Ubuntu Services

sudo service --status-all


https://askubuntu.com/questions/912216/16-04-command-to-list-all-services-started-on-boot/912218

Linux small distro

Damn Small Project (bad)
Lubuntu 
Linux Lite (based on Ubuntu/Testing)
Tiny Core (Testing), works for Raspberry Pi
  Download:
  Installation GUI:
 

 $tce-load -wi Xvesa.tcz Xlibs.tcz Xprogs.tcz aterm.tcz flwm_topside.tcz wbar.tcz

 $tce-load -wi Xorg-7.7 #if Xvesa not found 

References:
[1] List of popular distros https://itsfoss.com/lightweight-linux-beginners/
[2] Comparison https://en.wikipedia.org/wiki/Light-weight_Linux_distribution
[3] Tiny Core installation https://iotbytes.wordpress.com/install-microcore-tiny-linux-on-local-disk/
[4] Tiny Core Packages http://distro.ibiblio.org/tinycorelinux/7.x/x86/tcz/
[5] Tiny Core Addin desktop http://wiki.tinycorelinux.net/wiki:adding_a_desktop_to_microcore
[6] WBar http://lxlinux.com/wbar.html

Ancho de Banda / Bandwidth Meter

Referencias
[1] www.speedtest.net
[2] http://openspeedtest.com
[3] https://www.meter.net

Ubuntu 16 - Setting PDF Printer

List of printers installed
$ls /etc/cups/ppd

Manually
Device URI:cups-pdf:/

By Command Line (Partial tested)

lpadmin -h localhost -p cups-pdf -v cups-pdf:/ -P /usr/share/cups/model/CUPS-PDF.ppd -E

Setting file (output/destination)
/etc/cups/cups-pdf.conf

Status Idle - File "/usr/lib/cups/backend/cups-pdf" has insecure permissions

$chmod 700 /usr/lib/cups/backend/cups-pdf

Null Printer
Device URI: file:/dev/null


References:
[1] Complete info https://en.opensuse.org/SDB:Printing_to_PDF

[2] openSUSE compile cups-pdf and ppd file https://pawn.physik.uni-wuerzburg.de/~vrbehr/cups-pdf/documentation.shtml
[3] CUPS PDF-WRITER Backend on Suse https://www.novell.com/coolsolutions/feature/17636.html

[4] Fake printer https://superuser.com/questions/304670/how-to-add-a-fake-dummy-null-printer-in-cups
[5] Install cups-pdf http://www.debianadmin.com/howto-install-and-customize-cups-pdf-in-debian.html

Fedora 29 Network Settings

References:
[1] https://alchemist.digital/articles/configure-a-static-ip-address-on-fedora-24-25/

Fedora 29 firewalld settings

$sudo service firewalld start 

$sudo firewall-cmd --list-all

$sudo firewall-cmd --get-zones

$sudo sudo firewall-cmd --zone=home --list-all

$sudo firewall-cmd --get-default-zone

$sudo firewall-cmd --get-active-zones

$sudo firewall-cmd --add-port=8081/tcp --permanent 
$sudo firewall-cmd --add-port=8081/udp --permanent 

$sudo firewall-cmd --reload  #important in Fedora 23 (VPS)
 
 
 
References:
[1] firewall-cmd https://docs.fedoraproject.org/en-US/Fedora/19/html/Security_Guide/sec-Open_Ports_in_the_firewall-CLI.html
[2] other firewall-cmd https://www.hiroom2.com/2017/07/12/fedora-26-firewalld-en/
[3] zones https://www.digitalocean.com/community/tutorials/how-to-set-up-a-firewall-using-firewalld-on-centos-7

Fedora - mySQL restoring root

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

#service mysqld stop // id doesn't stop run #mysqladmin -u root -p shutdown

#mysqld_safe --skip-grant-tables &

#mysql -u root 

> use mysql;

> update user set password=PASSWORD("mynewpassword") where User='root';

> flush privileges;

> quit

#service mysqld stop 

#service mysqld start &

if mysqld_safe not exist (updated 2019)
# systemctl stop mysqld
# systemctl set-environment MYSQLD_OPTS="--skip-grant-tables"
# systemctl start mysqld
$ mysql -u root
get temporaly password (updated 2019)

$sudo grep 'temporary password' /var/log/mysqld.log

A temporary password is generated for root@localhost: cvcvcv 

$mysql -u root -p 

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass4!'; 

https://dev.mysql.com/doc/refman/8.0/en/linux-installation-yum-repo.html
reference:
http://www.rackspace.com/knowledge_center/article/mysql-resetting-a-lost-mysql-root-password

Ubuntu 18 add Samba

References:
[1] https://websiteforstudents.com/samba-setup-on-ubuntu-16-04-17-10-18-04-with-windows-systems/

Monitor network bandwidth on Linux server

References:
[1] https://www.binarytides.com/linux-commands-monitor-network/

Ubuntu Memory type ddr2 ddr3

$ sudo dmidecode --type 17

$ sudo lshw -short -C memory
 
From [1]

DDR1: 2.5 V, 133–200 MHz
DDR2: 200–400 MHz
DDR3: 1.5 V, 400–800 MHz (up to 1400 MHz for super-high-end)
DDR4: 1.2 V, 2133–4266 MHz

For example: if shows up in lshw -short -C memory as simply 16GiB DIMM Synchronous 2133 MHz (0.5 ns). The MHz rating indicates that it's almost certainly DDR4.

