how do you write to stderr

[-EquinoX-]

How do I write:

("Country %d and country %d are not connected\n", d1, d2);
("Returning to the main menu");


to the file stderr, assuming that d1 and d2 already exists above??

I tried to use fprintf but it prints out the sentence too.

I tried to to this but it also prints out the Country.... bla bla bla, how do I just write it to stderr without having to print it?
fprintf(stderr, "Country %d and country %d are not connected\n", d1, d2);
fprintf(stderr, "Returning to the main menu");

[Codeplug]

Are you saying you don't want stderr output to show up on the terminal/console output?

gg

[xuftugulus]

If that is the case, if you want to redirect the output of stderr to somewhere else, you would use freopen(), on stderr.
Check freopen reference for details on how to do it.

[Dino]

How do I write:

("Country %d and country %d are not connected\n", d1, d2);
("Returning to the main menu");


to the file stderr, assuming that d1 and d2 already exists above??

I tried to use fprintf but it prints out the sentence too.

I tried to to this but it also prints out the Country.... bla bla bla, how do I just write it to stderr without having to print it?
fprintf(stderr, "Country %d and country %d are not connected\n", d1, d2);
fprintf(stderr, "Returning to the main menu");

Well, first of all, stderr is not a file. It's a stream. When you send data to it via functions line fprintf(), they get written to where ever the stream is pointing. Typically, that's the console.

Now, you are very confusing when you ask how do I just write it to stderr without having to print it?, that is illogical. To have output show up on stderr, you have to print to it.

stderr is no different (functionally) that stdout. How do you write to stdout without printing? You don't!

Printing here, encapsulates printf(), fprintf(), putc(), fputc(), blah blah blah.

What are you trying to do?

[-EquinoX-]

what I mean is how do I redirect that string "Country.... bla bla bla" to stderr

[Dino]

fprintf(), just like you are doing. By default, stdout and stderr go to the same place. You can redirect stderr via a command line switch. See your OS doc.

[Codeplug]

You can also redirect stderr to a real file with freopen(), which would prevent it from showing on to the terminal/console.

gg

[foxman]

what I mean is how do I redirect that string "Country.... bla bla bla" to stderr

Or you could try what xuftugulus said and use reopen. There's an example given on how to use it in the link.

So you'll have some portable code (i didn't look at the rest of your code, tough) instead of using some OS specific function call.

(Oops, too slow)