Re: ifstream problem?

From:

James Kanze <james.kanze@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Sun, 1 Mar 2009 16:46:22 -0800 (PST)

Message-ID:

<87e55453-8997-4281-bd49-f4234fca31e5@t3g2000yqa.googlegroups.com>

On Feb 26, 11:11 pm, Victor Bazarov <v.Abaza...@comAcast.net> wrote:

kazik.lak...@gmail.com wrote:

could you help me with this stuff, it compiles fine, but
when starting the program there is segmentation fault. I
enclose a message from debugger:
----------
Program received signal SIGSEGV, Segmentation fault.
0x0000000000400ce0 in ReadInitialConditions (TabX=0x7fffb62f1880,
TabY=0x7fffb62f1480, TableSize=128, InitCondFile=@0x7fffb62f1c=

80)

at readprog.cpp:9
9 while(! InitCondFile.eof() ){
----------

This is the code:

#include <iostream>
#include <fstream>
using namespace std;

void ReadInitialConditions(double* TabX, double* TabY, int TableSize,
ifstream & InitCondFile){
int XorYCounter = 0;
int XYPairsCounter = 0;
if(InitCondFile.is_open()){
while(! InitCondFile.eof() ){

You should probably change this to

while( InitCondFile.good() ) {

In no case. Both are questionable. The idiomatic way of doing
this is:

    double num ;
    while ( InitCondFile >> num ) {
        ...
    }

double num;
InitCondFile>>num;

Also make this a condition:

if (InitCondFile >> num) {

So why not move the condition up to the top of the loop, and be
done with it?

--
James Kanze (GABI Software) email:james.kanze@gmail.com
Conseils en informatique orient=E9e objet/
Beratung in objektorientierter Datenverarbeitung
9 place S=E9mard, 78210 St.-Cyr-l'=C9cole, France, +33 (0)1 30 23 00 34