itoa.c

来自「操作系统源代码」· C语言 代码 · 共 37 行

#include <lib.h>
/* Integer to ASCII for signed decimal integers. */

PRIVATE int next;
PRIVATE char qbuf[8];

_PROTOTYPE( char *itoa, (int n));

char *itoa(n)
int n;
{
  register int r, k;
  int flag = 0;

  next = 0;
  if (n < 0) {
	qbuf[next++] = '-';
	n = -n;
  }
  if (n == 0) {
	qbuf[next++] = '0';
  } else {
	k = 10000;
	while (k > 0) {
		r = n / k;
		if (flag || r > 0) {
			qbuf[next++] = '0' + r;
			flag = 1;
		}
		n -= r * k;
		k = k / 10;
	}
  }
  qbuf[next] = 0;
  return(qbuf);
}