PostgreSQL 8.4 en CentOS

1) Deshabilitar repositorios

#vi /etc/yum.repos.d/CentOS-Base.repo

agregar la siguiente linea a [base] y [updates]
exclude=postgresql*

2) Añadir los repositorios de PostgreSQL 8.4
Descargar el rpm apropiado desde http://yum.pgsqlrpms.org/reporpms/repoview/pgdg-centos.html

#wget http://yum.pgsqlrpms.org/reporpms/8.4/pgdg-centos-8.4-2.noarch.rpm
#rpm -ivh pgdg-centos-8.4-2.noarch.rpm (este archivos es el que descargamos)

3) Instalar PostgreSQL

3.1 verifique version
#yum list postgresql*

#yum install postgresql postgresql-server

3.1 Error probable de dependencia a apr-util
#yum install apr-util
#yum install postgresql postgresql-server

4) Arrancar el servidor y habilitar conexiones remotas

#service postgresql initdb
#service postgresql start

5) Configurar Accesos en /var/lib/pgsql/data/
5.1 pg_hba.conf
host all all 0.0.0.0/0 trust   #no need password , use md5
5.2 postgresql.conf
listen_addresses='*'
port=5432
max_connections=100
superuser_reserved_connections=5

6) Reinicia servicio
#/etc/init.d/postgresql restart


Referencias
[0] Postgres 9.1 http://wiki.postgresql.org/wiki/YUM_Installation
[1] Auto Start/Stop http://www.michaelhinds.com/tech/linux/install-postgres.html
[2] http://www.ixavi.com/2010/01/instalar-postgresql-8-3-en-centos-desde-yum/

Linux root password reset

Mode 1:Recover mode

In recover mode try to remount and after that change password

mount -o remount,rw /
 
Mode 2: Using live

mkdir /mnt/recover
mount /dev/sda2 /mnt/recover
 
chroot /mnt/recover
 
passwd  #or
passwd user 
exit
umount /mnt/recover

Other way : Using files(for root or any user)
 
 /etc/passwd
 /etc/shadow
  
root:x:0:0:root:/root:/bin/bash
to
root::0:0:root:/root:/bin/bash 

References:

[1] http://www.microhowto.info/howto/reset_a_forgotten_root_password_using_a_live_distribution.html

[2] https://www.computersecuritystudent.com/UNIX/UBUNTU/1204/lesson5/index.html

Epson Drivers

Resources:
[1]  https://goo.gl/4vrWdC

Raspberry Resources

DOSBox and rpi-x86 will play DOS games and run Win31/Win95.

QEMU can be used to emulate an x86 PC but performance will be terrible.

Wine will not work because it does not translate binary data, only Windows API calls, the binaries are still incompatible.

This is a difficult problem to solve which is probably why ExaGear charge money for it.

Resources:
[1] Chart comparison all famous Arm processors https://www.loverpi.com/blogs/news/85588545-raspberry-pi-banana-pi-orange-pi-odroid-differences-and-chart
[2] Odroid vs other https://tudosobreraspberry.info/2017/08/comparacao-raspberry-pi-orange-pi-banana-pi-e-odroid/

[3] Raspberry Pi3 vs UDOO x86 https://www.youtube.com/watch?v=dJkHxDjFuNA
[4] Combine qemu and wine for run Windows applications https://github.com/AlbrechtL/RPi-QEMU-x86-wine
[5] https://www.kickstarter.com/projects/udoo/udoo-x86-the-most-powerful-maker-board-ever/?src=soc
[6] https://www.raspberrypi.org/forums/viewtopic.php?t=189198

[7] https://elchapuzasinformatico.com/2016/04/udoo-x86-10-veces-mas-potente-raspberry-pi-3-79e/
[8] https://www.redeszone.net/2016/05/20/udoo-x86-mini-ordenador-10-veces-mas-potente-raspberry-pi-3/
[9] https://www.anandtech.com/show/11978/macom-sells-off-appliedmicros-xgene-cpu-business
[1] Experimental comparison Raspberry and Orange https://raspberryparatorpes.net/rivales/raspberry-pi-vs-orange-pi-2017/

Ubuntu users

#adduser username

#usermod -aG sudo username

$su - username

$whoami

$sudo whoami   

Examples to use

$fdisk -l

$sudo fdisk -l

$sudo ls -l /root



mySql Optimization parameters or commands

Query

SHOW GLOBAL STATUS

SHOW VARIABLES LIKE '%size%';
SHOW GLOBAL VARIABLES LIKE '%size%';

Settings

SET GLOBAL join_buffer_size = 1024 * 1024 * 128 #128M

or

[mysqld]
join_buffer_size = 128M  #default ~256K

 

References:

[0] Compute memory http://mysqlcalculator.com/ 

[1] join_buffer_size https://dba.stackexchange.com/questions/74693/how-to-break-table-into-two-without-losing-performance 

