Problem in reading file

[mayassia]

Hello,
I have a problem to read file, here is the pseudo code :
Graph is a class

void Graph :: lecture_fichier(char *nom) {


ifstream fich;
fich.open(nom);
if(fich){
cout<<"good";
fich.close();
}
else
cout<<"bad";
}


int main(){
int op,ov;
double lv,lp;
list<int> P1;
list <int> P2;
char *nom;

cout<<"saisir le nom du fichier : "<<endl;
cin>>nom;
Graph G;
G.lecture_fichier(nom);

thank u

[Moschops]

char *nom;
...
cin>>nom;

Bad.

nom is a char pointer with a random value. It will be pointing at some random memory somewhere. Could be anywhere. All you did was create a pointer; that's not enough. You also have to create something for it to point at, and make sure the pointer does point at the right thing.

cin>>nom will be attempting to write the input over some random memory. The operating system will not like this and will stop the program.

[legolizard]

To solve the problem addresed by Moschops, why not use the std::string class, and then cin, or possibly even getline, since file names can have spaces in them.
(saisir le nom du fichier means enter file name in french...I think; it has been a long time since I have taken french lol.)

Secondly, you don't seem to be doing any actually reading of a file... @w@
Even if you were to fix the char pointer problem, you are still not really reading a file.
This code here:

ifstream fich;
fich.open(nom);
if(fich){
cout<<"good";
fich.close();
}
else
cout<<"bad";
}

Simply checks to see if the file exists, yet it does not actually READ.

If you want to read the file, then I suggest looping through each line, and inputting them into a container, such as another array, or better yet, a vector. I don't really know what you want though, maybe all you need to do is check to see if the file exists or not, lawl.