Posts Tagged ‘command’

Getting Console and Graphical hardware system information on Linux with cpuinfo, neofetch, CPU-X (CPU-Z Unix alternative), I-nex and inxi

Tuesday, September 17th, 2019

getting-console-information-and-graphical-hardware-system-information-Linux-cpuinfo-neofetch-cpu-x-i-nex-1

Earlier I've wrote extensive article on how to get hardware information on Linux using tools such as dmidecode, hardinfo, lshw, hwinfo, x86info and biosdecode but there are few other hardware reporting tools for Linux worthy to mention that has been there for historical reasons such as cpuinfo as we as some new shiny ones such as neofetch (a terminal / console hardware report tool as well the CPU-X and I-Nex  which is Linux equivalent to the all known almost standard for Windows hardware detection CPU-Z worthy to say few words about.
 

1. cpuinfo

 

Perhaps the most basic tool to give you a brief information about your Processor type (model) number of Cores and Logical Processors is cpuinfo

I remember cpuinfo has been there since the very beginning on almost all Linux distributions's repository, nowadays its popularity of the days when the kings on the Linux OS server scenes were Slackware, Caldera OpenLinux and Redhat 6.0 Linux and Debian 3.0  declined but still for scripting purposes it is handy small proggie.

To install and run it in Debian  / Ubuntu / Mint Linux etc.:

 

aptitude install -y cpuinfo

/usr/bin/cpu-info

 

Linux-get-processor-system-info-in-console-cpu-info

 

2. neofetch

 

The next one worthy to install and check is neofetch (a cross-platform and easy-to-use system information
 command line script that collects your Linux system information and display it on the terminal next to an image, it could be your distributions logo or any ascii art of your choice.)

The cool thing about neofetch is besides being able to identify the System server / desktop hardware parameters, it gives some basic info about number of packages installed on the system, memory free and in use, used kernel and exact type of System (be it Dell PowerEdge Model XX, IBM eSeries Model / HP Proliant Model etc.

neofetch-OS-hardware-information-Linux-ascii-system-info-desktop-notebook

neofetch info generated on my home used Lenovo Thikpad T420

neofetch-OS-hardware-information-Linux-ascii-system-info-pcfreak-home-server
neofetch info from pc-freak.net running current machine

neofetch even supports Mac OS X and Windows OS ! 🙂

To install neofetch on Mac OS X:
 

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"


or via Mac ported packages using brew

brew install neofetch


neofetch-screenshot-from-Mac-OS-X

neofetch is even installable on Windows OS that has the scoop command line installer tool installer manager with below PowerShell code in cmd.exe (Command line):

powershell Set-ExecutionPolicy RemoteSigned -scope CurrentUser
iex (new-object net.webclient).downloadstring('https://get.scoop.sh')
scoop install git
scoop install neofetch

neofetch-microsoft-windows-hardware-command-line-report-tool-screenshot


By the way Scoop was quite a finding for me and it is pretty handy to install plenty of useful command line Linux / UNIX tools, such as curl, wget, git etc. in the same easy straight forward way as a standard yum or apt-get on Windows (without explicitly installing things as GnuWin and CygWin).
 

3. CPU-X graphical user interface hardware report Linux GUI alternative to Windows CPU-Z


The packages for CPU-X are a bit outdated and even though there are rpm packages for Fedora, OpenSuSE and .deb package for Debian for Debian, Ubuntu and ArchLinux (pacman), there is no up to date version for Debian 10 and the package builds distributed for different Linux distros are a bit outdated.

Thus to install CPU-X on any Linux distribution it is perhaps best to use the portable version (static binary) of CPU-X.
It is currently available on https://github.com/X0rg/CPU-X/releases

To install latest portable version of CPU-X

wget https://github.com/X0rg/CPU-X/releases/download/v3.2.4/CPU-X_v3.2.4_portable.tar.gz

mkdir CPU-X
cd CPU-X

tar -zxvvf CPU-X_v3.2.4_portable.tar.gz
-rwxr-xr-x yohan/users 4563032 2019-01-13 22:15 CPU-X_v3.2.4_portable.bsd64
-rwxr-xr-x yohan/users 5484968 2019-01-13 22:15 CPU-X_v3.2.4_portable.linux64

 

cp -rpf CPU-X_v3.2.4_portable.linux64 /usr/local/bin/
ln -sf /usr/local/bin/CPU-X_v3.2.4_portable.linux64 /usr/local/bin/cpu-x


Next run as superuser (root)
 

hipo@jeremiah:~$ su -c 'cpu-x'

 

As seen from below screenshots cpu-x reports a lot of concrete specific hardware data on:

  • Processor
  • Motherboard
  • Memory
  • System
  • Graphic card
  • Performance

cpu-x-cpu-cpu-z-alternative-linux-screenshot-CPU-info

cpu-x-cpu-cpu-z-alternative-linux-screenshot-caches-info

cpu-x-cpu-cpu-z-alternative-linux-screenshot-Motherboard-info

cpu-x-cpu-cpu-z-alternative-linux-screenshot-memory-info

cpu-x-cpu-cpu-z-alternative-linux-screenshot-system-info

cpu-x-cpu-cpu-z-alternative-linux-screenshot-graphics-info

CPU-X can be installed also on FreeBSD very easily by just installing from BSD port tree sysutils/cpu-x/
It is also said to work on other *BSDs, NetBSD, OpenBSD Unixes but I guess this will require a manual compilation based on FreeBSD's port Makefile.

4. I-Nex another GUI alternative to CPU-Z for UNIX / Linux

I-Nex is even more useful for general hardware reporting as it reports many hardware specifications not reported by CPU-X such as Battery type and Model Name  (if the hardware report is on a laptop), info on USB devices slots or plugged USB devices brand and specifications, the available Network devices on the system (MAC Addresses) of each of it, Installed and used drivers on Hard Disk (ATA / SATA / SCSI / SSD), HW Sector size, Logical Block size, HDD Sectors count and other specific Hard Drive data as well as information on available Audio (Sound Blaster) devices (HDA-Intel), used Codecs, loaded kernel ALSA driver, Video card used and most importantly indicators on Processor reported CPU (temperature).

