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v0.5.1
https://github.com/python/cpython
09 December 2020, 11:06:31 UTC
Revision 0ae1490d6fb8f762eb0df4f9a03e892641f228b4 authored by cvs2svn on 02 January 2001, 17:07:49 UTC, committed by cvs2svn on 02 January 2001, 17:07:49 UTC 
This commit was manufactured by cvs2svn to create branch
 
'release20-maint'.
1 parent ff139a8
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Tip revision: 0ae1490d6fb8f762eb0df4f9a03e892641f228b4 authored by cvs2svn on 02 January 2001, 17:07:49 UTC
This commit was manufactured by cvs2svn to create branch
Tip revision: 0ae1490
atof.c 

/* Just in case you haven't got an atof() around...
   This one doesn't check for bad syntax or overflow,
   and is slow and inaccurate.
   But it's good enough for the occasional string literal... */

#include "config.h"

#include <ctype.h>

double atof(char *s)
{
	double a = 0.0;
	int e = 0;
	int c;
	while ((c = *s++) != '\0' && isdigit(c)) {
		a = a*10.0 + (c - '0');
	}
	if (c == '.') {
		while ((c = *s++) != '\0' && isdigit(c)) {
			a = a*10.0 + (c - '0');
			e = e-1;
		}
	}
	if (c == 'e' || c == 'E') {
		int sign = 1;
		int i = 0;
		c = *s++;
		if (c == '+')
			c = *s++;
		else if (c == '-') {
			c = *s++;
			sign = -1;
		}
		while (isdigit(c)) {
			i = i*10 + (c - '0');
			c = *s++;
		}
		e += i*sign;
	}
	while (e > 0) {
		a *= 10.0;
		e--;
	}
	while (e < 0) {
		a *= 0.1;
		e++;
	}
	return a;
}
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