1 72197f89 2014-10-21 rsc /* col - eliminate reverse line feeds */
  2 72197f89 2014-10-21 rsc #include <u.h>
  3 72197f89 2014-10-21 rsc #include <libc.h>
  4 72197f89 2014-10-21 rsc #include <ctype.h>
  5 72197f89 2014-10-21 rsc #include <bio.h>
  6 72197f89 2014-10-21 rsc 
  7 72197f89 2014-10-21 rsc enum {
  8 72197f89 2014-10-21 rsc 	ESC	= '\033',
  9 72197f89 2014-10-21 rsc 	RLF	= '\013',
 10 72197f89 2014-10-21 rsc 
 11 72197f89 2014-10-21 rsc 	PL	= 256,
 12 72197f89 2014-10-21 rsc 	LINELN	= 800,
 13 72197f89 2014-10-21 rsc 
 14 72197f89 2014-10-21 rsc 	Tabstop	= 8,		/* must be power of 2 */
 15 72197f89 2014-10-21 rsc };
 16 72197f89 2014-10-21 rsc 
 17 72197f89 2014-10-21 rsc static int bflag, xflag, fflag;
 18 72197f89 2014-10-21 rsc static int cp, lp;
 19 72197f89 2014-10-21 rsc static int half;
 20 72197f89 2014-10-21 rsc static int ll, llh, mustwr;
 21 72197f89 2014-10-21 rsc static int pcp = 0;
 22 72197f89 2014-10-21 rsc 
 23 72197f89 2014-10-21 rsc static char *page[PL];
 24 72197f89 2014-10-21 rsc static char *line;
 25 72197f89 2014-10-21 rsc static char lbuff[LINELN];
 26 72197f89 2014-10-21 rsc static Biobuf bin, bout;
 27 72197f89 2014-10-21 rsc 
 28 72197f89 2014-10-21 rsc void	emit(char *s, int lineno);
 29 72197f89 2014-10-21 rsc void	incr(void), decr(void);
 30 72197f89 2014-10-21 rsc void	outc(Rune);
 31 72197f89 2014-10-21 rsc 
 32 72197f89 2014-10-21 rsc static void
 33 72197f89 2014-10-21 rsc usage(void)
 34 72197f89 2014-10-21 rsc {
 35 72197f89 2014-10-21 rsc 	fprint(2, "usage: %s [-bfx]\n", argv0);
 36 72197f89 2014-10-21 rsc 	exits("usage");
 37 72197f89 2014-10-21 rsc }
 38 72197f89 2014-10-21 rsc 
 39 72197f89 2014-10-21 rsc void
 40 72197f89 2014-10-21 rsc main(int argc, char **argv)
 41 72197f89 2014-10-21 rsc {
 42 72197f89 2014-10-21 rsc 	int i, lno;
 43 72197f89 2014-10-21 rsc 	long ch;
 44 72197f89 2014-10-21 rsc 	Rune c;
 45 72197f89 2014-10-21 rsc 
 46 72197f89 2014-10-21 rsc 	ARGBEGIN{
 47 72197f89 2014-10-21 rsc 	case 'b':
 48 72197f89 2014-10-21 rsc 		bflag++;
 49 72197f89 2014-10-21 rsc 		break;
 50 72197f89 2014-10-21 rsc 	case 'f':
 51 72197f89 2014-10-21 rsc 		fflag++;
 52 72197f89 2014-10-21 rsc 		break;
 53 72197f89 2014-10-21 rsc 	case 'x':
 54 72197f89 2014-10-21 rsc 		xflag++;
 55 72197f89 2014-10-21 rsc 		break;
 56 72197f89 2014-10-21 rsc 	default:
 57 72197f89 2014-10-21 rsc 		usage();
 58 72197f89 2014-10-21 rsc 	}ARGEND;
 59 72197f89 2014-10-21 rsc 
 60 72197f89 2014-10-21 rsc 	for (ll=0; ll < PL; ll++)
 61 72197f89 2014-10-21 rsc 		page[ll] = nil;
 62 72197f89 2014-10-21 rsc 
 63 72197f89 2014-10-21 rsc 	cp = 0;
 64 72197f89 2014-10-21 rsc 	ll = 0;
 65 72197f89 2014-10-21 rsc 	mustwr = PL;
 66 72197f89 2014-10-21 rsc 	line = lbuff;
 67 72197f89 2014-10-21 rsc 
 68 72197f89 2014-10-21 rsc 	Binit(&bin, 0, OREAD);
 69 72197f89 2014-10-21 rsc 	Binit(&bout, 1, OWRITE);
 70 72197f89 2014-10-21 rsc 	while ((ch = Bgetrune(&bin)) != Beof) {
