aboutsummaryrefslogblamecommitdiff
path: root/st.c
blob: 7f35b8ae8882604e2f17c485999e590c9c7bbcb1 (plain) (tree)
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334




































                                                                       
                          






                                                                    


                                                                                 








































































                                                                          


                                                 





































                                                                               
                                      






























                                              

                                       



































































































































































































































                                                                               
                                             

                         
                                                 











































































































                                                                                                   
                                        













                                                                    
                                                                      





                                                   
                                                



















                                                                            
                                                                  





                                                                  
                                                                





























                                                                 
                                                 

                                         
                                                                     

                                                                        
                                                        









































































































































































































































                                                                               


                                          






































































































































































































                                                                                   




                                      











                                    



















                                                          

































                                          





                                     






                                                                    








                                                            

                                   


    
                                        





                                     









                                                         








                                                    

                                    



























                                                                                     
                                          





























































































                                                                                   


                                                     





































































                                                                 
                                            





                                                  
                                          



















































































































































































































































































































































































































































                                                                                      
                                                         


                                                  
                                                           






















































































































































































































































































































































































































































































































                                                                                     
                                                  











                                                         
                                                    
















































































































































































































                                                                                     
                 



































                                                                        







                                                                           

























































                                                                            
                                               



















                                                             


                                                                                   












                                               
/* See LICENSE for license details. */
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <pwd.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <sys/select.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <termios.h>
#include <unistd.h>
#include <wchar.h>

#include "st.h"
#include "win.h"

#if   defined(__linux)
 #include <pty.h>
#elif defined(__OpenBSD__) || defined(__NetBSD__) || defined(__APPLE__)
 #include <util.h>
#elif defined(__FreeBSD__) || defined(__DragonFly__)
 #include <libutil.h>
#endif

/* Arbitrary sizes */
#define UTF_INVALID   0xFFFD
#define UTF_SIZ       4
#define ESC_BUF_SIZ   (128*UTF_SIZ)
#define ESC_ARG_SIZ   16
#define STR_BUF_SIZ   ESC_BUF_SIZ
#define STR_ARG_SIZ   ESC_ARG_SIZ
#define HISTSIZE      2000

/* macros */
#define IS_SET(flag)		((term.mode & (flag)) != 0)
#define ISCONTROLC0(c)		(BETWEEN(c, 0, 0x1f) || (c) == 0x7f)
#define ISCONTROLC1(c)		(BETWEEN(c, 0x80, 0x9f))
#define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
#define ISDELIM(u)		(u && wcschr(worddelimiters, u))
#define TLINE(y)		((y) < term.scr ? term.hist[((y) + term.histi - \
				term.scr + HISTSIZE + 1) % HISTSIZE] : \
				term.line[(y) - term.scr])

enum term_mode {
	MODE_WRAP        = 1 << 0,
	MODE_INSERT      = 1 << 1,
	MODE_ALTSCREEN   = 1 << 2,
	MODE_CRLF        = 1 << 3,
	MODE_ECHO        = 1 << 4,
	MODE_PRINT       = 1 << 5,
	MODE_UTF8        = 1 << 6,
};

enum cursor_movement {
	CURSOR_SAVE,
	CURSOR_LOAD
};

enum cursor_state {
	CURSOR_DEFAULT  = 0,
	CURSOR_WRAPNEXT = 1,
	CURSOR_ORIGIN   = 2
};

enum charset {
	CS_GRAPHIC0,
	CS_GRAPHIC1,
	CS_UK,
	CS_USA,
	CS_MULTI,
	CS_GER,
	CS_FIN
};

enum escape_state {
	ESC_START      = 1,
	ESC_CSI        = 2,
	ESC_STR        = 4,  /* DCS, OSC, PM, APC */
	ESC_ALTCHARSET = 8,
	ESC_STR_END    = 16, /* a final string was encountered */
	ESC_TEST       = 32, /* Enter in test mode */
	ESC_UTF8       = 64,
};

typedef struct {
	Glyph attr; /* current char attributes */
	int x;
	int y;
	char state;
} TCursor;

typedef struct {
	int mode;
	int type;
	int snap;
	/*
	 * Selection variables:
	 * nb – normalized coordinates of the beginning of the selection
	 * ne – normalized coordinates of the end of the selection
	 * ob – original coordinates of the beginning of the selection
	 * oe – original coordinates of the end of the selection
	 */
	struct {
		int x, y;
	} nb, ne, ob, oe;

	int alt;
} Selection;

/* Internal representation of the screen */
typedef struct {
	int row;      /* nb row */
	int col;      /* nb col */
	Line *line;   /* screen */
	Line *alt;    /* alternate screen */
	Line hist[HISTSIZE]; /* history buffer */
	int histi;    /* history index */
	int scr;      /* scroll back */
	int *dirty;   /* dirtyness of lines */
	TCursor c;    /* cursor */
	int ocx;      /* old cursor col */
	int ocy;      /* old cursor row */
	int top;      /* top    scroll limit */
	int bot;      /* bottom scroll limit */
	int mode;     /* terminal mode flags */
	int esc;      /* escape state flags */
	char trantbl[4]; /* charset table translation */
	int charset;  /* current charset */
	int icharset; /* selected charset for sequence */
	int *tabs;
	Rune lastc;   /* last printed char outside of sequence, 0 if control */
} Term;

/* CSI Escape sequence structs */
/* ESC '[' [[ [<priv>] <arg> [;]] <mode> [<mode>]] */
typedef struct {
	char buf[ESC_BUF_SIZ]; /* raw string */
	size_t len;            /* raw string length */
	char priv;
	int arg[ESC_ARG_SIZ];
	int narg;              /* nb of args */
	char mode[2];
} CSIEscape;

/* STR Escape sequence structs */
/* ESC type [[ [<priv>] <arg> [;]] <mode>] ESC '\' */
typedef struct {
	char type;             /* ESC type ... */
	char *buf;             /* allocated raw string */
	size_t siz;            /* allocation size */
	size_t len;            /* raw string length */
	char *args[STR_ARG_SIZ];
	int narg;              /* nb of args */
} STREscape;

static void execsh(char *, char **);
static char *getcwd_by_pid(pid_t pid);
static void stty(char **);
static void sigchld(int);
static void ttywriteraw(const char *, size_t);

static void csidump(void);
static void csihandle(void);
static void csiparse(void);
static void csireset(void);
static int eschandle(uchar);
static void strdump(void);
static void strhandle(void);
static void strparse(void);
static void strreset(void);

static void tprinter(char *, size_t);
static void tdumpsel(void);
static void tdumpline(int);
static void tdump(void);
static void tclearregion(int, int, int, int);
static void tcursor(int);
static void tdeletechar(int);
static void tdeleteline(int);
static void tinsertblank(int);
static void tinsertblankline(int);
static int tlinelen(int);
static void tmoveto(int, int);
static void tmoveato(int, int);
static void tnewline(int);
static void tputtab(int);
static void tputc(Rune);
static void treset(void);
static void tscrollup(int, int, int);
static void tscrolldown(int, int, int);
static void tsetattr(int *, int);
static void tsetchar(Rune, Glyph *, int, int);
static void tsetdirt(int, int);
static void tsetscroll(int, int);
static void tswapscreen(void);
static void tsetmode(int, int, int *, int);
static int twrite(const char *, int, int);
static void tfulldirt(void);
static void tcontrolcode(uchar );
static void tdectest(char );
static void tdefutf8(char);
static int32_t tdefcolor(int *, int *, int);
static void tdeftran(char);
static void tstrsequence(uchar);

static void drawregion(int, int, int, int);

static void selnormalize(void);
static void selscroll(int, int);
static void selsnap(int *, int *, int);

static size_t utf8decode(const char *, Rune *, size_t);
static Rune utf8decodebyte(char, size_t *);
static char utf8encodebyte(Rune, size_t);
static size_t utf8validate(Rune *, size_t);

static char *base64dec(const char *);
static char base64dec_getc(const char **);

static ssize_t xwrite(int, const char *, size_t);

/* Globals */
static Term term;
static Selection sel;
static CSIEscape csiescseq;
static STREscape strescseq;
static int iofd = 1;
static int cmdfd;
static pid_t pid;

static uchar utfbyte[UTF_SIZ + 1] = {0x80,    0, 0xC0, 0xE0, 0xF0};
static uchar utfmask[UTF_SIZ + 1] = {0xC0, 0x80, 0xE0, 0xF0, 0xF8};
static Rune utfmin[UTF_SIZ + 1] = {       0,    0,  0x80,  0x800,  0x10000};
static Rune utfmax[UTF_SIZ + 1] = {0x10FFFF, 0x7F, 0x7FF, 0xFFFF, 0x10FFFF};

ssize_t
xwrite(int fd, const char *s, size_t len)
{
	size_t aux = len;
	ssize_t r;

	while (len > 0) {
		r = write(fd, s, len);
		if (r < 0)
			return r;
		len -= r;
		s += r;
	}

	return aux;
}

void *
xmalloc(size_t len)
{
	void *p;

	if (!(p = malloc(len)))
		die("malloc: %s\n", strerror(errno));

	return p;
}

void *
xrealloc(void *p, size_t len)
{
	if ((p = realloc(p, len)) == NULL)
		die("realloc: %s\n", strerror(errno));

	return p;
}

char *
xstrdup(char *s)
{
	if ((s = strdup(s)) == NULL)
		die("strdup: %s\n", strerror(errno));

	return s;
}

size_t
utf8decode(const char *c, Rune *u, size_t clen)
{
	size_t i, j, len, type;
	Rune udecoded;

