web notes - a blog

With sincere thanks to the link above, this is how you can adjust the screen resolution under CentOS 6.

Run this command (with the appropriate resolution):

cvt 1920 1080

You’ll get output similar to this:

# 1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz
Modeline “1920x1080_60.00″ 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync

Copy the modeline and paste it after –newmode, like so:

xrandr --newmode "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync

Then assign the new mode to the device:

xrandr --addmode VGA-1 "1920x1080_60.00"

This was done on a clean stock CentOS 6.4 installation, no custom drivers.

To get the settings to persist across sessions, I created /etc/gdm/PostLogin/Default
like so:

#!/bin/sh
#
if [ -f "$HOME/.gdm/PostLogin/Default" ];
then
	exec -l "$SHELL" -c "$HOME/.gdm/PostLogin/Default"
fi;

Under the account, I add the Default file:

xrandr --newmode "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync
xrandr --addmode VGA-1 "1920x1080_60.00"
xrandr --output VGA-1 --mode "1920x1080_60.00"

Be sure to grant execute permissions on both /etc/gdm/PostLogin/Default and $HOME/.gdm/PostLogin/Default.

Adding nVidia drivers didn’t help, adding hplip didn’t help. There is a Tripp-Lite KVM switch. This was the answer.

And, it looks great.

An example of a base class.

Sample extension and call for instantiation:

<?php
class Course extends Base {

        public function __construct($properties) {
                $this->_properties = array(
                        'id'=>array(
                                'required' => false,
                                'default' => null,
                                'filter' => FILTER_VALIDATE_INT,
                                'options' => array('min_range' => 0, 'max_range' => PHP_INT_MAX)),
                        'name' => array(
                                'required' => true,
                                'default' => null,
                                'filter' => FILTER_VALIDATE_REGEXP,
                                'options' => array('regexp' => '/^[\w\,\.\'\-\(\)\$ ]{3,}$/')),
                        'isCore' => array(
                                'required' => true,
                                'default' => true,
                                'filter' => FILTER_VALIDATE_BOOLEAN));

                return parent::__construct($properties);
        }
}

<?php
Abstract Class Base {

        protected $_properties = null;
        protected $_data = array();
        protected $_valid = false;
        protected $_error_message = array();

        function __construct($properties = null) {
                if (is_array($properties)) {
                        foreach ($this->_properties as $k => $v) {
                                if (isset($properties[$k])) {
                                        $p = $properties[$k];
                                        if (is_string($p)) {
                                                $p = trim($p);
                                                if ($p === "") {
                                                        if (empty($p) && $v['required']) {  // this should never happen
                                                                return null;
                                                        }
                                                }
                                        }
                                } else {
                                        $p = $v['default'];
                                }
                                $this->_data[$k] = $p;
                        }
                        $filter = filter_var_array($this->_data,$this->_properties);
                        if ($filter === false || in_array(false,$filter,true)) {
                                foreach ($filter as $k => $v) {
                                        if (($v === false) &&
                                                ($this->_properties[$k]['filter'] !== FILTER_VALIDATE_BOOLEAN)) {
                                                // This is an important test, a boolean false, 
                                                // validated as such, doesn't mean the filter
                                                // failed.  
                                                trigger_error('Invalid data');
                                        }
                                }
                        }
                }
                return $this->_data;
        }

        function __get($property) {
                return isset($this->_data[$property]) ? $this->_data[$property] : null;
        }

        function __set($property, $value) {
                $this->_data[$property] = $value;
        }

        function toJson() {
                return json_encode($this->_data);
        }

        function isValid($property = null) {
                if ($property === null)
                        return $this->_valid || (count($this->_error_message) == 0);
                else
                        return !isset($this->_error_message[$property]);
        }

        function error($property) {
                if (isset($this->_error_message[$property])) {
                        return $this->_error_message[$property];
                } else {
                        return '';
                }
        }
}

This is a very simple PHP contact form validation script.

