ftruncate() trying to trim begining and end of file

[rubing]

I am trying to take a file that is 600000 bytes and truncate it so that i only have the middle 250000bytes (trimming begining and end off).  The following code using the ftruncate() function is not working   ???

 

 

$handle=fopen($mp3,'w');
fseek($handle,200000);
ftruncate($handle,250000);

[rubing]

The code above just gives me an empty 250k file

[cooldude832]

are u sure the file is of at least 250000+200000 bytes

[rubing]

yes the file is at least 584000 bytes

[JasonLewis]

Check out fopen()

The mode 'w' will truncate the file to zero length. Change the mode to something more appropriate, perhaps 'a'.

[cooldude832]

Check out fopen()

The mode 'w' will truncate the file to zero length. Change the mode to something more appropriate, perhaps 'a'.

 

 

exactly

testing you gonna point out 'a' or 'w+' are what you are seeking to do this appending.

[rubing]

OK, so I changed my code to the following:

 

$handle=fopen($mp3,'a');
fseek($handle,200000);
ftruncate($handle,260000);

 

Yet this still truncates the file from the beginning till the 260000 byte.  I thought specifying the file pointer with fseek would start the truncate in the middle of the file.  Is there a way to do this in php without using some foreign class?

[rubing]

Ok I figured out a way to do what i wanted as follows:

 

$mp3string=file_get_contents($mp3,FILE_BINARY,$context=NULL,$offset=200000,470000);
file_put_contents($mp3,$mp3string);
[/code

1.  I read the mp3 file in as a string with my desired offset
2.  Save this new (truncated;offset) file.