Reading a .dat file.

tablex

Hi,

I got a small problem here, usually I fetch information from a database, but in this case I have choosen to read information from a .dat file.

Here a small description:

help_design.php = the page where the faq are displayed in plain html, with all a unique id as hyperlinks.

layout.css = not important in this case, just a css file.

design.dat = the file with the answers.
Structure like this:
1|VRML is not supported
2|You are right about that
3|...

Etc.

Now I get this error:

"Sorry couldn't find the answer."

Which is strange, because the file is there, I have set the permissions to 777 and the id is ok.

I think it's my script?

I hope anyone can tell me what I am doing wrong.
Thanks in advance.

<?php
include("/home/blablabla/bla/layout.css");

if (isset($GET['id']))
{
$datfile = sprintf('/home/blablabla/bla/%u.dat', $GET['id']);
if (file_exists($datfile))
{
show_detailed($datfile);
}
else
{
echo"<META HTTP-EQUIV=\"refresh\" CONTENT=\"3; URL=http://www.mysite.com/help_design.php?<?=SID?>\">";
echo"<center><a href=\"$HTTP_REFERER\">Sorry couldn't find the answer.</a></center>";
exit;
}
}
else
{
echo"<META HTTP-EQUIV=\"refresh\" CONTENT=\"3; URL=http://www.mysite.com/help_design.php?<?=SID?>\">";
echo"<center><a href=\"$HTTP_REFERER\">Sorry please try again later.</a></center>";
exit;
}

function show_detailed ($file) {
$arr = file('/home/blablabla/bla/design.dat');
foreach ($arr AS $line)
{
$line = trim($line);
list($id, $answer) = explode('|', $line);

printf('<li><a href="help_design.php?id=%u">%s</a><br>', $id, $id, $answer);
print "\n";
}

}

merkinmuffley

so, the file_exists() check is failing, yes? have you tried peeking at the contents of the $datfile variable just before file_exists() gets called? perhaps the string in that variable isn't exactly what you think it is.

p.s.
it really helps make your code readable if you stick it between the php code-formatting tags, [ php ] and [ /php ] (but without the spaces)

theslinky

Okay, first of all, where are you using ID.dat (where ID is the stuff from the get variable)? I only see that you are using design.dat.

Secondly, like merkinmuffley suggest, try printing out the contents of that string. Also, error_reporting set to report all errors might say something about the file not existing.

Also, try changing %u with %d. %d is for signed integers. I doubt this will make a difference, but personally, i rarely used %u in PHP (even in C 🙂).

-sridhar

tablex

1)
The ID is from a previous page:

http://www.mysite.com/page.php?username=guest&id=50

Now this should fetch following line from design.dat

50|answer to question

2)
Ok I changed and echoed $datfile, the page seems to refer to 1.dat when the id=1, 2.dat when the id=2 and so on.

That's the mistake, because 1.dat doesn't exist.
What should I change to make requests for an answer being fetched as above?

I hope someone can help me out here, because I am really stucked here...

Thanks in advance...

theslinky

Okay, first let's establish what you're trying to do:

you want to open the design.dat file and see if the ID exists, if not, it will say "sorry no answer blah blah", correct?

If that's what you're trying to do, then do this:

<?php

// first get the ID
if( (isset($_GET['id'])) && ($_GET['id'] != "") ) {
$id = $_GET['id'];
}
else {
echo "not ID specified";
exit;
}

// now open the file and check whether that ID is valid
$fcontents = file("/path/to/design.dat");
foreach($fcontents as $line) {
list($id, $line) = explode("|", $line);
if($id == $_GET['id']) {
// we found a match
print "found answer... do what you want here";
break; // we don't need to search anymore
}
}

?>

what you should do is put the various pieces of the above code into functions so you won't have to call exit like I did. I'm too lazy to type the full well constructed code (so i'll leave that up to you 🙂).

-sridhar

tablex

You have put an end to my misery!

Thanks a lot!