Main Page

From Wiki at Neela Nurseries

Revision as of 14:55, 27 December 2017 by Ted (talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Jump to: navigation, search

MediaWiki installation at Neela Nurseries, 2017 June

Consult the User's Guide for information on using the wiki software.

Getting started - this is MediaWiki's default main page section

1 Getting started - this is MediaWiki's default main page section
2 ^ Linux Distributions
- 2.1 ^ lists of Linux distribution releases
3 ^ Linux and Linux Kernel Projects
4 ^ Linux Administration
5 ^ Linux User Space Configuration
- 5.1 ^ Edit point . . .
- 5.2 ^ SSH key pair configuration and use
6 ^ Unix and Linux utilities
7 ^ Shell scripting
8 ^ How To Use Git
9 ^ Drupal Content Management
10 ^ Composer, a dependency manager of PHP
11 ^ Geography and Science
12 ^ Technology
13 ^ Music and Culture
14 ^ Outdoors

^ Linux Distributions

Following section holds links to some commonly used server and desktop Linux distributions, available for download as install isos and sometimes as minimal net install isos. After these full-scale distros are listed some of the smaller distributions of Linux and supporting softwares. These smaller distros appear to be a good starting point for learning how to design and build embedded Linux systems . . .

- 2017-11-30 -

- 2017-12-08 -

http://trac.clfs.org/

^ lists of Linux distribution releases

Red Hat Enterprise releases

^ Linux and Linux Kernel Projects

^ Linux Administration

Debian upgrade from wheezy to jessie

multiple IPs assigned to one network interface

Article detailing how to add IPV4 route to configured network interface:

https://my.esecuredata.com/index.php?/knowledgebase/article/2/add-a-static-route-on-centos

^ Linux User Space Configuration

To configure xserver-xorg

Snippet from work on getting xserver-xorg to recognize a 1920x1080 native resolution monitor, ViewSonic VX2250 Series monitor . . .


user@localhost:~$ gtf 1920 1080 60

  # 1920x1080 @ 60.00 Hz (GTF) hsync: 67.08 kHz; pclk: 172.80 MHz
  Modeline "1920x1080_60.00"  172.80  1920 2040 2248 2576  1080 1081 1084 1118  -HSync +Vsync

user@localhost:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 8.9 (jessie)
Release:        8.9
Codename:       jessie

user@localhost:~$

Looking at /var/log/Xorg.0.log there appear to be two or more issues keeping xserver-xorg framework from fully recognizing the resolutions of the attached monitor. First we'll sift for errors from X, then we look at loading of modules, unloading of modules, the module named 'radeon', and also look at the timing of these X-logged events:


user@localhost:/var/log$ grep -n EE Xorg.0.log
15:     (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
342:[    27.938] (EE) open /dev/dri/card0: No such file or directory
344:[    27.938] (EE) open /dev/dri/card0: No such file or directory
351:[    27.945] (EE) open /dev/fb0: No such file or directory
359:[    27.946] (EE) open /dev/fb0: No such file or directory
360:[    27.946] (EE) Screen 0 deleted because of no matching config section.
362:[    27.946] (EE) Screen 0 deleted because of no matching config section.
364:[    27.946] (EE) Screen 0 deleted because of no matching config section.
2689:[    28.915] (EE) AIGLX: reverting to software rendering

user@localhost:/var/log$ grep -n 'LoadModule: ' Xorg.0.log
47:[    27.193] (II) LoadModule: "glx"
58:[    27.669] (II) LoadModule: "ati"
64:[    27.719] (II) LoadModule: "radeon"
70:[    27.795] (II) LoadModule: "modesetting"
76:[    27.832] (II) LoadModule: "fbdev"
82:[    27.842] (II) LoadModule: "vesa"
346:[    27.938] (II) LoadModule: "fbdevhw"
354:[    27.946] (II) LoadModule: "fbdevhw"
368:[    27.946] (II) LoadModule: "vbe"
374:[    27.994] (II) LoadModule: "int10"
396:[    28.200] (II) LoadModule: "ddc"
2651:[    28.611] (II) LoadModule: "shadow"
2657:[    28.621] (II) LoadModule: "fb"
2664:[    28.630] (II) LoadModule: "int10"
2694:[    31.327] (II) LoadModule: "evdev"

user@localhost:/var/log$ grep -n UnloadModule Xorg.0.log
361:[    27.946] (II) UnloadModule: "radeon"
363:[    27.946] (II) UnloadModule: "modesetting"
365:[    27.946] (II) UnloadModule: "fbdev"

user@localhost:/var/log$ grep -n radeon Xorg.0.log
64:[    27.719] (II) LoadModule: "radeon"
65:[    27.720] (II) Loading /usr/lib/xorg/modules/drivers/radeon_drv.so
66:[    27.795] (II) Module radeon: vendor="X.Org Foundation"
361:[    27.946] (II) UnloadModule: "radeon"

user@localhost:/var/log$

^ Edit point . . .

