42 lines
684 B
C
42 lines
684 B
C
/* $NetBSD: hextoint.c,v 1.2 2003/12/04 16:23:36 drochner Exp $ */
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/*
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* hextoint - convert an ascii string in hex to an unsigned
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* long, with error checking
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*/
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#include <ctype.h>
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#include "ntp_stdlib.h"
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int
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hextoint(
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const char *str,
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u_long *ival
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)
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{
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register u_long u;
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register const char *cp;
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cp = str;
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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 (!isxdigit((int)*cp))
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return 0;
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if (u >= 0x10000000)
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return 0; /* overflow */
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u <<= 4;
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if (*cp <= '9') /* very ascii dependent */
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u += *cp++ - '0';
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else if (*cp >= 'a')
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u += *cp++ - 'a' + 10;
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else
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u += *cp++ - 'A' + 10;
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}
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*ival = u;
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return 1;
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}
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