utf8.c - tmux - Rivoreo Source Code Repositories

 /* $OpenBSD$ */

 /*
  * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */

 #include <sys/types.h>

 #include <ctype.h>
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <wchar.h>

 #include "tmux.h"

 struct utf8_item {
 	RB_ENTRY(utf8_item)	index_entry;
 	u_int			index;

 	RB_ENTRY(utf8_item)	data_entry;
 	char			data[UTF8_SIZE];
 	u_char			size;
 };

 static int
 utf8_data_cmp(struct utf8_item *ui1, struct utf8_item *ui2)
 {
 	if (ui1->size < ui2->size)
 		return (-1);
 	if (ui1->size > ui2->size)
 		return (1);
 	return (memcmp(ui1->data, ui2->data, ui1->size));
 }
 RB_HEAD(utf8_data_tree, utf8_item);
 RB_GENERATE_STATIC(utf8_data_tree, utf8_item, data_entry, utf8_data_cmp);
 static struct utf8_data_tree utf8_data_tree = RB_INITIALIZER(utf8_data_tree);

 static int
 utf8_index_cmp(struct utf8_item *ui1, struct utf8_item *ui2)
 {
 	if (ui1->index < ui2->index)
 		return (-1);
 	if (ui1->index > ui2->index)
 		return (1);
 	return (0);
 }
 RB_HEAD(utf8_index_tree, utf8_item);
 RB_GENERATE_STATIC(utf8_index_tree, utf8_item, index_entry, utf8_index_cmp);
 static struct utf8_index_tree utf8_index_tree = RB_INITIALIZER(utf8_index_tree);

 static u_int utf8_next_index;

 #define UTF8_GET_SIZE(uc) (((uc) >> 24) & 0x1f)
 #define UTF8_GET_WIDTH(flags) (((uc) >> 29) - 1)

 #define UTF8_SET_SIZE(size) (((utf8_char)(size)) << 24)
 #define UTF8_SET_WIDTH(width) ((((utf8_char)(width)) + 1) << 29)

 /* Get a UTF-8 item from data. */
 static struct utf8_item *
 utf8_item_by_data(const char *data, size_t size)
 {
 	struct utf8_item	ui;

 	memcpy(ui.data, data, size);
 	ui.size = size;

 	return (RB_FIND(utf8_data_tree, &utf8_data_tree, &ui));
 }

 /* Get a UTF-8 item from data. */
 static struct utf8_item *
 utf8_item_by_index(u_int index)
 {
 	struct utf8_item	ui;

 	ui.index = index;

 	return (RB_FIND(utf8_index_tree, &utf8_index_tree, &ui));
 }

 /* Add a UTF-8 item. */
 static int
 utf8_put_item(const char *data, size_t size, u_int *index)
 {
 	struct utf8_item	*ui;

 	ui = utf8_item_by_data(data, size);
 	if (ui != NULL) {
 		*index = ui->index;
 		log_debug("%s: found %.*s = %u", __func__, (int)size, data,
 		    *index);
 		return (0);
 	}

 	if (utf8_next_index == 0xffffff + 1)
 		return (-1);

 	ui = xcalloc(1, sizeof *ui);
 	ui->index = utf8_next_index++;
 	RB_INSERT(utf8_index_tree, &utf8_index_tree, ui);

 	memcpy(ui->data, data, size);
 	ui->size = size;
 	RB_INSERT(utf8_data_tree, &utf8_data_tree, ui);

 	*index = ui->index;
 	log_debug("%s: added %.*s = %u", __func__, (int)size, data, *index);
 	return (0);
 }

 /* Get UTF-8 character from data. */
 enum utf8_state
 utf8_from_data(const struct utf8_data *ud, utf8_char *uc)
 {
 	u_int	index;

 	if (ud->width > 2)
 		fatalx("invalid UTF-8 width: %u", ud->width);

 	if (ud->size > UTF8_SIZE)
 		goto fail;
 	if (ud->size <= 3) {
 		index = (((utf8_char)ud->data[2] << 16)|
 		          ((utf8_char)ud->data[1] << 8)|
 		          ((utf8_char)ud->data[0]));
 	} else if (utf8_put_item(ud->data, ud->size, &index) != 0)
 		goto fail;
 	*uc = UTF8_SET_SIZE(ud->size)|UTF8_SET_WIDTH(ud->width)|index;
 	log_debug("%s: (%d %d %.*s) -> %08x", __func__, ud->width, ud->size,
 	    (int)ud->size, ud->data, *uc);
 	return (UTF8_DONE);

 fail:
 	if (ud->width == 0)
 		*uc = UTF8_SET_SIZE(0)|UTF8_SET_WIDTH(0);
 	else if (ud->width == 1)
 		*uc = UTF8_SET_SIZE(1)|UTF8_SET_WIDTH(1)|0x20;
 	else
 		*uc = UTF8_SET_SIZE(1)|UTF8_SET_WIDTH(1)|0x2020;
 	return (UTF8_ERROR);
 }

