radare2/libr/util/seven.c

/* radare - LGPL - Copyright 2012-2022 - pancake */

#include <r_util.h>

// return void
R_API int r_print_pack7bit(const char *src, char *dest) {
	int i, j = 0, shift = 0;
	ut8 ch1, ch2;
	char tmp[4];

	*dest = '\0';
	int len = strlen (src);

	for (i = 0; i < len; i++) {
		ch1 = src[i] & 0x7F;
		ch1 = ch1 >> shift;
		ch2 = src[(i + 1)] & 0x7F;
		ch2 = ch2 << (7 - shift);
		ch1 = ch1 | ch2;

		j = strlen(dest);
		snprintf (tmp, sizeof (tmp), "%x", (ch1 >> 4));
		dest[j++] = tmp[0];
		snprintf (tmp, sizeof (tmp), "%x", (ch1 & 0x0F));
		dest[j++] = tmp[0];
		dest[j++] = '\0';
		shift++;
		if (7 == shift) {
			shift = 0;
			i++;
		}
	}
	return 0;
}

R_API int r_print_unpack7bit(const char *src, char *dest) {
	int i, j, shift = 0, len = strlen (src);
	ut8 ch1, ch2 = '\0';
	char buf[8];

	*dest = '\0';

	for (i = 0; i < len; i += 2) {
		snprintf (buf, sizeof (buf), "%c%c", src[i], src[i + 1]);
		ch1 = strtol (buf, NULL, 16);
		j = strlen(dest);
		dest[j++] = ((ch1 & (0x7F >> shift)) << shift) | ch2;
		dest[j++] = '\0';
		ch2 = ch1 >> (7 - shift);
		shift++;
	}
	return 0;
}