Doubt on passing an array of chars by ref

[Microemission]

Hi, i have a big doubt about passing an array of chars to a function.
What i need is to pass from main an array of chars to a function where a new array constant of chars is created and then copied to the original array to be returned back to main.
This is a "debug" code i've done from the original app i'm doing on linux Gcc.
I admit I'm a little weak on C these days

#include <stdlib.h>
#include <stdio.h>
#include <string.h>


void r(char *buf)
{
	char buf1[1]; //This needs to be a constant lenght char array, not a malloc/calloc!

	buf1[0]='O';
	buf1[1]='\0';
	memcpy(buf, buf1, 2);
	//strcpy(buf, buf1);
	//buf=buf1;
	printf ("%s\n", buf);
	printf ("%s\n", buf1);
	}

int main(int argc, char *argv[])
{
	char buf[1];
	buf[0]='A';
	buf[1]='\0';
	r(buf);
	printf ("res %s\n", buf);
	
}

The result of the program on console is this:

O
O
res
Segmentation fault

of course the expected would be

O
O
res O

Appreciate some help plz
Tkx

 

[maui]

It apears to me that you have declared an array of size 1 "char buf1[1]" and used two memory locations, one of which is outside the array, "buf1[1]='\0';"

try declaring "char buf[2]" to stop your segmentation fault.

 

[Microemission]

Thank you solved the problem!