 71 72197f89 2014-10-21 rsc 		c = ch;
 72 72197f89 2014-10-21 rsc 		switch (c) {
 73 72197f89 2014-10-21 rsc 		case '\n':
 74 72197f89 2014-10-21 rsc 			incr();
 75 72197f89 2014-10-21 rsc 			incr();
 76 72197f89 2014-10-21 rsc 			cp = 0;
 77 72197f89 2014-10-21 rsc 			break;
 78 72197f89 2014-10-21 rsc 
 79 72197f89 2014-10-21 rsc 		case '\0':
 80 72197f89 2014-10-21 rsc 			break;
 81 72197f89 2014-10-21 rsc 
 82 72197f89 2014-10-21 rsc 		case ESC:
 83 72197f89 2014-10-21 rsc 			c = Bgetrune(&bin);
 84 72197f89 2014-10-21 rsc 			switch (c) {
 85 72197f89 2014-10-21 rsc 			case '7':	/* reverse full line feed */
 86 72197f89 2014-10-21 rsc 				decr();
 87 72197f89 2014-10-21 rsc 				decr();
 88 72197f89 2014-10-21 rsc 				break;
 89 72197f89 2014-10-21 rsc 
 90 72197f89 2014-10-21 rsc 			case '8':	/* reverse half line feed */
 91 72197f89 2014-10-21 rsc 				if (fflag)
 92 72197f89 2014-10-21 rsc 					decr();
 93 72197f89 2014-10-21 rsc 				else
 94 72197f89 2014-10-21 rsc 					if (--half < -1) {
 95 72197f89 2014-10-21 rsc 						decr();
 96 72197f89 2014-10-21 rsc 						decr();
 97 72197f89 2014-10-21 rsc 						half += 2;
 98 72197f89 2014-10-21 rsc 					}
 99 72197f89 2014-10-21 rsc 				break;
100 72197f89 2014-10-21 rsc 
101 72197f89 2014-10-21 rsc 			case '9':	/* forward half line feed */
102 72197f89 2014-10-21 rsc 				if (fflag)
103 72197f89 2014-10-21 rsc 					incr();
104 72197f89 2014-10-21 rsc 				else
105 72197f89 2014-10-21 rsc 					if (++half > 0) {
106 72197f89 2014-10-21 rsc 						incr();
107 72197f89 2014-10-21 rsc 						incr();
108 72197f89 2014-10-21 rsc 						half -= 2;
109 72197f89 2014-10-21 rsc 					}
110 72197f89 2014-10-21 rsc 				break;
111 72197f89 2014-10-21 rsc 			}
112 72197f89 2014-10-21 rsc 			break;
113 72197f89 2014-10-21 rsc 
114 72197f89 2014-10-21 rsc 		case RLF:
115 72197f89 2014-10-21 rsc 			decr();
116 72197f89 2014-10-21 rsc 			decr();
117 72197f89 2014-10-21 rsc 			break;
118 72197f89 2014-10-21 rsc 
119 72197f89 2014-10-21 rsc 		case '\r':
120 72197f89 2014-10-21 rsc 			cp = 0;
121 72197f89 2014-10-21 rsc 			break;
122 72197f89 2014-10-21 rsc 
123 72197f89 2014-10-21 rsc 		case '\t':
124 72197f89 2014-10-21 rsc 			cp = (cp + Tabstop) & -Tabstop;
125 72197f89 2014-10-21 rsc 			break;
126 72197f89 2014-10-21 rsc 
127 72197f89 2014-10-21 rsc 		case '\b':
128 72197f89 2014-10-21 rsc 			if (cp > 0)
129 72197f89 2014-10-21 rsc 				cp--;
130 72197f89 2014-10-21 rsc 			break;
131 72197f89 2014-10-21 rsc 
132 72197f89 2014-10-21 rsc 		case ' ':
133 72197f89 2014-10-21 rsc 			cp++;
134 72197f89 2014-10-21 rsc 			break;
135 72197f89 2014-10-21 rsc 
136 72197f89 2014-10-21 rsc 		default:
137 72197f89 2014-10-21 rsc 			if (!isascii(c) || isprint(c)) {
138 72197f89 2014-10-21 rsc 				outc(c);
139 72197f89 2014-10-21 rsc 				cp++;
140 72197f89 2014-10-21 rsc 			}
141 72197f89 2014-10-21 rsc 			break;
142 72197f89 2014-10-21 rsc 		}
143 72197f89 2014-10-21 rsc 	}
144 72197f89 2014-10-21 rsc 
