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/* Copyright (c) 2014 Corinna Vinschen <corinna@vinschen.de> */
/*
FUNCTION
<<utoa>>---unsigned integer to string
INDEX
utoa
SYNOPSIS
#include <stdlib.h>
char *utoa(unsigned <[value]>, char *<[str]>, int <[base]>);
char *__utoa(unsigned <[value]>, char *<[str]>, int <[base]>);
DESCRIPTION
<<utoa>> converts the unsigned integer [<value>] to a null-terminated string
using the specified base, which must be between 2 and 36, inclusive.
<[str]> should be an array long enough to contain the converted
value, which in the worst case is sizeof(int)*8+1 bytes.
RETURNS
A pointer to the string, <[str]>, or NULL if <[base]> is invalid.
PORTABILITY
<<utoa>> is non-ANSI.
No supporting OS subroutine calls are required.
*/
#define _DEFAULT_SOURCE
#include <stdlib.h>
char *
__utoa(unsigned value, char *str, int base)
{
const char digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
int i, j;
unsigned remainder;
char c;
/* Check base is supported. */
if ((base < 2) || (base > 36)) {
str[0] = '\0';
return NULL;
}
/* Convert to string. Digits are in reverse order. */
i = 0;
do {
remainder = value % base;
str[i++] = digits[remainder];
value = value / base;
} while (value != 0);
str[i] = '\0';
/* Reverse string. */
for (j = 0, i--; j < i; j++, i--) {
c = str[j];
str[j] = str[i];
str[i] = c;
}
return str;
}
char *
utoa(unsigned value, char *str, int base)
{
return __utoa(value, str, base);
}
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