Problem Converting String to Float - Using ATOF

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Hello yet again... Anyway, I'm trying to convert a string that has the form of "1097.04", that is, decimal fixed point with two digits after the decimal point. My code currently reads this number from a file then stores it in a *char. Then when i try to convert this *char into a double it instead returns a 0. Here's my code:

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char *price_1, *price_2;
double price1, price2;
 
if(strncmp(t, stock_id, 5) == 0)
{
	printf("Found the stock in %s!\n", argv[1]);
//	printf ("Splitting string \"%s\" into tokens:\n", t);
	out = strtok(t," ");
 
	int i = 0;
	while (i < 1)
	{
		printf ("%s\n", out);
		out = strtok(NULL, " ");
		price_1 = out;
		i++;
	}
	//printf("Printing price_1: %s\n", price_1);
	while (i < 2)
	{
		out = strtok(NULL, " ");
		price_2 = out;
		i++;
	}
	printf("Printing price_1: %s\n", price_1);
	price1 = atof(price_1);
	printf("Printing price1: %d\n", price1);
 
	break;
}
char *price_1, *price_2;
double price1, price2;

if(strncmp(t, stock_id, 5) == 0)
{
	printf("Found the stock in %s!\n", argv[1]);
//	printf ("Splitting string \"%s\" into tokens:\n", t);
	out = strtok(t," ");

	int i = 0;
	while (i < 1)
	{
		printf ("%s\n", out);
		out = strtok(NULL, " ");
		price_1 = out;
		i++;
	}
	//printf("Printing price_1: %s\n", price_1);
	while (i < 2)
	{
		out = strtok(NULL, " ");
		price_2 = out;
		i++;
	}
	printf("Printing price_1: %s\n", price_1);
	price1 = atof(price_1);
	printf("Printing price1: %d\n", price1);

	break;
}

Where 't', is the buffer that reads from the file line-by-line and argv[1] is the file being read in, 'datafile', which is of form [Stock] [Price_1] [Price_2]:
IPHON 400.00 500.00
WALMA 50.00 75.00
KROGE 100.00 120.00
CHOOC 24.00 34.24
MICRO 1234.56 2000.00

Here's my output:

-bash-3.2$ ./StockOrders datafile logfile server client
Broker is waiting for request...
Request quote to buy MICRO by 5555.

Client says, "Request quote to buy MICRO by 5555.
."
Client wants to buy...
Printing stock_id: MICRO
Printing cust_id: 5555
Broker is generating quote...
Found the stock in datafile!
MICRO
Printing price_1: 1234.56
Printing price1: 0
-bash-3.2$

Thanks again!

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Problem converting to a double in C

Krysis

Reputation Points: 10

Solved Threads: 0

Newbie Poster

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15 posts
since Nov 2008

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Nov 25th, 2008

Re: Problem Converting String to Float - Using ATOF

I'm thinking that your problem is actually the format character in the last printf. '%d' is for decimals/integers. Try using a '%f' instead.

Murtan

Reputation Points: 344

Solved Threads: 116

Practically a Master Poster

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670 posts
since May 2008

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Aug 12th, 2010

Help!

I am having a very similiar problem. Read in a string from a file and need to preform basic math equations with it, therefor assuming it can't be in string form. I am attempting to use ATOF but am getting 0's and nan's in return...any suggestions?

#include <stdio.h>
#include <string.h>
#include <math.h>

int main()
{
/*Define Everything*/
FILE * fp;
FILE * fp2;
char String[50000];
char read[500000];
char out[500000];
char Diff[100];
float Decimal;
int i, j;

strcpy(read, "GREP_MARK");
strcpy(out, "Average");
fp = fopen(read,"r");
fp2 = fopen(out, "w+");

while (!feof(fp))
{
i = 0;
j = 334;
Decimal = 0;
fgets(String, 50000, fp);
while (i<=1)
{
Diff[i] = String[j];
j++;
i++;
}
Decimal = atof(Diff);
fprintf(fp2,"The int is: %f\n", Decimal);
}
}

Astro2010

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Solved Threads: 0

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3 posts
since Aug 2010

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