 /* Get UTF-8 data from character. */
 void
 utf8_to_data(utf8_char uc, struct utf8_data *ud)
 {
 	struct utf8_item	*ui;
 	u_int			 index;

 	memset(ud, 0, sizeof *ud);
 	ud->size = ud->have = UTF8_GET_SIZE(uc);
 	ud->width = UTF8_GET_WIDTH(uc);

 	if (ud->size <= 3) {
 		ud->data[2] = (uc >> 16);
 		ud->data[1] = ((uc >> 8) & 0xff);
 		ud->data[0] = (uc & 0xff);
 	} else {
 		index = (uc & 0xffffff);
 		if ((ui = utf8_item_by_index(index)) == NULL)
 			memset(ud->data, ' ', ud->size);
 		else
 			memcpy(ud->data, ui->data, ud->size);
 	}

 	log_debug("%s: %08x -> (%d %d %.*s)", __func__, uc, ud->width, ud->size,
 	    (int)ud->size, ud->data);
 }

 /* Get UTF-8 character from a single ASCII character. */
 u_int
 utf8_build_one(u_char ch)
 {
 	return (UTF8_SET_SIZE(1)|UTF8_SET_WIDTH(1)|ch);
 }

 /* Set a single character. */
 void
 utf8_set(struct utf8_data *ud, u_char ch)
 {
 	static const struct utf8_data empty = { { 0 }, 1, 1, 1 };

 	memcpy(ud, &empty, sizeof *ud);
 	*ud->data = ch;
 }

 /* Copy UTF-8 character. */
 void
 utf8_copy(struct utf8_data *to, const struct utf8_data *from)
 {
 	u_int	i;

 	memcpy(to, from, sizeof *to);

 	for (i = to->size; i < sizeof to->data; i++)
 		to->data[i] = '\0';
 }

 /* Get width of Unicode character. */
 static enum utf8_state
 utf8_width(struct utf8_data *ud, int *width)
 {
 	wchar_t	wc;

 	switch (mbtowc(&wc, ud->data, ud->size)) {
 	case -1:
 		log_debug("UTF-8 %.*s, mbtowc() %d", (int)ud->size, ud->data,
 		    errno);
 		mbtowc(NULL, NULL, MB_CUR_MAX);
 		return (UTF8_ERROR);
 	case 0:
 		return (UTF8_ERROR);
 	}
 	*width = wcwidth(wc);
 	if (*width >= 0 && *width <= 0xff)
 		return (UTF8_DONE);
 	log_debug("UTF-8 %.*s, wcwidth() %d", (int)ud->size, ud->data, *width);

 #ifndef __OpenBSD__
 	/*
 	 * Many platforms (particularly and inevitably OS X) have no width for
 	 * relatively common characters (wcwidth() returns -1); assume width 1
 	 * in this case. This will be wrong for genuinely nonprintable
 	 * characters, but they should be rare. We may pass through stuff that
 	 * ideally we would block, but this is no worse than sending the same
 	 * to the terminal without tmux.
 	 */
 	if (*width < 0) {
 		*width = 1;
 		return (UTF8_DONE);
 	}
 #endif
 	return (UTF8_ERROR);
 }

 /*
  * Open UTF-8 sequence.
  *
  * 11000010-11011111 C2-DF start of 2-byte sequence
  * 11100000-11101111 E0-EF start of 3-byte sequence
  * 11110000-11110100 F0-F4 start of 4-byte sequence
  */
 enum utf8_state
 utf8_open(struct utf8_data *ud, u_char ch)
 {
 	memset(ud, 0, sizeof *ud);
 	if (ch >= 0xc2 && ch <= 0xdf)
 		ud->size = 2;
 	else if (ch >= 0xe0 && ch <= 0xef)
 		ud->size = 3;
 	else if (ch >= 0xf0 && ch <= 0xf4)
 		ud->size = 4;
 	else
 		return (UTF8_ERROR);
 	utf8_append(ud, ch);
 	return (UTF8_MORE);
 }