It fails silently, based on the expectation the client is validating the data prior to submitting it. In this case, if the server receives invalid inputs, inputs with invalid data, or a data set missing required inputs, it is assumed the data is either not being submitted by the expected client code, or it has been tampered with en route.

The silent fail is a die with no output. This provides no information for potentially malicious visitors.

If the data is valid, it is echoed back to the server JSON encoded.

if (isset($_POST) && !empty($_POST)) {
        $required = array('name', 'email', 'interest', 'relationship', 'message');
        $optional = array('phone', 'subscribe');
        $inputs = array_merge($required, $optional);
        foreach ($_POST as $k => $v) {
                if (!in_array($k, $inputs)) {
                        die;
                }
                $v = trim($v);
                if (!empty($v)) {
                        $data[$k] = $v;
                } else {
                        if (in_array($k, $required)) {
                                die;
                        } else {
                                $data[$k] = '';
                        }
                }
        }

        $filter = filter_var_array($data, array(
                'name' => array('filter' => FILTER_VALIDATE_REGEXP,
                                'options' => array('regexp' => '/^[ \w\,\.\'\-]{5,}$/')),
                'email' => FILTER_VALIDATE_EMAIL,
                'interest' => array('filter' => FILTER_VALIDATE_REGEXP,
                                'options' => array('regexp' => '/^(Sales|Support)$/')),
                'relationship' => array('filter' => FILTER_VALIDATE_REGEXP,
                                'options' => array('regexp' => '/^(Client|Partner|Vendor)$/')),
                'subscribe' => array('filter' => FILTER_VALIDATE_REGEXP,
                                'options' => array('regexp' => '/^(on)?$/')),
                'message' => array('filter' => FILTER_VALIDATE_REGEXP,
                                'options' => array('regexp' => '/^[\w\,\.\'\-\(\)\$ ]{5,}$/')),
                'phone' => array('filter' => FILTER_VALIDATE_REGEXP,
                                'options' => array('regexp' => '/^(1[ \-\.])?(\d{3})?[ \-\.]?\d{3}[ \-\.]?\d{4}$/'))));

        if ($filter === false || in_array(false,$filter)) {
                die;
        }
        echo json_encode($filter);
}

In an environment where security is important (security is important in all environments), this code should be extended to include a unique token validation, where a token is sent to the client on the initial request and the next request must have the identical token or it will be considered invalid.

This code was converted from a bash version to create pie charts. It is much faster and does not require bc on the server.

PHP is used to create the ImageMagick command line.

This code creates pie chart and legend images which can then be placed on a web page or added in to a document.

To call the code, create an array of values, instantiate the GFX objects, establish the label_color_map as an associative array where the label text is the key and the value is a hex color code, and finally create the chart, sending a name and the data array, like so:

                        $data = array(50, 70, 100, 3, 49);
                        $chart = new GFX();
                        $chart->label_color_map(array('one' => '#1c28a1', 
                          'two' => '#600087',
                          'three' => '#107a3f',
                          'four' => '#bf0000',
                          'five' => '#ff6d00'));
                        $chart->piechart('project',$data);

<?php 
Class GFX extends Base {

        public function __construct($parms = null) {
                $this->_properties = array('centerx','centery','width','height',
'radius');
                if (!is_array($parms)) {
                        $parms['width'] = $parms ['height'] = 330;
                        $parms['centerx'] = $parms['centery'] = 160;
                        $parms['radius'] = 135;
                }
                parent::__construct($parms);
        }

        public function label_color_map ($map = array()) {
                $this->_data['labels'] = array();
                foreach ($map as $k => $v) {
                        $this->_data['labels'][$k] = $v;
                }
        }
        public function piechart($name = null, $data = array()) {
                // Thanks to: http://jbkflex.wordpress.com/2011/07/28/creating-a-svg-pie-chart-html5/
                if ($name === null) return;

