1/*	$NetBSD: vis.c,v 1.74 2017/11/27 16:37:21 christos Exp $	*/
2
3/*-
4 * Copyright (c) 1989, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32/*-
33 * Copyright (c) 1999, 2005 The NetBSD Foundation, Inc.
34 * All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions
38 * are met:
39 * 1. Redistributions of source code must retain the above copyright
40 *    notice, this list of conditions and the following disclaimer.
41 * 2. Redistributions in binary form must reproduce the above copyright
42 *    notice, this list of conditions and the following disclaimer in the
43 *    documentation and/or other materials provided with the distribution.
44 *
45 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
46 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
47 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
48 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
49 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
50 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
51 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
52 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
53 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
54 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
55 * POSSIBILITY OF SUCH DAMAGE.
56 */
57
58#include <sys/cdefs.h>
59#if defined(LIBC_SCCS) && !defined(lint)
60__RCSID("$NetBSD: vis.c,v 1.74 2017/11/27 16:37:21 christos Exp $");
61#endif /* LIBC_SCCS and not lint */
62#ifdef __FBSDID
63__FBSDID("$FreeBSD: head/contrib/libc-vis/vis.c 326307 2017-11-28 01:35:28Z brooks $");
64#define	_DIAGASSERT(x)	assert(x)
65#endif
66
67#include <sys/types.h>
68#include <sys/param.h>
69
70#include <assert.h>
71#include <vis.h>
72#include <errno.h>
73#include <stdlib.h>
74#include <wchar.h>
75#include <wctype.h>
76
77#ifdef __weak_alias
78__weak_alias(strvisx,_strvisx)
79#endif
80
81#if !HAVE_VIS || !HAVE_SVIS
82#include <ctype.h>
83#include <stdint.h>
84#include <limits.h>
85#include <stdio.h>
86#include <string.h>
87
88/*
89 * The reason for going through the trouble to deal with character encodings
90 * in vis(3), is that we use this to safe encode output of commands. This
91 * safe encoding varies depending on the character set. For example if we
92 * display ps output in French, we don't want to display French characters
93 * as M-foo.
94 */
95
96static wchar_t *do_svis(wchar_t *, wint_t, int, wint_t, const wchar_t *);
97
98#undef BELL
99#define BELL L'\a'
100
101#if defined(LC_C_LOCALE)
102#define iscgraph(c)      isgraph_l(c, LC_C_LOCALE)
103#else
104/* Keep it simple for now, no locale stuff */
105#define iscgraph(c)	isgraph(c)
106#ifdef notyet
107#include <locale.h>
108static int
109iscgraph(int c) {
110	int rv;
111	char *ol;
112
113	ol = setlocale(LC_CTYPE, "C");
114	rv = isgraph(c);
115	if (ol)
116		setlocale(LC_CTYPE, ol);
117	return rv;
118}
119#endif
120#endif
121
122#define ISGRAPH(flags, c) \
123    (((flags) & VIS_NOLOCALE) ? iscgraph(c) : iswgraph(c))
124
125#define iswoctal(c)	(((u_char)(c)) >= L'0' && ((u_char)(c)) <= L'7')
126#define iswwhite(c)	(c == L' ' || c == L'\t' || c == L'\n')
127#define iswsafe(c)	(c == L'\b' || c == BELL || c == L'\r')
128#define xtoa(c)		L"0123456789abcdef"[c]
129#define XTOA(c)		L"0123456789ABCDEF"[c]
130
131#define MAXEXTRAS	30
132
133static const wchar_t char_shell[] = L"'`\";&<>()|{}]\\$!^~";
134static const wchar_t char_glob[] = L"*?[#";
135
136#if !HAVE_NBTOOL_CONFIG_H
137#if !defined(__NetBSD__) && !defined(__HAIKU__)
138/*
139 * On NetBSD MB_LEN_MAX is currently 32 which does not fit on any integer
140 * integral type and it is probably wrong, since currently the maximum
141 * number of bytes and character needs is 6. Until this is fixed, the
142 * loops below are using sizeof(uint64_t) - 1 instead of MB_LEN_MAX, and
143 * the assertion is commented out.
144 */
145#if defined(__FreeBSD__)
146/*
147 * On FreeBSD including <sys/systm.h> for CTASSERT only works in kernel
148 * mode.
