70 lines
1.5 KiB
C
70 lines
1.5 KiB
C
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/*
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FUNCTION
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<<itoa>>---integer to string
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INDEX
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itoa
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ANSI_SYNOPSIS
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#include <stdlib.h>
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char *itoa(int <[value]>, char *<[str]>, int <[base]>);
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char *__itoa(int <[value]>, char *<[str]>, int <[base]>);
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DESCRIPTION
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<<itoa>> converts the 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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If <[base]> is 10, <[value]> is treated as signed and the string will be
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prefixed with '-' if negative. For all other bases, <[value]> is treated as
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unsigned. <[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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<<itoa>> 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 (__itoa, (value, str, base),
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int value _AND
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char *str _AND
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int base)
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{
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unsigned uvalue;
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int i = 0;
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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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/* Negative numbers are only supported for decimal.
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* Cast to unsigned to avoid overflow for maximum negative value. */
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if ((base == 10) && (value < 0))
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{
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str[i++] = '-';
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uvalue = (unsigned)-value;
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}
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else
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uvalue = (unsigned)value;
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__utoa (uvalue, &str[i], base);
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return str;
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}
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char *
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_DEFUN (itoa, (value, str, base),
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int value _AND
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char *str _AND
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int base)
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{
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return __itoa (value, str, base);
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}
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