 

To install I-nex

Go to https://launchpad.net/i-nex or any of the mirror links where it resides and install the respective package, in my case, I was doing the installation on Debian Linux, so fetched current latest amd64 package which as of moment of writting this article is i-nex_7.6.0-0-bzr977-20161012-ubuntu16.10.1_amd64.deb , next installed it with dpkg
 

dpkg -i i-nex_7.6.0-0-bzr977-20161012-ubuntu16.10.1_amd64.deb

 

As the package was depending on some other .deb packages, which failed to install to install the missing ones I had to further run
 

apt –fix-broken install

i-nex-cpu-info-linux-hardware-info-program

 

hre

I-Nex thermal indicators about CPU temperature on a Linux Desktop notebook

i-nex-gpu-info-linux-hardware-info-program

i-nex-mobo-info-linux-hardware-info-program

i-nex-audio-info-linux-hardware-info-program

i-nex-drivers-info-linux-hardware-info-program

i-nex-system-info-linux-hardware-info-program

i-nex-battery-info-linux-hardware-info-program

 

There are other Hardware identification report tools such as CUDA-Z that are useful to check if you have Nvidia Video Card hardware Installed on the PC to check the status of CUDA enabled GPUs, useful if working with nVidia Geforce, Quadro, Tesla cards and ION chipsets.

If you use it however be aware that CUDA-Z is not compatible with 3rd-party linux drivers for NVidia so make sure you have the current official Nvidia version.

 

5. Inxi full featured system information script

 

Inxi is a 10000 lines mega bash script that fetches hardware details from multiple different sources in /proc /sys and from commands on the system, and generates a beautiful looking console report that non technical users can read easily.

inxi-10-k-mega-bash-shell-script-reporting-on-installed-system-computer-hardware

 

inxi -Fx

 

 

inxi-report-on-installed-hardware-on-my-lenovo-thinkpad-home-laptop

Each of the pointed above tools has different method of collection of Hardware information from various resources e.g. – kernel loaded modules, dmesg, files like /proc/meminfo /proc/version /proc/scsi/scsi /proc/partitions.
Hence some of the tools are likely to report more info than otheres, so in case if some information you need regarding the system plugged in hardware is missing you can perhaps obtain it from another program. Most Linux distribution desktop provided GNOME package are including Hardinfo gui tool, but in many cases above mentioned tools are likely to add even more on info on what is inside your PC Box.
If you're aware of others tools that are useful not mentioned here please share it.

Scanning ports with netcat “nc” command on Linux and UNIX / Checking for firewall filtering between source and destination with nc

Friday, September 6th, 2019

scanning-ports-with-netcat-nc-command-on-Linux-and-UNIX-checking-for-firewall-filtering-between-source-destination-host-with-netcat

Netcat ( nc ) is one of that tools, that is well known in the hacker (script kiddie) communities, but little underestimated in the sysadmin world, due to the fact nmap (network mapper) – the network exploratoin and security auditing tool has become like the standard penetration testing TCP / UDP port tool
 

nc is feature-rich network debugging and investigation tool with tons of built-in capabilities for reading from and writing to network connections using TCP or UDP.

Its Plethora of features includes port listening, port scanning & Transferring files due to which it is often used by Hackers and PenTesters as Backdoor. Netcat was written by a guy we know as the Hobbit <hobbit@avian.org>.

For a start-up and middle sized companies if nmap is missing on server usually it is okay to install it without risking to open a huge security hole, however in Corporate world, due to security policies often nmap is not found on the servers but netcat (nc) is present on the servers so you have to learn, if you haven't so to use netcat for the usual IP range port scans, if you're so used to nmap.

There are different implementations of Netcat, whether historically netcat was UNIX (BSD) program with a latest release of March 1996. The Linux version of NC is GNU Netcat (official source here) and is POSIX compatible. The other netcat in Free Software OS-es is OpenBSD's netcat whose ported version is also used in FreeBSD. Mac OS X also comes with default prebundled netcat on its Mac OS X from OS X version (10.13) onwards, on older OS X-es it is installable via MacPorts package repo, even FreeDOS has a port of it called NTOOL.

The (Swiss Army Knife of Embedded Linux) busybox includes a default leightweight version of netcat and Solaris has the OpenBSD netcat version bundled.

A cryptography enabled version fork exists that supports that supports integrated transport encryption capabilities called Cryptcat.

The Nmap suite also has included rewritten version of GNU Netcat named Ncat, featuring new possibilities such as "Connection Brokering", TCP/UDP Redirection, SOCKS4 client and server support, ability to "Chain" Ncat processes, HTTP CONNECT proxying (and proxy chaining), SSL connect/listen support and IP address/connection filtering. Just like Nmap, Ncat is cross-platform.

In this small article I'll very briefly explain on basic netcat – known as the TCP Army knife tool port scanning for an IP range of UDP / TCP ports.

 

1. Scanning for TCP opened / filtered ports remote Linux / Windows server

 

Everyone knows scanning of a port is possible with a simple telnet request towards the host, e.g.:

telnet SMTP.EMAIL-HOST.COM 25

 

The most basic netcat use that does the same is achiavable with:

 

$ nc SMTP.EMAIL-HOST.COM 25
220 jeremiah ESMTP Exim 4.92 Thu, 05 Sep 2019 20:39:41 +0300


Beside scanning the remote port, using netcat interactively as pointing in above example, if connecting to HTTP Web services, you can request remote side to return a webpage by sending a false referer, source host and headers, this is also easy doable with curl / wget and lynx but doing it with netcat just like with telnet could be fun, here is for example how to request an INDEX page with spoofed HTTP headers.
 

nc Web-Host.COM 25
GET / HTTP/1.1
Host: spoofedhost.com
Referrer: mypage.com
User-Agent: my-spoofed-browser

 

2. Performing a standard HTTP request with netcat

 

To do so just pype the content with a standard bash integrated printf function with the included end of line (the unix one is \n but to be OS independent it is better to use r\n  – the end of line complition character for Windows.

 

printf "GET /index.html HTTP/1.0\r\nHost: www.pc-freak.net\r\n\r\n" | nc www.pc-freak.net 80

 

3. Scanning a range of opened / filtered UDP ports

 

To scan for lets say opened remote system services on the very common important ports opened from UDP port 25 till, 1195 – more specifically for:

  • UDP Bind Port 53
  • Time protocol Port (37)
  • TFTP (69)
  • Kerberos (88)
  • NTP 123
  • Netbios (137,138,139)
  • SNMP (161)
  • LDAP 389
  • Microsoft-DS (Samba 445)
  • Route BGP (52)
  • LDAPS (639)
  • openvpn (1194)

 

nc -vzu 192.168.0.1 25 1195

 

UDP tests will show opened, if no some kind of firewall blocking, the -z flag is given to scan only for remote listening daemons without sending any data to them.

