What have I done wrong now???

DAL · #1 (**permalink**) 11-24-03, 09:06 AM

(Ive repeated this thread as I think ppl where missing it in the last board)
(Forgive me if you have already seen it and Im now getting on ur wick! :s )
Another problem

I want to search through a pl file (HTML file really) and find the eof. Then I want to take so-many bytes backward to a place in that file for append.

Header info perl & <HTML>. This part of the file puts out the graphic for the board and sets up the tables ready.

Middle Each new entry is based on
<tr>
format for board. Message information ,pic,number of posts ect
</tr>

This is duplicated for each new message...

<tr>
format for board. Message information ,pic,number of posts ect
</tr>

Footer finishes the </table> and puts the graphic and form at the bottom of the page.

Since Footer is always a static lenght I want to find the start of footer for append for the new message;

<tr>
format for board. Message information ,pic,number of posts ect
</tr>

--------------------------

Syswrite statment clames in many resources that it can contain a negitive number!
"An OFFSET may be specified to write the data from some part of the string other than the beginning. A negative OFFSET specifies writing that many bytes counting backwards from the end of the string. In the case the SCALAR is empty you can use OFFSET but only zero offset. "

when I try;
open (ADDTHEPOST, ">>/homepages/39/d87399782/htdocs/Internal/Boardsys/general/GEN300001.pl") or die "Unable to write open file. Reason: $!";

syswrite ADDTHEPOST, "HELLO",-105,2;

close (ADDTHEPOST);

I get a server error of the following;

Software error:
Negative length at /homepages/39/d87399782/htdocs/Internal/Boardsys/general/Addpost.pl line 85.

?Whats up..
syswrite FILEHANDLE,SCALAR,LENGTH,OFFSET
syswrite ADDTHEPOST,"HELLO",-105,2

I am using offset 2 to find the end of file. What have I done wrong this time?

Thanks
DAL

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Millennium · #2 (**permalink**) 11-24-03, 12:42 PM

delete it from the other thread so things don't get confusing.

DAL · #3 (**permalink**) 11-24-03, 01:40 PM

Cant delete - is says I only can delete 60 min after creating - its past that now

Anyone got any clue how to seek through the file? I dont need to put it in a scalar as the thing is already stored in a file! Never had a problem with this in the past with other programming/scripting langauges. why the sudden change???

Millennium · #4 (**permalink**) 11-24-03, 03:56 PM

OK. I didn't realize that you can't delete the post.

I think you have LENGTH and OFFSET confused. OFFSET is the value to use to write from the end of the file (or the beginning). You can't write a file that is -105 bytes long, at least I don't think you can.

But I am not sure how using the file option ">>" (apppend mode) will affect using an offset, if at all.

DAL · #5 (**permalink**) 11-24-03, 06:26 PM

Never mind I figured it out another way anyhow. by use of reading the file into an array

Ie;
open(INF,"/homepages/39/d87399782/htdocs$thefile") or dienice("Can't open survey.out: $!");
@ary = <INF>;
close(INF);

@Tophtml = @ary[0..$EndBlock];

@Bottomhtml = @ary[$EndBlock..$Total-2];

$AbsoluteBottom = "EOF\n";

And then I put in the code that i was wanting to append to, in the file.

Then I wrote the whole file again replacing the original content - It works gr8

chomp($thefile);
open (NEWMESSAGE, ">/homepages/39/d87399782/htdocs$thefile") or die "Unable to write open file. Reason: $!";

print NEWMESSAGE "@Tophtml";
print NEWMESSAGE "$html";
print NEWMESSAGE "@Bottomhtml";
print NEWMESSAGE "$AbsoluteBottom";
close (NEWMESSAGE);