149 */
150#ifndef CTASSERT
151#define CTASSERT(x)             _CTASSERT(x, __LINE__)
152#define _CTASSERT(x, y)         __CTASSERT(x, y)
153#define __CTASSERT(x, y)        typedef char __assert ## y[(x) ? 1 : -1]
154#endif
155#endif /* __FreeBSD__ */
156CTASSERT(MB_LEN_MAX <= sizeof(uint64_t));
157#endif /* !__NetBSD__ */
158#endif
159
160/*
161 * This is do_hvis, for HTTP style (RFC 1808)
162 */
163static wchar_t *
164do_hvis(wchar_t *dst, wint_t c, int flags, wint_t nextc, const wchar_t *extra)
165{
166	if (iswalnum(c)
167	    /* safe */
168	    || c == L'$' || c == L'-' || c == L'_' || c == L'.' || c == L'+'
169	    /* extra */
170	    || c == L'!' || c == L'*' || c == L'\'' || c == L'(' || c == L')'
171	    || c == L',')
172		dst = do_svis(dst, c, flags, nextc, extra);
173	else {
174		*dst++ = L'%';
175		*dst++ = xtoa(((unsigned int)c >> 4) & 0xf);
176		*dst++ = xtoa((unsigned int)c & 0xf);
177	}
178
179	return dst;
180}
181
182/*
183 * This is do_mvis, for Quoted-Printable MIME (RFC 2045)
184 * NB: No handling of long lines or CRLF.
185 */
186static wchar_t *
187do_mvis(wchar_t *dst, wint_t c, int flags, wint_t nextc, const wchar_t *extra)
188{
189	if ((c != L'\n') &&
190	    /* Space at the end of the line */
191	    ((iswspace(c) && (nextc == L'\r' || nextc == L'\n')) ||
192	    /* Out of range */
193	    (!iswspace(c) && (c < 33 || (c > 60 && c < 62) || c > 126)) ||
194	    /* Specific char to be escaped */
195	    wcschr(L"#$@[\\]^`{|}~", c) != NULL)) {
196		*dst++ = L'=';
197		*dst++ = XTOA(((unsigned int)c >> 4) & 0xf);
198		*dst++ = XTOA((unsigned int)c & 0xf);
199	} else
200		dst = do_svis(dst, c, flags, nextc, extra);
201	return dst;
202}
203
204/*
205 * Output single byte of multibyte character.
206 */
207static wchar_t *
208do_mbyte(wchar_t *dst, wint_t c, int flags, wint_t nextc, int iswextra)
209{
210	if (flags & VIS_CSTYLE) {
211		switch (c) {
212		case L'\n':
213			*dst++ = L'\\'; *dst++ = L'n';
214			return dst;
215		case L'\r':
216			*dst++ = L'\\'; *dst++ = L'r';
217			return dst;
218		case L'\b':
219			*dst++ = L'\\'; *dst++ = L'b';
220			return dst;
221		case BELL:
222			*dst++ = L'\\'; *dst++ = L'a';
223			return dst;
224		case L'\v':
225			*dst++ = L'\\'; *dst++ = L'v';
226			return dst;
227		case L'\t':
228			*dst++ = L'\\'; *dst++ = L't';
229			return dst;
230		case L'\f':
231			*dst++ = L'\\'; *dst++ = L'f';
232			return dst;
233		case L' ':
234			*dst++ = L'\\'; *dst++ = L's';
235			return dst;
236		case L'\0':
237			*dst++ = L'\\'; *dst++ = L'0';
238			if (iswoctal(nextc)) {
239				*dst++ = L'0';
240				*dst++ = L'0';
241			}
242			return dst;
243		/* We cannot encode these characters in VIS_CSTYLE
244		 * because they special meaning */
245		case L'n':
246		case L'r':
247		case L'b':
248		case L'a':
249		case L'v':
250		case L't':
251		case L'f':
252		case L's':
253		case L'0':
254		case L'M':
255		case L'^':
256		case L'$': /* vis(1) -l */
257			break;
258		default:
259			if (ISGRAPH(flags, c) && !iswoctal(c)) {
260				*dst++ = L'\\';
261				*dst++ = c;
262				return dst;
263			}
264		}
265	}
266	if (iswextra || ((c & 0177) == L' ') || (flags & VIS_OCTAL)) {
267		*dst++ = L'\\';
268		*dst++ = (u_char)(((uint32_t)(u_char)c >> 6) & 03) + L'0';
269		*dst++ = (u_char)(((uint32_t)(u_char)c >> 3) & 07) + L'0';
270		*dst++ =			     (c	      & 07) + L'0';
271	} else {
272		if ((flags & VIS_NOSLASH) == 0)
273			*dst++ = L'\\';
274
275		if (c & 0200) {
276			c &= 0177;
277			*dst++ = L'M';
278		}
279
280		if (iswcntrl(c)) {
281			*dst++ = L'^';
282			if (c == 0177)
283				*dst++ = L'?';
284			else
285				*dst++ = c + L'@';
286		} else {
287			*dst++ = L'-';
288			*dst++ = c;
289		}
290	}
291
292	return dst;
293}
294
295/*
296 * This is do_vis, the central code of vis.
