How can I declare a global array whose size I calculate in a function later on (based on # of rows & columns of terminal ).
Error I am getting: variably modified 'box' at file scopeCode:// global vars int row, col; char box[row][col]; // causes error ... void getsize(){ isatty(STDIN_FILENO); struct winsize sz; ioctl(STDIN_FILENO,TIOCGWINSZ,&sz); row=sz.ws_row; col=sz.ws_col; }
you need to use malloc
All problems in computer science can be solved by another level of indirection,
except for the problem of too many layers of indirection.
– David J. Wheeler
How can I do this?
Or could someone please point me to a good tutorial.
Thanks
The tutorial on pointers has something to say about malloc.
Look up a C++ Reference and learn How To Ask Questions The Smart WayOriginally Posted by Bjarne Stroustrup (2000-10-14)
I wasn't sure myself, based on that tutorial I'd say malloc a size to a created pointer and then use that pointer to point to the rows and columns
int *ptrRow = malloc (sizeof(int));
int *ptrCol = malloc (sizeof(int));
=========================================
Everytime you segfault, you murder some part of the world
Not right.
A 2D array allocation needs one malloc, then a loop to malloc memory for the other dimension:
--Code:int **ptr; int i; ptr = malloc(sizeof(*ptr) * rows); if (!ptr) allocerror(); for(i = 0; i < rows; i++) { ptr[i] = malloc(sizeof(int) * cols); if (!ptr[i]) allocerror(); }
Mats
Compilers can produce warnings - make the compiler programmers happy: Use them!
Please don't PM me for help - and no, I don't do help over instant messengers.
What's wrong with doing it my way? Then assigning values to the pointer after row and column have been determined?
[*ptrRow][*ptrCol]
=========================================
Everytime you segfault, you murder some part of the world
But you are only allocating a single integer - in which case, 99% of the time, you can just use the ORIGINAL int value, instead of storing it in a pointer.
--
Mats
Compilers can produce warnings - make the compiler programmers happy: Use them!
Please don't PM me for help - and no, I don't do help over instant messengers.
Cool BIG thanks for the help!
Last edited by Tupcia; 04-15-2008 at 03:55 PM.
