboard bright lamps
xset led off


If you want to make the keyboard backlight be enabled permanent the easiest solution is to

– add the 3 command lines to /etc/rc.local

E.g. to do so open /etc/rc.local and before exit 0 command just add the lines:

 

vim /etc/rc.local

 

xmodmap -e 'add mod3 = Screen_Lock'

# Turn on the keyboard bright lamps
xset led on

# Turns off the keyboard bright lamps
xset led off


If you prefer to have the keyboard colorful backlight enable and disabled from X environment on lets say GNOME , here is how to make yourself an icon that enabled and disables the colors.

That's handy because at day time it is a kind of meaningless for the keyboard to glow.

Here is the shell script:

#!/bin/bash
sleep 1
xset led 3
xmodmap -e 'add mod3 = Scroll_Lock'


I saved it as /home/hipo/scripts/backlight.sh

(don't forget to make it executable!, to do so run):

 

chmod +x /home/hipo/scripts/backlight.sh


Then create  the .desktop file at /etc/xdg/autostart/backlight.desktop so that it runs the new shell script, like so:

[Desktop Entry]
Type=Application
Name=Devastator Backlight
Exec=/home/hipo/scripts/backlight.sh
Icon=system-run
X-GNOME-Autostart-enabled=true

Fix dosbox – setting: cycles=auto. If the game runs too fast try a fixed cycles amount in DOSBox’s options. Exit to error: DRC64:Unhandled memory reference

Thursday, October 12th, 2017

fix-dosbox-error-setting-cycles-auto-game-runs-too-fast-exit-err-drc64-unhandled-memory-reference

I've recently installed Debian GNU / Linux 9.1 Stretch and on Ubuntu 16.10 Yakkety Yak and as an old school true gamer addict decided to play some games to recall the good old memories from the past of the glorious DOS games times, when all was simple people was real and there was no terrible people dividers such as Facebook  / GooglePlus, no skype fuzzy craziness and no people watching all time at their mobile smart phones like zoombies .

Well anyways, so I wanted to play my favourite DOS games Terminal Velocity, StarGunner, Raptor, Heroes of Might and Magic 2, Doom II, Duke 3d etc. etc. the list goes on and on – BTW What's your favourite old school DOS Game??

So I issues in Terminal:

$ dosbox TV.EXE

DOSBox version 0.74
Copyright 2002-2010 DOSBox Team, published under GNU GPL.

CONFIG:Loading primary settings from config file /home/zetathon/.dosbox/dosbox-0.74.conf
MIXER:Got different values from SDL: freq 44100, blocksize 512
ALSA:Can't subscribe to MIDI port (65:0) nor (17:0)
MIDI:Opened device:none
DOSBox switched to max cycles, because of the setting: cycles=auto. If    the game runs too fast try a fixed cycles amount in DOSBox's options.
Exit to error: DRC64:Unhandled memory reference

 

So what is the solution to  Exit to error: DRC64:Unhandled memory reference
error and why it happens?

Well, as the error clearly states the whole problem
comes from a default dosbox dos emulator configuration, that's the
setting:
 

cycles=auto


Perhaps the CPU beat of a Core I7 CPUs is too strong for some of the old games which are expecting a slower PC with less memory that's why the exception

Exit to Error: DRC64:Unhandled memory reference
is spit out by Dosemu.

So how to solve DRC64:Unhandled memory reference dosemu error?

By default DOSBOX places its configuration at  Linux / BSD / *nix-es at home folder /dosbox – e.g. ~/.dosbox/ the naming of dosbox.conf might differ according to dosbox version and the respective Linux / BSD distro, on Debian and Ubuntu Linux usually the naming includes a version number.

On Debian 9 Strecth Linux dosbox config is at ~/.dosbox/dosbox-0.74.conf

Edit the file
 

$ vim ~/.dosbox/dosbox-0.74.conf


and change inside the value for:

 

 

 

core=auto

to

core=normal

Then give dosbox with the erroring game another try, it worked for me
for me and everything seemed to run fine.

I've only run a handful of games but so far it seems to be working well.

If it does work but performance is degraded and tooks a huch hit on Gameplay you better try to substitute
 

core=normal

to
 

core=simple


AND HOORAY IT WORKS AGAIN! THE GAME RUN SUCCESSFULLY JOY TO THE WORLD! 🙂

Enable printing from Windows and Macs remotely through Linux Print server – Share Brother Printer DCP-1610W with Linux CUPS and Samba Windows Share

Thursday, March 23rd, 2017

Brother-Printer-model-DCP-1610W-printer-scanner-and-copier-in-one-picture
I've recently bought a new Printer model Brother DCP 1610W and as in my home I have already a small Linux router and a web server where this blog and a couple of other websites runs and I need multiple PC / notebook / mobile phone enabled people to print on the Printer easily pretty much like a Printing server for a Small Office environment.

