php 给GIF 缩略图实例代码

<?php

try
{
    /*** Read in the animated gif ***/
    $animation = new Imagick("animation.gif");

    /*** Loop through the frames ***/
    foreach ($animation as $frame)
    {
        /*** Thumbnail each frame ***/
        $frame->thumbnailImage(100, 100);
   
        /*** Set virtual canvas size to 100x100 ***/
        $frame->setImagePage(100, 100, 0, 0);
    }

    /*** Write image to disk. Notice writeImages instead of writeImage ***/
    $animation->writeImages("animation_thumbnail.gif");

    echo "Images written";
}
catch(Exception $e)
{
    echo $e->getMessage();
}

?>

例子

<?php

/**
 *
 * Read a line number from a file
 *
 * @param    string    $file    The path to the file
 * @param    int    $line_num    The line number to read
 * @param    string    $delimiter    The character that delimits lines
 * @return    string    The line that is read
 *
 */
function readLine($file, $line_num, $delimiter=" ")
{
    /*** set the counter to one ***/
    $i = 1;

    /*** open the file for reading ***/
    $fp = fopen( $file, 'r' );

    /*** loop over the file pointer ***/
    while ( !feof ( $fp) )
    {
        /*** read the line into a buffer ***/
        $buffer = stream_get_line( $fp, 1024, $delimiter );
        /*** if we are at the right line number ***/
        if( $i == $line_num )
        {
            /*** return the line that is currently in the buffer ***/
            return $buffer;
        }
        /*** increment the line counter ***/
        $i++;
        /*** clear the buffer ***/
        $buffer = '';
    }
    return false;
}
?>

Example Usage

<?php

/*** make sure the file exists ***/
$file = 'my_file.txt';

if( file_exists( $file ) && is_readable( $file ) )
{
    echo readLine($file, 6);
}
else
{
    echo "Cannot read from $file";
}
?>

This method of iterating over the file and seeking to the line number works well and is memory efficient, but it would be nice to have PHP do the work for us. PHP provides the SPL File Object which will do exactly what is required.

<?php

/*** the file to read ***/
$file = 'foo.txt';

       
/**
 *
 * Read a line number from a file
 *
 * @param    string    $file    The path to the file
 * @param    int    $line_num    The line number to read
 * @return    string    The line that is read
 *
 */
function readLine( $file, $line_number )
{
        /*** read the file into the iterator ***/
        $file_obj = new SplFileObject( $file );

        /*** seek to the line number ***/
        $file_obj->seek( $line_number );

        /*** return the current line ***/
        return $file_obj->current();
}

echo readLine( $file, 345678 );

?>

<?php

    error_reporting(E_ALL);

    $width = 80;

    /*** the image file to thumbnail ***/
    $image = 'spork.jpg';

    if(!file_exists($image))
    {
        echo 'No file found';
    }
    else
    {
        /*** image info ***/
        list($width_orig, $height_orig, $image_type) = getimagesize($image);

        /*** check for a supported image type ***/
        if($image_type !== 2)
        {
            echo 'invalid image';
        }
        else
        {
            /*** thumb image name ***/
            $thumb = 'thumb.jpg';

            /*** maintain aspect ratio ***/
            $height = (int) (($width / $width_orig) * $height_orig);

            /*** resample the image ***/
            $image_p = imagecreatetruecolor($width, $height);
            $image = imageCreateFromJpeg($image);
            imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);

            /*** write the file to disc ***/
            if(!is_writeable(dirname($thumb)))
            {
                echo 'unable to write image in ' . dirname($thumb);
            }
            else
            {
                imageJpeg($image_p, $thumb, 100);
            }
        }
    }
?>

 <?php
    /**
    *
    * Validate a date
    *
    * @param    string    $date
    * @param    string    format
    * @return    bool
    *
    */
    function validateDate( $date, $format='YYYY-MM-DD')
    {
        switch( $format )
        {
            case 'YYYY/MM/DD':
            case 'YYYY-MM-DD':
            list( $y, $m, $d ) = preg_split( '/[-./ ]/', $date );
            break;

            case 'YYYY/DD/MM':
            case 'YYYY-DD-MM':
            list( $y, $d, $m ) = preg_split( '/[-./ ]/', $date );
            break;

            case 'DD-MM-YYYY':
            case 'DD/MM/YYYY':
            list( $d, $m, $y ) = preg_split( '/[-./ ]/', $date );
            break;

            case 'MM-DD-YYYY':
            case 'MM/DD/YYYY':
            list( $m, $d, $y ) = preg_split( '/[-./ ]/', $date );
            break;

            case 'YYYYMMDD':
            $y = substr( $date, 0, 4 );
            $m = substr( $date, 4, 2 );
            $d = substr( $date, 6, 2 );
            break;

            case 'YYYYDDMM':
            $y = substr( $date, 0, 4 );
            $d = substr( $date, 4, 2 );
            $m = substr( $date, 6, 2 );
            break;

            default:
            throw new Exception( "Invalid Date Format" );
        }
        return checkdate( $m, $d, $y );
    }
?>

Example Usage

<?php
        echo validateDate( '2007-04-21' ) ? 'good'. " " : 'bad' . " ";
        echo validateDate( '2007-21-04', 'YYYY-DD-MM' )  ? 'good'. " " : 'bad' . " ";
        echo validateDate( '2007-21-04', 'YYYY/DD/MM' )  ? 'good'. " " : 'bad' . " ";
        echo validateDate( '21/4/2007', 'DD/MM/YYYY' )  ? 'good'. " " : 'bad' . " ";
        echo validateDate( '4/21/2007', 'MM/DD/YYYY' )  ? 'good'. " " : 'bad' . " ";
        echo validateDate( '20070421', 'YYYYMMDD' )  ? 'good'. " " : 'bad' . " ";
        echo validateDate( '04212007', 'YYYYDDMM' )  ? 'good'. " " : 'bad' . " ";
?>

<?php
/*** an array of attributes about a dog ***/
$array = array('animal'=>'dog', 'name'=>'Offenbach', 'owner'=>'Mr Smith');

/*** add the dogs favourite food to the array ***/
$array = ($array, 'food', 'postmans leg');

/*** print the array ***/
print_r($array);

/**
 * @Push and element onto the end of an array with associative key
 *
 * @param array $array
 *
 * @string $key
 *
 * @mixed $value
 *
 * @return array
 *
 */
function ($array, $key, $value){
 $array[$key] = $value;
 return $array;
}

?>

This will return the following results

Array
(
   [animal] => dog
   [name] => Offenbach
   [owner] => Mr Smith
   [food] => postmans leg
)