	*u = UTF_INVALID;
	if (!clen)
		return 0;
	udecoded = utf8decodebyte(c[0], &len);
	if (!BETWEEN(len, 1, UTF_SIZ))
		return 1;
	for (i = 1, j = 1; i < clen && j < len; ++i, ++j) {
		udecoded = (udecoded << 6) | utf8decodebyte(c[i], &type);
		if (type != 0)
			return j;
	}
	if (j < len)
		return 0;
	*u = udecoded;
	utf8validate(u, len);

	return len;
}

Rune
utf8decodebyte(char c, size_t *i)
{
	for (*i = 0; *i < LEN(utfmask); ++(*i))
		if (((uchar)c & utfmask[*i]) == utfbyte[*i])
			return (uchar)c & ~utfmask[*i];

	return 0;
}

size_t
utf8encode(Rune u, char *c)
{
	size_t len, i;

	len = utf8validate(&u, 0);
	if (len > UTF_SIZ)
		return 0;

	for (i = len - 1; i != 0; --i) {
		c[i] = utf8encodebyte(u, 0);
		u >>= 6;
	}
	c[0] = utf8encodebyte(u, len);

	return len;
}

char
utf8encodebyte(Rune u, size_t i)
{
	return utfbyte[i] | (u & ~utfmask[i]);
}

size_t
utf8validate(Rune *u, size_t i)
{
	if (!BETWEEN(*u, utfmin[i], utfmax[i]) || BETWEEN(*u, 0xD800, 0xDFFF))
		*u = UTF_INVALID;
	for (i = 1; *u > utfmax[i]; ++i)
		;

	return i;
}

static const char base64_digits[] = {
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 62, 0, 0, 0,
	63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 0, 0, 0, -1, 0, 0, 0, 0, 1,
	2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
	22, 23, 24, 25, 0, 0, 0, 0, 0, 0, 26, 27, 28, 29, 30, 31, 32, 33, 34,
	35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

char
base64dec_getc(const char **src)
{
	while (**src && !isprint(**src))
		(*src)++;
	return **src ? *((*src)++) : '=';  /* emulate padding if string ends */
}

char *
base64dec(const char *src)
{
	size_t in_len = strlen(src);
	char *result, *dst;

	if (in_len % 4)
		in_len += 4 - (in_len % 4);
	result = dst = xmalloc(in_len / 4 * 3 + 1);
	while (*src) {
		int a = base64_digits[(unsigned char) base64dec_getc(&src)];
		int b = base64_digits[(unsigned char) base64dec_getc(&src)];
		int c = base64_digits[(unsigned char) base64dec_getc(&src)];
		int d = base64_digits[(unsigned char) base64dec_getc(&src)];

		/* invalid input. 'a' can be -1, e.g. if src is "\n" (c-str) */
		if (a == -1 || b == -1)
			break;

		*dst++ = (a << 2) | ((b & 0x30) >> 4);
		if (c == -1)
			break;
		*dst++ = ((b & 0x0f) << 4) | ((c & 0x3c) >> 2);
		if (d == -1)
			break;
		*dst++ = ((c & 0x03) << 6) | d;
	}
	*dst = '\0';
	return result;
}

void
selinit(void)
{
	sel.mode = SEL_IDLE;
	sel.snap = 0;
	sel.ob.x = -1;
}

int
tlinelen(int y)
{
	int i = term.col;

	if (TLINE(y)[i - 1].mode & ATTR_WRAP)
		return i;

	while (i > 0 && TLINE(y)[i - 1].u == ' ')
		--i;

	return i;
}

void
selstart(int col, int row, int snap)
{
	selclear();
	sel.mode = SEL_EMPTY;
	sel.type = SEL_REGULAR;
	sel.alt = IS_SET(MODE_ALTSCREEN);
	sel.snap = snap;
	sel.oe.x = sel.ob.x = col;
	sel.oe.y = sel.ob.y = row;
	selnormalize();

	if (sel.snap != 0)
		sel.mode = SEL_READY;
	tsetdirt(sel.nb.y, sel.ne.y);
}

void
selextend(int col, int row, int type, int done)
{
	int oldey, oldex, oldsby, oldsey, oldtype;

	if (sel.mode == SEL_IDLE)
		return;
	if (done && sel.mode == SEL_EMPTY) {
		selclear();
		return;
	}

	oldey = sel.oe.y;
	oldex = sel.oe.x;
	oldsby = sel.nb.y;
	oldsey = sel.ne.y;
	oldtype = sel.type;

	sel.oe.x = col;
	sel.oe.y = row;
	selnormalize();
	sel.type = type;

	if (oldey != sel.oe.y || oldex != sel.oe.x || oldtype != sel.type || sel.mode == SEL_EMPTY)
		tsetdirt(MIN(sel.nb.y, oldsby), MAX(sel.ne.y, oldsey));

	sel.mode = done ? SEL_IDLE : SEL_READY;
}

void
selnormalize(void)
{
	int i;

	if (sel.type == SEL_REGULAR && sel.ob.y != sel.oe.y) {
		sel.nb.x = sel.ob.y < sel.oe.y ? sel.ob.x : sel.oe.x;
		sel.ne.x = sel.ob.y < sel.oe.y ? sel.oe.x : sel.ob.x;
	} else {
		sel.nb.x = MIN(sel.ob.x, sel.oe.x);
		sel.ne.x = MAX(sel.ob.x, sel.oe.x);
	}
	sel.nb.y = MIN(sel.ob.y, sel.oe.y);
	sel.ne.y = MAX(sel.ob.y, sel.oe.y);

	selsnap(&sel.nb.x, &sel.nb.y, -1);
	selsnap(&sel.ne.x, &sel.ne.y, +1);

	/* expand selection over line breaks */
	if (sel.type == SEL_RECTANGULAR)
		return;
	i = tlinelen(sel.nb.y);
	if (i < sel.nb.x)
		sel.nb.x = i;
	if (tlinelen(sel.ne.y) <= sel.ne.x)
		sel.ne.x = term.col - 1;
}

int
selected(int x, int y)
{
	if (sel.mode == SEL_EMPTY || sel.ob.x == -1 ||
			sel.alt != IS_SET(MODE_ALTSCREEN))
		return 0;

	if (sel.type == SEL_RECTANGULAR)
		return BETWEEN(y, sel.nb.y, sel.ne.y)
		    && BETWEEN(x, sel.nb.x, sel.ne.x);

	return BETWEEN(y, sel.nb.y, sel.ne.y)
	    && (y != sel.nb.y || x >= sel.nb.x)
	    && (y != sel.ne.y || x <= sel.ne.x);
}

void
selsnap(int *x, int *y, int direction)
{
	int newx, newy, xt, yt;
	int delim, prevdelim;
	Glyph *gp, *prevgp;

	switch (sel.snap) {
	case SNAP_WORD:
		/*
		 * Snap around if the word wraps around at the end or
		 * beginning of a line.
		 */
		prevgp = &TLINE(*y)[*x];
		prevdelim = ISDELIM(prevgp->u);
		for (;;) {
			newx = *x + direction;
			newy = *y;
			if (!BETWEEN(newx, 0, term.col - 1)) {
				newy += direction;
				newx = (newx + term.col) % term.col;
				if (!BETWEEN(newy, 0, term.row - 1))
					break;

				if (direction > 0)
					yt = *y, xt = *x;
				else
					yt = newy, xt = newx;
				if (!(TLINE(yt)[xt].mode & ATTR_WRAP))
					break;
			}

			if (newx >= tlinelen(newy))
				break;

			gp = &TLINE(newy)[newx];
			delim = ISDELIM(gp->u);
			if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim
					|| (delim && gp->u != prevgp->u)))
				break;

			*x = newx;
			*y = newy;
			prevgp = gp;
			prevdelim = delim;
		}
		break;
	case SNAP_LINE:
		/*
		 * Snap around if the the previous line or the current one
		 * has set ATTR_WRAP at its end. Then the whole next or
		 * previous line will be selected.
		 */
		*x = (direction < 0) ? 0 : term.col - 1;
		if (direction < 0) {
			for (; *y > 0; *y += direction) {
				if (!(TLINE(*y-1)[term.col-1].mode
						& ATTR_WRAP)) {
					break;
				}
			}
		} else if (direction > 0) {
			for (; *y < term.row-1; *y += direction) {
				if (!(TLINE(*y)[term.col-1].mode
						& ATTR_WRAP)) {
					break;
				}
			}
		}
		break;
	}
}

char *
getsel(void)
{
	char *str, *ptr;
	int y, bufsize, lastx, linelen;
	Glyph *gp, *last;

	if (sel.ob.x == -1)
		return NULL;

	bufsize = (term.col+1) * (sel.ne.y-sel.nb.y+1) * UTF_SIZ;
	ptr = str = xmalloc(bufsize);