 /* Append character to UTF-8, closing if finished. */
 enum utf8_state
 utf8_append(struct utf8_data *ud, u_char ch)
 {
 	int	width;

 	if (ud->have >= ud->size)
 		fatalx("UTF-8 character overflow");
 	if (ud->size > sizeof ud->data)
 		fatalx("UTF-8 character size too large");

 	if (ud->have != 0 && (ch & 0xc0) != 0x80)
 		ud->width = 0xff;

 	ud->data[ud->have++] = ch;
 	if (ud->have != ud->size)
 		return (UTF8_MORE);

 	if (ud->width == 0xff)
 		return (UTF8_ERROR);
 	if (utf8_width(ud, &width) != UTF8_DONE)
 		return (UTF8_ERROR);
 	ud->width = width;

 	return (UTF8_DONE);
 }

 /*
  * Encode len characters from src into dst, which is guaranteed to have four
  * bytes available for each character from src (for \abc or UTF-8) plus space
  * for \0.
  */
 int
 utf8_strvis(char *dst, const char *src, size_t len, int flag)
 {
 	struct utf8_data	 ud;
 	const char		*start = dst, *end = src + len;
 	enum utf8_state		 more;
 	size_t			 i;

 	while (src < end) {
 		if ((more = utf8_open(&ud, *src)) == UTF8_MORE) {
 			while (++src < end && more == UTF8_MORE)
 				more = utf8_append(&ud, *src);
 			if (more == UTF8_DONE) {
 				/* UTF-8 character finished. */
 				for (i = 0; i < ud.size; i++)
 					*dst++ = ud.data[i];
 				continue;
 			}
 			/* Not a complete, valid UTF-8 character. */
 			src -= ud.have;
 		}
 		if (src[0] == '$' && src < end - 1) {
 			if (isalpha((u_char)src[1]) ||
 			    src[1] == '_' ||
 			    src[1] == '{')
 				*dst++ = '\\';
 			*dst++ = '$';
 		} else if (src < end - 1)
 			dst = vis(dst, src[0], flag, src[1]);
 		else if (src < end)
 			dst = vis(dst, src[0], flag, '\0');
 		src++;
 	}
 	*dst = '\0';
 	return (dst - start);
 }

 /* Same as utf8_strvis but allocate the buffer. */
 int
 utf8_stravis(char **dst, const char *src, int flag)
 {
 	char	*buf;
 	int	 len;

 	buf = xreallocarray(NULL, 4, strlen(src) + 1);
 	len = utf8_strvis(buf, src, strlen(src), flag);

 	*dst = xrealloc(buf, len + 1);
 	return (len);
 }

 /* Same as utf8_strvis but allocate the buffer. */
 int
 utf8_stravisx(char **dst, const char *src, size_t srclen, int flag)
 {
 	char	*buf;
 	int	 len;

 	buf = xreallocarray(NULL, 4, srclen + 1);
 	len = utf8_strvis(buf, src, srclen, flag);

 	*dst = xrealloc(buf, len + 1);
 	return (len);
 }

 /* Does this string contain anything that isn't valid UTF-8? */
 int
 utf8_isvalid(const char *s)
 {
 	struct utf8_data ud;
 	const char	*end;
 	enum utf8_state	 more;

 	end = s + strlen(s);
 	while (s < end) {
 		if ((more = utf8_open(&ud, *s)) == UTF8_MORE) {
 			while (++s < end && more == UTF8_MORE)
 				more = utf8_append(&ud, *s);
 			if (more == UTF8_DONE)
 				continue;
 			return (0);
 		}
 		if (*s < 0x20 || *s > 0x7e)
 			return (0);
 		s++;
 	}
 	return (1);
 }

 /*
  * Sanitize a string, changing any UTF-8 characters to '_'. Caller should free
  * the returned string. Anything not valid printable ASCII or UTF-8 is
  * stripped.
  */
 char *
 utf8_sanitize(const char *src)
 {
 	char		*dst = NULL;
 	size_t		 n = 0;
 	enum utf8_state	 more;
 	struct utf8_data ud;
 	u_int		 i;

 	while (*src != '\0') {
 		dst = xreallocarray(dst, n + 1, sizeof *dst);
 		if ((more = utf8_open(&ud, *src)) == UTF8_MORE) {
 			while (*++src != '\0' && more == UTF8_MORE)
 				more = utf8_append(&ud, *src);
 			if (more == UTF8_DONE) {
 				dst = xreallocarray(dst, n + ud.width,
 				    sizeof *dst);
 				for (i = 0; i < ud.width; i++)
 					dst[n++] = '_';
 				continue;
 			}
 			src -= ud.have;
 		}
 		if (*src > 0x1f && *src < 0x7f)
 			dst[n++] = *src;
 		else
 			dst[n++] = '_';
 		src++;
 	}
 	dst = xreallocarray(dst, n + 1, sizeof *dst);
 	dst[n] = '\0';
 	return (dst);
 }

