Help with strcpy

[kopo85]

I was just wondering if you could see anything wrong with this code off had that wouldn't make it work

char mid_store[6];
char output[512];
unsigned char sample[16][9];
int j;
int i;
int str_length = 0;

for(j = 0; j<9; j++)
{
for(j = 0; j<16; j++)
{
sample[j] = read_adc(0);
itoa(sample[j], mid_store);
strcpy(output, mid_store);
strcpy(output, ',');
}
for(i = 0; i < 16; i++)
{
if(sample[j]<10)
{str_length = str_length + 3;}
else if(sample[j]<100&&sample[j]>9)
{str_length = str_length + 4;}
else
{str_length = str_length + 5;}
}
}

printf("W 1 %d\r", str_length);
printf("%s", output);

 

[Salem]

1. Please use the [code][/code] tags when posting code

2. unsigned char sample[16][9];
But your for loops treat it as [9][16]

Or they would do, if not for

for(j = 0; j<9; j++)
for(j = 0; j<16; j++)

using the same subscript for both loops.
Your i subscript remains uninitialised, and probably accessing WAY outside of your array.

> strcpy(output, ',');
Do you get any warnings with this - you should do. strcpy copies strings, not characters.
So it would be [tt]strcpy(output, ",");[/tt]

Additionally, you probably want all these to be strcat() calls if you intend to build up a large line.
start with
[tt]output[0] = '\0';[/tt]
then use strcat()

--

 

[kopo85]

Sorry, the second for statement is actually suppose to be

for([b]i[/b] = 0; [b]i[/b]<16; [b]i[/b]++)
{
sample[i][j] = read_adc(0);
itoa(sample[i][j], mid_store);
strcpy(output, mid_store);
strcpy(output, ',');
}

I guess I made another mistake in my code when I posted it on this forum also.

for(i = 0; i < 16; i++)
{       
if(sample[i][j]<10)
{str_length = str_length + [b]2[/b];}                
else if(sample[i][j]<100&&sample[i][j]>9)
{str_length = str_length + [b]3[/b];}
else
{str_length = str_length + [b]4[/b];}
}

Taking this into account, I don't see how I would be writing past my array, I have a array of 512, and would write at max
512 (16*8*4) = 512

To get this I should probably make the first loop

for(j = 0; j<[b]8[/b]; j++)

I haven't run into any problems using the strcpy(output,','), but will try strcpy(output, ",").

I really dont' think this is the problem, because when I tried to write the first 5 characters, the information written was completely incorrect and lacked a comma.

I'll look more into strcat(), this may be my whole problem. Thank you very much, and if anyone else has any comments to add, it would still be appreciated

 

[kopo85]

Sorry, actually it should be

for(j=0;j<9;j++)

that would make my equation correct. This forum could really use an edit button.