Skip to main content

Browse the archive

Staging
v0.8.1
https://github.com/python/cpython
09 December 2020, 11:06:31 UTC
Revision fb0928d1176a1e517cc5e46aeafbf54ff5c2554c authored by Barry Warsaw on 09 March 2010, 22:31:52 UTC, committed by Barry Warsaw on 09 March 2010, 22:31:52 UTC 
Bumping to 2.6.5rc2
1 parent 2a5b622
Raw File
Tip revision: fb0928d1176a1e517cc5e46aeafbf54ff5c2554c authored by Barry Warsaw on 09 March 2010, 22:31:52 UTC
Bumping to 2.6.5rc2
Tip revision: fb0928d
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 "pyconfig.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;
}
back to top