 /* Get UTF-8 buffer length. */
 size_t
 utf8_strlen(const struct utf8_data *s)
 {
 	size_t	i;

 	for (i = 0; s[i].size != 0; i++)
 		/* nothing */;
 	return (i);
 }

 /* Get UTF-8 string width. */
 u_int
 utf8_strwidth(const struct utf8_data *s, ssize_t n)
 {
 	ssize_t	i;
 	u_int	width = 0;

 	for (i = 0; s[i].size != 0; i++) {
 		if (n != -1 && n == i)
 			break;
 		width += s[i].width;
 	}
 	return (width);
 }

 /*
  * Convert a string into a buffer of UTF-8 characters. Terminated by size == 0.
  * Caller frees.
  */
 struct utf8_data *
 utf8_fromcstr(const char *src)
 {
 	struct utf8_data	*dst = NULL;
 	size_t			 n = 0;
 	enum utf8_state		 more;

 	while (*src != '\0') {
 		dst = xreallocarray(dst, n + 1, sizeof *dst);
 		if ((more = utf8_open(&dst[n], *src)) == UTF8_MORE) {
 			while (*++src != '\0' && more == UTF8_MORE)
 				more = utf8_append(&dst[n], *src);
 			if (more == UTF8_DONE) {
 				n++;
 				continue;
 			}
 			src -= dst[n].have;
 		}
 		utf8_set(&dst[n], *src);
 		n++;
 		src++;
 	}
 	dst = xreallocarray(dst, n + 1, sizeof *dst);
 	dst[n].size = 0;
 	return (dst);
 }

 /* Convert from a buffer of UTF-8 characters into a string. Caller frees. */
 char *
 utf8_tocstr(struct utf8_data *src)
 {
 	char	*dst = NULL;
 	size_t	 n = 0;

 	for(; src->size != 0; src++) {
 		dst = xreallocarray(dst, n + src->size, 1);
 		memcpy(dst + n, src->data, src->size);
 		n += src->size;
 	}
 	dst = xreallocarray(dst, n + 1, 1);
 	dst[n] = '\0';
 	return (dst);
 }

 /* Get width of UTF-8 string. */
 u_int
 utf8_cstrwidth(const char *s)
 {
 	struct utf8_data	tmp;
 	u_int			width;
 	enum utf8_state		more;

 	width = 0;
 	while (*s != '\0') {
 		if ((more = utf8_open(&tmp, *s)) == UTF8_MORE) {
 			while (*++s != '\0' && more == UTF8_MORE)
 				more = utf8_append(&tmp, *s);
 			if (more == UTF8_DONE) {
 				width += tmp.width;
 				continue;
 			}
 			s -= tmp.have;
 		}
 		if (*s > 0x1f && *s != 0x7f)
 			width++;
 		s++;
 	}
 	return (width);
 }

 /* Pad UTF-8 string to width on the left. Caller frees. */
 char *
 utf8_padcstr(const char *s, u_int width)
 {
 	size_t	 slen;
 	char	*out;
 	u_int	 n, i;

 	n = utf8_cstrwidth(s);
 	if (n >= width)
 		return (xstrdup(s));

 	slen = strlen(s);
 	out = xmalloc(slen + 1 + (width - n));
 	memcpy(out, s, slen);
 	for (i = n; i < width; i++)
 		out[slen++] = ' ';
 	out[slen] = '\0';
 	return (out);
 }