	/* append every set & selected glyph to the selection */
	for (y = sel.nb.y; y <= sel.ne.y; y++) {
		if ((linelen = tlinelen(y)) == 0) {
			*ptr++ = '\n';
			continue;
		}

		if (sel.type == SEL_RECTANGULAR) {
			gp = &TLINE(y)[sel.nb.x];
			lastx = sel.ne.x;
		} else {
			gp = &TLINE(y)[sel.nb.y == y ? sel.nb.x : 0];
			lastx = (sel.ne.y == y) ? sel.ne.x : term.col-1;
		}
		last = &TLINE(y)[MIN(lastx, linelen-1)];
		while (last >= gp && last->u == ' ')
			--last;

		for ( ; gp <= last; ++gp) {
			if (gp->mode & ATTR_WDUMMY)
				continue;

			ptr += utf8encode(gp->u, ptr);
		}

		/*
		 * Copy and pasting of line endings is inconsistent
		 * in the inconsistent terminal and GUI world.
		 * The best solution seems like to produce '\n' when
		 * something is copied from st and convert '\n' to
		 * '\r', when something to be pasted is received by
		 * st.
		 * FIXME: Fix the computer world.
		 */
		if ((y < sel.ne.y || lastx >= linelen) &&
		    (!(last->mode & ATTR_WRAP) || sel.type == SEL_RECTANGULAR))
			*ptr++ = '\n';
	}
	*ptr = 0;
	return str;
}

void
selclear(void)
{
	if (sel.ob.x == -1)
		return;
	sel.mode = SEL_IDLE;
	sel.ob.x = -1;
	tsetdirt(sel.nb.y, sel.ne.y);
}

void
die(const char *errstr, ...)
{
	va_list ap;

	va_start(ap, errstr);
	vfprintf(stderr, errstr, ap);
	va_end(ap);
	exit(1);
}

void
execsh(char *cmd, char **args)
{
	char *sh, *prog, *arg;
	const struct passwd *pw;

	errno = 0;
	if ((pw = getpwuid(getuid())) == NULL) {
		if (errno)
			die("getpwuid: %s\n", strerror(errno));
		else
			die("who are you?\n");
	}

	if ((sh = getenv("SHELL")) == NULL)
		sh = (pw->pw_shell[0]) ? pw->pw_shell : cmd;

	if (args) {
		prog = args[0];
		arg = NULL;
	} else if (scroll) {
		prog = scroll;
		arg = utmp ? utmp : sh;
	} else if (utmp) {
		prog = utmp;
		arg = NULL;
	} else {
		prog = sh;
		arg = NULL;
	}
	DEFAULT(args, ((char *[]) {prog, arg, NULL}));

	unsetenv("COLUMNS");
	unsetenv("LINES");
	unsetenv("TERMCAP");
	setenv("LOGNAME", pw->pw_name, 1);
	setenv("USER", pw->pw_name, 1);
	setenv("SHELL", sh, 1);
	setenv("HOME", pw->pw_dir, 1);
	setenv("TERM", termname, 1);

	signal(SIGCHLD, SIG_DFL);
	signal(SIGHUP, SIG_DFL);
	signal(SIGINT, SIG_DFL);
	signal(SIGQUIT, SIG_DFL);
	signal(SIGTERM, SIG_DFL);
	signal(SIGALRM, SIG_DFL);

	execvp(prog, args);
	_exit(1);
}

void
sigchld(int a)
{
	int stat;
	pid_t p;

	if ((p = waitpid(pid, &stat, WNOHANG)) < 0)
		die("waiting for pid %hd failed: %s\n", pid, strerror(errno));

	if (pid != p)
		return;

	if (WIFEXITED(stat) && WEXITSTATUS(stat))
		die("child exited with status %d\n", WEXITSTATUS(stat));
	else if (WIFSIGNALED(stat))
		die("child terminated due to signal %d\n", WTERMSIG(stat));
	_exit(0);
}

void
stty(char **args)
{
	char cmd[_POSIX_ARG_MAX], **p, *q, *s;
	size_t n, siz;

	if ((n = strlen(stty_args)) > sizeof(cmd)-1)
		die("incorrect stty parameters\n");
	memcpy(cmd, stty_args, n);
	q = cmd + n;
	siz = sizeof(cmd) - n;
	for (p = args; p && (s = *p); ++p) {
		if ((n = strlen(s)) > siz-1)
			die("stty parameter length too long\n");
		*q++ = ' ';
		memcpy(q, s, n);
		q += n;
		siz -= n + 1;
	}
	*q = '\0';
	if (system(cmd) != 0)
		perror("Couldn't call stty");
}

int
ttynew(char *line, char *cmd, char *out, char **args)
{
	int m, s;

	if (out) {
		term.mode |= MODE_PRINT;
		iofd = (!strcmp(out, "-")) ?
			  1 : open(out, O_WRONLY | O_CREAT, 0666);
		if (iofd < 0) {
			fprintf(stderr, "Error opening %s:%s\n",
				out, strerror(errno));
		}
	}

	if (line) {
		if ((cmdfd = open(line, O_RDWR)) < 0)
			die("open line '%s' failed: %s\n",
			    line, strerror(errno));
		dup2(cmdfd, 0);
		stty(args);
		return cmdfd;
	}

	/* seems to work fine on linux, openbsd and freebsd */
	if (openpty(&m, &s, NULL, NULL, NULL) < 0)
		die("openpty failed: %s\n", strerror(errno));

	switch (pid = fork()) {
	case -1:
		die("fork failed: %s\n", strerror(errno));
		break;
	case 0:
		close(iofd);
		setsid(); /* create a new process group */
		dup2(s, 0);
		dup2(s, 1);
		dup2(s, 2);
		if (ioctl(s, TIOCSCTTY, NULL) < 0)
			die("ioctl TIOCSCTTY failed: %s\n", strerror(errno));
		close(s);
		close(m);
#ifdef __OpenBSD__
		if (pledge("stdio getpw proc exec", NULL) == -1)
			die("pledge\n");
#endif
		execsh(cmd, args);
		break;
	default:
#ifdef __OpenBSD__
		if (pledge("stdio rpath tty proc", NULL) == -1)
			die("pledge\n");
#endif
		close(s);
		cmdfd = m;
		signal(SIGCHLD, sigchld);
		break;
	}
	return cmdfd;
}

size_t
ttyread(void)
{
	static char buf[BUFSIZ];
	static int buflen = 0;
	int ret, written;

	/* append read bytes to unprocessed bytes */
	ret = read(cmdfd, buf+buflen, LEN(buf)-buflen);

	switch (ret) {
	case 0:
		exit(0);
	case -1:
		die("couldn't read from shell: %s\n", strerror(errno));
	default:
		buflen += ret;
		written = twrite(buf, buflen, 0);
		buflen -= written;
		/* keep any incomplete UTF-8 byte sequence for the next call */
		if (buflen > 0)
			memmove(buf, buf + written, buflen);
		return ret;
	}
}

void
ttywrite(const char *s, size_t n, int may_echo)
{
	const char *next;
	Arg arg = (Arg) { .i = term.scr };

	kscrolldown(&arg);

	if (may_echo && IS_SET(MODE_ECHO))
		twrite(s, n, 1);

	if (!IS_SET(MODE_CRLF)) {
		ttywriteraw(s, n);
		return;
	}

	/* This is similar to how the kernel handles ONLCR for ttys */
	while (n > 0) {
		if (*s == '\r') {
			next = s + 1;
			ttywriteraw("\r\n", 2);
		} else {
			next = memchr(s, '\r', n);
			DEFAULT(next, s + n);
			ttywriteraw(s, next - s);
		}
		n -= next - s;
		s = next;
	}
}

void
ttywriteraw(const char *s, size_t n)
{
	fd_set wfd, rfd;
	ssize_t r;
	size_t lim = 256;

	/*
	 * Remember that we are using a pty, which might be a modem line.
	 * Writing too much will clog the line. That's why we are doing this
	 * dance.
	 * FIXME: Migrate the world to Plan 9.
	 */
	while (n > 0) {
		FD_ZERO(&wfd);
		FD_ZERO(&rfd);
		FD_SET(cmdfd, &wfd);
		FD_SET(cmdfd, &rfd);

		/* Check if we can write. */
		if (pselect(cmdfd+1, &rfd, &wfd, NULL, NULL, NULL) < 0) {
			if (errno == EINTR)
				continue;
			die("select failed: %s\n", strerror(errno));
		}
		if (FD_ISSET(cmdfd, &wfd)) {
			/*
			 * Only write the bytes written by ttywrite() or the
			 * default of 256. This seems to be a reasonable value
			 * for a serial line. Bigger values might clog the I/O.
			 */
			if ((r = write(cmdfd, s, (n < lim)? n : lim)) < 0)
				goto write_error;
			if (r < n) {
				/*
				 * We weren't able to write out everything.
				 * This means the buffer is getting full
				 * again. Empty it.
				 */
				if (n < lim)
					lim = ttyread();
				n -= r;
				s += r;
			} else {
				/* All bytes have been written. */
				break;
			}
		}
		if (FD_ISSET(cmdfd, &rfd))
			lim = ttyread();
	}
	return;

write_error:
	die("write error on tty: %s\n", strerror(errno));
}

void
ttyresize(int tw, int th)
{
	struct winsize w;

	w.ws_row = term.row;
	w.ws_col = term.col;
	w.ws_xpixel = tw;
	w.ws_ypixel = th;
	if (ioctl(cmdfd, TIOCSWINSZ, &w) < 0)
		fprintf(stderr, "Couldn't set window size: %s\n", strerror(errno));
}

void
ttyhangup()
{
	/* Send SIGHUP to shell */
	kill(pid, SIGHUP);
}

int
tattrset(int attr)
{
	int i, j;

	for (i = 0; i < term.row-1; i++) {
		for (j = 0; j < term.col-1; j++) {
			if (term.line[i][j].mode & attr)
				return 1;
		}
	}

	return 0;
}

void
tsetdirt(int top, int bot)
{
	int i;

