File I/O

pcp

Hello,

Allright, I have a somewhat strangly simple, in another language like perl, question for some one to answer. My problem has to do with a message book that I am trying to change over from perl to php code. Now my perl code can insert text into a file in the following mannor:

...
<body>

new message appended to the file.

 old and existing message.
<!--end-->

</body>
...

So I tried to do the same thing with php using fopen() and fwrite(), and of course I used the "a+" option for fopen(), but unfortunatly I was unable to append text to the middle of a file.
Now I'm not sure if their is a way to do this, other than regenerating the page every time a new message is added, but if someone knows how could you please let me know how this is done..

Also which method, either regenerating the html code or editing the file, is less costly as far as load time is concerned.

I would appreciate any help on this matter.

Thank you,
pcp

levi_501_dehaan

I am not quite understanding the problem 🙂
You want to place entered text from a form into a file without submitting the page to the php script?

thats what I got.

you cant do it without submission. however to write to the middle of the file you have to set the file pointer to the middle of the file.
use the r+ option to start at the beginning of the file.
then

$fd = [man]fopen[/man] ($filename, "r+");
then this to read the file
$contents = [man]fread[/man] ($fd, filesize($filename));
$length = [man]strlen/man
$length = $length/2;
[man]fseek[/man]($fd, $length);
[man]fputs[/man]($fd, $yourdatastring);

this opens the file counts how long the string is, divides by 2, takes that number and sets the file pointer. then writes the data to the middle of the file.

hope this helped in some way.
-=Levi=-

pcp

Ok, so I was a bit unclear.. Sorry, I can be that way some times.

What I have is a file say index.php and I also have a comment tag in which to do a regular expression check to locate where I want to insert the new text.

I.E.

...
<body>
 (coment: this is my comment tag to search for.)

Then I want to insert text after the  tag with out disrupting any old messages or text, which is already located be low the  tag.

I.E.

old:
...
<body>

some sort of text message...

</body>
...

Now with the new user form input message:

...
<body>

A new text message...

   some sort of text message...
 <!--end-->

</body>
...

I hope that I have come off a bit clearer. If not I will have to rethink how I should be asking my question.

Thanks,
pcp

levi_501_dehaan

Hmm...
I dunno dude, your still a bit fuzzy on the edges but I think I'm starting to get what you want.

it almost sounds like you want to modify the php file to add in the text into the php file, after a user had submitted it?

ok first off this isnt really perl 🙂, and unfortunantly i have not yet decided to learn perl yet 🙂.

so i need you to put it in php terms.
your accepting user input, you want to put it on your page after a user has entered it. i am supposing you want other users to be able to browse it.
so you are going to have to store the information somewhere.
they way you are putting it makes me think you want to change the actualy php file. which is...ok...but it would not make much sense.

you are want to put your data, which is in a string now, after the user submitted it. underneath more data.

why dont you tell me what your script does? is it a forum? does it accept user input? from what? whats the name of the string that takes data, do you want other users to see it? where are you storing the data? what format are you storing your data in (if not a db).

maybe that will clear stuff up. cuz even though i kind of understand what your asking, some of it just doesnt make sense without knowing what you want to do with it all ect...

-=Levi=-
also, someone may know perl if you want to wait for them to answer, they may understand your question better. 🙂

pcp

Ok, what I am trying to do is a simple guestbook. The files I am using are guestbook.html, for viewing the entries, addguest.html, for gathering the data via an html form with at least the following data, user name and a message:
user name is a simple text box.
message is a textarea.
I also use guestbook.php for all of my form parsing and what not.

So, guestbook.html calls addguest.html via a '<a href' link where addguest.html is basically just the form that has an action = "guestbook.php", so you could just say that addguest.html calls guestbook.php to parse form data. When things check out ok and I am ready to save the message, which I am trying to store in guestbook.html, I open guestbook.html and look for the html comment "" so that I can add the new message after the comment. Here is a code snipit:
$env_vars['guestbookreal'] = "guestbook.html";
...
$file = fopen ("{$env_vars['guestbookreal']}", "a+");

if (!$file)
{
print ("<p>Unable to open remote file.\n");
}
$begin_edit = 0;
while (!feof ($file)) {
$line = fgets ($file);
if (eregi ("", $line, $out)){
$begin_edit = 0;

}
if ($begin_edit == 1) {
fwrite ($file, "{$f_data['message']}");
}
if (eregi ("", $line, $out)) {
$begin_edit = 1;
}
}
fclose($file);

Again, I'm not even sure if this is the right way to attempt this, but this is why I am here asking. I did not mean to suggest that any of what I was writting was perl, I only meant that I had this working in perl and was trying to convert it to php, mainly just for learning purposes. In other words I'm trying to lean php a bit better than I already know it.

If this is still unclear then I will struggle thru it hacking my way as I go an I appologize for chewing up your time.

Thanks,
pcp

levi_501_dehaan

ohhhhh 🙂
ok dude, gotcha,
here this may help a bit, and speed up the process a little.

/* if env_vars isnt working for you, you may just want to put guestbook.html :) */
$file = fopen ("{$env_vars['guestbookreal']}", "r+"); 
     if (!$file) 
          { 
           print ("<p>Unable to open remote file.\n"); 
          } 
    $begin_edit = 0; 
while (!feof ($file)) 
{ 
     $line = fgets ($file);
/* this finds the position of the first occurence of <!--begin--> 
also, this may set your pointer to ! instead of the end of <!--
begin--> so you may want to set +1 to +12 or the length of the needle :) */

 $find = strpos($line, "<!--begin-->", +1)
/* this sets the file pointer to the <!--begin--> */
     fseek($file, $find); 
/* this puts your data there */
     fputs($file, $yourdatastring); 
}
fclose($file);

pcp

Hey levi,

Thanks for the help, but I ended up having to take a different route. I decided to use a temp text file to store the messages in and then just load them into the display page when needed. Later, after I further my knowledge of php I will create a database and use it to do the same thing.

Just so you know, fseek() does not work on any http or ftp files and if used it can really mess your system up. As in, I use XP prof. and when I used fseek() my system crashed hard. I have never had XP prof crash on me until the other day. O'well I am a true believer in linux, but because of my wifes school related stuff I must stick with Windows for the time being.

Thanks again,

pcp.

levi_501_dehaan

No problem.
Yeah, fseek isnt for remote files, it is for files on your machine, but your guestbook was on the same machine as the script 🙂. so it should have worked. but if your using windows php, and stuff, then yeah, who knows what will happen 🙂.
some functions will give windows xp a buffer overflow, giving your maching a nice kick in the ass 🙂. but good thing you found a workaround

ahh, yes, well to furthur your knowledge quickly, with one of the best tutorials i've read on this subject goto www.mysql.com/articles/ddws/2.html
it'll learn ya reel quik 🙂

-=Levi=-