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v0.5.1
https://github.com/python/cpython
09 December 2020, 11:06:31 UTC
Revision 112d20d5274acbb606acfe3594fd10aa10287b52 authored by cvs2svn on 20 July 2001, 14:55:28 UTC, committed by cvs2svn on 20 July 2001, 14:55:28 UTC 
This commit was manufactured by cvs2svn to create tag 'r211'.
1 parent 2e03ba8
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Tip revision: 112d20d5274acbb606acfe3594fd10aa10287b52 authored by cvs2svn on 20 July 2001, 14:55:28 UTC
This commit was manufactured by cvs2svn to create tag 'r211'.
Tip revision: 112d20d
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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