 

4. Port Scanning TCP listening ports with Netcat

 

As prior said using netcat to scan for remote opened HTTP Web Server on port 80 an FTP on Port 23 or a Socks Proxy or MySQL Database on 3306 / PostgreSQL DB on TCP 5432 is very rare case scenario.

Below is example to scan a Local network situated IP for TCP open ports from port 1 till 7000.

 

# nc -v -n -z -w 5 192.168.1.2 1-7000

           nc: connect to host.example.com 80 (tcp) failed: Connection refused
           nc: connect to host.example.com 20 (tcp) failed: Connection refused
           Connection to host.example.com port [tcp/ssh] succeeded!
           nc: connect to host.example.com 23 (tcp) failed: Connection refused

 

Be informed that scanning with netcat is much more slower, than nmap, so specifying smaller range of ports is always a good idea to reduce annoying waiting …


The -w flag is used to set a timeout to remote connection, usually on a local network situated machines the timeout could be low -w 1 but for machines across different Data Centers (let say one in Berlin and one in Seattle), use as a minimum -w 5.

If you expect remote service to be responsive (as it should always be), it is a nice idea to use netcat with a low timeout (-w) value of 1 below is example:
 

netcat -v -z -n -w 1 scanned-hosts 1-1023

 

5. Port scanning range of IP addresses with netcat


If you have used Nmap you know scanning for a network range is as simple as running something like nmap -sP -P0 192.168.0.* (to scan from IP range 1-255 map -sP -P0 192.168.0.1-150 (to scan from local IPs ending in 1-150) or giving the network mask of the scanned network, e.g. nmap -sF 192.168.0.1/24 – for more examples please check my previous article Checking port security on Linux with nmap (examples).

But what if nmap is not there and want to check a bunch 10 Splunk servers (software for searching, monitoring, and analyzing machine-generated big data, via a Web-style interface.), with netcat to find, whether the default Splunk connection port 9997 is opened or not:

 

for i in `seq 1 10`; do nc -z -w 5 -vv splunk0$i.server-domain.com 9997; done

 

6. Checking whether UDP port traffic is allowed to destination server

 

Assuring you have access on Source traffic (service) Host A  and Host B (remote destination server where a daemon will be set-upped to listen on UDP port and no firewall in the middle Network router or no traffic control and filtering software HUB is preventing the sent UDP proto traffic, lets say an ntpd will be running on its standard 123 port there is done so:

– On host B (the remote machine which will be running ntpd and should be listening on port 123), run netcat to listen for connections

 

# nc -l -u -p 123
Listening on [0.0.0.0] (family 2, port 123)


Make sure there is no ntpd service actively running on the server, if so stop it with /etc/init.d/ntpd stop
and run above command. The command should run as superuser as UDP port 123 is from the so called low ports from 1-1024 and binding services on such requires root privileges.

– On Host A (UDP traffic send host

 

nc -uv remote-server-host 123

 

netcat-linux-udp-connection-succeeded

If the remote port is not reachable due to some kind of network filtering, you will get "connection refused".
An important note to make is on some newer Linux distributions netcat might be silently trying to connect by default using IPV6, bringing false positives of filtered ports due to that. Thus it is generally a good idea, to make sure you're connecting to IPV6

 

$ nc -uv -4 remote-server-host 123

 

Another note to make here is netcat's UDP connection takes 2-3 seconds, so make sure you wait at least 4-8 seconds for a very distant located hosts that are accessed over a multitude of routers.
 

7. Checking whether TCP port traffic allowed to DST remote server


To listen for TCP connections on a specified location (external Internet IP or hostname), it is analogous to listening for UDP connections.

Here is for example how to bind and listen for TCP connections on all available Interface IPs (localhost, eth0, eth1, eth2 etc.)
 

nc -lv 0.0.0.0 12345

 

Then on client host test the connection with

 

nc -vv 192.168.0.103 12345
Connection to 192.168.0.103 12345 port [tcp/*] succeeded!

 

8. Proxying traffic with netcat


Another famous hackers use of Netcat is its proxying possibility, to proxy anything towards a third party application with UNIX so any content returned be printed out on the listening nc spawned daemon like process.
For example one application is traffic SMTP (Mail traffic) with netcat, below is example of how to proxy traffic from Host B -> Host C (in that case the yandex current mail server mx.yandex.ru)

linux-srv:~# nc -l 12543 | nc mx.yandex.ru 25


Now go to Host A or any host that has TCP/IP protocol access to port 12543 on proxy-host Host B (linux-srv) and connect to it on 12543 with another netcat or telnet.

to make netcat keep connecting to yandex.ru MX (Mail Exchange) server you can run it in a small never ending bash shell while loop, like so:

 

linux-srv:~# while :; do nc -l 12543 | nc mx.yandex.ru 25; done


 Below are screenshots of a connection handshake between Host B (linux-srv) proxy host and Host A (the end client connecting) and Host C (mx.yandex.ru).

host-B-running-as-a-proxy-daemon-towards-Host-C-yandex-mail-exchange-server

 

Host B netcat as a (Proxy)

Host-A-Linux-client-connection-handshake-to-proxy-server-with-netcat
that is possible in combination of UNIX and named pipes (for more on Named pipes check my previous article simple linux logging with named pipes), here is how to run a single netcat version to proxy any traffic in a similar way as the good old tinyproxy.

On Proxy host create the pipe and pass the incoming traffic towards google.com and write back any output received back in the named pipe.
 

# mkfifo backpipe
# nc -l 8080 0<backpipe | nc www.google.com 80 1>backpipe

Other useful netcat proxy set-up is to simulate a network connectivity failures.

For instance, if server:port on TCP 1080 is the normal host application would connect to, you can to set up a forward proxy from port 2080 with

    nc -L server:1080 2080

then set-up and run the application to connect to localhost:2080 (nc proxy port)

    /path/to/application_bin –server=localhost –port=2080

Now application is connected to localhost:2080, which is forwarded to server:1080 through netcat. To simulate a network connectivity failure, just kill the netcat proxy and check the logs of application_bin.

