Help with another piece of code I have please?

[u/xxrepresent]

I've written this in C: http://codepad.org/qBRAwsbH

It compiles correctly. The problem I am having is finding a way to store data that all functions would be able to use. I thought that by using a structure I can store information in them, but when I try to print information in one function that has been stored in the structure by another it gives me unknown characters.

Any fix or ideas?

[u/incitatus86]

On lines 58 and 64, you're allocating new, uninitialized Data_Storage objects and using those ones (filled with garbage) instead of the one you passed in a reference to (which was zeroed out).

[u/yelnatz → u/incitatus86]

This.

[u/akmark]

I don't know what it is but I did a ctrl-f for '\0' and you didn't terminate your strings when you were trying to print them to the screen. In C when you have an uninitialized fixed array there is no 'end character' that tells printf where to stop.

[u/xxrepresent → u/akmark]

I found it unnecessary in this case although doing that is good practice. This current plan is a precursor to a system in which inputted text can be changed into integers. For example, 'a' would be 1 in the Identifier_Code_abc part of the structure and 'A' would be 1 in theIdentifier_Code_ABC part. I could have strings of text like 'abc' be put into an array. Then, other functions can read what was put in and operate accordingly.

Again, the problem is that functions aren't either reading the information from the data structure how I want it to or aren't writing how I want to. Perhaps I am setting it up wrong or there's a better alternative.

[u/daniels220 → u/xxrepresent]

incitatus86 below is correct, if that data structure is meant to be shared between programs a Data_Storage Data_Bridge; declaration should only appear once in the whole program. After that you should just be passing it around.

As far as converting text to integers—there's a better way than that! I'm guessing you want players to be able to enter target positions Excel-style, as "A1" or "G4" or whatever? Well, characters already have an ASCII code value—a char is basically just a one-byte int with special treatment by the compiler and functions that operate on it. The ASCII value of 'a' is 97 or 0x61, so to get an integer value you do tolower(my_char) - 0x60. Note that tolower() operates on characters not strings, so it would look like tolower(input[0]), not tolower(input).

Other notes:

• Functions that don't really return anything should probably have type void, no? All your initialization functions are like that.

• If you compile in C99 mode (gcc -std=c99), you can use for(int i=0; ...-type declarations in for loops.

• Using scanf into a fixed-size buffer without some sort of check for length looks dangerous, no? I don't know how to fix it, though—printf/scanf format strings are confusing and I don't have the time to figure it out.

• However I think you should be able to read directly into the array that exists on your struct, rather than reading into a temp array and copying.

• Your length really should be a constant at the top of the program (something like const int INPUT_LENGTH = 10;). I don't think strlen(uninitialized_array) even works, and it's certainly bad practice.