Files!

[dogla12]

Good afternoon. I'm new here and i have a few questions.
1. you request the user to enter the name of the file that you want to write info to, how do you open that file in another function? say the file name is never the same.
2. if the user enter the file name stocks20121117. the program should be using 4 separate files. is it possible to automatically generate the files? example when the user enters stocks20121117, list20121117, numbers20121117 and calls20121117 should be created.

thanks in advance !

[qny]

What have you tried?

[dogla12]

 char fname[128];
    printf("Enter the file name: \n");
    scanf("%123s",fname);
    strcat(fname,".txt");
    FILE *inputf;

thats what im using to ask the user for the name. i tried reading fname in another function, but its not working.

[qny]

You need to either pass the filename to the function (and open the file there) or open the file here and pass the FILE pointer to the function.

[dogla12]

void weekly_prices(FILE*fPtr) 
{
    system("cls");
    struct cropprices price={0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0};
char fname[128];
    printf("Enter the file name: \n");
    scanf("%123s",fname);
    strcat(fname,".txt");
    FILE *inputf

this is the start of one function.

void newOrder(FILE*fPtr) 
{
    system("cls");
    struct cusInfo cus={0,"","","","",};
    char fname[128];
    printf("Enter the file name: \n");
    scanf("%123s",fname);
    strcat(fname,".txt");
    FILE *inputf;
fPtr=fopen("fname","r");
			 if (fPtr==NULL){
				   printf("Error opening source file\n");
			}

			fscanf(fPtr,"%.2f\n",price.pumpkinsp);

thats how i did it, but in the new order function it is telling me that price was not delcared. how do i pass the file name or pointer?

[Adak]

You didn't pass a pointer to cropprices struct, or create a cropprices struct in newOrder(). It only has a cusInfo struct.

[dogla12]

and how to do that exactly?

struct cusInfo cus={0,"","","","",0.0,0};

i assume i cant declare cropprices struct like how i did cusinfo. Cause then that would erase all the data gather from the previous function?

Sorry for the hassle but im new to C

[AndiPersti]

i assume i cant declare cropprices struct like how i did cusinfo. Cause then that would erase all the data gather from the previous function?

"price" is local to weekly_prices(). If you declare another struct cropprices called "price" in newOrder(), it's local to that function. Both are independent from each other and only visible in the scope where they are declared.

Bye, Andreas

[dogla12]

what about the file names now?

[AndiPersti]

what about the file names now?

It's the same. Each "fname" is local to the function where it is declared.

Every variable in C has a scope.
All variables declared inside a function are only visible there (they have block scope).
Any variable declared outside of a function is visible in the whole file (it has file scope).

Bye, Andreas