To do that of course I needed it configured to be accessible remotely for print via LAN and Wireless network. The task is not a complex one and printing remotely over the network is a standard thing many company organizations / universities and univerities does for quite some time and hence nowadays most printers are network connect ready so you just have to place them inside your home or corporate network and use the time to configure them via their web configuration interface or even some have their own embedded wifi adapter, as well as many printers nowdays can even be ready to print directly by just connecting the Printer to the Wi-Fi network and installing its drivers on a Win host.

Anyhow the most common way for both home printer configurations and corporate I'm aware of still is to Share the printer via Windows Server or Win Server Domain so anyone connected to the Network to be able to Add the printer via Winblows.

In the case i'm going to describe below my home the Wi-Fi router is connected to an 5 Port Network Switch (HUB) which on its hand is connected to the Linux router which serves multiple things (a Linux router, a hosting server (web server and a database server hosted, a mail server, traffic proxy server, a firewall and a NAT router), I decided to Share the printer to Wi-Fi connected and LAN clients directly switched via an UTP cable to the switch by using the good old Linux Samba Sharing server.

I did not actually do that for a really long time hence before I started I did some quick research to get an idea on the general steps to partake to succeed in Sharing the Printer over the network of this Debian's Wiki SystemPrinting Guide was mostly helpful.

 

1. Downloading and Installing necessery Brother Printer deb packages
 

A small remark to make here is my Linux server is running Debian GNU / Linux and hence this article is giving details on how Printer can be Shared on Debian though a minor adaptation of the article should make it possible to install also on any RHEL / CentOS / SuSE etc. Redhat based RPM Linux distribution.)

First step to do is to download Brother printer vendor provided drivers as of moment of writting this article they're here

To download the drivers get the proper links and use wget or curl to download all the necessery .deb archives in lets say in /root/brother-printer-drivers e.g. before that create the folder with:
 

root@linux:/root# mkdir /root/brother-printer-drivers

Also it might be helpful for those who need some other Brother Printer Linux driver complete list of Brother Printer all Linux drivers as of time of writting this post is found on this URL here

Next you need to install following Brother printer driver deb packages brscan-skey brscan4 dcp1610wcupswrapper dcp1610wlpr

root@linux:/root# cd brother-printer-drivers
root@linux:/root/brother-printer-drivers# dpkg -i –force-all brscan-skey-0.2.4-1.amd64.deb

root@linux:/root# dpkg -i –force-all brscan4-0.4.4-1.amd64.deb

root@linux:/root# dpkg -i –force-all dcp1610wcupswrapper-3.0.1-1.i386.deb

root@linux:/root# dpkg -i –force-all dcp1610wlpr-3.0.1-1.i386.deb

root@linux/root# cd  ../


Once installed dpkg -l should show like so:
 

root@linux:/root# dpkg -l |grep -i brother
ii  brscan-skey                                0.2.4-1                      Brother Linux scanner S-KEY tool
ii  brscan4                                    0.4.4-1                      Brother Scanner Driver
ii  dcp1610wcupswrapper                        3.0.1-1                      Brother DCP-1610W CUPS wrapper driver
ii  dcp1610wlpr                                3.0.1-1                      Brother DCP-1610W LPR driver

Brother's vendor provided packages will install drivers under /opt/brother
 

root@linux:/root# ls -al /opt/brother/
общо 16
drwxr-xr-x 4 root root 4096 яну 26 13:58 ./
drwxr-xr-x 3 root root 4096 яну 26 13:55 ../
drwxr-xr-x 3 root root 4096 яну 26 13:58 Printers/
drwxr-xr-x 4 root root 4096 яну 26 13:58 scanner/

 

2. Installing CUPS Printing Service and related Filters and Postscript packages necessery for PDF processing on CUPS server side

 

root@linux:/root#  apt-get install –yes cups cups-client cups-common cups-pdf cups-ppdc foomatic-db foomatic-db-engine foomatic-filters foomatic-filters-ppds openprinting-ppds lpr hp-ppd hpijs cups-pdf ghostscript-cups

Your printing should work normally without cups-pdf and ghostscript-cups packages installed but I install them just in case if PDF processing is problematic you can skip that.