Using netcat as a bind shell (make any local program / process listen and deliver via nc)

 

netcat can be used to make any local program that can receive input and send output to a server, this use is perhaps little known by the junior sysadmin, but a favourite use of l337 h4x0rs who use it to spawn shells on remote servers or to make connect back shell. The option to do so is -e

-e – option spawns the executable with its input and output redirected via network socket.

One of the most famous use of binding a local OS program to listen and receive / send content is by
making netcat as a bind server for local /bin/bash shell.

Here is how

nc -l -p 4321 -e /bin/sh


If necessery specify the bind hostname after -l. Then from any client connect to 4321 (and if it is opened) you will gain a shell with the user with which above netcat command was run. Note that many modern distribution versions such as Debian / Fedora / SuSE Linux's netcat binary is compiled without the -e option (this works only when compiled with -DGAPING_SECURITY_HOLE), removal in this distros is because option is potentially opening a security hole on the system.

If you're interested further on few of the methods how modern hackers bind new backdoor shell or connect back shell, check out Spawning real tty shells article.

 

For more complex things you might want to check also socat (SOcket CAT) – multipurpose relay for bidirectional data transfer under Linux.
socat is a great Linux Linux / UNIX TCP port forwarder tool similar holding the same spirit and functionality of netcat plus many, many more.
 

On some of the many other UNIX operating systems that are lacking netcat or nc / netcat commands can't be invoked a similar utilitiesthat should be checked for and used instead are:

ncat, pnetcat, socat, sock, socket, sbd

To use nmap's ncat to spawn a shell for example that allows up to 3 connections and listens for connects only from 192.168.0.0/24 network on port 8081:

ncat –exec "/bin/bash" –max-conns 3 –allow 192.168.0.0/24 -l 8081 –keep-open

 

9. Copying files over network with netcat


Another good hack often used by hackers to copy files between 2 servers Server1 and Server2 who doesn't have any kind of FTP / SCP / SFTP / SSH / SVN / GIT or any kind of Web copy support service – i.e. servers only used as a Database systems that are behind a paranoid sysadmin firewall is copying files between two servers with netcat.

On Server2 (the Machine on which you want to store the file)
 

nc -lp 2323 > files-archive-to-copy.tar.gz


On server1 (the Machine from where file is copied) run:
 

nc -w 5 server2.example.com 2323 < files-archive-to-copy.tar.gz

 

Note that the downside of such transfers with netcat is data transferred is unencrypted so any one with even a simple network sniffer or packet analyzier such as iptraf or tcpdump could capture the file, so make sure the file doesn't contain sensitive data such as passwords.

Copying partition images like that is perhaps best way to get disk images from a big server onto a NAS (when you can't plug the NAS into the server).
 

10. Copying piped archived directory files with netcat

 

On computer A:

export ARIBTRARY_PORT=3232
nc -l $ARBITRARY_PORT | tar vzxf –

On Computer B:

tar vzcf – files_or_directories | nc computer_a $ARBITRARY_PORT

 

11. Creating a one page webserver with netcat and ncat


As netcat could listen to port and print content of a file, it can be set-up with a bit of bash shell scripting to serve
as a one page webserver, or even combined with some perl scripting and bash to create a multi-serve page webserver if needed.

To make netact serve a page to any connected client run in a screen / tmux session following code:

 

while true; do nc -l -p 80 -q 1 < somepage.html; done

 

Another interesting fun example if you have installed ncat (is a small web server that connects current time on server on connect).
 

ncat -lkp 8080 –sh-exec 'echo -ne "HTTP/1.0 200 OK\r\n\r\nThe date is "; date;'

 

12. Cloning Hard disk partitions with netcat


rsync is a common tool used to clone hard disk partitions over network. However if rsync is not installed on a server and netcat is there you can use it instead, lets say we want to clone /dev/sdb
from Server1 to Server2 assuming (Server1 has a configured working Local or Internet connection).

 

On Server2 run:
 

nc -l -p 4321 | dd of=/dev/sdb

 

Following on Server2 to start the Partition / HDD cloning process run

 

dd if=/dev/sdb | nc 192.168.0.88 4321

 


Where 192.168.0.88 is the IP address listen configured on Server2 (in case you don't know it, check the listening IP to access with /sbin/ifconfig).

Next you have to wait for some short or long time depending on the partiiton or Hard drive, number of files / directories and allocated disk / partition size.

To clone /dev/sda (a main partiiton) from Server1 to Server2 first requirement is that it is not mounted, thus to have it unmounted on a system assuming you have physical access to the host, you can boot some LiveCD Linux distribution such as Knoppix Live CD on Server1, manually set-up networking with ifconfig or grab an IP via DHCP from the central DHCP server and repeat above example.


Happy netcating 🙂

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

 

 

How to build Linux logging bash shell script write_log, logging with Named Pipe buffer, Simple Linux common log files logging with logger command

Monday, August 26th, 2019

how-to-build-bash-script-for-logging-buffer-named-pipes-basic-common-files-logging-with-logger-command

Logging into file in GNU / Linux and FreeBSD is as simple as simply redirecting the output, e.g.:
 

echo "$(date) Whatever" >> /home/hipo/log/output_file_log.txt


or with pyping to tee command

 

echo "$(date) Service has Crashed" | tee -a /home/hipo/log/output_file_log.txt


But what if you need to create a full featured logging bash robust shell script function that will run as a daemon continusly as a background process and will output
all content from itself to an external log file?
In below article, I've given example logging script in bash, as well as small example on how a specially crafted Named Pipe buffer can be used that will later store to a file of choice.
Finally I found it interesting to mention few words about logger command which can be used to log anything to many of the common / general Linux log files stored under /var/log/ – i.e. /var/log/syslog /var/log/user /var/log/daemon /var/log/mail etc.
 

