[Resolved] Resource usage with fopen( )

Bah__Name

Does fopen( )'ing a 200kb file use any more server resource than fopen( )'ing a 6kb file?
I would have thought yes, but if all you're doing is creating a file handle, where is the strain coming from?

I can understand fread( )'ing 200kb being more demanding than 6, but not fopen( ).

Anyone know really, ?

128kb_com

To my knowledge, the resource returned by fopen() would be a php internal file pointer wrapped in a zval structure, storing just the resource id and certain information about the file pointer like its current position in the file (for functions like rewind(), fread(), fgets() ...) and not all the bytes in the file.

Have you monitored proformance with fopen and been able to reproduce this several different times on different file sizes?

Bah__Name

I haven't done any testing yet. I want to see if I can fopen larger files and reference byte start and end points, rather than fopen/read/close frequently, but I thought I'd ask first to see if anyone knew for sure.

I will knock something up for testing. Its localhost though, I can;t test multiple users I don;'t think. EG, If the PHP file handle limit is say, 100 open files, is this for one user at the site, or for all users open files combined, that sort of thing, I have no clue.

128kb_com

I want to see if I can fopen larger files and reference byte start and end points

Sure, check out fseek() and ftell().

// open file for reading and writing
$fp = fopen($filename, "r+");
// lock file to ensure your position
flock($fp, LOCK_EX); 
// move pointer to end of file
fseek($fp, 0, SEEK_END);
/* current file position, at the end of file, will return actual bytes in size as opposed to using filesize() function */
$bytes = ftell($fp);
// move pointer to the begining
rewind($fp); 
//move 1/3 down the file
fseek($fp, ($bytes / 3), SEEK_SET);
// read next ten bytes 
$str = fgets($fp, 10); 
//skip next ten bytes
fseek($fp, ftell($fp) + 10, SEEK_SET); 

// unlock file
flock($fp, LOCK_UN); 
fclose($fp);

As you can see you have some decent control over the file pointer.