	LIMIT(top, 0, term.row-1);
	LIMIT(bot, 0, term.row-1);

	for (i = top; i <= bot; i++)
		term.dirty[i] = 1;
}

void
tsetdirtattr(int attr)
{
	int i, j;

	for (i = 0; i < term.row-1; i++) {
		for (j = 0; j < term.col-1; j++) {
			if (term.line[i][j].mode & attr) {
				tsetdirt(i, i);
				break;
			}
		}
	}
}

void
tfulldirt(void)
{
	tsetdirt(0, term.row-1);
}

void
tcursor(int mode)
{
	static TCursor c[2];
	int alt = IS_SET(MODE_ALTSCREEN);

	if (mode == CURSOR_SAVE) {
		c[alt] = term.c;
	} else if (mode == CURSOR_LOAD) {
		term.c = c[alt];
		tmoveto(c[alt].x, c[alt].y);
	}
}

void
treset(void)
{
	uint i;

	term.c = (TCursor){{
		.mode = ATTR_NULL,
		.fg = defaultfg,
		.bg = defaultbg
	}, .x = 0, .y = 0, .state = CURSOR_DEFAULT};

	memset(term.tabs, 0, term.col * sizeof(*term.tabs));
	for (i = tabspaces; i < term.col; i += tabspaces)
		term.tabs[i] = 1;
	term.top = 0;
	term.bot = term.row - 1;
	term.mode = MODE_WRAP|MODE_UTF8;
	memset(term.trantbl, CS_USA, sizeof(term.trantbl));
	term.charset = 0;

	for (i = 0; i < 2; i++) {
		tmoveto(0, 0);
		tcursor(CURSOR_SAVE);
		tclearregion(0, 0, term.col-1, term.row-1);
		tswapscreen();
	}
}

void
tnew(int col, int row)
{
	term = (Term){ .c = { .attr = { .fg = defaultfg, .bg = defaultbg } } };
	tresize(col, row);
	treset();
}

int tisaltscr(void)
{
	return IS_SET(MODE_ALTSCREEN);
}

void
tswapscreen(void)
{
	Line *tmp = term.line;

	term.line = term.alt;
	term.alt = tmp;
	term.mode ^= MODE_ALTSCREEN;
	tfulldirt();
}

void
newterm(const Arg* a)
{
	switch (fork()) {
	case -1:
		die("fork failed: %s\n", strerror(errno));
		break;
	case 0:
		chdir(getcwd_by_pid(pid));
		execlp("st", "./st", NULL);
		break;
	}
}

static char *getcwd_by_pid(pid_t pid) {
	char buf[32];
	snprintf(buf, sizeof buf, "/proc/%d/cwd", pid);
	return realpath(buf, NULL);
}

void
kscrolldown(const Arg* a)
{
	int n = a->i;

	if (n < 0)
		n = term.row + n;

	if (n > term.scr)
		n = term.scr;

	if (term.scr > 0) {
		term.scr -= n;
		selscroll(0, -n);
		tfulldirt();
	}
}

void
kscrollup(const Arg* a)
{
	int n = a->i;

	if (n < 0)
		n = term.row + n;

	if (term.scr <= HISTSIZE-n) {
		term.scr += n;
		selscroll(0, n);
		tfulldirt();
	}
}

void
tscrolldown(int orig, int n, int copyhist)
{
	int i;
	Line temp;

	LIMIT(n, 0, term.bot-orig+1);

	if (copyhist) {
		term.histi = (term.histi - 1 + HISTSIZE) % HISTSIZE;
		temp = term.hist[term.histi];
		term.hist[term.histi] = term.line[term.bot];
		term.line[term.bot] = temp;
	}

	tsetdirt(orig, term.bot-n);
	tclearregion(0, term.bot-n+1, term.col-1, term.bot);

	for (i = term.bot; i >= orig+n; i--) {
		temp = term.line[i];
		term.line[i] = term.line[i-n];
		term.line[i-n] = temp;
	}

	if (term.scr == 0)
		selscroll(orig, n);
}

void
tscrollup(int orig, int n, int copyhist)
{
	int i;
	Line temp;

	LIMIT(n, 0, term.bot-orig+1);

	if (copyhist) {
		term.histi = (term.histi + 1) % HISTSIZE;
		temp = term.hist[term.histi];
		term.hist[term.histi] = term.line[orig];
		term.line[orig] = temp;
	}

	if (term.scr > 0 && term.scr < HISTSIZE)
		term.scr = MIN(term.scr + n, HISTSIZE-1);

	tclearregion(0, orig, term.col-1, orig+n-1);
	tsetdirt(orig+n, term.bot);

	for (i = orig; i <= term.bot-n; i++) {
		temp = term.line[i];
		term.line[i] = term.line[i+n];
		term.line[i+n] = temp;
	}

	if (term.scr == 0)
		selscroll(orig, -n);
}

void
selscroll(int orig, int n)
{
	if (sel.ob.x == -1)
		return;

	if (BETWEEN(sel.nb.y, orig, term.bot) != BETWEEN(sel.ne.y, orig, term.bot)) {
		selclear();
	} else if (BETWEEN(sel.nb.y, orig, term.bot)) {
		sel.ob.y += n;
		sel.oe.y += n;
		if (sel.ob.y < term.top || sel.ob.y > term.bot ||
		    sel.oe.y < term.top || sel.oe.y > term.bot) {
			selclear();
		} else {
			selnormalize();
		}
	}
}

void
tnewline(int first_col)
{
	int y = term.c.y;

	if (y == term.bot) {
		tscrollup(term.top, 1, 1);
	} else {
		y++;
	}
	tmoveto(first_col ? 0 : term.c.x, y);
}

void
csiparse(void)
{
	char *p = csiescseq.buf, *np;
	long int v;

	csiescseq.narg = 0;
	if (*p == '?') {
		csiescseq.priv = 1;
		p++;
	}

	csiescseq.buf[csiescseq.len] = '\0';
	while (p < csiescseq.buf+csiescseq.len) {
		np = NULL;
		v = strtol(p, &np, 10);
		if (np == p)
			v = 0;
		if (v == LONG_MAX || v == LONG_MIN)
			v = -1;
		csiescseq.arg[csiescseq.narg++] = v;
		p = np;
		if (*p != ';' || csiescseq.narg == ESC_ARG_SIZ)
			break;
		p++;
	}
	csiescseq.mode[0] = *p++;
	csiescseq.mode[1] = (p < csiescseq.buf+csiescseq.len) ? *p : '\0';
}

/* for absolute user moves, when decom is set */
void
tmoveato(int x, int y)
{
	tmoveto(x, y + ((term.c.state & CURSOR_ORIGIN) ? term.top: 0));
}

void
tmoveto(int x, int y)
{
	int miny, maxy;

	if (term.c.state & CURSOR_ORIGIN) {
		miny = term.top;
		maxy = term.bot;
	} else {
		miny = 0;
		maxy = term.row - 1;
	}
	term.c.state &= ~CURSOR_WRAPNEXT;
	term.c.x = LIMIT(x, 0, term.col-1);
	term.c.y = LIMIT(y, miny, maxy);
}

void
tsetchar(Rune u, Glyph *attr, int x, int y)
{
	static char *vt100_0[62] = { /* 0x41 - 0x7e */
		"↑", "↓", "→", "←", "█", "▚", "☃", /* A - G */
		0, 0, 0, 0, 0, 0, 0, 0, /* H - O */
		0, 0, 0, 0, 0, 0, 0, 0, /* P - W */
		0, 0, 0, 0, 0, 0, 0, " ", /* X - _ */
		"◆", "▒", "␉", "␌", "␍", "␊", "°", "±", /* ` - g */
		"␤", "␋", "┘", "┐", "┌", "└", "┼", "⎺", /* h - o */
		"⎻", "─", "⎼", "⎽", "├", "┤", "┴", "┬", /* p - w */
		"│", "≤", "≥", "π", "≠", "£", "·", /* x - ~ */
	};

	/*
	 * The table is proudly stolen from rxvt.
	 */
	if (term.trantbl[term.charset] == CS_GRAPHIC0 &&
	   BETWEEN(u, 0x41, 0x7e) && vt100_0[u - 0x41])
		utf8decode(vt100_0[u - 0x41], &u, UTF_SIZ);

	if (term.line[y][x].mode & ATTR_WIDE) {
		if (x+1 < term.col) {
			term.line[y][x+1].u = ' ';
			term.line[y][x+1].mode &= ~ATTR_WDUMMY;
		}
	} else if (term.line[y][x].mode & ATTR_WDUMMY) {
		term.line[y][x-1].u = ' ';
		term.line[y][x-1].mode &= ~ATTR_WIDE;
	}

	term.dirty[y] = 1;
	term.line[y][x] = *attr;
	term.line[y][x].u = u;

	if (isboxdraw(u))
		term.line[y][x].mode |= ATTR_BOXDRAW;
}

void
tclearregion(int x1, int y1, int x2, int y2)
{
	int x, y, temp;
	Glyph *gp;

	if (x1 > x2)
		temp = x1, x1 = x2, x2 = temp;
	if (y1 > y2)
		temp = y1, y1 = y2, y2 = temp;

	LIMIT(x1, 0, term.col-1);
	LIMIT(x2, 0, term.col-1);
	LIMIT(y1, 0, term.row-1);
	LIMIT(y2, 0, term.row-1);

	for (y = y1; y <= y2; y++) {
		term.dirty[y] = 1;
		for (x = x1; x <= x2; x++) {
			gp = &term.line[y][x];
			if (selected(x, y))
				selclear();
			gp->fg = term.c.attr.fg;
			gp->bg = term.c.attr.bg;
			gp->mode = 0;
			gp->u = ' ';
		}
	}
}

void
tdeletechar(int n)
{
	int dst, src, size;
	Glyph *line;

	LIMIT(n, 0, term.col - term.c.x);

	dst = term.c.x;
	src = term.c.x + n;
	size = term.col - src;
	line = term.line[term.c.y];

	memmove(&line[dst], &line[src], size * sizeof(Glyph));
	tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
}

void
tinsertblank(int n)
{
	int dst, src, size;
	Glyph *line;