1. Bash script function for logging write_log();


Perhaps the simplest method is just to use a small function routine in your shell script like this:
 

write_log()
LOG_FILE='/root/log.txt';
{
  while read text
  do
      LOGTIME=`date "+%Y-%m-%d %H:%M:%S"`
      # If log file is not defined, just echo the output
      if [ “$LOG_FILE” == “” ]; then
    echo $LOGTIME": $text";
      else
        LOG=$LOG_FILE.`date +%Y%m%d`
    touch $LOG
        if [ ! -f $LOG ]; then echo "ERROR!! Cannot create log file $LOG. Exiting."; exit 1; fi
    echo $LOGTIME": $text" | tee -a $LOG;
      fi
  done
}

 

  •  Using the script from within itself or from external to write out to defined log file

 

echo "Skipping to next copy" | write_log

 

2. Use Unix named pipes to pass data – Small intro on what is Unix Named Pipe.


Named Pipe –  a named pipe (also known as a FIFO (First In First Out) for its behavior) is an extension to the traditional pipe concept on Unix and Unix-like systems, and is one of the methods of inter-process communication (IPC). The concept is also found in OS/2 and Microsoft Windows, although the semantics differ substantially. A traditional pipe is "unnamed" and lasts only as long as the process. A named pipe, however, can last as long as the system is up, beyond the life of the process. It can be deleted if no longer used.
Usually a named pipe appears as a file, and generally processes attach to it for IPC.

 

Once named pipes were shortly explained for those who hear it for a first time, its time to say named pipe in unix / linux is created with mkfifo command, syntax is straight foward:
 

mkfifo /tmp/name-of-named-pipe


Some older Linux-es with older bash and older bash shell scripts were using mknod.
So idea behind logging script is to use a simple named pipe read input and use date command to log the exact time the command was executed, here is the script.

 

#!/bin/bash
named_pipe='/tmp/output-named-pipe';
output_named_log='
/tmp/output-named-log.txt ';

if [ -p $named_pipe ]; then
rm -f $named_pipe
fi
mkfifo $named_pipe

while true; do
read LINE <$named_pipe
echo $(date): "$LINE" >>/tmp/output-named-log.txt
done


To write out any other script output and get logged now, any of your output with a nice current date command generated output write out any output content to the loggin buffer like so:

 

echo 'Using Named pipes is so cool' > /tmp/output-named-pipe
echo 'Disk is full on a trigger' > /tmp/output-named-pipe

  • Getting the output with the date timestamp

# cat /tmp/output-named-log.txt
Mon Aug 26 15:21:29 EEST 2019: Using Named pipes is so cool
Mon Aug 26 15:21:54 EEST 2019: Disk is full on a trigger


If you wonder why it is better to use Named pipes for logging, they perform better (are generally quicker) than Unix sockets.

 

3. Logging files to system log files with logger

 

If you need to do a one time quick way to log any message of your choice with a standard Logging timestamp, take a look at logger (a part of bsdutils Linux package), and is a command which is used to enter messages into the system log, to use it simply invoke it with a message and it will log your specified output by default to /var/log/syslog common logfile

 

root@linux:/root# logger 'Here we go, logging'
root@linux:/root # tail -n 3 /var/log/syslog
Aug 26 15:41:01 localhost CRON[24490]: (root) CMD (chown qscand:qscand -R /var/run/clamav/ 2>&1 >/dev/null)
Aug 26 15:42:01 localhost CRON[24547]: (root) CMD (chown qscand:qscand -R /var/run/clamav/ 2>&1 >/dev/null)
Aug 26 15:42:20 localhost hipo: Here we go, logging

 

If you have took some time to read any of the init.d scripts on Debian / Fedora / RHEL / CentOS Linux etc. you will notice the logger logging facility is heavily used.

With logger you can print out message with different priorities (e.g. if you want to write an error message to mail.* logs), you can do so with:
 

 logger -i -p mail.err "Output of mail processing script"


To log a normal non-error (priority message) with logger to /var/log/mail.log system log.

 

 logger -i -p mail.notice "Output of mail processing script"


A whole list of supported facility named priority valid levels by logger (as taken of its current Linux manual) are as so:

 

FACILITIES AND LEVELS
       Valid facility names are:

              auth
              authpriv   for security information of a sensitive nature
              cron
              daemon
              ftp
              kern       cannot be generated from userspace process, automatically converted to user
              lpr
              mail
              news
              syslog
              user
              uucp
              local0
                to
              local7
              security   deprecated synonym for auth

       Valid level names are:

              emerg
              alert
              crit
              err
              warning
              notice
              info
              debug
              panic     deprecated synonym for emerg
              error     deprecated synonym for err
              warn      deprecated synonym for warning

       For the priority order and intended purposes of these facilities and levels, see syslog(3).

 


If you just want to log to Linux main log file (be it /var/log/syslog or /var/log/messages), depending on the Linux distribution, just type', even without any shell quoting:

 

logger 'The reason to reboot the server Currently was a System security Update

 

So what others is logger useful for?

 In addition to being a good diagnostic tool, you can use logger to test if all basic system logs with its respective priorities work as expected, this is especially
useful as I've seen on a Cloud Holsted OpenXEN based servers as a SAP consultant, that sometimes logging to basic log files stops to log for months or even years due to
syslog and syslog-ng problems hungs by other thirt party scripts and programs.
To test test all basic logging and priority on system logs as expected use the following logger-test-all-basic-log-logging-facilities.sh shell script.

 

#!/bin/bash
for i in {auth,auth-priv,cron,daemon,kern, \
lpr,mail,mark,news,syslog,user,uucp,local0 \
,local1,local2,local3,local4,local5,local6,local7}

do        
# (this is all one line!)

 

for k in {debug,info,notice,warning,err,crit,alert,emerg}
do

logger -p $i.$k "Test daemon message, facility $i priority $k"

done

done

Note that on different Linux distribution verions, the facility and priority names might differ so, if you get

logger: unknown facility name: {auth,auth-priv,cron,daemon,kern,lpr,mail,mark,news, \
syslog,user,uucp,local0,local1,local2,local3,local4, \
local5,local6,local7}

check and set the proper naming as described in logger man page.

 

4. Using a file descriptor that will output to a pre-set log file


Another way is to add the following code to the beginning of the script

#!/bin/bash
exec 3>&1 4>&2
trap 'exec 2>&4 1>&3' 0 1 2 3
exec 1>log.out 2>&1
# Everything below will go to the file 'log.out':

The code Explaned

  •     Saves file descriptors so they can be restored to whatever they were before redirection or used themselves to output to whatever they were before the following redirect.
    trap 'exec 2>&4 1>&3' 0 1 2 3
  •     Restore file descriptors for particular signals. Not generally necessary since they should be restored when the sub-shell exits.

          exec 1>log.out 2>&1

  •     Redirect stdout to file log.out then redirect stderr to stdout. Note that the order is important when you want them going to the same file. stdout must be redirected before stderr is redirected to stdout.