                $total = array_sum($data);

                $max=0;$kmax='None';
                foreach ($data as $k => $v) {
                        $value[$k] = (int)(($v/$total) * 100);
                        if ($value[$k] > $max) {
                                $kmax=$k;
                                $max=$value[$k];
                        }
                }
                while (array_sum($value) < 100) {
                        $value[$kmax]++;
                }

                foreach ($data as $k => $v) {
                        $value[$k] = (int)(($v/$total) * 100);
                        if ($value[$k] > $max) {
                                $kmax=$k;
                                $max=$value[$k];
                        }
                }
                while (array_sum($value) < 100) {
                        $value[$kmax]++;
                }
                $centerx = $this->_data['centerx'];
                $centery = $this->_data['centery'];
                $radius= $this->_data['radius'];
                $count=0;
                $startAngle=0;
                $endAngle=0;
                $arc=0;
                $x1=0;
                $x2=0;
                $y1=0;
                $y2=0;
                $pi=pi();
                $cmd='convert -size '.$this->_data['width'].'x'.$this->_data['height'].' xc:white -stroke white -strokewidth 5 ';

                foreach ($value as $k => $v) {
                        $startAngle=$endAngle;
                        $endAngle=$startAngle+(360*$v/100);
                        $theta = $pi*$startAngle/180;
                        $x1=$centerx+$radius*cos($theta);
                        $y1=$centery+$radius*sin($theta);
                        $theta = $pi*$endAngle/180;
                        $x2=$centerx+$radius*cos($theta);
                        $y2=$centery+$radius*sin($theta);
                        $arc = ($v >= 50) ? '1' : '0';
                        $cmd.=' -fill "'.$this->_data['labels'][$k].'" -draw "path \'M '.$centerx.','.$centery.' L '.$x1.','.$y1.
                                ' A '.$radius.','.$radius.' 0 '.$arc.',1 '.$x2.','.$y2.' Z"';
                        $count++;
                }
                $cmd.=' '.escapeshellarg(_GFX_DIR_.'/'.$name.'_chart.jpg');
                `$cmd`;

                if (!is_array($this->_data['labels'])) return;

                $KEY_SIZE=20;
                $MARGIN=5;
                $TEXT_X=$KEY_SIZE+$MARGIN;

                $height =  $TEXT_X * count($value);

                $cmd = 'convert -size 135x'.$height.' xc:white -fill white ';
                $label = " -font 'Nimbus-Sans-Bold' -stroke none -pointsize 12 ";
                $count=0;
                $y1=5;
                foreach ($value as $k => $v) {
                        $y2=$y1+$KEY_SIZE;
                        $y3=$y2-$MARGIN;
                        $label.=' -fill "'.$this->_data['labels'][$k].'" -draw "rectangle 0,'.$y1.' '.$KEY_SIZE.','.$y2.'"'.
                                ' -draw "text '.$TEXT_X.','.$y3.' '.escapeshellarg(/*$data[$k].' '.*/$v.'% '.$k).'"';
                        $count++;
                        $y1=$y1+$KEY_SIZE+$MARGIN;
                }
                $cmd.= $label.' '.escapeshellarg(_GFX_DIR_.'/'.$name.'_legend.jpg');
                `$cmd`;
        }
}

<?php
Abstract Class Base {

        protected $_properties;
        protected $_data;
        protected $_valid = false;
        protected $_error_message = array();

        function __construct($props) {
                $this->_data = array_fill_keys($this->_properties, null);
                $this->_data = array_merge($this->_data, $props);
        }

        function __get($property) {
                return isset($this->_data[$property]) ? $this->_data[$property] : null;
        }

        function __set($property, $value) {
                $this->_data[$property] = $value;
        }

        function isValid($property = null) {
                if ($property === null)
                        return $this->_valid || (count($this->_error_message) == 0);
                else
                        return !isset($this->_error_message[$property]);
        }

        function error($property) {
                if (isset($this->_error_message[$property])) {
                        return $this->_error_message[$property];
                } else {
                        return '';
                }
        }
}

Many thanks to the link above for the chart algorithm.