 /* Pad UTF-8 string to width on the right. Caller frees. */
 char *
 utf8_rpadcstr(const char *s, u_int width)
 {
 	size_t	 slen;
 	char	*out;
 	u_int	 n, i;

 	n = utf8_cstrwidth(s);
 	if (n >= width)
 		return (xstrdup(s));

 	slen = strlen(s);
 	out = xmalloc(slen + 1 + (width - n));
 	for (i = 0; i < width - n; i++)
 		out[i] = ' ';
 	memcpy(out + i, s, slen);
 	out[i + slen] = '\0';
 	return (out);
 }

 int
 utf8_cstrhas(const char *s, const struct utf8_data *ud)
 {
 	struct utf8_data	*copy, *loop;
 	int			 found = 0;

 	copy = utf8_fromcstr(s);
 	for (loop = copy; loop->size != 0; loop++) {
 		if (loop->size != ud->size)
 			continue;
 		if (memcmp(loop->data, ud->data, loop->size) == 0) {
 			found = 1;
 			break;
 		}
 	}
 	free(copy);

 	return (found);
 }
	/* $OpenBSD$ */

	/*
	* Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
	*
	* Permission to use, copy, modify, and distribute this software for any
	* purpose with or without fee is hereby granted, provided that the above
	* copyright notice and this permission notice appear in all copies.
	*
	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
	* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
	* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	*/

	#include <sys/types.h>

	#include <ctype.h>
	#include <errno.h>
	#include <stdlib.h>
	#include <string.h>
	#include <wchar.h>

	#include "tmux.h"

	struct utf8_item {
	RB_ENTRY(utf8_item) index_entry;
	u_int index;

	RB_ENTRY(utf8_item) data_entry;
	char data[UTF8_SIZE];
	u_char size;
	};

	static int
	utf8_data_cmp(struct utf8_item ui1, struct utf8_item ui2)
	{
	if (ui1->size < ui2->size)
	return (-1);
	if (ui1->size > ui2->size)
	return (1);
	return (memcmp(ui1->data, ui2->data, ui1->size));
	}
	RB_HEAD(utf8_data_tree, utf8_item);
	RB_GENERATE_STATIC(utf8_data_tree, utf8_item, data_entry, utf8_data_cmp);
	static struct utf8_data_tree utf8_data_tree = RB_INITIALIZER(utf8_data_tree);

	static int
	utf8_index_cmp(struct utf8_item ui1, struct utf8_item ui2)
	{
	if (ui1->index < ui2->index)
	return (-1);
	if (ui1->index > ui2->index)
	return (1);
	return (0);
	}
	RB_HEAD(utf8_index_tree, utf8_item);
	RB_GENERATE_STATIC(utf8_index_tree, utf8_item, index_entry, utf8_index_cmp);
	static struct utf8_index_tree utf8_index_tree = RB_INITIALIZER(utf8_index_tree);

	static u_int utf8_next_index;

	#define UTF8_GET_SIZE(uc) (((uc) >> 24) & 0x1f)
	#define UTF8_GET_WIDTH(flags) (((uc) >> 29) - 1)

	#define UTF8_SET_SIZE(size) (((utf8_char)(size)) << 24)
	#define UTF8_SET_WIDTH(width) ((((utf8_char)(width)) + 1) << 29)

	/* Get a UTF-8 item from data. */
	static struct utf8_item *
	utf8_item_by_data(const char *data, size_t size)
	{
	struct utf8_item ui;

	memcpy(ui.data, data, size);
	ui.size = size;

	return (RB_FIND(utf8_data_tree, &utf8_data_tree, &ui));
	}

	/* Get a UTF-8 item from data. */
	static struct utf8_item *
	utf8_item_by_index(u_int index)
	{
	struct utf8_item ui;

	ui.index = index;

	return (RB_FIND(utf8_index_tree, &utf8_index_tree, &ui));
	}

	/* Add a UTF-8 item. */
	static int
	utf8_put_item(const char data, size_t size, u_int index)
	{
	struct utf8_item *ui;

	ui = utf8_item_by_data(data, size);
	if (ui != NULL) {
	*index = ui->index;
	log_debug("%s: found %.*s = %u", __func__, (int)size, data,
	*index);
	return (0);
	}

	if (utf8_next_index == 0xffffff + 1)
	return (-1);

	ui = xcalloc(1, sizeof *ui);
	ui->index = utf8_next_index++;
	RB_INSERT(utf8_index_tree, &utf8_index_tree, ui);

	memcpy(ui->data, data, size);
	ui->size = size;
	RB_INSERT(utf8_data_tree, &utf8_data_tree, ui);

	*index = ui->index;
	log_debug("%s: added %.s = %u", __func__, (int)size, data, index);
	return (0);
	}

