error on closing serial port

[amitpatel22]

Hi...
I have successfully open serial port and also able to read and write data on serial port with the following code:
int fd;
struct termios options;
fd=open("/dev/ttyS0",O_RDWR | O_NOCTTY | O_NDELAY);

But when i try to close serial port with close(fd) function,my application has been crashed and it gives segmentation fault.

So please tell me that how can i close serial port without my app crash..
Waiting for quick reply

Thanks..

[mcosta]

We cannot help you if you don't show your code.

Are you sure that open () doesn't fail?

fd=open("/dev/ttyS0",O_RDWR | O_NOCTTY | O_NDELAY);
if (-1 == fd) {
    // open failed!!
}

fd=open("/dev/ttyS0",O_RDWR | O_NOCTTY | O_NDELAY);
if (-1 == fd) {
    // open failed!!
}

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[amitpatel22]

Yes mcosta, I am damm sure that open function doesn't fail becoz it returns non-negative value.

[mcosta]

ok,

can you show the code that crashes?

[amitpatel22]

For open port:-
int fd = 0;
struct termios options;
tcgetattr(fd, &options);
fd=open("/dev/ttyS0",O_RDWR | O_NOCTTY | O_NDELAY);
fcntl(fd,F_SETFL,FNDELAY);
cfsetispeed(&options,B9600);
cfsetospeed(&options,B9600);
options.c_cflag |= (CLOCAL | CREAD);
options.c_cflag &= ~PARENB;
options.c_cflag &= ~CSTOPB;
options.c_cflag &= ~CSIZE;
options.c_cflag |= CS8;
options.c_lflag &= ~(ICANON | ECHO | ISIG);
tcsetattr(fd, TCSANOW, &options);

For close port:-
close(fd);

[squidge]

Maybe you have some kind of memory corruption problem which is causing the close call to crash?

[mcosta]

have you checked the value of "fd" just before call "close"?

[amitpatel22]

yes i have checked the value of fd.It gives non-negetive value when i call close(fd).

[mcosta]

try to debug your application and see how and why the program crash. post the debug output.

[squidge]

yes i have checked the value of fd.It gives non-negetive value when i call close(fd).

But is this the same value as returned by open?

[amitpatel22]

Thanks to all for your support..

I think i got the solution..

I have tried ::close(fd) instead of close(fd) and it works..

Thanks..