fopen and fclose

> can i use fopen and fclose in niosII ide?

yes

> is'it possible to read and write from a file in the hard disk?

it depends on if your system has a hard disk?

and I'm guessing it doesn't

> or should i program the flash after that read and write from the flash memory?

I think this way is first step for you.

> how can i read and write from the flash memory?http://www.alteraforum.com/images/smilies/eek.gif http://www.alteraforum.com/images/smilies/eek.gif http://www.alteraforum.com/images/smilies/eek.gif

in basic way, you have to access devices via address.

if you want file-system, you have to create file-system some how.

there is several way like Linux/uC-OSII...

you can create file-system by your self(it's difficult)

so, if you are new to NiosII.

you can read and write data via UART(RS-232C) , JTAG, SPI, I2C...