	/* Get UTF-8 character from data. */
	enum utf8_state
	utf8_from_data(const struct utf8_data ud, utf8_char uc)
	{
	u_int index;

	if (ud->width > 2)
	fatalx("invalid UTF-8 width: %u", ud->width);

	if (ud->size > UTF8_SIZE)
	goto fail;
	if (ud->size <= 3) {
	index = (((utf8_char)ud->data[2] << 16)\|
	((utf8_char)ud->data[1] << 8)\|
	((utf8_char)ud->data[0]));
	} else if (utf8_put_item(ud->data, ud->size, &index) != 0)
	goto fail;
	*uc = UTF8_SET_SIZE(ud->size)\|UTF8_SET_WIDTH(ud->width)\|index;
	log_debug("%s: (%d %d %.*s) -> %08x", __func__, ud->width, ud->size,
	(int)ud->size, ud->data, *uc);
	return (UTF8_DONE);

	fail:
	if (ud->width == 0)
	*uc = UTF8_SET_SIZE(0)\|UTF8_SET_WIDTH(0);
	else if (ud->width == 1)
	*uc = UTF8_SET_SIZE(1)\|UTF8_SET_WIDTH(1)\|0x20;
	else
	*uc = UTF8_SET_SIZE(1)\|UTF8_SET_WIDTH(1)\|0x2020;
	return (UTF8_ERROR);
	}

	/* Get UTF-8 data from character. */
	void
	utf8_to_data(utf8_char uc, struct utf8_data *ud)
	{
	struct utf8_item *ui;
	u_int index;

	memset(ud, 0, sizeof *ud);
	ud->size = ud->have = UTF8_GET_SIZE(uc);
	ud->width = UTF8_GET_WIDTH(uc);

	if (ud->size <= 3) {
	ud->data[2] = (uc >> 16);
	ud->data[1] = ((uc >> 8) & 0xff);
	ud->data[0] = (uc & 0xff);
	} else {
	index = (uc & 0xffffff);
	if ((ui = utf8_item_by_index(index)) == NULL)
	memset(ud->data, ' ', ud->size);
	else
	memcpy(ud->data, ui->data, ud->size);
	}

	log_debug("%s: %08x -> (%d %d %.*s)", __func__, uc, ud->width, ud->size,
	(int)ud->size, ud->data);
	}

	/* Get UTF-8 character from a single ASCII character. */
	u_int
	utf8_build_one(u_char ch)
	{
	return (UTF8_SET_SIZE(1)\|UTF8_SET_WIDTH(1)\|ch);
	}

	/* Set a single character. */
	void
	utf8_set(struct utf8_data *ud, u_char ch)
	{
	static const struct utf8_data empty = { { 0 }, 1, 1, 1 };

	memcpy(ud, &empty, sizeof *ud);
	*ud->data = ch;
	}

	/* Copy UTF-8 character. */
	void
	utf8_copy(struct utf8_data to, const struct utf8_data from)
	{
	u_int i;

	memcpy(to, from, sizeof *to);

	for (i = to->size; i < sizeof to->data; i++)
	to->data[i] = '\0';
	}

	/* Get width of Unicode character. */
	static enum utf8_state
	utf8_width(struct utf8_data ud, int width)
	{
	wchar_t wc;

	switch (mbtowc(&wc, ud->data, ud->size)) {
	case -1:
	log_debug("UTF-8 %.*s, mbtowc() %d", (int)ud->size, ud->data,
	errno);
	mbtowc(NULL, NULL, MB_CUR_MAX);
	return (UTF8_ERROR);
	case 0:
	return (UTF8_ERROR);
	}
	*width = wcwidth(wc);
	if (width >= 0 && width <= 0xff)
	return (UTF8_DONE);
	log_debug("UTF-8 %.s, wcwidth() %d", (int)ud->size, ud->data, width);

	#ifndef __OpenBSD__
	/*
	* Many platforms (particularly and inevitably OS X) have no width for
	* relatively common characters (wcwidth() returns -1); assume width 1
	* in this case. This will be wrong for genuinely nonprintable
	* characters, but they should be rare. We may pass through stuff that
	* ideally we would block, but this is no worse than sending the same
	* to the terminal without tmux.
	*/
	if (*width < 0) {
	*width = 1;
	return (UTF8_DONE);
	}
	#endif
	return (UTF8_ERROR);
	}

	/*
	* Open UTF-8 sequence.
	*
	* 11000010-11011111 C2-DF start of 2-byte sequence
	* 11100000-11101111 E0-EF start of 3-byte sequence
	* 11110000-11110100 F0-F4 start of 4-byte sequence
	*/
	enum utf8_state
	utf8_open(struct utf8_data *ud, u_char ch)
	{
	memset(ud, 0, sizeof *ud);
	if (ch >= 0xc2 && ch <= 0xdf)
	ud->size = 2;
	else if (ch >= 0xe0 && ch <= 0xef)
	ud->size = 3;
	else if (ch >= 0xf0 && ch <= 0xf4)
	ud->size = 4;
	else
	return (UTF8_ERROR);
	utf8_append(ud, ch);
	return (UTF8_MORE);
	}

