view libcommon/revnibbles.c @ 123:09a66626647d

doc/Sysmocom-SIM-notes article written
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 20 Feb 2021 04:11:48 +0000
parents 4360a7906f34
children
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/*
 * This module implements some reversed-nibbles parsing functions.
 */

#include <sys/types.h>

encode_hex_digit(d)
	unsigned d;
{
	if (d <= 9)
		return(d + '0');
	else
		return(d - 10 + 'A');
}

decode_reversed_nibbles(bytes, nbytes, dest)
	u_char *bytes;
	unsigned nbytes;
	char *dest;
{
	u_char *sp;
	char *dp;
	unsigned n, c;

	sp = bytes;
	dp = dest;
	for (n = 0; n < nbytes; n++) {
		c = *sp & 0xF;
		*dp++ = encode_hex_digit(c);
		c = *sp >> 4;
		*dp++ = encode_hex_digit(c);
		sp++;
	}
}