General question of string

[manisha]

Can we define the string of size greater than 255 bytes??? If so how???

How to send large data using append file function from ex_fat.c file available in examples to the sd card??

[Ttelmah]

1) Compiler version.
2) Chip.

A 'string' is just a character array ending with a NULL ('\0') character.

On a chip like a 18F24J50, nothing to stop you having (say):

char buffer[2048];

Limit depends on the size of the RAM in the chip, less whatever else is using this.

Best Wishes

[temtronic]

And, if you're a reasonably 'clever' programmer, depending on how the data is created and arranged to be sent, physical RAM is not a real limit.
Keywords like 'double buffering' and 'handshaking' are clues...