PHP replace character in file without open file - php

Question

I have a file, that contain:
file content NULNULNULNUL something else.
When I try get file content
$str = file_get_contents($fileName), in $str appear just file content.
How I can replace the NUL in file, without open file?

Answer 1

1.) To get the replaced content as a string. First get the file content just like you did.
$str = file_get_contents($fileName)
Then replace all occurances of NUL with a blank space like:
$new_content = str_replace('NUL'," ",$str);
OR
2.) To replace the content inside the file (to replace content and write it back to the file):
file_put_contents($fileName,str_replace('NUL',' ',file_get_contents($fileName)));
here we are using file_put_contents — which writes a string to a file. We pass the filename and the replaced-string as a parameter

Answer 2

I convert each character to assci code. This is work now:
$newStr='';
$str = file_get_contents($fileName);
$length = strlen($str);
for ($i=0; $i < $length; $i++)
{
$current = ord($str{$i});
if ($current != 0x0)
{
$newStr .= chr($current);
}
else
{
$newStr .= "";
}
}
$num = file_put_contents($fileName,$newStr);