297 * dst:	      Pointer to the destination buffer
298 * c:	      Character to encode
299 * flags:     Flags word
300 * nextc:     The character following 'c'
301 * extra:     Pointer to the list of extra characters to be
302 *	      backslash-protected.
303 */
304static wchar_t *
305do_svis(wchar_t *dst, wint_t c, int flags, wint_t nextc, const wchar_t *extra)
306{
307	int iswextra, i, shft = 0;
308	uint64_t bmsk, wmsk;
309
310	iswextra = wcschr(extra, c) != NULL;
311	if (!iswextra && (ISGRAPH(flags, c) || iswwhite(c) ||
312	    ((flags & VIS_SAFE) && iswsafe(c)))) {
313		*dst++ = c;
314		return dst;
315	}
316
317	/* See comment in istrsenvisx() output loop, below. */
318	wmsk = 0;
319	for (i = sizeof(wmsk) - 1; i >= 0; i--) {
320		shft = i * 8 /* NBBY */;
321		bmsk = (uint64_t)0xffLL << shft;
322		wmsk |= bmsk;
323		if ((c & wmsk) || i == 0)
324			dst = do_mbyte(dst, (wint_t)(
325			    (uint64_t)(c & bmsk) >> shft),
326			    flags, nextc, iswextra);
327	}
328
329	return dst;
330}
331
332typedef wchar_t *(*visfun_t)(wchar_t *, wint_t, int, wint_t, const wchar_t *);
333
334/*
335 * Return the appropriate encoding function depending on the flags given.
336 */
337static visfun_t
338getvisfun(int flags)
339{
340	if (flags & VIS_HTTPSTYLE)
341		return do_hvis;
342	if (flags & VIS_MIMESTYLE)
343		return do_mvis;
344	return do_svis;
345}
346
347/*
348 * Expand list of extra characters to not visually encode.
349 */
350static wchar_t *
351makeextralist(int flags, const char *src)
352{
353	wchar_t *dst, *d;
354	size_t len;
355	const wchar_t *s;
356	mbstate_t mbstate;
357
358	bzero(&mbstate, sizeof(mbstate));
359	len = strlen(src);
360	if ((dst = calloc(len + MAXEXTRAS, sizeof(*dst))) == NULL)
361		return NULL;
362
363	if ((flags & VIS_NOLOCALE) || mbsrtowcs(dst, &src, len, &mbstate) == (size_t)-1) {
364		size_t i;
365		for (i = 0; i < len; i++)
366			dst[i] = (wchar_t)(u_char)src[i];
367		d = dst + len;
368	} else
369		d = dst + wcslen(dst);
370
371	if (flags & VIS_GLOB)
372		for (s = char_glob; *s; *d++ = *s++)
373			continue;
374
375	if (flags & VIS_SHELL)
376		for (s = char_shell; *s; *d++ = *s++)
377			continue;
378
379	if (flags & VIS_SP) *d++ = L' ';
380	if (flags & VIS_TAB) *d++ = L'\t';
381	if (flags & VIS_NL) *d++ = L'\n';
382	if (flags & VIS_DQ) *d++ = L'"';
383	if ((flags & VIS_NOSLASH) == 0) *d++ = L'\\';
384	*d = L'\0';
385
386	return dst;
387}
388
389/*
390 * istrsenvisx()
391 * 	The main internal function.
