UBB.Developers Forums Community Development Programming PHP and Server-side Scripting any quick code to discover if a file is jpg or gif?

any quick code to discover if a file is an image, and if this image is either a jpg or a gif?

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Right-click on the image then select properties???

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The Fusion of Goku & Trunks...GoTorankusuKu

hehe perl

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The Image::Size module at http://www.cpan.org/ can do this.

how? i mean, i read all the size.pm code but couldnt understand his (the autor) use of the $handle variable, wich he uses to compare different image types.

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($file,$extention) = split(/./,$filename);

print "This file is not an image" if $extention ne 'gif' or $extention ne 'jpg';
print "This is a .jpg image" if $extention eq 'jpg';
print "This is a .gif image" if $extention eq 'gif';

That would do that trick

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yeah you are right..

but if the guy has some "." in the middle of the name of the file, or in the path of the file. this code is for use with an upload utility.

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Here's an example. $image_file_fh is the file handle returned by CGI::upload(). The parameter to imgsize() can also be a file name.


If you want to check the file extension, you can ignore periods in the middle like this:


(Using 'die' in CGI scripts is generally not a good appproach. But these are just examples, and I wanted to keep them simple.)

This message has been edited by Dave_L on December 09, 2000 at 10:04 AM

great does imagesize tests the code of the file to return $type, or just the filename

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It reads the actual file. So if someone creates a .bmp file, and renames it to .jpg, Image::Size::imgsize() will correctly recognize that it's really a .bmp file.

That is entirely untrue.

--mark

thanks

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Really? Why is that?

I use 'die' for serious errors that shouldn't ever occur, but for most error-checking, I try to do something more user-friendly.

In my current search CGI script, I use die. I find it more, well, helpful, than something more "user friendly" as you say.


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MasterMind

Something user friendly as a matter of preference is fine, but that should not be presented as "generally not a good approach" which implies that there is something wrong with doing that.

Using $! in a die statement gives the error that was caused, so other then making the output page look pretty, there really isn't any thing different about doing that.

--mark

Yep.

But thats not my preference.

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MasterMind

I didn't mean to start a controversy with my 'die' comment

Perhaps "generally not a good approach" was a poor choice of words.

If a script is intended for use by yourself, or other programmers, then a message like "Incorrect file type at line 123 myscript.cgi" may be fine. If the script is intended for use by Mr. Average Websurfer, then I would prefer to handle the error in a way that provides the user with information that he understands.

Just my opinion


This message has been edited by Dave_L on December 09, 2000 at 06:36 PM

"I didn't mean to start a controversy with my 'die' comment"

But you didn't

You did spark a discussion of methods and preferences, not a controversy. That would imply a different intent that is not present here.

(hint on translating Markisms: Just because he is not wordy sometimes doesn't mean he was giving you a slapdown. He might just have been real busy at the time, when he IS giving you a slapdown it is usually painfully obvious)

"If a script is intended for use by yourself, or other programmers, then a message like "Incorrect file type at line 123 myscript.cgi" may be fine. If the script is intended for use by Mr. Average Websurfer, then I would prefer to handle the error in a way that provides the user with information that he understands."

That's what you did here:
die 'Image file type must be either .gif or .jpg';

Seems just as effective to me as spinning out a fancy webpage with the error message then exit; just not a nice looking.

howabout die 'Image file type must be either .gif or .jpg, hit your backbutton'; ?

You *could* always do it the UBB way, make a sub to pass messages like StandardHTML but for smaller scripts it seems like overkill to me.

I use die 'message'; in everything I write except the UBB. But then again all of the stuff I write for my own websites are a lot smaller, mail scripts, upload scripts, etc. Little nobranier 100 liner stuff. I don't see the need in getting more fancy for my crappy little websites Your mileage will vary.

Anyhow, point was that "Perhaps "generally not a good approach" was a poor choice of words" was a correct statement. Using die 'message'; is perfectly acceptable depending on circumstances. maybe just not in yours

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"There is no spoon" is back.

This message has been edited by navaho on December 09, 2000 at 09:47 PM

Tis, true... I wasn't meaning it as a controversy, just in that the way you had stated it gave the impression to folk that using die is a bad thing, and that goes against a lot of hard work i've put in trying to instill the notion of using it over the past X months

--mark

yay ^^

upload custom avatar

thanks guys.

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