It is also useful to install sane and sane-utils packages if you're going to use the brother's scanner capabilities.

root@linux:/root# apt-get install –yes sane sane-utils

Note that considering that all packages installed fine and the CUPS service is running, this should have set a proper printer into /etc/printcap a short database used to describe printers. printcap file is being used by UNIX's spooling system and allows you to dynamic addition and deletion of printers, for Linux / *Nix hosts which have more than one printer connected and added in CUPs records for the various printer goes there.
With a single Brother DCP-1610W Printer like my case is you should have records similar to these:

root@linux:~/brother-printer-drivers# cat /etc/printcap
DCP1610W:\
        :mx=0:\
        :sd=/var/spool/lpd/DCP1610W:\
        :sh:\
        :lp=/dev/usb/lp0:\
        :if=/opt/brother/Printers/DCP1610W/lpd/filter_DCP1610W:

 

 

3. Adding a Printer in CUPS the easy way through CUPS Printing System Web Interface

 

CUPS has a nice web interface for setting up and administering printers and print queues.

Below is a selfexplanatory screenshot of Add Printer screen 

add-a-new-printer-cups-web-admin-interface-screenshot-in-a-firefox-browser  .

 

Use your favourite browser (Firefox, Opera, Chromium, lynx, elinks – yes the great news is console / terminal browsers are also supported well by cups web iface) to display interface and add a printer via the Administration screen. If you are asked for a username and password see here.

cups-web-admin-interface-accessed-in-browser-listing-brother-dcp1610w-printer-screenshot

There are three sections. The first is for local printers; that is, printers which are usually attached to the machine you are using. These are very often printers using a USB connection but can be parallel or serial port printers.

Adding a USB printer is a common occurance and one should automatically be detected as a local printer and a URI (Unified Resource Indicator) for its connection displayed on the next page.
 

The Other Network Printers section requires you to specify the destination for the remote print queue/printer, which could be on the local network or many kilometres away. AppSocket is almost always available on a network printer and other devices and requires only the IP address of the printer and a port number. An Internet Printing Protocol (IPP) URI is the preferrred choice for connecting to another CUPS server because it is CUPS' native protocol. ipp14 is the ipp backend from CUPS 1.4 and Debian-specific. It is provided because some devices do not work with the current ipp backend, which has a stricter adherence to the IPP standard. A Line Printer Daemon (LPD) URI could be considered if the remote printing service does not support IPP satisfactorily or at all. As before, when a remote print queue is doing the filtering choose RAW as the Make/Manufacturer.

 

4. Printer Status and Control testing whether CUPS printing is up and running


 

Once cups is installed and hopefully up and running you should see the cups process up and running to check it do:

root@linux:/root# /etc/init.d/cups status; ps axuwwf|grep -i cups|grep -v grep
Status of Common Unix Printing System: cupsd is running.
root      2815  0.0  0.0  75364  2912 ?        Ss   Mar17   0:00 /usr/sbin/cupsd -C /etc/cups/cupsd.conf

To get some further testing you can also use lpstat command and should get ouput similar to belows:
 

root@linux:/root# lpstat -t
scheduler is running
no system default destination
device for DCP1610W: usb://Brother/DCP-1610W%20series
DCP1610W accepting requests since Fri Mar 17 23:03:37 2017
printer DCP1610W disabled since Fri Mar 17 23:03:37 2017 –
        Unplugged or turned off

At the moment of issuing above command it shows printer is disabled because of moment of execution the printer was turned off for a while cause I was not needing it you should get usually an output of enabled and ready to print.

lpstat is also about to report whether a queue is accepting jobs and what is yet to be printed you can do

 

 

5. Install and Configure Samba Sharing Server on the Linux server


 

You can setup CUPS to allow Windows machines to print to a CUPS server using an http address.

First, install the samba package. When you are asked to use WINS, say yes.

root@linux:/root#  apt-get install samba

Next you might want to set setup your /etc/cups/cupsd.conf file by default CUPS would listen to LPD's port 631 if you don't have a strong firewall isolating you from the Internet on port 631 you might want to change that port to another one lets say to Port 49651.


I personally prefer keep the default port 631 and do use a robust firewall. If you want to change it modify config to something like:

# Our private connection we listen to Listen *:49651 # Allow machines on local network to use printers <Location /printers> Order allow,deny Allow 192.168.0.* Allow 192.168.1.* </Location>

If you like to filter access to CUPs daemon to receive Printing requests to be originating only from the local network place in smb.conf also something with your private network ranges:

# Allow machines on local network to use printers

<Location /printers>
Order allow,deny
Allow 192.168.0.*
Allow 192.168.1.*
Allow 192.168.2.*
</Location>
<Location />
  # Allow remote administration…
  Order allow,deny
##  Allow all
Allow 192.168.0.*
Allow 192.168.1.*
Allow 192.168.2.*
</Location>
<Location />
  # Allow remote administration…
  Order allow,deny
##  Allow all
Allow 192.168.0.*
Allow 192.168.1.*
Allow 192.168.2.*
</Location>
<Location /admin>
  # Allow remote administration…
  Order allow,deny
##  Allow all
Allow 192.168.0.*
Allow 192.168.1.*
Allow 192.168.2.*
</Location>

 

This will listen on port 49651 from any network. You may use some other port number besides 631. Note that the dynamic and/or private ports as specified by the IANA are in the range 49152 through 65535. Also, this will only allow computers from the local network to print to the CUPS printers.
 

