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Sprintf memory leak ?????????????????

Posted by nano (nano), 19 January 2007
Hi,

I am using sprintf like so where i want my numeric to be converted to a string
char string[100];
int result;
ret = sprintf(string, "%d", result);

does any one know if this will cause a memory leak ?


Another question.

I have the following scenario -12.34 is a numeric
I want to convert this to a string like so "-12.34"

What would be the best c function to do this ?


Posted by Yash (Yash), 6 March 2007
There is a function called _ecvt() which converts float to string, compatible only in Windows platform.

Prototype of this is as below:
char *_ecvt(
  double value,
  int count,
  int *dec,
  int *sign
);

Below program for the output your expecting can give you.

#include <stdlib.h>
#include <stdio.h>

int main( void )
{
  int     decimal,   sign;
  char    *buffer;
  int     precision = 2;
  double  source = -12.34;

  buffer = _ecvt( source, precision, &decimal, &sign );    printf( "source: %2.2f   buffer: '%s'  decimal: %d  sign: %d\n", source, buffer, decimal, sign );
}

output of above program is like this:

source: -12.34   buffer: '12'  decimal: 2  sign: 1

Hope this is useful to you.. I am new to opentalk..  

Cheers
Yash


Posted by Yash (Yash), 6 March 2007
For the first question (sprintf question),

my answer is YES, because you have declared array of 100  char's. Also you are declaring result of integer data type which can take maximum of 5 digits( Max num of 32767 ), so remaining 95  chars are not not under use called memory leak.

so declare the variable as char string[6];

(one for '/0' char)

Cheers
Yash




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