emptying memory when coming from a function

[Gades]

I'm sure that there's been a thread with this question before (more or less), but I couldn't find it.

My program has a function that shows the values in a project. When I call this function (caracteristics) it runs perfectly, but as soon as it goes back to main, there's something wrong. A menu should be displayed (calling the function MENU()), but it displayed twice, and also, when I enter an option, it doesn't work correctly.

I thought that maybe I should have the memory emptied, when I finish the caracteristics() function, but I don't know how (this is actually what I've been looking for).

I attach the whole code (which compiles and runs), and I post the function caracteristics() as well (in case you don't want to download the whole thing, even it's quite small).

There it goes:

void
caracteristics(void)
{

   double getval;  // this variable GETs the VALues from the existing project
   char  file_name[PATH_MAX];
   FILE *input;


   clrscr();
   strcpy (file_name, actual);

   input = fopen(file_name, "r");


   if (( input = fopen(file_name, "r+")) == NULL ) // check it for errors
       {
       printf("There was an error reading from the file!! \n");
       printf("Press any key to continue ");
       getch();
       main();

       }

   printf("The caracteristics of the actual project are: \n");

   fscanf(input, "%lf\n", &getval);
   printf("1) LOA: %.2f\n", getval);
   fscanf(input, "%lf\n", &getval);
   printf("2) I: %.2f\n", getval);
   fscanf(input, "%lf\n", &getval);
   printf("3) J: %.2f\n", getval);
   fscanf(input, "%lf\n", &getval);
   printf("4) P: %.2f\n", getval);
   fscanf(input, "%lf\n", &getval);
   printf("5) E: %.2f\n", getval);
   fscanf(input, "%lf\n", &getval);
   printf("6) Displacement: %.0f\n", getval);
   fscanf(input, "%lf\n", &getval);
   printf("7) GM: %.3f\n", getval);
   fscanf(input, "%lf\n", &getval);
   printf("8) H1: %.2f\n", getval);
   fscanf(input, "%lf\n", &getval);
   printf("9) H2: %.2f\n", getval);
   fscanf(input, "%lf\n", &getval);
   printf("10) H3: %.2f\n", getval);
   fscanf(input, "%lf\n", &getval);
   printf("11) S1: %.2f\n", getval);
   fscanf(input, "%lf\n", &getval);
   printf("12) S2: %.2f\n", getval);
   fscanf(input, "%lf\n", &getval);
   printf("13) S3: %.2f\n", getval);
   fclose(input);

   printf("\n\n		Press any key to continue");
   getch();

   main();

}

[Sayeh]

Why are you calling 'main()' from within your function? That isn't how you bail out of a function.

In caracteristics(), the first time you do this, you should instead have called- 'return;'.

The second call in caracteristics(), is unnecessary.

Do what you are doing might trash your stackframe.

--

Why do you call 'caracteristics()' from within 'new_project', when if you returned to main(), it would call it there?

--

Instead of doing an explicit check for choice '5' in main, you should create another variable called 'quitFlag', a boolean. Set it to false before you enter your while. Then put choice '5' in your switch/case. If they hit 5, then set quitFlag to TRUE, and let your application exit gracefully.

---

You have some more fundamental stuff to learn before you try writing a menu system---

[Gades]

>Why are you calling 'main()' from within your function? That isn't >how you bail out of a function.
I guess I've misunderstood someone then, I tought that was the proper way. What is the meaning of "bail out of a function"? My English isn't perfect.

>In caracteristics(), the first time you do this, you should instead >have called- 'return;'

OK, now I've changed it now. But I don't see any difference.

> The second call in caracteristics(), is unnecessary.
What second call?

>Do what you are doing might trash your stackframe
What's the result of this?

>Why do you call 'caracteristics()' from within 'new_project', when if you returned to main(), it would call it there?

Sorry, I didn't see it. It's changed now.

>Instead of doing an explicit check for choice '5' in main, you >should create another variable called 'quitFlag', a boolean. Set it >to false before you enter your while. Then put choice '5' in your >switch/case. If they hit 5, then set quitFlag to TRUE, and let your >application exit gracefully.
I don't really know how to do it, so if I can get away without it, I'll leave it for later. I'll keep it in mind.

>You have some more fundamental stuff to learn before you try >writing a menu system---

I completely agree with you, I wish I had the time to do it, but I have to finish it for uni. If I had money I'd pay someone to do it for me! I'm going to keep on with C after I pass the subject anyway, because I enjoy it.

I really appreciate your time, and I'm sorry I couldn't understand most of your points (because of my low knowledge of C and the difficulty of the English as well).

Really, thanks a lot.

[oskilian]

I think I got it, it the function MENU, you have fgets on stdin, it's supposed to work, but for some strange reason it doesn't.

use scanf instead!

try

scanf("%s",buff);

I tried it here and it works!

Oskilian