	LIMIT(n, 0, term.col - term.c.x);

	dst = term.c.x + n;
	src = term.c.x;
	size = term.col - dst;
	line = term.line[term.c.y];

	memmove(&line[dst], &line[src], size * sizeof(Glyph));
	tclearregion(src, term.c.y, dst - 1, term.c.y);
}

void
tinsertblankline(int n)
{
	if (BETWEEN(term.c.y, term.top, term.bot))
		tscrolldown(term.c.y, n, 0);
}

void
tdeleteline(int n)
{
	if (BETWEEN(term.c.y, term.top, term.bot))
		tscrollup(term.c.y, n, 0);
}

int32_t
tdefcolor(int *attr, int *npar, int l)
{
	int32_t idx = -1;
	uint r, g, b;

	switch (attr[*npar + 1]) {
	case 2: /* direct color in RGB space */
		if (*npar + 4 >= l) {
			fprintf(stderr,
				"erresc(38): Incorrect number of parameters (%d)\n",
				*npar);
			break;
		}
		r = attr[*npar + 2];
		g = attr[*npar + 3];
		b = attr[*npar + 4];
		*npar += 4;
		if (!BETWEEN(r, 0, 255) || !BETWEEN(g, 0, 255) || !BETWEEN(b, 0, 255))
			fprintf(stderr, "erresc: bad rgb color (%u,%u,%u)\n",
				r, g, b);
		else
			idx = TRUECOLOR(r, g, b);
		break;
	case 5: /* indexed color */
		if (*npar + 2 >= l) {
			fprintf(stderr,
				"erresc(38): Incorrect number of parameters (%d)\n",
				*npar);
			break;
		}
		*npar += 2;
		if (!BETWEEN(attr[*npar], 0, 255))
			fprintf(stderr, "erresc: bad fgcolor %d\n", attr[*npar]);
		else
			idx = attr[*npar];
		break;
	case 0: /* implemented defined (only foreground) */
	case 1: /* transparent */
	case 3: /* direct color in CMY space */
	case 4: /* direct color in CMYK space */
	default:
		fprintf(stderr,
		        "erresc(38): gfx attr %d unknown\n", attr[*npar]);
		break;
	}

	return idx;
}

void
tsetattr(int *attr, int l)
{
	int i;
	int32_t idx;

	for (i = 0; i < l; i++) {
		switch (attr[i]) {
		case 0:
			term.c.attr.mode &= ~(
				ATTR_BOLD       |
				ATTR_FAINT      |
				ATTR_ITALIC     |
				ATTR_UNDERLINE  |
				ATTR_BLINK      |
				ATTR_REVERSE    |
				ATTR_INVISIBLE  |
				ATTR_STRUCK     );
			term.c.attr.fg = defaultfg;
			term.c.attr.bg = defaultbg;
			break;
		case 1:
			term.c.attr.mode |= ATTR_BOLD;
			break;
		case 2:
			term.c.attr.mode |= ATTR_FAINT;
			break;
		case 3:
			term.c.attr.mode |= ATTR_ITALIC;
			break;
		case 4:
			term.c.attr.mode |= ATTR_UNDERLINE;
			break;
		case 5: /* slow blink */
			/* FALLTHROUGH */
		case 6: /* rapid blink */
			term.c.attr.mode |= ATTR_BLINK;
			break;
		case 7:
			term.c.attr.mode |= ATTR_REVERSE;
			break;
		case 8:
			term.c.attr.mode |= ATTR_INVISIBLE;
			break;
		case 9:
			term.c.attr.mode |= ATTR_STRUCK;
			break;
		case 22:
			term.c.attr.mode &= ~(ATTR_BOLD | ATTR_FAINT);
			break;
		case 23:
			term.c.attr.mode &= ~ATTR_ITALIC;
			break;
		case 24:
			term.c.attr.mode &= ~ATTR_UNDERLINE;
			break;
		case 25:
			term.c.attr.mode &= ~ATTR_BLINK;
			break;
		case 27:
			term.c.attr.mode &= ~ATTR_REVERSE;
			break;
		case 28:
			term.c.attr.mode &= ~ATTR_INVISIBLE;
			break;
		case 29:
			term.c.attr.mode &= ~ATTR_STRUCK;
			break;
		case 38:
			if ((idx = tdefcolor(attr, &i, l)) >= 0)
				term.c.attr.fg = idx;
			break;
		case 39:
			term.c.attr.fg = defaultfg;
			break;
		case 48:
			if ((idx = tdefcolor(attr, &i, l)) >= 0)
				term.c.attr.bg = idx;
			break;
		case 49:
			term.c.attr.bg = defaultbg;
			break;
		default:
			if (BETWEEN(attr[i], 30, 37)) {
				term.c.attr.fg = attr[i] - 30;
			} else if (BETWEEN(attr[i], 40, 47)) {
				term.c.attr.bg = attr[i] - 40;
			} else if (BETWEEN(attr[i], 90, 97)) {
				term.c.attr.fg = attr[i] - 90 + 8;
			} else if (BETWEEN(attr[i], 100, 107)) {
				term.c.attr.bg = attr[i] - 100 + 8;
			} else {
				fprintf(stderr,
					"erresc(default): gfx attr %d unknown\n",
					attr[i]);
				csidump();
			}
			break;
		}
	}
}

void
tsetscroll(int t, int b)
{
	int temp;

	LIMIT(t, 0, term.row-1);
	LIMIT(b, 0, term.row-1);
	if (t > b) {
		temp = t;
		t = b;
		b = temp;
	}
	term.top = t;
	term.bot = b;
}

void
tsetmode(int priv, int set, int *args, int narg)
{
	int alt, *lim;

	for (lim = args + narg; args < lim; ++args) {
		if (priv) {
			switch (*args) {
			case 1: /* DECCKM -- Cursor key */
				xsetmode(set, MODE_APPCURSOR);
				break;
			case 5: /* DECSCNM -- Reverse video */
				xsetmode(set, MODE_REVERSE);
				break;
			case 6: /* DECOM -- Origin */
				MODBIT(term.c.state, set, CURSOR_ORIGIN);
				tmoveato(0, 0);
				break;
			case 7: /* DECAWM -- Auto wrap */
				MODBIT(term.mode, set, MODE_WRAP);
				break;
			case 0:  /* Error (IGNORED) */
			case 2:  /* DECANM -- ANSI/VT52 (IGNORED) */
			case 3:  /* DECCOLM -- Column  (IGNORED) */
			case 4:  /* DECSCLM -- Scroll (IGNORED) */
			case 8:  /* DECARM -- Auto repeat (IGNORED) */
			case 18: /* DECPFF -- Printer feed (IGNORED) */
			case 19: /* DECPEX -- Printer extent (IGNORED) */
			case 42: /* DECNRCM -- National characters (IGNORED) */
			case 12: /* att610 -- Start blinking cursor (IGNORED) */
				break;
			case 25: /* DECTCEM -- Text Cursor Enable Mode */
				xsetmode(!set, MODE_HIDE);
				break;
			case 9:    /* X10 mouse compatibility mode */
				xsetpointermotion(0);
				xsetmode(0, MODE_MOUSE);
				xsetmode(set, MODE_MOUSEX10);
				break;
			case 1000: /* 1000: report button press */
				xsetpointermotion(0);
				xsetmode(0, MODE_MOUSE);
				xsetmode(set, MODE_MOUSEBTN);
				break;
			case 1002: /* 1002: report motion on button press */
				xsetpointermotion(0);
				xsetmode(0, MODE_MOUSE);
				xsetmode(set, MODE_MOUSEMOTION);
				break;
			case 1003: /* 1003: enable all mouse motions */
				xsetpointermotion(set);
				xsetmode(0, MODE_MOUSE);
				xsetmode(set, MODE_MOUSEMANY);
				break;
			case 1004: /* 1004: send focus events to tty */
				xsetmode(set, MODE_FOCUS);
				break;
			case 1006: /* 1006: extended reporting mode */
				xsetmode(set, MODE_MOUSESGR);
				break;
			case 1034:
				xsetmode(set, MODE_8BIT);
				break;
			case 1049: /* swap screen & set/restore cursor as xterm */
				if (!allowaltscreen)
					break;
				tcursor((set) ? CURSOR_SAVE : CURSOR_LOAD);
				/* FALLTHROUGH */
			case 47: /* swap screen */
			case 1047:
				if (!allowaltscreen)
					break;
				alt = IS_SET(MODE_ALTSCREEN);
				if (alt) {
					tclearregion(0, 0, term.col-1,
							term.row-1);
				}
				if (set ^ alt) /* set is always 1 or 0 */
					tswapscreen();
				if (*args != 1049)
					break;
				/* FALLTHROUGH */
			case 1048:
				tcursor((set) ? CURSOR_SAVE : CURSOR_LOAD);
				break;
			case 2004: /* 2004: bracketed paste mode */
				xsetmode(set, MODE_BRCKTPASTE);
				break;
			/* Not implemented mouse modes. See comments there. */
			case 1001: /* mouse highlight mode; can hang the
				      terminal by design when implemented. */
			case 1005: /* UTF-8 mouse mode; will confuse
				      applications not supporting UTF-8
				      and luit. */
			case 1015: /* urxvt mangled mouse mode; incompatible
				      and can be mistaken for other control
				      codes. */
				break;
			default:
				fprintf(stderr,
					"erresc: unknown private set/reset mode %d\n",
					*args);
				break;
			}
		} else {
			switch (*args) {
			case 0:  /* Error (IGNORED) */
				break;
			case 2:
				xsetmode(set, MODE_KBDLOCK);
				break;
			case 4:  /* IRM -- Insertion-replacement */
				MODBIT(term.mode, set, MODE_INSERT);
				break;
			case 12: /* SRM -- Send/Receive */
				MODBIT(term.mode, !set, MODE_ECHO);
				break;
			case 20: /* LNM -- Linefeed/new line */
				MODBIT(term.mode, set, MODE_CRLF);
				break;
			default:
				fprintf(stderr,
					"erresc: unknown set/reset mode %d\n",
					*args);
				break;
			}
		}
	}
}

void
csihandle(void)
{
	char buf[40];
	int len;

