Displaying an image pulled from database

Anon

I am having trouble getting an image to display after pulling it from the database.

Because my images are be dynamic in the page I cannot rely on printing header information to the page (keep getting errors) and so I am searching for a workaround without using frames.

I got the idea to take the image out of the database and stick it into an temporary file then read the file with a typical <img src> tag. The code I am using to create the temporary file is as follows:

exec ('cat $data > /.../$file_name');

this creates a file say penguin.jpg , I then use a typical <img src> tag with the filename, and I receive an image placeholder on the webpage.

Because it did not work I decided to check the file in the gimp to see if it was a valid jpeg. It appeared to be, then using samba I opened it in the browser it originally failed in directly by double clicking the file. The browser displayed the image correctly. At this point I am stumped. I know the browser can display the image, I can open it with any program that can open images, but I cannot display it with an <img src> tag.

Does anyone know of any additional information I need to add to the file, for example do I need to encode the file type into the image somehow (other than by properly appending the file type to the name)?

Any help would be appreciated.

brandonschnell

your file on the system is ok and the web server will detect the mime type using the file extension and the contents of the file. check the img src tag and be sure the path is a relative path to the web root, and not a filesystem path.

for example if you're sending the file to "/home/httpd/html/images/penguin.jpg" and your web root is "/home/httpd/html/" then in the img src just specify "/images/penguin.jpg" as the file location.

seriously look at storing just the file location in the db and not the contents of the image. there seems to be too many issues with storing the images in the database.

something like the below should also work:

define("GIF", "1");
define("JPG", "2");
define("PNG", "3");
define("SWF", "4");

$temp_image = tempnam ("/tmp", "img");
$fp = fopen($temp_image, "w+");
fwrite($fp,$data);
fclose($fp);

$Image_Info = GetImageSize($temp_image);

if($Image_Info[2] == GIF)
$im = @ImageCreateFromGIF($temp_image); / Attempt to open /
else if($Image_Info[2] == JPG)
$im = @ImageCreateFromJPG($temp_image); / Attempt to open /

else if($Image_Info[2] == PNG)
$im = @ImageCreateFromPNG($temp_image); / Attempt to open /
else
Image_Error("Image Format Not Supported!");

if (!$im) / See if it failed /
echo "Failed To Open Tmp File";

unlink($temp_image);
if($Image_Info[2] == GIF)
ImageGif($im);
else if($Image_Info[2] == JPG)
ImageJPG($im);
else if($Image_Info[2] == PNG)
ImagePNG($im);
else
Image_Error("Image Format Not Supported!");

Anon

Brandon,

Thank you for your help.

I appreciate the time you spent writing the code. The problem WAS that I had the filesystem pathname, not relative to document root.

Stupid mistake that I wasted two hours on.

As far as not storing files in the database, I agree with you, however in this case the database will have many files with the same name stored in it, and I do not want to have to handle the duplicate name issue.

Thanks again
-Jeff

brandonschnell

np.

who says i spent more than a second writing code? cut and paste, man! =)

yah, i've had this issue before. it seems like you either play around with file names and worry about file permissions but can use the php image functions and easily handle mime types, or you stick everything into a database and have to extract the data to a file to do anything. if the mime types are known and are consistent you can work around this and output the data straight to the browser without creating a temp file.

would be nice if the php image functions would work on php vars (raw data).

ledruide

I have a weird problem :

i can echo my data

// echo $data;

but i can not cat it in a file.

// $MyCommand = "cat $data > /tmp/$filename";
// system($MyCommand);

error :
// cat: ÿØÿáØExif: No such file or directory

Any idea ?

yelvington

You should fix the real problem, which is "I cannot rely on printing header information to the page (keep getting errors)...." You don't need temporary files. If you're getting errors when calling header() to set the content-type, look at your code and make certain it does not send data before header() is called.

[deleted]

Rookie mistake: cat reads a file, echo prints text.

Anon

i have a similar problem, i keep images in a database (know i should probably have only kept the filenames there and stored images as files, but anyways, done is done.

i use a simple php file to display the image in a <img src="show_img.php"> type tag, this works GREAT in IE without using headers, but it doesnt work in NS, ok i decided to put in some header information, still work in IE and helped a little bit in NS , that is to say the image will still not show inside another page (with img tag) BUT, if i for instance use:
<a href="show_img.php"><IMG SRC="show_img.php"></a>
the image will appear when i click on it (when browser then redirects to what it thinks is an image), but why will it still not work "inside" another page as img tag ?

Anon

hmm seemed i fixed it by removing a lowsrc tag in the img tag.. so forget it 🙂

neilm

I stopped storing images in a database after my binary table corrupted on my twice in one year. MySQL on FreeBSD. Better have a back up plan.

Neil