Segmentation fault

[JM K]

Hi,

I am working with an EV2 Radio and cannot utilize the sms-utils package. I am trying to write a small application that accepts a message and sends an sms to a custom phone number also entered by the user.

I wrote a small C program that would just open the ‘file’, ttyUSB0 and send out an SMS to a phone number using the AT commands. I am however getting a Segmentation fault when I try to open the file ttyUSB0 and write an AT command to it. Here is my program:

void main()

{

FILE *fileptr;

fileptr = fopen(” /dev/ttyUSB0 ” :,”a”);

puts(“AT!SSMS=0,xxxxxxxx,0,yyyyyyyyyy”); /* xxxxxxxxx is the phone number and yyyyyyyyy is the message */

fclose(fileptr);

}

I bitbaked it successfully and also copied and installed the package on the CDP Unit. I got a segmentation fault only when I tried running it.

I would appreciate it, if someone could let me know where my program went wrong. Thank you very much and have a great day.

Best Regards,

JM

[JM K]

Hi,

I modified my program yet still not able to open the /dev/ttyUSB0 file. Here is a copy of the program:

# include <stdio.h>

# incluse <stdlib.h>

# include <unistd.h>

# include <getopt.h>

# include <errno.h>

# include <sys/types.h>

# include <sys/stat.h>

# include <fcntl.h>

# include <termios.h>

# include <string.h>

int main()

{

int fileptr;

fileptr = open (“/dev/ttyUSB0 “, O_RDWR | O_NOCTTY | O_NDELAY);

fnctl(fileptr, F_SETFL, 0);

printf(“Port has been successfully opened and the file description is %d “, fileptr);

close(fileptr);

return 0

}

The output I get when I run this program is:

Port has been successfully opened and the file description is -1.

If the file description is -1, the event of opening the file has failed. Is this correct?

I would very much appreciate it if someone could let me know the error in my program.

Best Regards,

JM

[Neil McGuire]

I personally had issues with the O_NDELAY flag, and once I removed it was able to open the port.

And yes, if (fileptr == -1) { printf( “Could not open port” }

It also looks like you have a space after /dev/ttyUSB0 in the open() command. Try removing that.

[JM K]

Hi Neil,

thank you very much for your reply. I removed the O_NDELAY flag and also removed the space after /dev/ttyUSB0 in the open command and am still getting the file description as -1. Is it because the port is already open? Is that a possibility? Is there any way to check that? Thanks again.

Best Regards,

JM

[JM K]

Hi Neil,

Thank you very much. I fixed the problem. The problem was the space before /dev/ttyUSB0. Thanks a lot.

Regards,

JM

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