392 *	All user-visible functions call this one.
393 */
394static int
395istrsenvisx(char **mbdstp, size_t *dlen, const char *mbsrc, size_t mblength,
396    int flags, const char *mbextra, int *cerr_ptr)
397{
398	wchar_t *dst, *src, *pdst, *psrc, *start, *extra;
399	size_t len, olen;
400	uint64_t bmsk, wmsk;
401	wint_t c;
402	visfun_t f;
403	int clen = 0, cerr, error = -1, i, shft = 0;
404	char *mbdst, *mdst;
405	ssize_t mbslength, maxolen;
406	mbstate_t mbstate;
407
408	_DIAGASSERT(mbdstp != NULL);
409	_DIAGASSERT(mbsrc != NULL || mblength == 0);
410	_DIAGASSERT(mbextra != NULL);
411
412	mbslength = (ssize_t)mblength;
413	/*
414	 * When inputing a single character, must also read in the
415	 * next character for nextc, the look-ahead character.
416	 */
417	if (mbslength == 1)
418		mbslength++;
419
420	/*
421	 * Input (mbsrc) is a char string considered to be multibyte
422	 * characters.  The input loop will read this string pulling
423	 * one character, possibly multiple bytes, from mbsrc and
424	 * converting each to wchar_t in src.
425	 *
426	 * The vis conversion will be done using the wide char
427	 * wchar_t string.
428	 *
429	 * This will then be converted back to a multibyte string to
430	 * return to the caller.
431	 */
432
433	/* Allocate space for the wide char strings */
434	psrc = pdst = extra = NULL;
435	mdst = NULL;
436	if ((psrc = calloc(mbslength + 1, sizeof(*psrc))) == NULL)
437		return -1;
438	if ((pdst = calloc((16 * mbslength) + 1, sizeof(*pdst))) == NULL)
439		goto out;
440	if (*mbdstp == NULL) {
441		if ((mdst = calloc((16 * mbslength) + 1, sizeof(*mdst))) == NULL)
442			goto out;
443		*mbdstp = mdst;
444	}
445
446	mbdst = *mbdstp;
447	dst = pdst;
448	src = psrc;
449
450	if (flags & VIS_NOLOCALE) {
451		/* Do one byte at a time conversion */
452		cerr = 1;
453	} else {
454		/* Use caller's multibyte conversion error flag. */
455		cerr = cerr_ptr ? *cerr_ptr : 0;
456	}
457
458	/*
459	 * Input loop.
460	 * Handle up to mblength characters (not bytes).  We do not
461	 * stop at NULs because we may be processing a block of data
462	 * that includes NULs.
463	 */
464	bzero(&mbstate, sizeof(mbstate));
465	while (mbslength > 0) {
466		/* Convert one multibyte character to wchar_t. */
467		if (!cerr)
468			clen = mbrtowc(src, mbsrc, MB_LEN_MAX, &mbstate);
469		if (cerr || clen < 0) {
470			/* Conversion error, process as a byte instead. */
471			*src = (wint_t)(u_char)*mbsrc;
472			clen = 1;
473			cerr = 1;
474		}
475		if (clen == 0) {
476			/*
477			 * NUL in input gives 0 return value. process
478			 * as single NUL byte and keep going.
479			 */
480			clen = 1;
481		}
482		/* Advance buffer character pointer. */
483		src++;
484		/* Advance input pointer by number of bytes read. */
485		mbsrc += clen;
486		/* Decrement input byte count. */
487		mbslength -= clen;
488	}
489	len = src - psrc;
490	src = psrc;
491
492	/*
493	 * In the single character input case, we will have actually
494	 * processed two characters, c and nextc.  Reset len back to
495	 * just a single character.
496	 */
497	if (mblength < len)
498		len = mblength;
499
500	/* Convert extra argument to list of characters for this mode. */
501	extra = makeextralist(flags, mbextra);
502	if (!extra) {
503		if (dlen && *dlen == 0) {
504			errno = ENOSPC;
505			goto out;
506		}
507		*mbdst = '\0';	/* can't create extra, return "" */
508		error = 0;
509		goto out;
510	}
511
512	/* Look up which processing function to call. */
513	f = getvisfun(flags);
514
515	/*
516	 * Main processing loop.