6. Use CUPS Printing server to print over the network directly

 

 

Next you need to restart the CUPS daemon once again as it will be used for samba printing
 


# service cups restart


Now on each Windows machine, Choose that you want to install a network printer and that you want to install a printer on the Internet or home/office network. The URL you will use should be smth like:
 


http://<cups_server_hostname>:49651/printers/DCP1610W

 

Lastly, select the Brother downloaded from Internet or the one that's available on the Install CD, for any other vendor printer if it is lets say HP Printer or Canon to install use the respective provided driver or as a last resort use the Generic section driver labeled MS Publisher Color Printer.

 

 

7. Configure Samba to Share CUPS network enabled printer


I've done a minor changes in default installed /etc/samba/smb.conf to make the printer accessible from The Samba server here is the main things to consider changing:
 

# Change this to the workgroup/NT-domain name your Samba server will part of
   workgroup = WORKGROUP

#   security = user
security = share

[printers]
   comment = PC Freak Printer
   browseable = yes
   path = /var/spool/samba
   printable = yes
   guest ok = yes
   read only = yes
   create mask = 0700

# Windows clients look for this share name as a source of downloadable
# printer drivers
[print$]
   comment = Printer Drivers
   path = /var/lib/samba/printers
   browseable = yes
   read only = yes
   guest ok = yes


Next restart Samba server to make the new setting take affect:
 

root@linux:/# /etc/init.d/samba restart
Stopping Samba daemons: nmbd smbd.
Starting Samba daemons: nmbd smbd.
root@linux:/# ps axu|grep -E "smb|nmb"
root     21887  0.0  0.0 169588  1904 ?        Ss   16:53   0:00 /usr/sbin/nmbd -D
root     21892  0.0  0.0 197560  3272 ?        Ss   16:53   0:00 /usr/sbin/smbd -D
root     21894  0.0  0.0 197560  1564 ?        S    16:53   0:00 /usr/sbin/smbd -D
root     21899  0.0  0.0 112368   840 pts/6    S+   16:53   0:00 grep -E smb|nmb

root@linux:/#

Complete current smb.conf configuration I use to make the Brother Printer DCP 1610W accesible via network share is here

This section needs updating as you can setup print server via samba print sharing just by uploading drivers.

When printing to windows printers in an NT domain using SMB the Device URI should use similar to:

 

smb://username:password@domain/server/printername

 

This allows Samba to authenticate against a domain controller for acces to the printer queue.

In my case as you can see in below smb.conf configuration I've configured Samba security = share which will allow anyone to access the samba server without authentication so you can omit  username:password@ part

One good way to determine the printername  (in case you are not sure of) is to use smbclient command line tool. computername refers to the name of the machine that shares the printer:

 

smbclient -L copmputername


computername is the name of the samba server machine or its IP address


E.g.
 

hipo@linux:~$ smbclient -L //192.168.0.1/
Enter Attitude's password:
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.5.6]

        Sharename       Type      Comment
        ———       —-      ——-
        print$          Disk      Printer Drivers
        IPC$            IPC       IPC Service (pcfreak server)
        DCP1610W        Printer   DCP1610W
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.5.6]

        Server               Comment
        ———            ——-
        PCFREAK              pcfreak server

        Workgroup            Master
        ———            ——-
        WORKGROUP            WORKGROUP


Check the ouput for entries of Type "Printer":


The resulting (Linux / Mac OS) Samba Share access URL from the output above would be

smb://192.168.0.1/DCP1610W


 

 

8. Adding Printer to your Windows machines to enable actual Remote Samba Sharing printing

Assuming you already know the Printer share name, here is what I needed to do to have the Printer Added on each of Windows Desktop PCs and Notebooks

 

Control Panel -> Devices and Printers -> Add a printer -> (Add a Network wireless or bluetooth printer)

Then instead of Searching the printer to click on:

The printer that I wasn't listed

add-samba-network-share-brother-dcp-1610w-printer-to-windows-7-machine-no-printer-found-from-add-printer

Then type in the URL or IP (as in my case) leading to the printer as you see in below screenshot:

 

9. Printer Samba Sharing Using Macintosh notebook as the Client and Debian as the Server

 

1. Assuming you have cups to set up the printer on Debian as described above.

2. On the Mac (OS X 10.4+) start Print and Fax from System Preferences. Use the + button to add a printer.

3. Look first in the "Default" tab. If the automagic printer-sharing has worked, and your Mac is connected to the local network properly, then the Debian-based printer should already be visible in the list.

Just select it and use the recommended print driver. If you face problems you can try to play with
Gutenprint Printer drivers to make it printing.

