53 lines
839 B
C
53 lines
839 B
C
/* $NetBSD: atoint.c,v 1.1.1.1 2000/03/29 12:38:49 simonb Exp $ */
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/*
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* atoint - convert an ascii string to a signed long, with error checking
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*/
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#include <sys/types.h>
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#include <ctype.h>
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#include "ntp_types.h"
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#include "ntp_stdlib.h"
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int
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atoint(
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const char *str,
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long *ival
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)
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{
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register long u;
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register const char *cp;
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register int isneg;
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register int oflow_digit;
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cp = str;
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if (*cp == '-') {
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cp++;
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isneg = 1;
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oflow_digit = '8';
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} else {
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isneg = 0;
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oflow_digit = '7';
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}
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if (*cp == '\0')
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return 0;
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u = 0;
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while (*cp != '\0') {
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if (!isdigit((int)*cp))
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return 0;
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if (u > 214748364 || (u == 214748364 && *cp > oflow_digit))
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return 0; /* overflow */
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u = (u << 3) + (u << 1);
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u += *cp++ - '0'; /* ascii dependent */
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}
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if (isneg)
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*ival = -u;
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else
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*ival = u;
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return 1;
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}
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