This post courtesy of Worktrainer.

This is a very simple script that will create a pie chart and legend using bash, bc, and ImageMagick. Many thanks to the link above which provided the algorithms to complete the SVG paths.

It accepts a list of parameters which must add up to 100. The script has two arrays, LABELS and COLORS which are applied to each parameter in order.

#!/bin/bash

function usage {
        echo "Usage: `basename $0` piece1 piece2 piece3 ..."
        echo -e "\tWhere each piece is a percentage of the pie"
        echo -e "\tThe pieces must add up to 100"
        exit $E_BADARGS
}

LABELS=("None"  "Accept" "Defer" "Discard")
COLORS=("#1c28a1"  "#107a3f" "#ff6d00" "#bf0000");

TARGET_DIR='images'

if [ $# -lt 3 ];
then
        usage
fi;

arc=()
sum=0
for piece in "$@"
do
        sum=$(( $piece + $sum ))
done

if [ $sum -ne 100 ];
then
        usage
fi

WIDTHxHEIGHT='330x330'
RADIUS=135
CENTERX=160
CENTERY=160

count=0
startAngle=0
endAngle=0
arc=0
total=0
x1=0
x2=0
y1=0
y2=0
pi=$(echo "scale=10; 4*a(1)" | bc -l)
cmd='convert -size '$WIDTHxHEIGHT' xc:white -stroke white -strokewidth 5 '
first=0
for piece in "$@"
do
        startAngle=$endAngle
        endAngle=$(echo "scale=10;$startAngle+(360*$piece/100)" | bc -l)
        x1=$(echo "scale=10;$CENTERX+$RADIUS*c($pi*$startAngle/180)" | bc -l)
        y1=$(echo "scale=10;$CENTERY+$RADIUS*s($pi*$startAngle/180)" | bc -l)
        x2=$(echo "scale=10;$CENTERX+$RADIUS*c($pi*$endAngle/180)" | bc -l)
        y2=$(echo "scale=10;$CENTERY+$RADIUS*s($pi*$endAngle/180)" | bc -l)
        if [ $piece -ge 50 ]
        then
                FIFTY=1
        else
                FIFTY=0
          fi
        cmd=$cmd"-fill '${COLORS[count]}' -draw \"path 'M $CENTERX,$CENTERY L $x1,$y1 A $RADIUS,$RADIUS 0 $FIFTY,1 $x2,$y2 Z'\" "

        count=$(( $count + 1 ))
done
cmd=$cmd" $TARGET_DIR/idea_chart.jpg"

eval $cmd

KEY_SIZE=20
MARGIN=5
TEXT_X=$(( $KEY_SIZE+$MARGIN ))

legends=$(( $#*($KEY_SIZE+$MARGIN) ))

cmd='convert -size 125x'$legends' xc:white -fill white '
label=" -font 'Nimbus-Sans-Bold' -stroke none -pointsize 12 "
count=0;
y1=5
for piece in "$@"
do
        y2=$(( $y1+$KEY_SIZE ))
        y3=$(( $y2-$MARGIN ))
        label=$label"-fill '${COLORS[count]}' -draw 'rectangle 0,$y1 $KEY_SIZE,$y2 ' -draw \"text $TEXT_X,$y3 '$piece% ${LABELS[count]}'\" "
        count=$(( $count + 1 ))
        y1=$(( $y1+$KEY_SIZE+$MARGIN ))
done
cmd=$cmd$label" $TARGET_DIR/idea_legend.jpg"

eval $cmd

exit; 

The FIFTY is used when an arc will span 50% or more of the pie, it sets the large-arc-flag.

This post courtesy of Worktrainer.