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