From then on, to see output on the console (maybe), you can simply redirect to &3. For example
,

echo "$(date) : Do print whatever you want logging to &3 file handler" >&3


I've initially found out about this very nice bash code from serverfault.com's post how can I fully log all bash script actions (but unfortunately on latest Debian 10 Buster Linux  that is prebundled with bash shell 5.0.3(1)-release the code doesn't behave exactly, well but still on older bash versions it works fine.

Sum it up


To shortlysummarize there is plenty of ways to do logging from a shell script logger command but using a function or a named pipe is the most classic. Sometimes if a script is supposed to write user or other script output to a a common file such as syslog, logger command can be used as it is present across most modern Linux distros.
If you have a better ways, please drop a common and I'll add it to this article.

 

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 ! 🙂

Export / Import PuTTY Tunnels SSH Sessions from one to another Windows machine howto

Thursday, January 31st, 2019

Putty-copy-ssh-tunnels-howto-from-one-to-another-windows-machine-3

As I've started on job position – Linux Architect in last November 2018 in Itelligence AG as a contractor (External Service) – a great German company who hires the best IT specialists out there and offers a flexible time schedules for emploees doing various very cool IT advanced operations and Strategic advancement of SAP's Cloud used Technology and Services improvements for SAP SE – SAP S4HANA and HEC (HANA Enterprise Cloud) and been given for work hardware a shiny Lenovo Thinkpad 500 Laptop with Windows 10 OS (SAP pre-installed), I needed to make some SSH Tunnels to machines to (Hop Station / Jump hosts) for that purpose, after some experimenting with MobaXterm Free (Personal Edition 11.0) and the presumable limitations of tunnels of the free client as well as my laziness to add the multiple ssh tunnels to different ssh / rdp / vnc etc. servers, finally I decided to just copy all the tunnels from a colleague who runs Putty and again use the good old Putty – old school Winblows SSH Terminal Client but just for creating the SSH tunnels and for rest use MobaXterm, just like in old times while still employe in Hewlett Packard. For that reason to copy the Tunnels from my dear German Colleague Henry Beck (A good herated collegue who works in field of Storage dealing with NetApps / filer Clusters QNap etc.).

Till that moment I had no idea how copying a saved SSH Tunnels definition is possible, I did a quick research just to find out this is done not with Putty Interface itself but, insetead through dumping Windows Putty Stored Registry records into a File, then transfer to the PC where Tunnels needs to be imported and then again (either double click the registry file) to load it, into registry or use Windows registry editor command line interface reg, here is how:
 

1. Export

 

Run cmd.exe (note below command) 

requires elevated Run as Administrator prompt:

Only sessions:

regedit /e "%USERPROFILE%\Desktop\putty-sessions.reg" HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\Sessions

All settings:

regedit /e "%USERPROFILE%\Desktop\putty.reg" HKEY_CURRENT_USER\Software\SimonTatham

Powershell:

If you have powershell installed on machine, to dump

Only sessions:


 

reg export HKCU\Software\SimonTatham\PuTTY\Sessions ([Environment]::GetFolderPath("Desktop") + "\putty-sessions.reg")

All settings:

reg export HKCU\Software\SimonTatham ([Environment]::GetFolderPath("Desktop") + "\putty.reg")


2. Import

Double-click on the 

*.reg

 file and accept the import.

 

Alternative ways:

 

cmd.exe

require elevated command prompt:

regedit /i putty-sessions.reg regedit /i putty.reg

PowerShell:

reg import putty-sessions.reg reg import putty.reg



Below are some things to consider:

Note !do not replace 

SimonTatham

 with your username.

 

Note !: It will create a 

reg

 file on the Desktop of the current user (for a different location modify path)

 

Note !: It will not export your related (old system stored) SSH keys.

What to expect next?

Putty-Tunnels-SSH-Sessions-screenshot-Windows

The result is in Putty you will have the Tunnel sessions loadable when you launch (Portable or installed) Putty version.
Press Load button over the required saved Tunnels list and there you go under

 

Connection SSH -> Tunnels 

 

you will see all the copied tunnels.

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! 🙂

How to install BlueJeans Video calls, sharing, Conference software on Debian / Ubuntu Linux – Convert RPM to DEB package with alien howto

Tuesday, August 28th, 2018

bluejeans-linux-logo

As I'm currently looking for ways to maximize my incomes without taking participation in 5 days week 8 hours schedule in a Big Corporation office job (which prooved for me to be a terrible slavery) I decided to give Free Lancing a try once again. 
Historically I have registrations in some of the most popular Free Lancing services Web platforms such as freelancer.com and upwork.com.
But none of them really was easy enough to handle as applying and winning a project there is usually a lot of headbanging into the walls and the platforms are full of clients that are looking for free lancers for short-term projects the work selection there required too much work, often projects offered there are seriously under-paid and its really hard to negotiate with many of the clients as they're unprofessional in the fields they're working (don't get me wrong I'm not saying many people are not very successful with this platforms, and that the platforms are not providing work for me I only say it is not really something to my liking …

In the mean time if you happen to read this article and looking for a High Quality Empoyee Cheap System Administrator or automation developmer, an IT counseling FreeLancer or a Ultra cheap WebHosting service in the European Union, I'll be very happy if you become my client.

Anyways … further on I decided to further experiment a little bit with other Free Lancing platforms (suggested by a friend Mitko Ivanov who helped me a lot with things and is continuing to help me over the last year ).

So following his kind suggestion I already tried one of the popular FreeLancing freeeup.com which is looking only for a best specialists into the fields of Marketing, Development, System Administration etc. but even though I tried hard with them the guys decided I am not matching there criteria for a the best 1% of all the people in the field of IT so my application for the platform was rejected twice over the last 1 month and a half.

Another similar new platform for free lancing that looks promising that I've learned about is toptal.com (there site Slogan is Hire FreeLance Talent from the Top 3%) so I went there and registered.

I had hit a road block there too as it seems, there website registration form was not tested enough with non-Windows operating systems with Mozilla Firefox and as it happens that I am using Debian GNU / Linux for my Desktop their drop-down menus was not working, just like some of the form on their website regular expression checks failed.