517	 * Call do_Xvis processing function one character at a time
518	 * with next character available for look-ahead.
519	 */
520	for (start = dst; len > 0; len--) {
521		c = *src++;
522		dst = (*f)(dst, c, flags, len >= 1 ? *src : L'\0', extra);
523		if (dst == NULL) {
524			errno = ENOSPC;
525			goto out;
526		}
527	}
528
529	/* Terminate the string in the buffer. */
530	*dst = L'\0';
531
532	/*
533	 * Output loop.
534	 * Convert wchar_t string back to multibyte output string.
535	 * If we have hit a multi-byte conversion error on input,
536	 * output byte-by-byte here.  Else use wctomb().
537	 */
538	len = wcslen(start);
539	maxolen = dlen ? *dlen : (wcslen(start) * MB_LEN_MAX + 1);
540	olen = 0;
541	bzero(&mbstate, sizeof(mbstate));
542	for (dst = start; len > 0; len--) {
543		if (!cerr)
544			clen = wcrtomb(mbdst, *dst, &mbstate);
545		if (cerr || clen < 0) {
546			/*
547			 * Conversion error, process as a byte(s) instead.
548			 * Examine each byte and higher-order bytes for
549			 * data.  E.g.,
550			 *	0x000000000000a264 -> a2 64
551			 *	0x000000001f00a264 -> 1f 00 a2 64
552			 */
553			clen = 0;
554			wmsk = 0;
555			for (i = sizeof(wmsk) - 1; i >= 0; i--) {
556				shft = i * 8 /* NBBY */;
557				bmsk = (uint64_t)0xffLL << shft;
558				wmsk |= bmsk;
559				if ((*dst & wmsk) || i == 0)
560					mbdst[clen++] = (char)(
561					    (uint64_t)(*dst & bmsk) >>
562					    shft);
563			}
564			cerr = 1;
565		}
566		/* If this character would exceed our output limit, stop. */
567		if (olen + clen > (size_t)maxolen)
568			break;
569		/* Advance output pointer by number of bytes written. */
570		mbdst += clen;
571		/* Advance buffer character pointer. */
572		dst++;
573		/* Incrment output character count. */
574		olen += clen;
575	}
576
577	/* Terminate the output string. */
578	*mbdst = '\0';
579
580	if (flags & VIS_NOLOCALE) {
581		/* Pass conversion error flag out. */
582		if (cerr_ptr)
583			*cerr_ptr = cerr;
584	}
585
586	free(extra);
587	free(pdst);
588	free(psrc);
589
590	return (int)olen;
591out:
592	free(extra);
593	free(pdst);
594	free(psrc);
595	free(mdst);
596	return error;
597}
598
599static int
600istrsenvisxl(char **mbdstp, size_t *dlen, const char *mbsrc,
601    int flags, const char *mbextra, int *cerr_ptr)
602{
603	return istrsenvisx(mbdstp, dlen, mbsrc,
604	    mbsrc != NULL ? strlen(mbsrc) : 0, flags, mbextra, cerr_ptr);
605}
606
607#endif
608
609#if !HAVE_SVIS
610/*
611 *	The "svis" variants all take an "extra" arg that is a pointer
612 *	to a NUL-terminated list of characters to be encoded, too.
613 *	These functions are useful e. g. to encode strings in such a
614 *	way so that they are not interpreted by a shell.