	switch (csiescseq.mode[0]) {
	default:
	unknown:
		fprintf(stderr, "erresc: unknown csi ");
		csidump();
		/* die(""); */
		break;
	case '@': /* ICH -- Insert <n> blank char */
		DEFAULT(csiescseq.arg[0], 1);
		tinsertblank(csiescseq.arg[0]);
		break;
	case 'A': /* CUU -- Cursor <n> Up */
		DEFAULT(csiescseq.arg[0], 1);
		tmoveto(term.c.x, term.c.y-csiescseq.arg[0]);
		break;
	case 'B': /* CUD -- Cursor <n> Down */
	case 'e': /* VPR --Cursor <n> Down */
		DEFAULT(csiescseq.arg[0], 1);
		tmoveto(term.c.x, term.c.y+csiescseq.arg[0]);
		break;
	case 'i': /* MC -- Media Copy */
		switch (csiescseq.arg[0]) {
		case 0:
			tdump();
			break;
		case 1:
			tdumpline(term.c.y);
			break;
		case 2:
			tdumpsel();
			break;
		case 4:
			term.mode &= ~MODE_PRINT;
			break;
		case 5:
			term.mode |= MODE_PRINT;
			break;
		}
		break;
	case 'c': /* DA -- Device Attributes */
		if (csiescseq.arg[0] == 0)
			ttywrite(vtiden, strlen(vtiden), 0);
		break;
	case 'b': /* REP -- if last char is printable print it <n> more times */
		DEFAULT(csiescseq.arg[0], 1);
		if (term.lastc)
			while (csiescseq.arg[0]-- > 0)
				tputc(term.lastc);
		break;
	case 'C': /* CUF -- Cursor <n> Forward */
	case 'a': /* HPR -- Cursor <n> Forward */
		DEFAULT(csiescseq.arg[0], 1);
		tmoveto(term.c.x+csiescseq.arg[0], term.c.y);
		break;
	case 'D': /* CUB -- Cursor <n> Backward */
		DEFAULT(csiescseq.arg[0], 1);
		tmoveto(term.c.x-csiescseq.arg[0], term.c.y);
		break;
	case 'E': /* CNL -- Cursor <n> Down and first col */
		DEFAULT(csiescseq.arg[0], 1);
		tmoveto(0, term.c.y+csiescseq.arg[0]);
		break;
	case 'F': /* CPL -- Cursor <n> Up and first col */
		DEFAULT(csiescseq.arg[0], 1);
		tmoveto(0, term.c.y-csiescseq.arg[0]);
		break;
	case 'g': /* TBC -- Tabulation clear */
		switch (csiescseq.arg[0]) {
		case 0: /* clear current tab stop */
			term.tabs[term.c.x] = 0;
			break;
		case 3: /* clear all the tabs */
			memset(term.tabs, 0, term.col * sizeof(*term.tabs));
			break;
		default:
			goto unknown;
		}
		break;
	case 'G': /* CHA -- Move to <col> */
	case '`': /* HPA */
		DEFAULT(csiescseq.arg[0], 1);
		tmoveto(csiescseq.arg[0]-1, term.c.y);
		break;
	case 'H': /* CUP -- Move to <row> <col> */
	case 'f': /* HVP */
		DEFAULT(csiescseq.arg[0], 1);
		DEFAULT(csiescseq.arg[1], 1);
		tmoveato(csiescseq.arg[1]-1, csiescseq.arg[0]-1);
		break;
	case 'I': /* CHT -- Cursor Forward Tabulation <n> tab stops */
		DEFAULT(csiescseq.arg[0], 1);
		tputtab(csiescseq.arg[0]);
		break;
	case 'J': /* ED -- Clear screen */
		switch (csiescseq.arg[0]) {
		case 0: /* below */
			tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
			if (term.c.y < term.row-1) {
				tclearregion(0, term.c.y+1, term.col-1,
						term.row-1);
			}
			break;
		case 1: /* above */
			if (term.c.y > 1)
				tclearregion(0, 0, term.col-1, term.c.y-1);
			tclearregion(0, term.c.y, term.c.x, term.c.y);
			break;
		case 2: /* all */
			tclearregion(0, 0, term.col-1, term.row-1);
			break;
		default:
			goto unknown;
		}
		break;
	case 'K': /* EL -- Clear line */
		switch (csiescseq.arg[0]) {
		case 0: /* right */
			tclearregion(term.c.x, term.c.y, term.col-1,
					term.c.y);
			break;
		case 1: /* left */
			tclearregion(0, term.c.y, term.c.x, term.c.y);
			break;
		case 2: /* all */
			tclearregion(0, term.c.y, term.col-1, term.c.y);
			break;
		}
		break;
	case 'S': /* SU -- Scroll <n> line up */
		DEFAULT(csiescseq.arg[0], 1);
		tscrollup(term.top, csiescseq.arg[0], 0);
		break;
	case 'T': /* SD -- Scroll <n> line down */
		DEFAULT(csiescseq.arg[0], 1);
		tscrolldown(term.top, csiescseq.arg[0], 0);
		break;
	case 'L': /* IL -- Insert <n> blank lines */
		DEFAULT(csiescseq.arg[0], 1);
		tinsertblankline(csiescseq.arg[0]);
		break;
	case 'l': /* RM -- Reset Mode */
		tsetmode(csiescseq.priv, 0, csiescseq.arg, csiescseq.narg);
		break;
	case 'M': /* DL -- Delete <n> lines */
		DEFAULT(csiescseq.arg[0], 1);
		tdeleteline(csiescseq.arg[0]);
		break;
	case 'X': /* ECH -- Erase <n> char */
		DEFAULT(csiescseq.arg[0], 1);
		tclearregion(term.c.x, term.c.y,
				term.c.x + csiescseq.arg[0] - 1, term.c.y);
		break;
	case 'P': /* DCH -- Delete <n> char */
		DEFAULT(csiescseq.arg[0], 1);
		tdeletechar(csiescseq.arg[0]);
		break;
	case 'Z': /* CBT -- Cursor Backward Tabulation <n> tab stops */
		DEFAULT(csiescseq.arg[0], 1);
		tputtab(-csiescseq.arg[0]);
		break;
	case 'd': /* VPA -- Move to <row> */
		DEFAULT(csiescseq.arg[0], 1);
		tmoveato(term.c.x, csiescseq.arg[0]-1);
		break;
	case 'h': /* SM -- Set terminal mode */
		tsetmode(csiescseq.priv, 1, csiescseq.arg, csiescseq.narg);
		break;
	case 'm': /* SGR -- Terminal attribute (color) */
		tsetattr(csiescseq.arg, csiescseq.narg);
		break;
	case 'n': /* DSR – Device Status Report (cursor position) */
		if (csiescseq.arg[0] == 6) {
			len = snprintf(buf, sizeof(buf), "\033[%i;%iR",
					term.c.y+1, term.c.x+1);
			ttywrite(buf, len, 0);
		}
		break;
	case 'r': /* DECSTBM -- Set Scrolling Region */
		if (csiescseq.priv) {
			goto unknown;
		} else {
			DEFAULT(csiescseq.arg[0], 1);
			DEFAULT(csiescseq.arg[1], term.row);
			tsetscroll(csiescseq.arg[0]-1, csiescseq.arg[1]-1);
			tmoveato(0, 0);
		}
		break;
	case 's': /* DECSC -- Save cursor position (ANSI.SYS) */
		tcursor(CURSOR_SAVE);
		break;
	case 'u': /* DECRC -- Restore cursor position (ANSI.SYS) */
		tcursor(CURSOR_LOAD);
		break;
	case ' ':
		switch (csiescseq.mode[1]) {
		case 'q': /* DECSCUSR -- Set Cursor Style */
			if (xsetcursor(csiescseq.arg[0]))
				goto unknown;
			break;
		default:
			goto unknown;
		}
		break;
	}
}

void
csidump(void)
{
	size_t i;
	uint c;

	fprintf(stderr, "ESC[");
	for (i = 0; i < csiescseq.len; i++) {
		c = csiescseq.buf[i] & 0xff;
		if (isprint(c)) {
			putc(c, stderr);
		} else if (c == '\n') {
			fprintf(stderr, "(\\n)");
		} else if (c == '\r') {
			fprintf(stderr, "(\\r)");
		} else if (c == 0x1b) {
			fprintf(stderr, "(\\e)");
		} else {
			fprintf(stderr, "(%02x)", c);
		}
	}
	putc('\n', stderr);
}

void
csireset(void)
{
	memset(&csiescseq, 0, sizeof(csiescseq));
}

void
strhandle(void)
{
	char *p = NULL, *dec;
	int j, narg, par;

	term.esc &= ~(ESC_STR_END|ESC_STR);
	strparse();
	par = (narg = strescseq.narg) ? atoi(strescseq.args[0]) : 0;

	switch (strescseq.type) {
	case ']': /* OSC -- Operating System Command */
		switch (par) {
		case 0:
		case 1:
		case 2:
			if (narg > 1)
				xsettitle(strescseq.args[1]);
			return;
		case 52:
			if (narg > 2 && allowwindowops) {
				dec = base64dec(strescseq.args[2]);
				if (dec) {
					xsetsel(dec);
					xclipcopy();
				} else {
					fprintf(stderr, "erresc: invalid base64\n");
				}
			}
			return;
		case 4: /* color set */
			if (narg < 3)
				break;
			p = strescseq.args[2];
			/* FALLTHROUGH */
		case 104: /* color reset, here p = NULL */
			j = (narg > 1) ? atoi(strescseq.args[1]) : -1;
			if (xsetcolorname(j, p)) {
				if (par == 104 && narg <= 1)
					return; /* color reset without parameter */
				fprintf(stderr, "erresc: invalid color j=%d, p=%s\n",
				        j, p ? p : "(null)");
			} else {
				/*
				 * TODO if defaultbg color is changed, borders
				 * are dirty
				 */
				redraw();
			}
			return;
		}
		break;
	case 'k': /* old title set compatibility */
		xsettitle(strescseq.args[0]);
		return;
	case 'P': /* DCS -- Device Control String */
	case '_': /* APC -- Application Program Command */
	case '^': /* PM -- Privacy Message */
		return;
	}

