xref: /freebsd/contrib/libc-vis/vis.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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$");
64 #define	_DIAGASSERT(x)	assert(x)
65 #endif
66 
67 #include "namespace.h"
68 #include <sys/types.h>
69 #include <sys/param.h>
70 
71 #include <assert.h>
72 #include <vis.h>
73 #include <errno.h>
74 #include <stdlib.h>
75 #include <wchar.h>
76 #include <wctype.h>
77 
78 #ifdef __weak_alias
79 __weak_alias(strvisx,_strvisx)
80 #endif
81 
82 #if !HAVE_VIS || !HAVE_SVIS
83 #include <ctype.h>
84 #include <limits.h>
85 #include <stdio.h>
86 #include <string.h>
87 
88 /*
89  * The reason for going through the trouble to deal with character encodings
90  * in vis(3), is that we use this to safe encode output of commands. This
91  * safe encoding varies depending on the character set. For example if we
92  * display ps output in French, we don't want to display French characters
93  * as M-foo.
94  */
95 
96 static wchar_t *do_svis(wchar_t *, wint_t, int, wint_t, const wchar_t *);
97 
98 #undef BELL
99 #define BELL L'\a'
100 
101 #if defined(LC_C_LOCALE)
102 #define iscgraph(c)      isgraph_l(c, LC_C_LOCALE)
103 #else
104 /* Keep it simple for now, no locale stuff */
105 #define iscgraph(c)	isgraph(c)
106 #ifdef notyet
107 #include <locale.h>
108 static int
109 iscgraph(int c) {
110 	int rv;
111 	char *ol;
112 
113 	ol = setlocale(LC_CTYPE, "C");
114 	rv = isgraph(c);
115 	if (ol)
116 		setlocale(LC_CTYPE, ol);
117 	return rv;
118 }
119 #endif
120 #endif
121 
122 #define ISGRAPH(flags, c) \
123     (((flags) & VIS_NOLOCALE) ? iscgraph(c) : iswgraph(c))
124 
125 #define iswoctal(c)	(((u_char)(c)) >= L'0' && ((u_char)(c)) <= L'7')
126 #define iswwhite(c)	(c == L' ' || c == L'\t' || c == L'\n')
127 #define iswsafe(c)	(c == L'\b' || c == BELL || c == L'\r')
128 #define xtoa(c)		L"0123456789abcdef"[c]
129 #define XTOA(c)		L"0123456789ABCDEF"[c]
130 
131 #define MAXEXTRAS	30
132 
133 static const wchar_t char_shell[] = L"'`\";&<>()|{}]\\$!^~";
134 static const wchar_t char_glob[] = L"*?[#";
135 
136 #if !HAVE_NBTOOL_CONFIG_H
137 #ifndef __NetBSD__
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 #ifdef __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__ */
156 CTASSERT(MB_LEN_MAX <= sizeof(uint64_t));
157 #endif /* !__NetBSD__ */
158 #endif
159 
160 /*
161  * This is do_hvis, for HTTP style (RFC 1808)
162  */
163 static wchar_t *
164 do_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'$' || c == L'-' || c == L'_' || c == L'.' || c == L'+'
169 	    /* extra */
170 	    || c == L'!' || c == L'*' || c == L'\'' || c == L'(' || c == L')'
171 	    || c == L',')
172 		dst = do_svis(dst, c, flags, nextc, extra);
173 	else {
174 		*dst++ = L'%';
175 		*dst++ = xtoa(((unsigned int)c >> 4) & 0xf);
176 		*dst++ = xtoa((unsigned int)c & 0xf);
177 	}
178 
179 	return dst;
180 }
181 
182 /*
183  * This is do_mvis, for Quoted-Printable MIME (RFC 2045)
184  * NB: No handling of long lines or CRLF.
185  */
186 static wchar_t *
187 do_mvis(wchar_t *dst, wint_t c, int flags, wint_t nextc, const wchar_t *extra)
188 {
189 	if ((c != L'\n') &&
190 	    /* Space at the end of the line */
191 	    ((iswspace(c) && (nextc == L'\r' || nextc == L'\n')) ||
192 	    /* Out of range */
193 	    (!iswspace(c) && (c < 33 || (c > 60 && c < 62) || c > 126)) ||
194 	    /* Specific char to be escaped */
195 	    wcschr(L"#$@[\\]^`{|}~", 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  */
207 static wchar_t *
208 do_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)(((u_int32_t)(u_char)c >> 6) & 03) + L'0';
269 		*dst++ = (u_char)(((u_int32_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  */
304 static wchar_t *
305 do_svis(wchar_t *dst, wint_t c, int flags, wint_t nextc, const wchar_t *extra)
306 {
307 	int iswextra, i, shft;
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 * 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 
332 typedef 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  */
337 static visfun_t
338 getvisfun(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  */
350 static wchar_t *
351 makeextralist(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  */
394 static int
395 istrsenvisx(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;
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 * 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;
591 out:
592 	free(extra);
593 	free(pdst);
594 	free(psrc);
595 	free(mdst);
596 	return error;
597 }
598 
599 static int
600 istrsenvisxl(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 
617 char *
618 svis(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 
632 char *
633 snvis(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 
647 int
648 strsvis(char *mbdst, const char *mbsrc, int flags, const char *mbextra)
649 {
650 	return istrsenvisxl(&mbdst, NULL, mbsrc, flags, mbextra, NULL);
651 }
652 
653 int
654 strsnvis(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 
659 int
660 strsvisx(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 
665 int
666 strsnvisx(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 
672 int
673 strsenvisx(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  */
684 char *
685 vis(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 
699 char *
700 nvis(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 
722 int
723 strvis(char *mbdst, const char *mbsrc, int flags)
724 {
725 	return istrsenvisxl(&mbdst, NULL, mbsrc, flags, "", NULL);
726 }
727 
728 int
729 strnvis(char *mbdst, size_t dlen, const char *mbsrc, int flags)
730 {
731 	return istrsenvisxl(&mbdst, &dlen, mbsrc, flags, "", NULL);
732 }
733 
734 int
735 stravis(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 
752 int
753 strvisx(char *mbdst, const char *mbsrc, size_t len, int flags)
754 {
755 	return istrsenvisx(&mbdst, NULL, mbsrc, len, flags, "", NULL);
756 }
757 
758 int
759 strnvisx(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 
764 int
765 strenvisx(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