References:
[1] memory types http://en.wikipedia.org/wiki/Synchronous_dynamic_random-access_memory#Generations_of_SDRAM
[2]

Ubuntu upgrade from i386 to x86_64

https://askubuntu.com/questions/5018/is-it-possible-to-upgrade-from-a-32bit-to-a-64bit-installation

Mono ASP.NET MVC

References
[1] http://www.developerslearnit.com/2016/11/build-master-details-crud-in-aspnet-mvc.html
[2] 

Search old pages, Archive of webpages

[1] https://web.archive.org
      for example compelligence.com
                          grpiaa.inf.pucp.edu.pe

Tensor resources

References:
 [1] Tensor decomposition https://www.slideshare.net/panisson/tensor-decomposition-with-python
 [2] Tensores (sp) http://bibing.us.es/proyectos/abreproy/12082/fichero/Cap%C3%ADtulo3.pdf

Ubuntu 16 OpenCV 2.4

Problems during compilation:

relocation R_X86_64_32 against `ff_a64_muxer' can not be used when making a shared object

Solution:
recompile ffmpeg-3.4.5 with(2018-11-29):
./configure --enable-nonfree --enable-pic --enable-shared

Download ffmpeg and build 3.4.5, 3.2.12 or 4.0 and try to compile opencv doesn't help, then

Final solution: disable ffmpeg
$cmake  -D WITH_CUDA=OFF -D WITH_FFMPEG=0 ..
$make

That compile opencv 2.4.x and 3.4.x



References:
[1] Error sys/videoio.h not found problem http://yutopapa.hatenadiary.com/entry/2017/06/08/173149

ASP.NET MVC Mono

Settings at 11/2018

.Net Framework 4.5.2 using project properties
Mysql.Data.Entity using NuGet(6.10.8)

Setup Web.config

<!--Added--> 
<configSections> <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.2.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</configSections> 
<connectionStrings> 
  <add name="ferredb" connectionString="server=127.0.0.1;Port=3306;Database=ferre;Uid=root;Pwd=Microsoft;" providerName="MySql.Data.MySqlClient"/> </connectionStrings> 
<!--Added--> 
<entityFramework> 
<providers> 
  <provider invariantName="MySql.Data.MySqlClient" type="MySql.Data.MySqlClient.MySqlProviderServices, MySql.Data.Entity.EF6, Version=6.10.8.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d">
  </provider> 
</providers> 
</entityFramework> 
<!--Added--> 
<system.data> 
<DbProviderFactories> <remove invariant="MySql.Data.MySqlClient" /> <add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data, Version=6.10.8.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d"/> 
 </DbProviderFactories> 
</system.data>

Fix version of entry System.Web.Mvc.MvcWebRazorHostFactory at views/Web.config


Classes

//Ado
using System;
using System.Data.Entity;
using MySQLEntity.Models;

namespace MySQLEntity.Entity
{

public class MyDb : DbContext
{
public MyDb() : base("ferredb")
//public MyDb() : base(nameOrConnectionString: "ferredb")
{
}
public DbSet<Usuario> Usuarios { get; set; }
}

}

//Entity
using System;
//Added
using System.ComponentModel.DataAnnotations.Schema;
using System.ComponentModel.DataAnnotations;


namespace MySQLEntity.Models
{
        [Table("Users")]
        public class Usuario
        {
            [Key]
            public string usuario { get; set; }
            public string apenom  { get; set; }
        }

}



Controller Snippet code

public ActionResult Index()
{
  MyDb db = new MyDb();
  var Model=db.Usuarios.ToList();
  return View(Model);
}
View Snippet code

@foreach (var item in Model)
{

<div> @item.usuario @item.apenom </div>

}

Action results

References:
[1] MySQL EntityFramework web.config https://iyalovoi.wordpress.com/2015/04/06/entity-framework-with-mysql-on-mac-os/
[2] Action results
https://www.c-sharpcorner.com/article/different-types-of-action-results-in-asp-net-mvc/
[3] ViewBag better than DataView http://www.tutorialsteacher.com/mvc/viewbag-in-asp.net-mvc

mySQL Develop Optimization

Select * from MOVPRO where fecmov>='2018-11-25' and tipmov='S'
EXPLAIN Select * from MOVPRO where fecmov>='2018-11-25' and tipmov='S'

CREATE INDEX MOVPRO_fecmov_tipmov_index ON MOVPRO (fecmov,tipmov)


References:
[1] faster using indexes https://blog.nodeswat.com/making-slow-queries-fast-with-composite-indexes-in-mysql-eb452a8d6e46

python3 using mysql connection

$pip3 install mysql-connector-python --user

from mysql.connector import (connection)


cnx=connection.MySQLConnection(user='user', password='*******',
             host='ip', database='db')

cnx.close()


Resources:
[1] https://dev.mysql.com/doc/connector-python/en/connector-python-installation.html

API Testing

References
[1] postman https://steelkiwi.com/blog/api-testing-useful-tools-postman-tutorial-and-hints/

Water Simulation

Compiling Sources:
[1] 2D SPH https://github.com/tizian/SPH-Water-Simulation
    $sudo apt-cache search sfml
    $sudo apt-get install libsfml-dev
    #change for's
    $make
    $./sph

[2] WebGL water simulation https://experiments.withgoogle.com/webgl-water-simulation

[3] Google webgl https://experiments.withgoogle.com/search?q=fluid
  [3.1] http://david.li/fluid/
  [3.2] http://madebyevan.com/webgl-water/
[4] 3D Simulation/Animation/Fluids and more https://www.fetchcfd.com/search-projects/type/cfd

Related:
[1] Stanford su2 https://su2code.github.io/
[2] Multiple Interacting Fluids https://www.yiningkarlli.com/projects/multifluid.html