I've contacted the guys to inform them about their problems (and they kindly advised) I just give a try a registration with different browser (i.e. Google Chrome) which I immediately did and registratoin there was finally a success.
I have to say the new user application form registration of toptal also annoyed me with the stupid requirement to provide a picture in 1000px x 1000px but as this freelancing platform is still new and has way to go until it is established name in the field of freelancing such as upwork.com and I warmly excuse them.

Once registerered for them the user has to schedule an entry interview just like it goes with a standard company interview with a kind of Human Resources (HR) specialist and I guess some technical guys in order to evaluate on your value (Ha-Ha, someone else to determine your value is already crazy but all crazy employees do it still, of course I don't care as I well know that my value is much more than what they put on me).
The online interview once scheduled has to be done in a Web Meeting (Online Rooms) Platform called BlueJeans similar to Cisco WebEx (that is today heavily used in Corporate world in companies such as Hewlett Packard where we used it heavily, IBM, Concentrix etc.) and others Zoom, JoinMe GotoMeeting, HighFive.

As you could guess BlueJeans (which is by the way a Cloud based meeting software – yackes !) is planned to work mainly on Windows and Mac OS Operating Systems and even though there is a BlueJeans Linux version the provided binary is only for RedHat based linuxes in the RPM binary package format, so in order for me to participate in the scheduled meeting, I either had to port the package and install it on my Debian (what triggeted me to write this article or) use a Virtual Machine such as VirtualBox or VMWare running some kind of Windows OS such as Windows 8 / 10 etc.

Even though I have a Windows 10 OS testbed in a Virtualbox container, I preferred to not use it for BlueJeans and do it the hard way and install BlueJeans on my Debian 9.5 Stretch Linux.

That appeared to be a relatively easy process, so below is how I did it:

1. Download alien convertion (tool) that allows you to convert RPM -> deb, Slackware -> Deb and Linux Standard Base (LDB) packages to deb package format

 

noah:~# apt-get install –yes alien

 

2. Download latest BlueJeans version from BlueJeans website
 

As of time of writting this article the download link for bluejeans online conferencing software is here

 

noah:~# wget https://swdl.bluejeans.com/desktop/linux/1.36/1.36.9/bluejeans-1.36.9.x86_64.rpm

 

3. Convert bluejeans rpm package with alien

 

noah:~# alien –to-deb bluejeans-*.rpm
 

 

 

Warning: Skipping conversion of scripts in package bluejeans: postinst postrm preinst prerm
Warning: Use the –scripts parameter to include the scripts.
bluejeans_1.36.9-2_amd64.deb generated
root@jericho:/home/hipo/Свалени# dpkg -i bluejeans_*.deb
Selecting previously unselected package bluejeans.
(Reading database … 516203 files and directories currently installed.)
Preparing to unpack bluejeans_1.36.9-2_amd64.deb …
Unpacking bluejeans (1.36.9-2) …
Setting up bluejeans (1.36.9-2) …

 


4. Install the deb package as usual with dpkg tool

 

noah: ~# dpkg -i bluejeans_*.deb

 

By default BlueJeans were installed under directory /opt/bluejeans

 

 

noah:~# ls -al /opt/bluejeans/bluejeans-bin
-rwxr-xr-x 1 root root 72423392 Jun 14 02:31 /opt/bluejeans/bluejeans-bin*

 

5. Fix missing library links if such are present in order to make BlueJeans workable

Historically I have dealt with many Linux programs that are provided only in RPM package format and I knew that often once an RPM is converted to DEB with alien due to the package dependency differences on Redhats (CentOS / Fedora etc.) there are problems with missing libraries.

This time this was the case as well, so as usual right after install I did a check up with ldd (print shared object dependencies Linux command) to find out about missing libraries and one library appeared missing.

 

