Re: what am I missing?
- Posted by mattlewis (admin) Jun 19, 2009
- 1161 views
jacques_desch said...
Matt, Following you suggestion, here de C code I tested and it crash too, but only if I free t pointer. The same is true in my euphoria binding.
#include <stdio.h>
#include <asm/termbits.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
int main(){
int fd, fnVal;
struct termios2 *t;
fd = open("/dev/tty0",O_RDONLY);
printf("file handle %d\n", fd);
t = malloc(sizeof(struct termios2));
fnVal = tcgetattr(fd, t);
printf("ispeed %d, ospeed %d\n",t->c_ispeed, t->c_ospeed);
free(t); // it doesn't crash if I don't free t.
puts("t freed\n");
close(fd);
}
Now the question is why freeing t, which is no more used, crash the program?
I think you're using the wrong header. See the man page, here.
Looks like the correct size is actually 60. Try this code:
#include <stdio.h>
#include <termios.h>
#include <fcntl.h>
int main(){
int fd, fnVal;
struct termios *t;
printf("termios %d\n", sizeof( struct termios ) );
fd = open("/dev/tty",O_RDONLY);
printf("file handle %d\n", fd);
t = malloc(sizeof(struct termios));
fnVal = tcgetattr(fd, t);
printf("fnVal %d ispeed %d, ospeed %d\n", fnVal, t->c_ispeed, t->c_ospeed);
free(t); // it doesn't crash if I don't free t.
puts("t freed\n");
close(fd);
}
Matt