4. If your printer is not visible in the Default tab, then try adding it on the "IP" tab.

Pick IPP as the protocol, give the plain IP address of the server in the address box (in my case that's 192.168.0.1, and in the Queue box put
"printers/DCP1610W

Put whatever helps you identify the printer in the Name and Location boxes (fields), and choose a printer driver than matches Brother DCP1610W or with another printer installed whatever you used to set up the printer on Debian .
Finally Pray that God help you to make it work and press the Add button. If you prayed honestly and repenting for your sins perhaps you will have mercy and it will work, of course if not try to research online on how to fix it further by God's grace.

Note that making printing work on Mac is a little bit of tricky and it might cause you some extra effort / nerves to complete.

 

10. Some other Useful maintanance commands you might need in future CUPS Printer queue jobs maintance

 

For displaying or setting print queue options and defaults:

lpoptions -p <print_queue_name> -l

Stopping and starting print queues. Acceptance and rejection of jobs sent to a destination:
 

cupsdisable <print_queue_name>
cupsenable <print_queue_name>
cupsaccept <print_queue_name>
cupsreject <print_queue_name>


To Cancel all jobs on a destination and additionally delete job data files:

cancel -a <print_queue_name>
cancel -a -x <print_queue_name>

That's all folks, Thanks God the printer should be working. Enjoy!

No space left on device with free disk space / Why no space left on device while there is plenty of disk space on drive – Running out of Inodes

Tuesday, November 17th, 2015

no_space_left-on-device-while-there-is-disk-space-running-out-of-file-inodes-unix_linux_file_system_diagram.gif

 

On one of the servers, I'm administrating the websites started showing some Mysql database table corrup errors like:
 

 

Table './database_name/site_news_list_com' is marked as crashed and last (automatic?) repair failed

The server is using Oracle MySQL server community stable edition on Debian GNU / Linux 6.0, so I first thought during work the server crashed either due to some bug issue in MySQL or it crashed due to some PHP cron job that did something messy. Thus to solve the crashed tables, tried using mysqlcheck tool which helped pretty fine, at many times whether there were database / table corruptions. I've run the following set of mysqlcheck commands with root (superuser) in a bash shell after logging in through SSH:

:

server:~# /usr/bin/mysqlcheck –defaults-extra-file=/etc/mysql/debian.cnf \–check –all-databases -u root -p`grep -i password /root/.my.cnf |sed -e 's#password=##g'`>> /var/log/cronwork.log
server:~# /usr/bin/mysqlcheck –defaults-extra-file=/etc/mysql/debian.cnf –analyze –all-databases -u root -p`grep -i password /root/.my.cnf |sed -e 's#password=##g'`>> /var/log/cronwork.log
server:~# /usr/bin/mysqlcheck –defaults-extra-file=/etc/mysql/debian.cnf \–auto-repair –optimize –all-databases -u root -p`grep -i password /root/.my.cnf |sed -e 's#password=##g'`>> /var/log/cronwork.log
server:~# /usr/bin/mysqlcheck –defaults-extra-file=/etc/mysql/debian.cnf \–optimize –all-databases -u root -p`grep -i password /root/.my.cnf |sed -e 's#password=##g'`>> /var/log/cronwork.log


In order for above commands to work, I've created the /root/.my.cnf containing my root (mysql CLI) mysql username and password, e.g. file has content like below:

 

[client]
user=root
password=MySecretPassword8821238

 

Btw a good note here is its generally a good idea (if you want to have consistent mysql databases) to automatically execute via a cron job 2 times a month, I've in root cronjob the following:

 

crontab -u root -l |grep -i mysqlcheck
04 06 5,10,15,20,25,1 * * /usr/bin/mysqlcheck –defaults-extra-file=/etc/mysql/debian.cnf \–check –all-databases –silent -u root -p`grep -i password /root/.my.cnf |sed -e 's#password=##g'`>> /var/log/cronwork.log 07 06 5,10,15,20,25,1 * * /usr/bin/mysqlcheck –defaults-extra-file=/etc/mysql/debian.cnf –analyze –all-databases –silent -u root -p`grep -i password /root/.my.cnf |sed -e 's#password=##g'`>> /var/log/cronwork.log 12 06 5,10,15,20,25,1 * * /usr/bin/mysqlcheck –defaults-extra-file=/etc/mysql/debian.cnf \–auto-repair –optimize –all-databases –silent -u root -p`grep -i password /root/.my.cnf |sed -e 's#password=##g'`>> /var/log/cronwork.log 17 06 5,10,15,20,25,1 * * /usr/bin/mysqlcheck –defaults-extra-file=/etc/mysql/debian.cnf \–optimize –all-databases –silent -u root -p`grep -i password /root/.my.cnf |sed -e 's#password=##g'`>> /var/log/cronwork.log


