treat large string like file

[Mark]

So, I've got some PHP code that reads in a file and parses some data as
it goes along.
However, now I'm thinking it might be easier for me to store chunks of
the file in the database rather than all the bits of data, so that it
can be interpreted in different ways if need be. But the problem is,
now I can't just use fread to read in two bytes of data, because I've
already got the whole chunk stored in a variable. And I really don't
want to deal with tons of substrings, it would be much easier to have a
sort of file pointer. So is there any way, or any set of functions
that I can use to deal with this?

[petersprc]

Re: treat large string like file

To get the data two chars at a time, you could do:

$len = strlen($data);
for ($i = 0; $i < $len; $i += 2) {
$str = substr($data, $i, 2);
echo "String is \"$str\".\n" ;
}

To access using a streams interface, you could dump the data into a
temporary file, then read it in. Or create a stream wrapper with
stream_wrapper_ register.

Mark wrote:

So, I've got some PHP code that reads in a file and parses some data as
it goes along.
However, now I'm thinking it might be easier for me to store chunks of
the file in the database rather than all the bits of data, so that it
can be interpreted in different ways if need be. But the problem is,
now I can't just use fread to read in two bytes of data, because I've
already got the whole chunk stored in a variable. And I really don't
want to deal with tons of substrings, it would be much easier to have a
sort of file pointer. So is there any way, or any set of functions
that I can use to deal with this?

[Mark]

Re: treat large string like file


petersprc wrote:

To get the data two chars at a time, you could do:
>
$len = strlen($data);
for ($i = 0; $i < $len; $i += 2) {
$str = substr($data, $i, 2);
echo "String is \"$str\".\n" ;
}
>
To access using a streams interface, you could dump the data into a
temporary file, then read it in. Or create a stream wrapper with
stream_wrapper_ register.

Well, the two characters at a time thing doesn't work very well,
because it's not always just two characters, and I've been doing a lot
of fseek-ing. The temp file solution could work, but that just sounds
like a horrible thing to do. Thanks anyway.

[Pedro Graca]

Re: treat large string like file

Mark wrote:

So, I've got some PHP code that reads in a file and parses some data as
it goes along.
However, now I'm thinking it might be easier for me to store chunks of
the file in the database rather than all the bits of data, so that it
can be interpreted in different ways if need be. But the problem is,
now I can't just use fread to read in two bytes of data, because I've
already got the whole chunk stored in a variable. And I really don't
want to deal with tons of substrings, it would be much easier to have a
sort of file pointer. So is there any way, or any set of functions
that I can use to deal with this?

Index into the whole chunk?

$two_chars = substr($whole_c hunk, 17655, 2);
switch ($two_chars) {
case 'C3': $three_chars = substr($whole_c hunk, 17657, 3);
break;
case '--': $three_chars = '---';
break;
default: $three_chars = substr($whole_c hunk, 17655, 3);
break;
}

--
I (almost) never check the dodgeit address.
If you *really* need to mail me, use the address in the Reply-To
header with a message in *plain* *text* *without* *attachments*.

[Mark]

Re: treat large string like file


Pedro Graca wrote:

Mark wrote:

So, I've got some PHP code that reads in a file and parses some data as
it goes along.
However, now I'm thinking it might be easier for me to store chunks of
the file in the database rather than all the bits of data, so that it
can be interpreted in different ways if need be. But the problem is,
now I can't just use fread to read in two bytes of data, because I've
already got the whole chunk stored in a variable. And I really don't
want to deal with tons of substrings, it would be much easier to have a
sort of file pointer. So is there any way, or any set of functions
that I can use to deal with this?

>
Index into the whole chunk?
>
$two_chars = substr($whole_c hunk, 17655, 2);
switch ($two_chars) {
case 'C3': $three_chars = substr($whole_c hunk, 17657, 3);
break;
case '--': $three_chars = '---';
break;
default: $three_chars = substr($whole_c hunk, 17655, 3);
break;
}
>
--
I (almost) never check the dodgeit address.
If you *really* need to mail me, use the address in the Reply-To
header with a message in *plain* *text* *without* *attachments*.

Err.. I think the best solution would be for me to make some sort of
wrapper class. Which deals with all the substr-ing and returns
whatever I ask for... so I can set up a function like

sseek($my_strin g_chunk_object, 2); // string seek

which returns 2 (or however many) characters from the string and
advances the internal pointer.. (which would probably just an integer
to be used in the substr function)

then I could set up wrappers for how the data should be interpreted too
while I'm at it...