615 */
616
617char *
618svis(char *mbdst, int c, int flags, int nextc, const char *mbextra)
619{
620	char cc[2];
621	int ret;
622
623	cc[0] = c;
624	cc[1] = nextc;
625
626	ret = istrsenvisx(&mbdst, NULL, cc, 1, flags, mbextra, NULL);
627	if (ret < 0)
628		return NULL;
629	return mbdst + ret;
630}
631
632char *
633snvis(char *mbdst, size_t dlen, int c, int flags, int nextc, const char *mbextra)
634{
635	char cc[2];
636	int ret;
637
638	cc[0] = c;
639	cc[1] = nextc;
640
641	ret = istrsenvisx(&mbdst, &dlen, cc, 1, flags, mbextra, NULL);
642	if (ret < 0)
643		return NULL;
644	return mbdst + ret;
645}
646
647int
648strsvis(char *mbdst, const char *mbsrc, int flags, const char *mbextra)
649{
650	return istrsenvisxl(&mbdst, NULL, mbsrc, flags, mbextra, NULL);
651}
652
653int
654strsnvis(char *mbdst, size_t dlen, const char *mbsrc, int flags, const char *mbextra)
655{
656	return istrsenvisxl(&mbdst, &dlen, mbsrc, flags, mbextra, NULL);
657}
658
659int
660strsvisx(char *mbdst, const char *mbsrc, size_t len, int flags, const char *mbextra)
661{
662	return istrsenvisx(&mbdst, NULL, mbsrc, len, flags, mbextra, NULL);
663}
664
665int
666strsnvisx(char *mbdst, size_t dlen, const char *mbsrc, size_t len, int flags,
667    const char *mbextra)
668{
669	return istrsenvisx(&mbdst, &dlen, mbsrc, len, flags, mbextra, NULL);
670}
671
672int
673strsenvisx(char *mbdst, size_t dlen, const char *mbsrc, size_t len, int flags,
674    const char *mbextra, int *cerr_ptr)
675{
676	return istrsenvisx(&mbdst, &dlen, mbsrc, len, flags, mbextra, cerr_ptr);
677}
678#endif
679
680#if !HAVE_VIS
681/*
682 * vis - visually encode characters
683 */
684char *
685vis(char *mbdst, int c, int flags, int nextc)
686{
687	char cc[2];
688	int ret;
689
690	cc[0] = c;
691	cc[1] = nextc;
692
693	ret = istrsenvisx(&mbdst, NULL, cc, 1, flags, "", NULL);
694	if (ret < 0)
695		return NULL;
696	return mbdst + ret;
697}
698
699char *
700nvis(char *mbdst, size_t dlen, int c, int flags, int nextc)
701{
702	char cc[2];
703	int ret;
704
705	cc[0] = c;
706	cc[1] = nextc;
707
708	ret = istrsenvisx(&mbdst, &dlen, cc, 1, flags, "", NULL);
709	if (ret < 0)
710		return NULL;
711	return mbdst + ret;
712}
713
714/*
715 * strvis - visually encode characters from src into dst
716 *
717 *	Dst must be 4 times the size of src to account for possible
718 *	expansion.  The length of dst, not including the trailing NULL,
719 *	is returned.
720 */
721
722int
723strvis(char *mbdst, const char *mbsrc, int flags)
724{
725	return istrsenvisxl(&mbdst, NULL, mbsrc, flags, "", NULL);
726}
727
728int
729strnvis(char *mbdst, size_t dlen, const char *mbsrc, int flags)
730{
731	return istrsenvisxl(&mbdst, &dlen, mbsrc, flags, "", NULL);
732}
733
734int
735stravis(char **mbdstp, const char *mbsrc, int flags)
736{
737	*mbdstp = NULL;
738	return istrsenvisxl(mbdstp, NULL, mbsrc, flags, "", NULL);
739}
740
741/*
742 * strvisx - visually encode characters from src into dst
743 *
744 *	Dst must be 4 times the size of src to account for possible
745 *	expansion.  The length of dst, not including the trailing NULL,
746 *	is returned.
747 *
748 *	Strvisx encodes exactly len characters from src into dst.
749 *	This is useful for encoding a block of data.
750 */
751
752int
753strvisx(char *mbdst, const char *mbsrc, size_t len, int flags)
754{
755	return istrsenvisx(&mbdst, NULL, mbsrc, len, flags, "", NULL);
756}
757
758int
759strnvisx(char *mbdst, size_t dlen, const char *mbsrc, size_t len, int flags)
760{
761	return istrsenvisx(&mbdst, &dlen, mbsrc, len, flags, "", NULL);
762}
763
764int
765strenvisx(char *mbdst, size_t dlen, const char *mbsrc, size_t len, int flags,
766    int *cerr_ptr)
767{
768	return istrsenvisx(&mbdst, &dlen, mbsrc, len, flags, "", cerr_ptr);
769}
770#endif
771