[2] https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html

[3] Example tunning https://dba.stackexchange.com/questions/127862/tuning-mysql-variables-to-accommodate-high-load

[4] Query variables https://dev.mysql.com/doc/refman/8.0/en/show-variables.html

Sunat Servicios Web

Resources:
[1] Code perl http://cpan.dei.uc.pt/authors/id/G/GP/GPAREDES/SUNAT/SEE.pm

[2] http://orientacion.sunat.gob.pe/index.php/empresas-menu/comprobantes-de-pago-empresas/comprobantes-de-pago-electronicos-empresas/see-desde-los-sistemas-del-contribuyente/guias-manuales-y-servicios-web

JavaScript Frameworks Lecture

References:

[1] https://reactjs.org/
[2] https://www.w3schools.com/whatis/whatis_react.asp
[3] Repository https://github.com/facebook/react

mySql Common Commands

CREATE TABLE foo LIKE bar;

CREATE TABLE IF NOT EXISTS offices_bk

SELECT * FROM

    offices;

==

CREATE TABLE IF NOT EXISTS new_table LIKE existing_table;

INSERT new_table

SELECT * FROM existing_table;

ALTER TABLE <tablename> CHANGE COLUMN <colname> <colname> VARCHAR(65536);

ALTER TABLE emp MODIFY COLUMN name VARCHAR(100);

Or use CHANGE, but that means you have to give the column name twice (because CHANGE allows you to change the name of the column too).
ALTER TABLE emp CHANGE COLUMN name name VARCHAR(100);

Linux Discover Teamviewer id

$sudo grep -n id /home/user/.local/share/teamviewer14/logfiles/TeamViewer14_Logfile.log

$whereis teamviewer
$/usr/bin/teamviewer help
$/usr/bin/teamviewer info #for get id too

$/usr/bin/teamviewer daemon stop
$/usr/bin/teamviewer setup
$/usr/bin/teamviewer daemon status
$/usr/bin/teamviewer daemon start

References:
[1] http://www.tonisoto.com/2013/07/launching-teamviewer-remotely-throught-ssh/

mySql change port problem

Can't start server: Bind on TCP/IP port: Permission denied
Do you already have another mysqld server running on port: 13306 ?


Common solution is change my.cnf adding port=newport, but in what section?

Discover who is the principal executable
$locate mysqld.service

/etc/systemd/system/multi-user.target.wants/mysqld.service
/usr/lib/systemd/system/mysqld.service

$vi /usr/lib/systemd/system/mysqld.service #for watch settings
In my case, was this:
ExecStart=/usr/bin/mysqld_safe --basedir=/usr

then i know what section i need to change

$vi /etc/my.cnf  # add new port in section [mysqld_safe]

Aditional commands during process:

tail -30 /var/log/mysql/error.log

sudo lsof -i TCP:3306
netstat -lp | grep 3306
 

$systemctl status iptables.service

$service iptables status

Ubuntu mySQL Backup/Restore

1)Create


2) Restore


$mysql -u root -p mysql
> create database mydb; mysql
> use mydb; mysql
> source db_backup.dump;


3) Another way, you  need to run:

$mysql -p -u[user] [database] < db_backup.dump

If the dump contains multiple databases you should omit the database name:

$mysql -p -u[user] < db_backup.dump

4) Restore specific database

$mysql -u onepoint -p --one-database maxx2016 < back_20190226.sql

Ubuntu Apache Django settings

References:
[1] main https://www.digitalocean.com/community/tutorials/how-to-serve-django-applications-with-apache-and-mod_wsgi-on-ubuntu-16-04

[2] https://coderwall.com/p/ooerda/python-django-apache-ubuntu
[3] https://www.digitalocean.com/community/tutorials/how-to-serve-django-applications-with-apache-and-mod_wsgi-on-debian-8

Fixing geopandas and osmnx problem: Could not find libspatialindex_c library file

For secondary problem trying to resolve (trying to find the library i got):
Traceback (most recent call last):
  File "", line 1, in
NameError: name 'find_library' is not defined
The solution is:

import ctypes
from ctypes.util import find_library

When you install environment and install geopandas, rtree and osmnx

pip install git+git://github.com/geopandas/geopandas.git

pip install rtree

pip install osmnx

No error, everythong aparently is ok, and you try to test

$python

>>> import rtree
Traceback (most recent call last):
 File "", line 1, in
 File "/var/www/sampleapp/crivist/myEnv/lib/python3.5/site-packages/rtree/__init__.py", line 1, in
   from .index import Rtree
 File "/var/www/sampleapp/crivist/myEnv/lib/python3.5/site-packages/rtree/index.py", line 5, in
   from . import core
 File "/var/www/sampleapp/crivist/myEnv/lib/python3.5/site-packages/rtree/core.py", line 125, in
   raise OSError("Could not find libspatialindex_c library file")
OSError: Could not find libspatialindex_c library file

