Writing IM code

<?php
$color = 'red';
$image = 'rose:';
$size = '70x46';
$string = 'A Rose by any Name';

// Example 1 - Using concatenate
exec("convert -background none -fill $color -gravity center " .
            " -font Candice -size $size caption:\"$string\" " .
            " \( $image -negate -flip \) +swap -composite " .
            " output.gif" );

// Example 2 - Using the imagemagick line continuation of \    
// You need to escape the \ with another \ so it becomes \\    
exec("convert -background none -fill $color -gravity center \\
    -font Candice -size $size caption:\"$string\" \\
    \( $image -negate -flip \) +swap -composite \\
    output.gif" );

// Example 3 - Writing the comand into a variable        
$cmd = "-background none -fill $color -gravity center " .
            " -font Candice -size $size caption:\"$string\" " .
            " \( $image -negate -flip \) +swap -composite ";            
exec("convert $cmd output.gif" );

// Example 4 - One long line        
exec("convert -background none -fill $color -gravity center -font Candice -size $size caption:\"$string\" \( $image -negate -flip \) +swap -composite output.gif" );
?>