	fprintf(stderr, "erresc: unknown str ");
	strdump();
}

void
strparse(void)
{
	int c;
	char *p = strescseq.buf;

	strescseq.narg = 0;
	strescseq.buf[strescseq.len] = '\0';

	if (*p == '\0')
		return;

	while (strescseq.narg < STR_ARG_SIZ) {
		strescseq.args[strescseq.narg++] = p;
		while ((c = *p) != ';' && c != '\0')
			++p;
		if (c == '\0')
			return;
		*p++ = '\0';
	}
}

void
strdump(void)
{
	size_t i;
	uint c;

	fprintf(stderr, "ESC%c", strescseq.type);
	for (i = 0; i < strescseq.len; i++) {
		c = strescseq.buf[i] & 0xff;
		if (c == '\0') {
			putc('\n', stderr);
			return;
		} else if (isprint(c)) {
			putc(c, stderr);
		} else if (c == '\n') {
			fprintf(stderr, "(\\n)");
		} else if (c == '\r') {
			fprintf(stderr, "(\\r)");
		} else if (c == 0x1b) {
			fprintf(stderr, "(\\e)");
		} else {
			fprintf(stderr, "(%02x)", c);
		}
	}
	fprintf(stderr, "ESC\\\n");
}

void
strreset(void)
{
	strescseq = (STREscape){
		.buf = xrealloc(strescseq.buf, STR_BUF_SIZ),
		.siz = STR_BUF_SIZ,
	};
}

void
sendbreak(const Arg *arg)
{
	if (tcsendbreak(cmdfd, 0))
		perror("Error sending break");
}

void
tprinter(char *s, size_t len)
{
	if (iofd != -1 && xwrite(iofd, s, len) < 0) {
		perror("Error writing to output file");
		close(iofd);
		iofd = -1;
	}
}

void
toggleprinter(const Arg *arg)
{
	term.mode ^= MODE_PRINT;
}

void
printscreen(const Arg *arg)
{
	tdump();
}

void
printsel(const Arg *arg)
{
	tdumpsel();
}

void
tdumpsel(void)
{
	char *ptr;

	if ((ptr = getsel())) {
		tprinter(ptr, strlen(ptr));
		free(ptr);
	}
}

void
tdumpline(int n)
{
	char buf[UTF_SIZ];
	Glyph *bp, *end;

	bp = &term.line[n][0];
	end = &bp[MIN(tlinelen(n), term.col) - 1];
	if (bp != end || bp->u != ' ') {
		for ( ; bp <= end; ++bp)
			tprinter(buf, utf8encode(bp->u, buf));
	}
	tprinter("\n", 1);
}

void
tdump(void)
{
	int i;

	for (i = 0; i < term.row; ++i)
		tdumpline(i);
}

void
tputtab(int n)
{
	uint x = term.c.x;

	if (n > 0) {
		while (x < term.col && n--)
			for (++x; x < term.col && !term.tabs[x]; ++x)
				/* nothing */ ;
	} else if (n < 0) {
		while (x > 0 && n++)
			for (--x; x > 0 && !term.tabs[x]; --x)
				/* nothing */ ;
	}
	term.c.x = LIMIT(x, 0, term.col-1);
}

void
tdefutf8(char ascii)
{
	if (ascii == 'G')
		term.mode |= MODE_UTF8;
	else if (ascii == '@')
		term.mode &= ~MODE_UTF8;
}

void
tdeftran(char ascii)
{
	static char cs[] = "0B";
	static int vcs[] = {CS_GRAPHIC0, CS_USA};
	char *p;

	if ((p = strchr(cs, ascii)) == NULL) {
		fprintf(stderr, "esc unhandled charset: ESC ( %c\n", ascii);
	} else {
		term.trantbl[term.icharset] = vcs[p - cs];
	}
}

void
tdectest(char c)
{
	int x, y;

	if (c == '8') { /* DEC screen alignment test. */
		for (x = 0; x < term.col; ++x) {
			for (y = 0; y < term.row; ++y)
				tsetchar('E', &term.c.attr, x, y);
		}
	}
}

void
tstrsequence(uchar c)
{
	switch (c) {
	case 0x90:   /* DCS -- Device Control String */
		c = 'P';
		break;
	case 0x9f:   /* APC -- Application Program Command */
		c = '_';
		break;
	case 0x9e:   /* PM -- Privacy Message */
		c = '^';
		break;
	case 0x9d:   /* OSC -- Operating System Command */
		c = ']';
		break;
	}
	strreset();
	strescseq.type = c;
	term.esc |= ESC_STR;
}

void
tcontrolcode(uchar ascii)
{
	switch (ascii) {
	case '\t':   /* HT */
		tputtab(1);
		return;
	case '\b':   /* BS */
		tmoveto(term.c.x-1, term.c.y);
		return;
	case '\r':   /* CR */
		tmoveto(0, term.c.y);
		return;
	case '\f':   /* LF */
	case '\v':   /* VT */
	case '\n':   /* LF */
		/* go to first col if the mode is set */
		tnewline(IS_SET(MODE_CRLF));
		return;
	case '\a':   /* BEL */
		if (term.esc & ESC_STR_END) {
			/* backwards compatibility to xterm */
			strhandle();
		} else {
			xbell();
		}
		break;
	case '\033': /* ESC */
		csireset();
		term.esc &= ~(ESC_CSI|ESC_ALTCHARSET|ESC_TEST);
		term.esc |= ESC_START;
		return;
	case '\016': /* SO (LS1 -- Locking shift 1) */
	case '\017': /* SI (LS0 -- Locking shift 0) */
		term.charset = 1 - (ascii - '\016');
		return;
	case '\032': /* SUB */
		tsetchar('?', &term.c.attr, term.c.x, term.c.y);
		/* FALLTHROUGH */
	case '\030': /* CAN */
		csireset();
		break;
	case '\005': /* ENQ (IGNORED) */
	case '\000': /* NUL (IGNORED) */
	case '\021': /* XON (IGNORED) */
	case '\023': /* XOFF (IGNORED) */
	case 0177:   /* DEL (IGNORED) */
		return;
	case 0x80:   /* TODO: PAD */
	case 0x81:   /* TODO: HOP */
	case 0x82:   /* TODO: BPH */
	case 0x83:   /* TODO: NBH */
	case 0x84:   /* TODO: IND */
		break;
	case 0x85:   /* NEL -- Next line */
		tnewline(1); /* always go to first col */
		break;
	case 0x86:   /* TODO: SSA */
	case 0x87:   /* TODO: ESA */
		break;
	case 0x88:   /* HTS -- Horizontal tab stop */
		term.tabs[term.c.x] = 1;
		break;
	case 0x89:   /* TODO: HTJ */
	case 0x8a:   /* TODO: VTS */
	case 0x8b:   /* TODO: PLD */
	case 0x8c:   /* TODO: PLU */
	case 0x8d:   /* TODO: RI */
	case 0x8e:   /* TODO: SS2 */
	case 0x8f:   /* TODO: SS3 */
	case 0x91:   /* TODO: PU1 */
	case 0x92:   /* TODO: PU2 */
	case 0x93:   /* TODO: STS */
	case 0x94:   /* TODO: CCH */
	case 0x95:   /* TODO: MW */
	case 0x96:   /* TODO: SPA */
	case 0x97:   /* TODO: EPA */
	case 0x98:   /* TODO: SOS */
	case 0x99:   /* TODO: SGCI */
		break;
	case 0x9a:   /* DECID -- Identify Terminal */
		ttywrite(vtiden, strlen(vtiden), 0);
		break;
	case 0x9b:   /* TODO: CSI */
	case 0x9c:   /* TODO: ST */
		break;
	case 0x90:   /* DCS -- Device Control String */
	case 0x9d:   /* OSC -- Operating System Command */
	case 0x9e:   /* PM -- Privacy Message */
	case 0x9f:   /* APC -- Application Program Command */
		tstrsequence(ascii);
		return;
	}
	/* only CAN, SUB, \a and C1 chars interrupt a sequence */
	term.esc &= ~(ESC_STR_END|ESC_STR);
}

/*
 * returns 1 when the sequence is finished and it hasn't to read
 * more characters for this sequence, otherwise 0
 */
int
eschandle(uchar ascii)
{
	switch (ascii) {
	case '[':
		term.esc |= ESC_CSI;
		return 0;
	case '#':
		term.esc |= ESC_TEST;
		return 0;
	case '%':
		term.esc |= ESC_UTF8;
		return 0;
	case 'P': /* DCS -- Device Control String */
	case '_': /* APC -- Application Program Command */
	case '^': /* PM -- Privacy Message */
	case ']': /* OSC -- Operating System Command */
	case 'k': /* old title set compatibility */
		tstrsequence(ascii);
		return 0;
	case 'n': /* LS2 -- Locking shift 2 */
	case 'o': /* LS3 -- Locking shift 3 */
		term.charset = 2 + (ascii - 'n');
		break;
	case '(': /* GZD4 -- set primary charset G0 */
	case ')': /* G1D4 -- set secondary charset G1 */
	case '*': /* G2D4 -- set tertiary charset G2 */
	case '+': /* G3D4 -- set quaternary charset G3 */
		term.icharset = ascii - '(';
		term.esc |= ESC_ALTCHARSET;
		return 0;
	case 'D': /* IND -- Linefeed */
		if (term.c.y == term.bot) {
			tscrollup(term.top, 1, 1);
		} else {
			tmoveto(term.c.x, term.c.y+1);
		}
		break;
	case 'E': /* NEL -- Next line */
		tnewline(1); /* always go to first col */
		break;
	case 'H': /* HTS -- Horizontal tab stop */
		term.tabs[term.c.x] = 1;
		break;
	case 'M': /* RI -- Reverse index */
		if (term.c.y == term.top) {
			tscrolldown(term.top, 1, 1);
		} else {
			tmoveto(term.c.x, term.c.y-1);
		}
		break;
	case 'Z': /* DECID -- Identify Terminal */
		ttywrite(vtiden, strlen(vtiden), 0);
		break;
	case 'c': /* RIS -- Reset to initial state */
		treset();
		resettitle();
		xloadcols();
		break;
	case '=': /* DECPAM -- Application keypad */
		xsetmode(1, MODE_APPKEYPAD);
		break;
	case '>': /* DECPNM -- Normal keypad */
		xsetmode(0, MODE_APPKEYPAD);
		break;
	case '7': /* DECSC -- Save Cursor */
		tcursor(CURSOR_SAVE);
		break;
	case '8': /* DECRC -- Restore Cursor */
		tcursor(CURSOR_LOAD);
		break;
	case '\\': /* ST -- String Terminator */
		if (term.esc & ESC_STR_END)
			strhandle();
		break;
	default:
		fprintf(stderr, "erresc: unknown sequence ESC 0x%02X '%c'\n",
			(uchar) ascii, isprint(ascii)? ascii:'.');
		break;
	}
	return 1;
}

