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Syntax Question

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audiopro

audiopro

Programmer
Apr 1, 2004
3,165
GB
The following code was working up until Monday this week.
Code: 
if(-e $JPG_PICTURE){
print "1";
}else{
print "0";
}
The next section creates a web page and simply prints a picture with the name of $JPG_PICTURE.
The code above always evaluates as false and prints a 0 on the screen, then it prints the actual picture.
It appears that there is a problem with PERL with the ISP. Please confirm that the syntax is correct as my ISP says there is something wrong with the script.


Keith
 
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Well, it appears to just be checking whether a file exists or not. Are you sure the file does not exist? Add this under print "1";

Code: 
print STDERR "JPG_PICTURE: '$JPG_PICTURE' exists\n";

That will give you the path to the file, if that file's existence is a problem, maybe just move/delete it?

--jim
 
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Added your code to the 1 option and nothing additional is printed.

This is part of a much more complex script but I have broken it down to its very basic form in the hope of finding out what is going wrong.

Code: 
$JPG_PICTURE= ...... (Full Path to Picture)
# The picture does exist

	if(-e $JPG_PICTURE){
		print "1<br>";
	}else{
		print "0<br>";
# Prints 0 as if file not found
	}

# A bit of HTML to view the picture
print <<"test html";
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
<meta name="GENERATOR" content="Microsoft FrontPage 4.0">
<meta name="ProgId" content="FrontPage.Editor.Document">
<title>New Page 2</title>
</head>
<body>
<p><img border="0" src=$JPG_PICTURE></p>
</body>
</html>
test html
exit;

Prints the picture I am expecting.



Keith
 
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Then tried the same code as above with your code in both options and still nothing additional printed.
Code: 
	if(-e $JPG_PICTURE){
print STDERR "JPG_PICTURE: '$JPG_PICTURE' exists\n";

		print "1<br>";
	}else{
print STDERR "JPG_PICTURE: '$JPG_PICTURE' exists\n";

		print "0<br>";
	}
My head is starting to hurt now.

Keith
 
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Ah, this is a CGI script. The output is sent to STDERR, so check your log files. Or, just take out the STDERR part. I was thinking the STDOUT output was used for something else, like input to another program.

--jim
 
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The problem seems to have been resolved.
The ISP has been moving files to new servers etc. and I think something had been destroyed/corrupted.
I didn't help the problem by my changing the original script to one which I now think, could never work. I had originally had a local reference to an images directory which stopped working on Monday. In my wisdom I had changed it to a full path reference.
It would seem that the -e function works locally but is unable to check files on a full http:// link.
A few experiments have shown this to be the case - worth remembering in the future.
Thanks for your help - it is always appreciated when someone takes the time to help for no reward.


Keith
 
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Are you saying domain as in windows work groups? Or as in domain names for URL's? Judging by your earlier post where you mentioned http:// you are trying to do something like this:

if( -e " ){ ... }

And you are correct in thinking this will not work because "-e" is just a file test operator for files on the local filesystem.

If you need to see if a file exists on another server there are many ways to do that, is that what you are trying to do?

--jim
 
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Another URL yes.
Not something I want to do at the moment but the thought came to mind when I was working out the subject of this post.
Why is it, the more we learn, the more we need to know.

Keith
 
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