Thread: Function calling curiosity

Just don't print any output. When you need to print output, call the function, and depending on the result, output what is necessary.

Originally Posted by lucas.lotr

I know i could just adjust the function to not output text and do that in the main program, but the situation made me curious about the possibility of "suppressing" text outputs...

You could do something like this:

Code:

void myfunc ([your existing args), int print) {
       [...blah blah...]
       if (print) ....

Depending on context, that may or may not be a better solution than optionally doing the output separately afterward. Eg, doing the output separately afterward might offer you greater flexibility, but at the expense of more coding.

If you want to use MK27's suggestion, then you might as well pass a FILE* instead of an int.

Originally Posted by lucas.lotr

Like i said, i know i could do that, i was just curious if there is a c equivalent to batch file`s ECHO which disables the displaying of messages.

You can temporarily dup() stdout or stderr, close them, then restore them again later:

Code:

#include <stdio.h>
#include <unistd.h>

int main(int argc, const char *argv[]) {
	int stdout_copy = dup(1);

	printf("hello world\n");
	close(1);
	printf("[suppressed]\n");
	dup2(stdout_copy, 1);
	close(stdout_copy);
	printf("hello again\n");

	return 0;
}

I don't know how portable that is because of unistd.h, but I'm sure all platforms must offer similar functionality.