value of stdin (not zero?)

Hi,

I have this x86 assembly code (I use it to flush the input away)

pushl stdin
pushl $STRING_LEN
pushl $long_string
call fgets

(it seems to works, because I don't have a segmentation fault)

but if I change pushl stdin with pushl $0, then I get a segmentation fault.

does this mean that stdin is not zero?
is the value stdin different on different computers?

(the program is run on a laptop)

> but if I change pushl stdin with pushl $0, then I get a segmentation fault.
Because that's like saying
fgets( long_string, STRING_LEN, NULL );

stdin is not a NULL pointer.

This is not the same as descriptor 0 which is stdin when using the POSIX API.

I remember writing some assembly code just recently where I needed at least one of the three standard FILE *'s.

You need to find the variable that represents all of the FILE *'s. The following code worked with Borland's assembler where I used fprintf() to print out an error message to stderr.

Obviously your situation will probably be much different, but the idea is the same. Find the way the standard FILE *'s are organized for your assembler/compiler and import them into your program.

Code:

---

extern __streams:near

....

push offset szMemErr
push dword ptr [__streams + 8]
call _fprintf
add esp, 8

---

Joys of assembly programming... :)

oeps, I thought file descriptor is the same as file pointer,

thank you,