You can solve using:
sudo apt install python3-rtree
But in some servers, you can't access to apt, then you decide do next commands:

$git clone https://github.com/libspatialindex/libspatialindex.git
$cd libspatialindex
$cmake --prefix=/usr .
$make
$sudo make install  #You cannot install on system

CMake Error at src/cmake_install.cmake:52 (file):
  file INSTALL cannot copy file
  "/home/fincahuanaco/Temp/libspatialindex/bin/libspatialindex.so.5.0.0" to
  "/usr/local/lib/libspatialindex.so.5.0.0".
Call Stack (most recent call first):
  cmake_install.cmake:42 (include)

But you compile, then you have the link to file, then set next variable

export SPATIALINDEX_C_LIBRARY=environmentpath/lib/libspatialindex_c.so


Enjoy

References:
[1] geopandas http://geopandas.org/install.html
[2] python environment https://docs.python-guide.org/dev/virtualenvs/
[3] python environment 2 https://docs.python.org/3/tutorial/venv.html

Level Set Topics

References:


[1] Methods In (Bio)Medical Image Analysis 2019 https://www.cs.cmu.edu/~galeotti/methods_course/

Print JavaScript

[1] PDF and HTML http://printjs.crabbly.com/

Latex On Line

Latex online

[1] Single/public https://www.papeeria.com

[2] Latex/R/Python/Octave/Julia/Shell/GPU https://cocalc.com/

[3] Single Latex & Octave http://www.verbosus.com/  #limit 4 resources

[4] Quick snap code to image quicklatex.com

 

Over google docs
http://docs.latexlab.org/


Single Compiler
[1] http://latex.informatik.uni-halle.de/latex-online/latex.php
[2] http://sciencesoft.at/latex/flatex.gsp?lang=en

After register
Unlimited https://www.sharelatex.com/
Monkey http://monkeytex.bradcater.webfactional.com/


 



Others References
[1] http://tex.stackexchange.com/questions/3/compiling-documents-online
[2] http://texblog.net/latex-link-archive/online-compiler/

Ubuntu VPN

References:

[1] https://www.digitalocean.com/community/tutorials/how-to-set-up-an-openvpn-server-on-ubuntu-16-04

[2] Setting clients https://www.utwente.nl/en/lisa/ict/manuals/network/vpn/openvpn-ubuntu-en/

Python 3D Interactive

[1] Python draw 2d and 3d http://jeffskinnerbox.me/notebooks/matplotlib-2d-and-3d-plotting-in-ipython.html

[2] Python 3D picking https://stackoverflow.com/questions/10424517/how-to-get-properties-of-picked-object-in-mplot3d-matplotlib-python

[3] Python mayavi picking http://docs.enthought.com/mayavi/mayavi/auto/example_pick_on_surface.html

[4] Python mayavi for 3D https://docs.enthought.com/mayavi/mayavi/mlab.html

Fedora 23 - Executing MONO Asp.NET MVC App

Table 'mysql.user' doesn't exist:ERROR
Or
ERROR 1146 (42S02): Table 'mysql.role_edges' doesn't exist

$mysql_upgrade -u root

Access problem (resolve inner mysql)

$mysql -u root -p
>show GRANTS FOR onepoint@localhost;


Execution problem



Turns out simply creating the folder using mkdir

$sudo mkdir /etc/mono/registry
$sudo chmod uog+rw /etc/mono/registry # setting the right permissions

Another way

You can set MONO_REGISTRY_PATH to point to a directory that you control:

$mkdir my-registry
$MONO_REGISTRY_PATH=`pwd`/my-registry
$xsp4

 

Next problem

System.MissingMethodException Method 'RouteCollection.get_AppendTrailingSlash' not found.




[uxxx@sxxx MaxxCoreWeb]$ mono --version
Mono JIT compiler version 4.0.5 (Stable 4.0.5.1/1d8d582 Mon Jan  4 11:09:45 UTC 2016)




These message showed because the system was build in mono 4.5 and mono 4.2 (both are compatible
for me in my system), but in my case i installed mono 4, lastest on Fedora 23.


Command for update repository to Fedora 27, but after update still doesn't ran
 

$rpm --import "https://keyserver.ubuntu.com/pks/lookup?op=get&search=0x3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF"
$su -c 'curl https://download.mono-project.com/repo/centos7-stable.repo | tee /etc/yum.repos.d/mono-centos7-stable.repo'
$dnf update

I removed mono and tried to install mono 5, mono 4.8 and mono 4.2, but i got error of conflicts. Then i executed next command:

$sudo dnf autoremove #for remove dependences


And tried again and was successful.

$ sudo dnf install mono-complete-4.8.1.0-0.xamarin.1.x86_64




References:
[1] Upgrade tips https://fedoraproject.org/wiki/DNF_system_upgrade
[2] mono https://www.mono-project.com/download/stable/#download-lin-fedora