Strangely I got a lot of errors that some .MYI / .MYD .frm temp files, necessery for the mysql tables recovery can't be written inside /home/mysql/database_name

That was pretty weird and I thought there might be some issues with permissions, causing the inability to write, due to some bug or something so I went straight and checked /home/mysql/database_name permissions, e.g.::

 

server:/home/mysql/database_name# ls -ld soccerfame
drwx—— 2 mysql mysql 36864 Nov 17 12:00 soccerfame
server:/home/mysql/database_name# ls -al1|head -n 10
total 1979012
drwx—— 2 mysql mysql 36864 Nov 17 12:00 .
drwx—— 36 mysql mysql 4096 Nov 17 11:12 ..
-rw-rw—- 1 mysql mysql 8712 Nov 17 10:26 1_campaigns_diez.frm
-rw-rw—- 1 mysql mysql 14672 Jul 8 18:57 1_campaigns_diez.MYD
-rw-rw—- 1 mysql mysql 1024 Nov 17 11:38 1_campaigns_diez.MYI
-rw-rw—- 1 mysql mysql 8938 Nov 17 10:26 1_campaigns.frm
-rw-rw—- 1 mysql mysql 8738 Nov 17 10:26 1_campaigns_logs.frm
-rw-rw—- 1 mysql mysql 883404 Nov 16 22:01 1_campaigns_logs.MYD
-rw-rw—- 1 mysql mysql 330752 Nov 17 11:38 1_campaigns_logs.MYI


As seen from above output, all was perfect with permissions, so it should have been something else, so I decided to try to create a random file with touch command inside /home/mysql/database_name directory:

 

touch /home/mysql/database_name/somefile-to-test-writtability.txt touch: cannot touch ‘/scr1/data/somefile-to-test-writtability.txt‘: No space left on device


Then logically I thought the /home/mysql/ mounted ext4 partition got filled, because of crashed SQL database or a bug thus, checked with disk free command df whether there is enough space on server:

server:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/md1 20G 7.6G 11G 42% /
udev 10M 0 10M 0% /dev
tmpfs 13G 1.3G 12G 10% /run
tmpfs 32G 0 32G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 32G 0 32G 0% /sys/fs/cgroup
/dev/md2 256G 134G 110G 55% /home

Well that's weird? Obviously only 55% of available disk space is used and available 134G which was more than enough so I got totally puzzled why, files can't be written.

Then very logically, I thought it might be that /home directory has remounted as read only, because the SSD memory disk on server is failing and checked for errors in dmesg, i.e.:

 

server:~# dmesg|grep -i error


Also checked how exactly was partition mounted, to check whether it is (RO) read-only:

 

server:~# mount -l|grep -i /home
/dev/md2 on /home type ext4 (rw,relatime,discard,data=ordered)


Now everything become even more weirder, as obviously the disk continued to be claiming no space left on device, while in reality there was plenty of disk space.

Then after running a quick research on the internet for the no space left on device with free disk space, I've come across this great superuser.com thread which let me realize the partition run out of inodes and that's why no new file inodes could be assigned and therefore, the linux kernel is refusing to write the file on ext4 partition.

For those who haven't heard of Linux Partition Inodes here is link to Wikipedia and a quick quote:

 

In a Unix-style file system, the inode is a data structure used to represent a filesystem object, which can be one of various things including a file or a directory. Each inode stores the attributes and disk block location(s) of the filesystem object's data.[1] Filesystem object attributes may include manipulation metadata (e.g. change,[2] access, modify time), as well as owner and permission data (e.g. group-id, user-id, permissions).[3]
Directories are lists of names assigned to inodes. The directory contains an entry for itself, its parent, and each of its children.


Once I understood it is the inodes, I checked how many of them are occupied with cmd:

 

server:~# df -i /home
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/md2 17006592 17006592 0 100% /home


You see, there were 0 (zero) free file inodes on server and that was the reason for no space left on device while there was actually free disk space

To clean up (free) some inodes on partition, first thing I did is to delete all old logs which were inside /home and files I positively know not to be necessery, then to find which directories allocating most innodes used:

 

server:~# find . -xdev -type f | cut -d "/" -f 2 | sort | uniq -c | sort -n


If you're on a regular old fashined IDE Hard Drive and not SSD or you have too much files inside this command will take really long …:

Therefore a better solution might be to frist:

a) Try to find root folders with large inodes count:

for i in /home/*; do echo $i; find $i |wc -l; done
Try to find specific folders:


You should get output like:

 

/home/new_website
606692
/home/common
73
/home/pcfreak
5661
/home/hipo
33
/home/blog
13570
/home/log
123
/home/lost+found
1

b) Then once you know the directory allocating most inodes, run the command again to see the sub-directories with most files (eating) partition innodes:

 

for i in /home/webservice/*; do echo $i; find $i |wc -l; done

 

One usual large folder which could free you some nodes is the linux source headers, but in my case it was simply a lot of tiny old logs being logged on the system for few years in the past without cleaning:

After deleting the log dirs and cache folder in my case /home/new_website/{log,cache}:

server:~# rm -rf /home/new_website/log/*
server:~# rm -rf /home/new_website/cache/*

 

 

a) Then, stopping Apache webserver to check prevent Apache to use MySQl databases while running database repair and restaring MySQL:
 

server:~# /etc/init.d/apache2 stop Restarting MySQL server
..
server:~# /etc/init.d/mysql restart
..


b) And re-issuing MySQL Check / Repair / Optimize database commands:
 

 

mysqlcheck –defaults-extra-file=/etc/mysql/debian.cnf \–check –all-databases -u root -p`grep -i password /root/.my.cnf |sed -e 's#password=##g'`>> /var/log/cronwork.log

mysqlcheck –defaults-extra-file=/etc/mysql/debian.cnf –analyze –all-databases -u root -p`grep -i password /root/.my.cnf |sed -e 's#password=##g'`>> /var/log/cronwork.log

mysqlcheck –defaults-extra-file=/etc/mysql/debian.cnf \–auto-repair –optimize –all-databases -u root -p`grep -i password /root/.my.cnf |sed -e 's#password=##g'`>> /var/log/cronwork.log

mysqlcheck –defaults-extra-file=/etc/mysql/debian.cnf \–optimize –all-databases -u root -p`grep -i password /root/.my.cnf |sed -e 's#password=##g'`>> /var/log/cronwork.log

c) And finally starting the Apache Webserver again:
 

server:~# /etc/init.d/apache2 start


Some innodse got freed up:
 

server:~# df -i /home Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/md2 17006592 16797196 209396 99% /home


And hooray by God's Grace and with help of prayers of The most Holy Theotokos (Virgin) Mary, websites started again !

How to colorize your Mac OS X Terminal – Beautify your Mac OS terminal and proper Page Up / Page Down and Home / End bindings

Thursday, March 19th, 2015


If you're a sysadmin (like me) or a programmer and love working on console most of the time on a recently bought Apple (Mac) PC, probably not like that by default Terminal App lacks nice color highlighting, color highlighly is already standard on Ubuntu / Debian / Mint and many of the streamline Linux distros for years, so it's weird that the shiny Mac lacks that in console 🙂
 I'm not blaming Mac OS developers for shipping by default Mac's console so much greyish as most Mac userbase almost never use terminals, however adding some appearance candy makes my boring digital life much more entertaining.

beautify-add-colors-to-Mac-OSX-default-app-program-add-shiny-clolors-improve-mac-os-x-terminal-screenshot.png

Put in your home directory $HOME/.profile or in .bash_profile file below code:

 

vim ~/.profile
PS1='\[\e[0;33m\]\u\[\e[0m\]@\[\e[0;32m\]\h\[\e[0m\]:\[\e[0;34m\]\w\[\e[0m\]\$ '
export PATH="/opt/local/bin:/opt/local/sbin:$PATH"
export CLICOLOR=1
export LSCOLORS=ExFxBxDxCxegedabagacad
alias ls='ls -GFh'

 

echo "PS1='\[\e[0;33m\]\u\[\e[0m\]@\[\e[0;32m\]\h\[\e[0m\]:\[\e[0;34m\]\w\[\e[0m\]\$ '
export PATH="/opt/local/bin:/opt/local/sbin:$PATH"" >> ~/.profile

echo "export CLICOLOR=1" >> ~/.profile
echo "export LSCOLORS=ExFxBxDxCxegedabagacad" >> ~/.profile
echo "alias ls='ls -GFh'"  >> ~/.profile

 


PS1 with above string do colorize Terminal's default “username@hostname:cwd $” following alias makes by default ls (dir) command to have colors enabled (show files and folders in shiny colors like on GNU / Linux). As you see the ls command perameter -G which actually adds colors is the same like in FreeBSD (since very big part of Mac OS is based on BSD UNIX utils), -F makes directories to be marked with / and -h (stands for human readable).
If you want to enable terminal ls colors for all existing Mac computer users open /etc/profile and (uncomment) / include:

 

export CLICOLOR=1
export LSCOLORS=GxFxCxDxBxegedabagaced

 


If you want to customize further Mac OS's default Terminal App (add different Colorize Theme), change default shell, change default Title, add Transparency, Change Term Encoding etc.  go and check settings in:
 

