view uptools/libcoding/decode_helpers.c @ 926:6a0aa8d36d06

rvinterf backslash escape: introduce libprint The new helper function library named libprint is meant to replace the badly misnamed libg23, and will soon contain functions for printing all of the same kinds of GPF TST packets that are now handled in libg23. However, we are also moving safe_print_trace() from libasync to this new library, and changing it to emit our new backslash escape format.
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 23 May 2023 03:47:46 +0000
parents 1c599681fd60
children
line wrap: on
line source

/*
 * This library module implements the is_decoded_char_ok() and emit_utf8_char()
 * functions used by gsm7_to_ascii_or_ext() and ucs2_to_ascii_or_ext().
 */

#include <sys/types.h>

is_decoded_char_ok(uni, ascii_ext)
	unsigned uni;
{
	unsigned upper_limit;

	/* weed out control chars first */
	if (uni < 0x20)
		return(0);
	if (uni >= 0x7F && uni <= 0x9F)
		return(0);
	/* see what range our output encoding allows */
	switch (ascii_ext) {
	case 0:
		upper_limit = 0x7F;
		break;
	case 1:
		upper_limit = 0xFF;
		break;
	case 2:
		upper_limit = 0xFFFF;
		break;
	default:
		upper_limit = 0;
	}
	if (uni <= upper_limit)
		return(1);
	else
		return(0);
}

emit_utf8_char(uni, outp)
	unsigned uni;
	u_char *outp;
{
	if (uni < 0x80) {
		*outp = uni;
		return(1);
	}
	if (uni < 0x800) {
		outp[0] = 0xC0 | (uni >> 6);
		outp[1] = 0x80 | (uni & 0x3F);
		return(2);
	}
	if (uni < 0x10000) {
		outp[0] = 0xE0 | (uni >> 12);
		outp[1] = 0x80 | ((uni >> 6) & 0x3F);
		outp[2] = 0x80 | (uni & 0x3F);
		return(3);
	}
	outp[0] = 0xF0 | (uni >> 18);
	outp[1] = 0x80 | ((uni >> 12) & 0x3F);
	outp[2] = 0x80 | ((uni >> 6) & 0x3F);
	outp[3] = 0x80 | (uni & 0x3F);
	return(4);
}