	/* Append character to UTF-8, closing if finished. */
	enum utf8_state
	utf8_append(struct utf8_data *ud, u_char ch)
	{
	int width;

	if (ud->have >= ud->size)
	fatalx("UTF-8 character overflow");
	if (ud->size > sizeof ud->data)
	fatalx("UTF-8 character size too large");

	if (ud->have != 0 && (ch & 0xc0) != 0x80)
	ud->width = 0xff;

	ud->data[ud->have++] = ch;
	if (ud->have != ud->size)
	return (UTF8_MORE);

	if (ud->width == 0xff)
	return (UTF8_ERROR);
	if (utf8_width(ud, &width) != UTF8_DONE)
	return (UTF8_ERROR);
	ud->width = width;

	return (UTF8_DONE);
	}

	/*
	* Encode len characters from src into dst, which is guaranteed to have four
	* bytes available for each character from src (for \abc or UTF-8) plus space
	* for \0.
	*/
	int
	utf8_strvis(char dst, const char src, size_t len, int flag)
	{
	struct utf8_data ud;
	const char start = dst, end = src + len;
	enum utf8_state more;
	size_t i;

	while (src < end) {
	if ((more = utf8_open(&ud, *src)) == UTF8_MORE) {
	while (++src < end && more == UTF8_MORE)
	more = utf8_append(&ud, *src);
	if (more == UTF8_DONE) {
	/* UTF-8 character finished. */
	for (i = 0; i < ud.size; i++)
	*dst++ = ud.data[i];
	continue;
	}
	/* Not a complete, valid UTF-8 character. */
	src -= ud.have;
	}
	if (src[0] == '$' && src < end - 1) {
	if (isalpha((u_char)src[1]) \|\|
	src[1] == '_' \|\|
	src[1] == '{')
	*dst++ = '\\';
	*dst++ = '$';
	} else if (src < end - 1)
	dst = vis(dst, src[0], flag, src[1]);
	else if (src < end)
	dst = vis(dst, src[0], flag, '\0');
	src++;
	}
	*dst = '\0';
	return (dst - start);
	}

	/* Same as utf8_strvis but allocate the buffer. */
	int
	utf8_stravis(char *dst, const char src, int flag)
	{
	char *buf;
	int len;

	buf = xreallocarray(NULL, 4, strlen(src) + 1);
	len = utf8_strvis(buf, src, strlen(src), flag);

	*dst = xrealloc(buf, len + 1);
	return (len);
	}

	/* Same as utf8_strvis but allocate the buffer. */
	int
	utf8_stravisx(char *dst, const char src, size_t srclen, int flag)
	{
	char *buf;
	int len;

	buf = xreallocarray(NULL, 4, srclen + 1);
	len = utf8_strvis(buf, src, srclen, flag);

	*dst = xrealloc(buf, len + 1);
	return (len);
	}

	/* Does this string contain anything that isn't valid UTF-8? */
	int
	utf8_isvalid(const char *s)
	{
	struct utf8_data ud;
	const char *end;
	enum utf8_state more;

	end = s + strlen(s);
	while (s < end) {
	if ((more = utf8_open(&ud, *s)) == UTF8_MORE) {
	while (++s < end && more == UTF8_MORE)
	more = utf8_append(&ud, *s);
	if (more == UTF8_DONE)
	continue;
	return (0);
	}
	if (s < 0x20 \|\| s > 0x7e)
	return (0);
	s++;
	}
	return (1);
	}

	/*
	* Sanitize a string, changing any UTF-8 characters to '_'. Caller should free
	* the returned string. Anything not valid printable ASCII or UTF-8 is
	* stripped.
	*/
	char *
	utf8_sanitize(const char *src)
	{
	char *dst = NULL;
	size_t n = 0;
	enum utf8_state more;
	struct utf8_data ud;
	u_int i;

	while (*src != '\0') {
	dst = xreallocarray(dst, n + 1, sizeof *dst);
	if ((more = utf8_open(&ud, *src)) == UTF8_MORE) {
	while (*++src != '\0' && more == UTF8_MORE)
	more = utf8_append(&ud, *src);
	if (more == UTF8_DONE) {
	dst = xreallocarray(dst, n + ud.width,
	sizeof *dst);
	for (i = 0; i < ud.width; i++)
	dst[n++] = '_';
	continue;
	}
	src -= ud.have;
	}
	if (src > 0x1f && src < 0x7f)
	dst[n++] = *src;
	else
	dst[n++] = '_';
	src++;
	}
	dst = xreallocarray(dst, n + 1, sizeof *dst);
	dst[n] = '\0';
	return (dst);
	}