Terminal -> Settings


Mac-OS-default-Terminal-shell-settings-interface-change-theme-mountain-lion-screenshot
One really annoying thing about Mac OS X terminal for being users is that by default Command + D which is like CTRL + D on a non-Mac PC sends Split Window command, splitting the screen by two,  if you're a new Mac user like me you will have to get used to Command + Shift + D which is the Mac equivalent of regular PC keyboard CTRL + D. Note that it is not possible to move between Splitted screens but instead the upper part of the split screen is just like a buffer where old output from terminal is put and can be used to keep an eye constantly on old content displayed on terminal …
If you're too lazy to edit files and stuff and just want to receive already well configured Terminal which has many of the features of gnome-terminal / konsole which are not there in  Mac's default Terminal App, just download and use iTerm2 (OS X Terminal Replacement)

iterm2-mac-osx-mounta-lion-10.8.5-best-terminal-application-for-mac-OSX-screenshot

Once over with Terminal customizations if you happen to use VI Improved (VIM) text editor as an editor of choice on Mac create at least following .vimrc in your HOME directory
 

$ vim ~/.vimrc

" End
map <C-E> <End>
imap <C-E> <C-O><End>

" Home
map <C-A> <Home>
map <C-A> <C-O><Home>

 


This maps Command + A / Command + E to (emulate) act like normal PC Home / End Keyboard key button, to emulate Page Up / Page Down keys on Mac OS keyboard inside Terminal app use Fn (key) + Up / Down arrows.
To make HOME / END buttons answer to Control + A / E on a Terminal App level:

 

Inside Terminal.app
Open the Preferences window (CMD+,)
Click the Settings tab
Select your current Settings theme, and click on the Keyboard tab
Edit (or Add) the entry for Home
Set Action: to send string to shell:
Set the string to \001 (or press Ctrl+a)
Edit (or Add) the entry for End
Set Action: to send string to shell:
Set the string to \005 (or press Ctrl+e)
Edit (or Add) the entry for Page Up
Set Action: to send string to shell:
Set the string to \033[5~ (copy and paste this in)
Edit (or Add) the entry for Page Down
Set Action: to send string to shell:
Set the string to \033[6~ (copy and paste this in)
Close the settings window.

Fix “tar: Error exit delayed from previous errors” and its cause and solution

Monday, August 18th, 2014

fix-solve-tar-error-delayed-exit-from-previous-errors-tarball-error

tar: Error exit delayed from previous errors

error is a very common error encountered when creating archives (or backing up server configurations / websites / sql binary data). The error is quite unexplanatory and whenever creating files verbose in order to see the files added to archve in "real time" with lets say:

tar -czvf /tmp/filename_backup_date-of-backup.tar.gz /home/websites /home/sql


its pretty hard to track on exactly which file is the backup producing the Error exit delayed from previous errors, this is especially the case whenever adding to archive directories containing millions of tiny few kilobyte sized files. Many novice on uncautious Linux admins , might simply ignore the warning if they're in a hurry / are having excessive work to be done as there will be .tar.gz backup produced and whenever uncompressed most of the files are there and the backup error would seem not of a big issue.

However as backuping files is vital stuff, especially when moving the files from a server to be decomissioned you have to be extra careful and make the backup properly, e.g. figure out the cause of the error, to do so log the full output of tar operations with tee command, like so:

tar -czvf /tmp/filename_backup_date-of-backup.tar.gz /home/websites/ /home/sql | tee /tmp/backup_tar_full_output.log

Then you will have to review the file and lookup for errors with less search string – / (slash) – look for "error" and "permission den" keywords and this should point you to what is causing the error. In cases when millions of files are to be archived, the log might grow really big and hard to process, therefore a much quicker way to understand what's happening is to only log and show in shell standard output last file error with > (shell redirect):
 

tar -czvf /tmp/filename_backup_date-of-backup.tar.gz /home/websites /home/sql > /tmp/backup_failure-cause.log

 

tar: www.ur-website.com-http/2.0.63/conf/tnsnames.ora.20080918: Cannot open: Permission denied
tar: Removing leading `/' from member names

The error indicates clearly the cause of error is lack of Permissions to read the file tnsnames.ora.20080918 so solution is to either grant permissions to non-root user with (chmod / chown) cmds, in my case grant perms to user hipo with which tar is ran, or run again the website backup with superuser, I usually just run with root user to prevent tampering with original permissions, e.g. to solve the error, either:

$ su root
# tar -czvf /tmp/filename_backup_date-of-backup.tar.gz /home/websites /home/sql

Or even better if sudo is installed and user is added to /etc/sudoers file

$ sudo tar -czvf /tmp/filename_backup_date-of-backup.tar.gz /home/websites /home/sql


Though permission errors is the most often reason for:

tar: Error exit delayed from previous errors, you should keep in mind that in some cases the error might be caused due to failing RAID membered disk drive or single hdd failure on systems that are not in some RAID array