noah:~# ldd /opt/bluejeans/bluejeans-bin
    linux-vdso.so.1 (0x00007fffa2182000)
    librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fae95f5e000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fae95d5a000)
    libgtk-x11-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0 (0x00007fae95718000)
    libgdk-x11-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgdk-x11-2.0.so.0 (0x00007fae95463000)
    libatk-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libatk-1.0.so.0 (0x00007fae9523d000)
    libpangocairo-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpangocairo-1.0.so.0 (0x00007fae95030000)
    libgdk_pixbuf-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgdk_pixbuf-2.0.so.0 (0x00007fae94e0c000)
    libcairo.so.2 => /usr/lib/x86_64-linux-gnu/libcairo.so.2 (0x00007fae94aef000)
    libpango-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpango-1.0.so.0 (0x00007fae948aa000)
    libfreetype.so.6 => /usr/lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007fae945f5000)
    libfontconfig.so.1 => /usr/lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007fae943b2000)
    libgobject-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 (0x00007fae9415e000)
    libglib-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007fae93e48000)
    libX11.so.6 => /usr/lib/x86_64-linux-gnu/libX11.so.6 (0x00007fae93b0a000)
    libXi.so.6 => /usr/lib/x86_64-linux-gnu/libXi.so.6 (0x00007fae938fa000)
    libnss3.so => /usr/lib/x86_64-linux-gnu/libnss3.so (0x00007fae935b1000)
    libnssutil3.so => /usr/lib/x86_64-linux-gnu/libnssutil3.so (0x00007fae93381000)
    libsmime3.so => /usr/lib/x86_64-linux-gnu/libsmime3.so (0x00007fae93154000)
    libplc4.so => /usr/lib/x86_64-linux-gnu/libplc4.so (0x00007fae92f4f000)
    libnspr4.so => /usr/lib/x86_64-linux-gnu/libnspr4.so (0x00007fae92d10000)
    libgconf-2.so.4 => /usr/lib/x86_64-linux-gnu/libgconf-2.so.4 (0x00007fae92adf000)
    libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007fae928ad000)
    libXext.so.6 => /usr/lib/x86_64-linux-gnu/libXext.so.6 (0x00007fae9269b000)
    libXfixes.so.3 => /usr/lib/x86_64-linux-gnu/libXfixes.so.3 (0x00007fae92495000)
    libXrender.so.1 => /usr/lib/x86_64-linux-gnu/libXrender.so.1 (0x00007fae9228b000)
    libXcomposite.so.1 => /usr/lib/x86_64-linux-gnu/libXcomposite.so.1 (0x00007fae92088000)
    libasound.so.2 => /usr/lib/x86_64-linux-gnu/libasound.so.2 (0x00007fae91d8a000)
    libXdamage.so.1 => /usr/lib/x86_64-linux-gnu/libXdamage.so.1 (0x00007fae91b87000)
    libXtst.so.6 => /usr/lib/x86_64-linux-gnu/libXtst.so.6 (0x00007fae91981000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fae91763000)
    libcap.so.2 => /lib/x86_64-linux-gnu/libcap.so.2 (0x00007fae9155d000)
    libudev.so.0 => not found
    libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007fae9130c000)
    libnotify.so.4 => /usr/lib/x86_64-linux-gnu/libnotify.so.4 (0x00007fae91104000)
    libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fae90d85000)
    libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fae909f2000)
    libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fae907db000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fae90421000)
    /lib64/ld-linux-x86-64.so.2 (0x00007fae96166000)
    libgmodule-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgmodule-2.0.so.0 (0x00007fae9021d000)
    libgio-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0 (0x00007fae8fe7f000)
    libpangoft2-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libpangoft2-1.0.so.0 (0x00007fae8fc6a000)
    libfribidi.so.0 => /usr/lib/x86_64-linux-gnu/libfribidi.so.0 (0x00007fae8fa53000)
    libXinerama.so.1 => /usr/lib/x86_64-linux-gnu/libXinerama.so.1 (0x00007fae8f850000)
    libXrandr.so.2 => /usr/lib/x86_64-linux-gnu/libXrandr.so.2 (0x00007fae8f645000)
    libXcursor.so.1 => /usr/lib/x86_64-linux-gnu/libXcursor.so.1 (0x00007fae8f43b000)
    libpng16.so.16 => /usr/lib/x86_64-linux-gnu/libpng16.so.16 (0x00007fae8f208000)
    libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007fae8efea000)
    libpixman-1.so.0 => /usr/lib/x86_64-linux-gnu/libpixman-1.so.0 (0x00007fae8ed44000)
    libxcb-shm.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-shm.so.0 (0x00007fae8eb41000)
    libxcb.so.1 => /usr/lib/x86_64-linux-gnu/libxcb.so.1 (0x00007fae8e919000)
    libxcb-render.so.0 => /usr/lib/x86_64-linux-gnu/libxcb-render.so.0 (0x00007fae8e70b000)
    libthai.so.0 => /usr/lib/x86_64-linux-gnu/libthai.so.0 (0x00007fae8e501000)
    libuuid.so.1 => /lib/x86_64-linux-gnu/libuuid.so.1 (0x00007fae8e2fa000)
    libffi.so.6 => /usr/lib/x86_64-linux-gnu/libffi.so.6 (0x00007fae8e0f1000)
    libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007fae8de7f000)
    libplds4.so => /usr/lib/x86_64-linux-gnu/libplds4.so (0x00007fae8dc7b000)
    libgthread-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgthread-2.0.so.0 (0x00007fae8da79000)
    libdbus-glib-1.so.2 => /usr/lib/x86_64-linux-gnu/libdbus-glib-1.so.2 (0x00007fae8d851000)
    libsystemd.so.0 => /lib/x86_64-linux-gnu/libsystemd.so.0 (0x00007fae8d5c9000)
    libselinux.so.1 => /lib/x86_64-linux-gnu/libselinux.so.1 (0x00007fae8d3a1000)
    libresolv.so.2 => /lib/x86_64-linux-gnu/libresolv.so.2 (0x00007fae8d18a000)
    libmount.so.1 => /lib/x86_64-linux-gnu/libmount.so.1 (0x00007fae8cf31000)
    libharfbuzz.so.0 => /usr/lib/x86_64-linux-gnu/libharfbuzz.so.0 (0x00007fae8cc81000)
    libXau.so.6 => /usr/lib/x86_64-linux-gnu/libXau.so.6 (0x00007fae8ca7d000)
    libXdmcp.so.6 => /usr/lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007fae8c877000)
    libdatrie.so.1 => /usr/lib/x86_64-linux-gnu/libdatrie.so.1 (0x00007fae8c66f000)
    liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007fae8c449000)
    liblz4.so.1 => /usr/lib/x86_64-linux-gnu/liblz4.so.1 (0x00007fae8c22c000)
    libgcrypt.so.20 => /lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007fae8bf10000)
    libblkid.so.1 => /lib/x86_64-linux-gnu/libblkid.so.1 (0x00007fae8bcc1000)
    libgraphite2.so.3 => /usr/lib/x86_64-linux-gnu/libgraphite2.so.3 (0x00007fae8ba94000)
    libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007fae8b87d000)
    libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007fae8b65d000)

 


As I am on my notebook with Debian 9 and on Debian / Ubuntus and other Linuxes udevd daemon and connected libraries are long time existing, it was obvious the problems to dependencies are because of missing library links (or library version inconsistencies).

To find out what kind of libudev.so* are present I used slocate package (locate) command.

 

noah:~# locate libudev.so
/lib/i386-linux-gnu/libudev.so.1
/lib/i386-linux-gnu/libudev.so.1.6.10
/lib/x86_64-linux-gnu/libudev.so
/lib/x86_64-linux-gnu/libudev.so.1
/lib/x86_64-linux-gnu/libudev.so.1.6.10

 

Obviously the missing library libudev.so.0 was present under a different name so I give a try to just create a new symbolic link from libudev.so.1 to libudev.so.0 hoping that the libudev library version Blue Jeans was compiled against did not have a missing binary objects from the ones installed on my OS.

 

noah:~# ln -sf /lib/x86_64-linux-gnu/libudev.so.1 /lib/x86_64-linux-gnu/libudev.so.0

 

noah:~# ldd /opt/bluejeans/bluejeans-bin |grep -i 'not found'

 

Above command did not return any missing libraries, so I went further and executed it.

6. Go start BlueJeans and register a user or use the anonymous login to be ready for the scheduled online meting

… And, Guess, what it works! 🙂
 

 

noah:~# /opt/bluejeans/bluejeans-bin

 

To make it easy to remember to later start the binary under a familiar name, I've also created a link into

 

noah:~# ln -sf /opt/bluejeans/bluejeans-bin /usr/bin/bluejeans
 

 

 

noah:~#  sudo su – hipo
hipo@noah:~$ /usr/bin/bluejeans

 

bluejeans-video-conferencing-online-sharing-meeting-software-running-on-debian-gnu-linux-screenshot