Thread: Dynamic allocation of an array of strings

Hey,

I am allocating a 2d array of char dynamically like this:

Code:

Params = (char **)calloc(NumParam, sizeof(char *));

   for(i=0; i<NumParam; ++i)
	   Params[i] = (char*)calloc(NameLengthP,sizeof(char));

it refuses to let me not typecast calloc.
Then I read in value into the array like so (It's a binary input file):

Code:

for (i=0; i<NumParam; ++i)
   {
	   j=0;

	   do
	   {
		   fread(&Params[i][j], sizeof(char), 1, inp);
		   j++;
	   }
	   while(Params[i][j] != ' ' && j<NameLengthP);
   }

When I print the array using printf("%s", Params[i]), the strings are longer then allocated. and the output is:

Code:

BARO    ýýýýÝÝÝÝÝÝÝÝÝÝÝÝA
V2201A00ýýýý
V4610M00ýýýý
SG      ýýýý
..........

instead of:

Code:

BARO    
V2201A00
V4610M00
SG

Where is this leak coming from?

Gotta NULL terminate your data after your read.

> it refuses to let me not typecast calloc.
Either
- you didn't include stdlib.h (the warning was about casting int to ptr)
- you're compiling your C code with a C++ compiler (the warning was about casting void* to some other ptr)

> while(Params[i][j] != ' ' && j<NameLengthP);
Should be
while(Params[i][j] != ' ' && j<NameLengthP-1);
If you fill up to j<NameLengthP, you've actually filled all the elements, and there is no longer a \0.