stdlib.c

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#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
#include <unistd.h>
#include <ctype.h> /* isXXXX */
#include <errno.h>

char **environ;

int atoi(const char *nptr)
{
        int i;

        for (i = 0; *nptr; nptr++) {
                i = (i * 10) + (*nptr - '0');
        }

        return i;
}

long atol(const char *nptr)
{
        long i;

        for (i = 0; *nptr; nptr++) {
                i = (i * 10) + (*nptr - '0');
        }

        return i;
}

long long atoll(const char *nptr)
{
        return 0;
}

long long atoq(const char *nptr)
{
        return 0;
}

int setenv(const char *name, const char *value, int overwrite)
{
        return 0;
}

char *getenv(const char *name)
{
        register int i;
        int namelen = strlen(name);

        for (i = 0; environ[i]; i++) {
                if (!strncmp(name, environ[i], namelen)) {
                        if (environ[i][namelen] == '=') {
                                return environ[i] + namelen + 1;
                        }
                }
        }

        return NULL;
}

static inline int todigit(char ch)
{
        int tmp;

        if (isdigit(ch)) {
                tmp = ch - '0';
        } else if (isupper(ch)) {
                tmp = ch - 'A';
        } else if (islower(ch)) {
                tmp = ch - 'a';
        } else {
                tmp = -EINVAL;
        }

        return tmp;
}

long int strtol(const char *nptr, char **endptr, int base)
{
        long sign = 1;
        long ret;
        int tmp;

        if (isspace(*nptr)) {
                nptr++;
        }

        if (*nptr == '-') {
                sign = -1;
                nptr++;
        } else if (*nptr == '+') {
                nptr++;
        }

        if (nptr[0] == '0') {
                if (nptr[1] == 'x') {
                        base = 16;
                } else {
                        base = 8;
                }
        }

        *endptr = NULL;
        if (!base) {
                char *ptr;

                ptr = (char *)nptr;
                while (*ptr) {
                        tmp = todigit(*ptr);
                        if (tmp < 0) {
                                break;
                        }

                        base = (base > tmp) ? base : tmp;
                        ptr++;
                }
                *endptr = ptr;
        }

        ret = 0;
        if (*endptr) {
                while (nptr != *endptr) {
                        ret *= base;

                        tmp = todigit(*nptr);
                        if (tmp < 0) {
                                break;
                        }
                        ret += tmp;
                        nptr++;
                }

        } else {
                while (*nptr) {
                        ret *= base;

                        tmp = todigit(*nptr);
                        if (tmp < 0) {
                                break;
                        }

                        if (tmp >= base) {
                                break;
                        }

                        ret += tmp;
                        nptr++;
                }

                *endptr = (char *)nptr;
        }

        ret *= sign;
        return ret;
}

long long int strtoll(const char *nptr, char **endptr, int base)
{
        return 0ll;
}

unsigned long int strtoul(const char *nptr, char **endptr, int base)
{
        long ret;
        ret = strtol(nptr, endptr, base);
        return (unsigned long)ret;
}

unsigned long long int strtoull(const char *nptr, char **endptr,
                                                     int base)
{
        long long ret;
        ret = strtoll(nptr, endptr, base);
        return (unsigned long long)ret;
}

/* End of a file */