void
tputc(Rune u)
{
	char c[UTF_SIZ];
	int control;
	int width, len;
	Glyph *gp;

	control = ISCONTROL(u);
	if (u < 127 || !IS_SET(MODE_UTF8)) {
		c[0] = u;
		width = len = 1;
	} else {
		len = utf8encode(u, c);
		if (!control && (width = wcwidth(u)) == -1)
			width = 1;
	}

	if (IS_SET(MODE_PRINT))
		tprinter(c, len);

	/*
	 * STR sequence must be checked before anything else
	 * because it uses all following characters until it
	 * receives a ESC, a SUB, a ST or any other C1 control
	 * character.
	 */
	if (term.esc & ESC_STR) {
		if (u == '\a' || u == 030 || u == 032 || u == 033 ||
		   ISCONTROLC1(u)) {
			term.esc &= ~(ESC_START|ESC_STR);
			term.esc |= ESC_STR_END;
			goto check_control_code;
		}

		if (strescseq.len+len >= strescseq.siz) {
			/*
			 * Here is a bug in terminals. If the user never sends
			 * some code to stop the str or esc command, then st
			 * will stop responding. But this is better than
			 * silently failing with unknown characters. At least
			 * then users will report back.
			 *
			 * In the case users ever get fixed, here is the code:
			 */
			/*
			 * term.esc = 0;
			 * strhandle();
			 */
			if (strescseq.siz > (SIZE_MAX - UTF_SIZ) / 2)
				return;
			strescseq.siz *= 2;
			strescseq.buf = xrealloc(strescseq.buf, strescseq.siz);
		}

		memmove(&strescseq.buf[strescseq.len], c, len);
		strescseq.len += len;
		return;
	}

check_control_code:
	/*
	 * Actions of control codes must be performed as soon they arrive
	 * because they can be embedded inside a control sequence, and
	 * they must not cause conflicts with sequences.
	 */
	if (control) {
		tcontrolcode(u);
		/*
		 * control codes are not shown ever
		 */
		if (!term.esc)
			term.lastc = 0;
		return;
	} else if (term.esc & ESC_START) {
		if (term.esc & ESC_CSI) {
			csiescseq.buf[csiescseq.len++] = u;
			if (BETWEEN(u, 0x40, 0x7E)
					|| csiescseq.len >= \
					sizeof(csiescseq.buf)-1) {
				term.esc = 0;
				csiparse();
				csihandle();
			}
			return;
		} else if (term.esc & ESC_UTF8) {
			tdefutf8(u);
		} else if (term.esc & ESC_ALTCHARSET) {
			tdeftran(u);
		} else if (term.esc & ESC_TEST) {
			tdectest(u);
		} else {
			if (!eschandle(u))
				return;
			/* sequence already finished */
		}
		term.esc = 0;
		/*
		 * All characters which form part of a sequence are not
		 * printed
		 */
		return;
	}
	if (selected(term.c.x, term.c.y))
		selclear();

	gp = &term.line[term.c.y][term.c.x];
	if (IS_SET(MODE_WRAP) && (term.c.state & CURSOR_WRAPNEXT)) {
		gp->mode |= ATTR_WRAP;
		tnewline(1);
		gp = &term.line[term.c.y][term.c.x];
	}

	if (IS_SET(MODE_INSERT) && term.c.x+width < term.col)
		memmove(gp+width, gp, (term.col - term.c.x - width) * sizeof(Glyph));

	if (term.c.x+width > term.col) {
		tnewline(1);
		gp = &term.line[term.c.y][term.c.x];
	}

	tsetchar(u, &term.c.attr, term.c.x, term.c.y);
	term.lastc = u;

	if (width == 2) {
		gp->mode |= ATTR_WIDE;
		if (term.c.x+1 < term.col) {
			gp[1].u = '\0';
			gp[1].mode = ATTR_WDUMMY;
		}
	}
	if (term.c.x+width < term.col) {
		tmoveto(term.c.x+width, term.c.y);
	} else {
		term.c.state |= CURSOR_WRAPNEXT;
	}
}

int
twrite(const char *buf, int buflen, int show_ctrl)
{
	int charsize;
	Rune u;
	int n;

	for (n = 0; n < buflen; n += charsize) {
		if (IS_SET(MODE_UTF8)) {
			/* process a complete utf8 char */
			charsize = utf8decode(buf + n, &u, buflen - n);
			if (charsize == 0)
				break;
		} else {
			u = buf[n] & 0xFF;
			charsize = 1;
		}
		if (show_ctrl && ISCONTROL(u)) {
			if (u & 0x80) {
				u &= 0x7f;
				tputc('^');
				tputc('[');
			} else if (u != '\n' && u != '\r' && u != '\t') {
				u ^= 0x40;
				tputc('^');
			}
		}
		tputc(u);
	}
	return n;
}

void
tresize(int col, int row)
{
	int i, j;
	int minrow = MIN(row, term.row);
	int mincol = MIN(col, term.col);
	int *bp;
	TCursor c;

	if (col < 1 || row < 1) {
		fprintf(stderr,
		        "tresize: error resizing to %dx%d\n", col, row);
		return;
	}

	/*
	 * slide screen to keep cursor where we expect it -
	 * tscrollup would work here, but we can optimize to
	 * memmove because we're freeing the earlier lines
	 */
	for (i = 0; i <= term.c.y - row; i++) {
		free(term.line[i]);
		free(term.alt[i]);
	}
	/* ensure that both src and dst are not NULL */
	if (i > 0) {
		memmove(term.line, term.line + i, row * sizeof(Line));
		memmove(term.alt, term.alt + i, row * sizeof(Line));
	}
	for (i += row; i < term.row; i++) {
		free(term.line[i]);
		free(term.alt[i]);
	}

	/* resize to new height */
	term.line = xrealloc(term.line, row * sizeof(Line));
	term.alt  = xrealloc(term.alt,  row * sizeof(Line));
	term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
	term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));

	for (i = 0; i < HISTSIZE; i++) {
		term.hist[i] = xrealloc(term.hist[i], col * sizeof(Glyph));
		for (j = mincol; j < col; j++) {
			term.hist[i][j] = term.c.attr;
			term.hist[i][j].u = ' ';
		}
	}

	/* resize each row to new width, zero-pad if needed */
	for (i = 0; i < minrow; i++) {
		term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
		term.alt[i]  = xrealloc(term.alt[i],  col * sizeof(Glyph));
	}

	/* allocate any new rows */
	for (/* i = minrow */; i < row; i++) {
		term.line[i] = xmalloc(col * sizeof(Glyph));
		term.alt[i] = xmalloc(col * sizeof(Glyph));
	}
	if (col > term.col) {
		bp = term.tabs + term.col;

		memset(bp, 0, sizeof(*term.tabs) * (col - term.col));
		while (--bp > term.tabs && !*bp)
			/* nothing */ ;
		for (bp += tabspaces; bp < term.tabs + col; bp += tabspaces)
			*bp = 1;
	}
	/* update terminal size */
	term.col = col;
	term.row = row;
	/* reset scrolling region */
	tsetscroll(0, row-1);
	/* make use of the LIMIT in tmoveto */
	tmoveto(term.c.x, term.c.y);
	/* Clearing both screens (it makes dirty all lines) */
	c = term.c;
	for (i = 0; i < 2; i++) {
		if (mincol < col && 0 < minrow) {
			tclearregion(mincol, 0, col - 1, minrow - 1);
		}
		if (0 < col && minrow < row) {
			tclearregion(0, minrow, col - 1, row - 1);
		}
		tswapscreen();
		tcursor(CURSOR_LOAD);
	}
	term.c = c;
}

void
resettitle(void)
{
	xsettitle(NULL);
}

void
drawregion(int x1, int y1, int x2, int y2)
{
	int y;

	for (y = y1; y < y2; y++) {
		if (!term.dirty[y])
			continue;

		term.dirty[y] = 0;
		xdrawline(TLINE(y), x1, y, x2);
	}
}

void
draw(void)
{
	int cx = term.c.x, ocx = term.ocx, ocy = term.ocy;

	if (!xstartdraw())
		return;

	/* adjust cursor position */
	LIMIT(term.ocx, 0, term.col-1);
	LIMIT(term.ocy, 0, term.row-1);
	if (term.line[term.ocy][term.ocx].mode & ATTR_WDUMMY)
		term.ocx--;
	if (term.line[term.c.y][cx].mode & ATTR_WDUMMY)
		cx--;

	drawregion(0, 0, term.col, term.row);
	if (term.scr == 0)
		xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
				term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
	term.ocx = cx;
	term.ocy = term.c.y;
	xfinishdraw();
	if (ocx != term.ocx || ocy != term.ocy)
		xximspot(term.ocx, term.ocy);
}

void
redraw(void)
{
	tfulldirt();
	draw();
}