View Full Version : Segmentation Fault Error

November 24th, 2009, 11:59 PM
Hello Gents,

Just stumbled upon this community and after reading a few posts, I find it very open and helpful. I am working on a project right now, and I was wondering if I could get assistance on it. It is for school (I read the FAQ regarding this), but I have it 99% finished. The only problem now is getting one bit of command line option handling to work properly. I will paste my code below and then describe a bit about the code and error.

p, li { white-space: pre-wrap; }

#include <QApplication>
#include <QtGui>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <limits.h>
#include <fstream>
#include <cctype>
#include <ctype.h>
#include "radar.h"
#include "math.h"

#define MAX_BUF 256
#define MAX_NAME 15
#define MAX_SYMBOL 3
#define STR_SIZE 256
#define MAX_ID 6

float tStart;
int tDisplay;
float timescale=1;

int main(int argc, char *argv[])
QApplication app(argc, argv); // create application object
QWidget *window = new QWidget; // create a window to hold all sub windows
window->resize(600, 600); // set its size
window->setWindowTitle("ATC Simulator");// and window title

int c=0;
extern char *optarg;
char *filename = "test_flight.txt"; /* file to be opened */
bool filespec=false, startspec=false, stepspec=false, scalespec=false; /*Vars to determine if command line option or default value should be used */

while ((c=getopt(argc,argv,"f:t:s:x")) !=EOF)
switch (c)
case 'f':
filespec=true; break;

case 't':
startspec=true; break;

case 'x':
timescale=atof(optarg); ;/*ERROR */
scalespec=true; break;

case 's':
stepspec=true; break;
The code obviously goes on after that, but I believe this is where my error lies. It seems to handle everything but case x fine. When I'm debugging, the debugger will not move past the /*ERROR*/ line. When I make the program and run it, it runs properly unless I pass it the -x command. I think I've included all relevant info but if there is something I can clarify more I would be happy to. Thanks for your help!



I know I may be using a mix of c and c++ but the teacher set some stuff up for us in c, and said we could use either c or c++.

November 25th, 2009, 01:53 AM
'x' marks the spot; it appears the with the -x option, you are looking for a value (optarg), yet you did not specify that this option required such.

Perhaps you intended this:

while ((c=getopt(argc,argv,"f:t:s:x:")) !=EOF)

Note the colon (':') character after the 'x'.

November 25th, 2009, 02:00 AM
Aha, it's always the little things isn't it? Thanks so much for your help I was staring at that for hours missing the obvious.