	/* Get UTF-8 buffer length. */
	size_t
	utf8_strlen(const struct utf8_data *s)
	{
	size_t i;

	for (i = 0; s[i].size != 0; i++)
	/* nothing */;
	return (i);
	}

	/* Get UTF-8 string width. */
	u_int
	utf8_strwidth(const struct utf8_data *s, ssize_t n)
	{
	ssize_t i;
	u_int width = 0;

	for (i = 0; s[i].size != 0; i++) {
	if (n != -1 && n == i)
	break;
	width += s[i].width;
	}
	return (width);
	}

	/*
	* Convert a string into a buffer of UTF-8 characters. Terminated by size == 0.
	* Caller frees.
	*/
	struct utf8_data *
	utf8_fromcstr(const char *src)
	{
	struct utf8_data *dst = NULL;
	size_t n = 0;
	enum utf8_state more;

	while (*src != '\0') {
	dst = xreallocarray(dst, n + 1, sizeof *dst);
	if ((more = utf8_open(&dst[n], *src)) == UTF8_MORE) {
	while (*++src != '\0' && more == UTF8_MORE)
	more = utf8_append(&dst[n], *src);
	if (more == UTF8_DONE) {
	n++;
	continue;
	}
	src -= dst[n].have;
	}
	utf8_set(&dst[n], *src);
	n++;
	src++;
	}
	dst = xreallocarray(dst, n + 1, sizeof *dst);
	dst[n].size = 0;
	return (dst);
	}

	/* Convert from a buffer of UTF-8 characters into a string. Caller frees. */
	char *
	utf8_tocstr(struct utf8_data *src)
	{
	char *dst = NULL;
	size_t n = 0;

	for(; src->size != 0; src++) {
	dst = xreallocarray(dst, n + src->size, 1);
	memcpy(dst + n, src->data, src->size);
	n += src->size;
	}
	dst = xreallocarray(dst, n + 1, 1);
	dst[n] = '\0';
	return (dst);
	}

	/* Get width of UTF-8 string. */
	u_int
	utf8_cstrwidth(const char *s)
	{
	struct utf8_data tmp;
	u_int width;
	enum utf8_state more;

	width = 0;
	while (*s != '\0') {
	if ((more = utf8_open(&tmp, *s)) == UTF8_MORE) {
	while (*++s != '\0' && more == UTF8_MORE)
	more = utf8_append(&tmp, *s);
	if (more == UTF8_DONE) {
	width += tmp.width;
	continue;
	}
	s -= tmp.have;
	}
	if (s > 0x1f && s != 0x7f)
	width++;
	s++;
	}
	return (width);
	}

	/* Pad UTF-8 string to width on the left. Caller frees. */
	char *
	utf8_padcstr(const char *s, u_int width)
	{
	size_t slen;
	char *out;
	u_int n, i;

	n = utf8_cstrwidth(s);
	if (n >= width)
	return (xstrdup(s));

	slen = strlen(s);
	out = xmalloc(slen + 1 + (width - n));
	memcpy(out, s, slen);
	for (i = n; i < width; i++)
	out[slen++] = ' ';
	out[slen] = '\0';
	return (out);
	}

	/* Pad UTF-8 string to width on the right. Caller frees. */
	char *
	utf8_rpadcstr(const char *s, u_int width)
	{
	size_t slen;
	char *out;
	u_int n, i;

	n = utf8_cstrwidth(s);
	if (n >= width)
	return (xstrdup(s));

	slen = strlen(s);
	out = xmalloc(slen + 1 + (width - n));
	for (i = 0; i < width - n; i++)
	out[i] = ' ';
	memcpy(out + i, s, slen);
	out[i + slen] = '\0';
	return (out);
	}

	int
	utf8_cstrhas(const char s, const struct utf8_data ud)
	{
	struct utf8_data copy, loop;
	int found = 0;

	copy = utf8_fromcstr(s);
	for (loop = copy; loop->size != 0; loop++) {
	if (loop->size != ud->size)
	continue;
	if (memcmp(loop->data, ud->data, loop->size) == 0) {
	found = 1;
	break;
	}
	}
	free(copy);

	return (found);
	}