References for Linux user-space configuration issues:

^ SSH key pair configuration and use

Ted copying some ssh key commands from Digital Ocean article on-line. Also noting that ssh keys and secure network connections is a topic to factor into its own wiki article at Neela wiki installation . . . - TMH

Digital Ocean ssh key pairs tutorial

Key ssh key generation and set up commands are:


   $ ssh-keygen -r rsa

   $ cat ~/.ssh/id_rsa.pub | ssh user@123.45.56.78 "mkdir -p ~/.ssh && cat >>  ~/.ssh/authorized_keys"

^ Unix and Linux utilities

Use of `date` command to convert Unix timestamps:

Vagrant Cascadian < * e-mail address here * >
	
AttachmentsDec 7 (1 day ago)
	
to Juergen, Santiago, Reprobuilds, bug-apl
On 2017-12-05, Juergen Sauermann wrote:
> I have adopted the environment variable approach, which is now
> contained in *SVN 1026*. (and therefore also in the next GNU APL release).

That's great news!


> I took the freedom to change your patch from:
>
> +    BUILD_DATE=`date -u "%F %R:%S %Z" --date=@$SOURDCE_DATE_EPOCH`
>
> to:
>
> + BUILD_DATE=`date -u "+%F %R:%S %Z" --date=$SOURCE_DATE_EPOCH`

Unfortunately, the "@" in the --date argument is necessary for it to
work correctly when SOURCE_DATE_EPOCH is specified:

  $ date -u "+%F %R:%S %Z" --date=1412583777
  date: invalid date ‘1412583777’
  $ date -u "+%F %R:%S %Z" --date=@1412583777
  2014-10-06 08:22:57 UTC
  $ date -u "+%F %R:%S %Z" --date=
  2017-12-06 00:00:00 UTC

At least, that's how it works on my Debian system...


live well,
  vagrant

^ Shell scripting

A well-written and comprehensive guide to bash shell scripting:

Advanced Bash Shell Scripting Guide

Simple bash script to back up MYSQL databases to local .sql file, in following figure. Ted noting that script variables are not consistently capitalized, would be better form to capitalize all or none of them. Ted also noting that script could read database user passphrase from a file, a file which could be root-only readable and located in a place different from the script, which is likely to be run as a cron job.

Figure x - shell script to dump MYSQL databases, first draft script:

#!/bin/bash


DATABASE_LIST="information_schema mysql phpmyadmin wikidb database_1 database_2 database_3 ..."

SERVER_NAME="example_database_server"

user="root"
pass_phrase_for_mysql="database-passphrase"
options_extra="--skip-lock-tables"


response="n"

mode_interactive="n"



echo "shell script starting,"



for database in ${DATABASE_LIST}; 
do echo "backing up $SERVER_NAME database $database . . .";

#    command="mysqldump --databases $database -u$user -p$pass_phrase_for_mysql $options_extra >> au-database-back-up--${database}.sql"
    command="mysqldump --databases $database -u$user -p$pass_phrase_for_mysql $options_extra"
    redirect="au-database-back-up--${database}.sql"

    if [ $mode_interactive = 'y' ]; then

        echo "build command '$command' and database back-up filename'$redirect',"
        echo "full command will be '$command' > '$redirect',"
        echo "trying running this command and redirect? [y/N/q]  yes, no, 'q' to quit"

        read response
        if [ $response = 'Y' -o $response = 'y' ]; then
            ${command} > $redirect
        elif [ $response = 'N' -o $response = 'n' ]; then
            echo "skipping present command . . ."
        elif [ $response = 'Q' -o $response = 'q' ]; then
            echo "stopping script '$0' and exiting."
            break
        fi
        echo

    else

        echo "$0:  backing up database '$database' to file '$redirect' . . ."
        ${command} > $redirect
        ls -l $redirect

    fi

done


echo "done."

exit 0

Figure x - script to show Linux kernel version in source tree makefile

#!/bin/bash


## - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
## Started 2017-12-15 FRI - script to parse and show Linux kernel
##  version from top-level makefile in set of kernel sources.  Patterns
##  to `grep` chosen based on kernel version identifiers in first
##  three lines of typical kernel top-level makefile.  Example:
##
##  $ head -n 6 Makefile
##  VERSION = 4
##  PATCHLEVEL = 9
##  SUBLEVEL = 66
##  EXTRAVERSION =
##  NAME = Roaring Lionus
##
##
## - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


if [ ]; then
    head -n 5 Makefile | grep ^VERSION | cut -d " " -f 3
    head -n 5 Makefile | grep ^PATCH | cut -d " " -f 3
    head -n 5 Makefile | grep ^SUBLEVEL | cut -d " " -f 3
fi

MAJOR=$(head -n 5 Makefile | grep ^VERSION | cut -d " " -f 3)
MINOR1=$(head -n 5 Makefile | grep ^PATCH | cut -d " " -f 3)
MINOR2=$(head -n 5 Makefile | grep ^SUBLEVEL | cut -d " " -f 3)

KERNEL_REVISION="${MAJOR}.${MINOR1}.${MINOR2}"

echo
echo "Kernel version in present kernel sources tree, per makefile, is ${KERNEL_REVISION}"
echo



exit 0

^ How To Use Git

- 2017-12-04 - Hey Ted moving Git notes to a separate article. Not a lot of notes but anticipating need to write down more detailed git-related stuff. Ted's git notes on Neela wiki will be here at Git notes article.

Wanting to understand and use git better, here are some on-line references to git version control. Also, Ted searching for a git reference posted by a female author, can't remember name but reference well-written with lots of commands and concise explanations of each command. First URL reference may be that page, now 2017-10-02 not sure of the author's name . . .

Basic git commands:

Git references found while answering specific git task questions:

Markdown and .md file formatting at Github