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feof bug?

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Dec 06.2004

hi

i have a loop where i read values line by line from file
something like:

[code=php]
while(!feof($fp))
{
$l=fgets($fp);
echo($l);
}
[php]
i noticed that when i read ordinary ascii file feof() ends the loop as it should but when i read utf-8 file, the loop does additinal iteration so i read some garbage and get errors and warning…

so for reading unicode files without errors i use this loop:
(i’m assuming filesize()>0)
[code=php]
do
{
$l=fgets($fp);
if(feof($fp))
break;
echo($l);
}while(!feof($fp));
[php]
and then it works fine…

Is it some known issue?

to post a comment
PHP

4 Comments(s) ↴

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@ShrineDesignsDec 06.2004 — there are some disadvantages for using feof(), it uses good amount of memory, which can bog a server down

also you are not doing any sort processing on the data retrived from the file so it is not nessacary to use feof()[code=php]<?php
while(($line = fgets($fp)) !== false)
{
echo $line;
}
?>[/code]or[code=php]<?php
echo fgets($fp, filesize($file));
?>[/code]
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@pti4kaauthorDec 06.2004 — i posted simplified loop...ofcourse i do some proccessing

if there is another way for testing file end please tell me...

after little testing now i know this:

what really matters is when eof() returns "true"...

example: reading file line by line and doing some proccessing:

this loop
[code=php]
while(!feof($fp))
{
$l=fgets($fp);
$data=explode(',',$l);
$l[0]+=1;
$l[1]+=4;
}
[/code]

is wrong because feof() will return true [B]only after there was an attemt to read afer file end[/B]...

so what this basicly means is that the last line will read EOF character or some other "garbage" and then script will attemt to proccess that and obviously will crash...
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@ShrineDesignsDec 06.2004 — give this a try:[code=php]<?php
$size = filesize('/path/to/file.txt');

while(ftell($fp) < $size)
{
$line = fgets($fp);
// ...
}
?>[/code]
Copy linkTweet thisAlerts:
@pti4kaauthorDec 06.2004 — ok

i thought about using ftell but i'm not sure how safe it is to use filesize because the file system can be compressed.
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