Skip to main content

Browse the archive

Staging
v0.5.1
https://github.com/python/cpython
09 December 2020, 11:06:31 UTC
Revision 65a139a9c4e794c780745684af724fbe216e9989 authored by Terry Jan Reedy on 04 June 2016, 20:15:53 UTC, committed by Terry Jan Reedy on 04 June 2016, 20:15:53 UTC 
Issue #24759: Add 'private' notice for idlelib.idle_test.
1 parent d37781e
Raw File
Tip revision: 65a139a9c4e794c780745684af724fbe216e9989 authored by Terry Jan Reedy on 04 June 2016, 20:15:53 UTC
Issue #24759: Add 'private' notice for idlelib.idle_test.
Tip revision: 65a139a
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