graphene/Pal/lib/string/atoi.c

/* Copyright (C) 1991, 1997 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include "api.h"

long strtol(const char* s, char** endptr, int base) {
    int neg  = 0;
    long val = 0;

    // gobble initial whitespace
    while (*s == ' ' || *s == '\t') {
        s++;
    }

    // plus/minus sign
    if (*s == '+')
        s++;
    else if (*s == '-')
        s++, neg = 1;

    // hex or octal base prefix
    if ((base == 0 || base == 16) && (s[0] == '0' && s[1] == 'x'))
        s += 2, base = 16;
    else if (base == 0 && s[0] == '0')
        s++, base = 8;
    else if (base == 0)
        base = 10;

    // digits
    while (1) {
        int dig;

        if (*s >= '0' && *s <= '9')
            dig = *s - '0';
        else if (*s >= 'a' && *s <= 'z')
            dig = *s - 'a' + 10;
        else if (*s >= 'A' && *s <= 'Z')
            dig = *s - 'A' + 10;
        else
            break;
        if (dig >= base)
            break;
        s++, val = (val * base) + dig;
        // we don't properly detect overflow!
    }

    if (endptr)
        *endptr = (char*)s;
    return (neg ? -val : val);
}

/* Convert a string to an int.  */
int atoi(const char* nptr) {
    return (int)strtol(nptr, (char**)NULL, 10);
}

/* Convert a string to an long int.  */
long int atol(const char* nptr) {
    return strtol(nptr, (char**)NULL, 10);
}