145 72197f89 2014-10-21 rsc 	for (i=0; i < PL; i++) {
146 72197f89 2014-10-21 rsc 		lno = (mustwr+i) % PL;
147 72197f89 2014-10-21 rsc 		if (page[lno] != 0)
148 72197f89 2014-10-21 rsc 			emit(page[lno], mustwr+i-PL);
149 72197f89 2014-10-21 rsc 	}
150 72197f89 2014-10-21 rsc 	emit(" ", (llh + 1) & -2);
151 72197f89 2014-10-21 rsc 	exits(0);
152 72197f89 2014-10-21 rsc }
153 72197f89 2014-10-21 rsc 
154 72197f89 2014-10-21 rsc void
155 72197f89 2014-10-21 rsc outc(Rune c)
156 72197f89 2014-10-21 rsc {
157 72197f89 2014-10-21 rsc 	if (lp > cp) {
158 72197f89 2014-10-21 rsc 		line = lbuff;
159 72197f89 2014-10-21 rsc 		lp = 0;
160 72197f89 2014-10-21 rsc 	}
161 72197f89 2014-10-21 rsc 
162 72197f89 2014-10-21 rsc 	while (lp < cp) {
163 72197f89 2014-10-21 rsc 		switch (*line) {
164 72197f89 2014-10-21 rsc 		case '\0':
165 72197f89 2014-10-21 rsc 			*line = ' ';
166 72197f89 2014-10-21 rsc 			lp++;
167 72197f89 2014-10-21 rsc 			break;
168 72197f89 2014-10-21 rsc 		case '\b':
169 72197f89 2014-10-21 rsc 			lp--;
170 72197f89 2014-10-21 rsc 			break;
171 72197f89 2014-10-21 rsc 		default:
172 72197f89 2014-10-21 rsc 			lp++;
173 72197f89 2014-10-21 rsc 			break;
174 72197f89 2014-10-21 rsc 		}
175 72197f89 2014-10-21 rsc 		line++;
176 72197f89 2014-10-21 rsc 	}
177 72197f89 2014-10-21 rsc 	while (*line == '\b')
178 72197f89 2014-10-21 rsc 		line += 2;
179 72197f89 2014-10-21 rsc 	if (bflag || *line == '\0' || *line == ' ')
180 72197f89 2014-10-21 rsc 		cp += runetochar(line, &c) - 1;
181 72197f89 2014-10-21 rsc 	else {
182 72197f89 2014-10-21 rsc 		char c1, c2, c3;
183 72197f89 2014-10-21 rsc 
184 72197f89 2014-10-21 rsc 		c1 = *++line;
185 72197f89 2014-10-21 rsc 		*line++ = '\b';
186 72197f89 2014-10-21 rsc 		c2 = *line;
187 72197f89 2014-10-21 rsc 		*line++ = c;
188 72197f89 2014-10-21 rsc 		while (c1) {
189 72197f89 2014-10-21 rsc 			c3 = *line;
190 72197f89 2014-10-21 rsc 			*line++ = c1;
191 72197f89 2014-10-21 rsc 			c1 = c2;
192 72197f89 2014-10-21 rsc 			c2 = c3;
193 72197f89 2014-10-21 rsc 		}
194 72197f89 2014-10-21 rsc 		lp = 0;
195 72197f89 2014-10-21 rsc 		line = lbuff;
196 72197f89 2014-10-21 rsc 	}
197 72197f89 2014-10-21 rsc }
198 72197f89 2014-10-21 rsc 
199 72197f89 2014-10-21 rsc void
200 72197f89 2014-10-21 rsc store(int lno)
201 72197f89 2014-10-21 rsc {
202 72197f89 2014-10-21 rsc 	lno %= PL;
203 72197f89 2014-10-21 rsc 	if (page[lno] != nil)
204 72197f89 2014-10-21 rsc 		free(page[lno]);
205 72197f89 2014-10-21 rsc 	page[lno] = malloc((unsigned)strlen(lbuff) + 2);
206 72197f89 2014-10-21 rsc 	if (page[lno] == nil)
207 72197f89 2014-10-21 rsc 		sysfatal("out of memory");
208 72197f89 2014-10-21 rsc 	strcpy(page[lno], lbuff);
209 72197f89 2014-10-21 rsc }
210 72197f89 2014-10-21 rsc 
211 72197f89 2014-10-21 rsc void
212 72197f89 2014-10-21 rsc fetch(int lno)
213 72197f89 2014-10-21 rsc {
214 72197f89 2014-10-21 rsc 	char *p;
215 72197f89 2014-10-21 rsc 
216 72197f89 2014-10-21 rsc 	lno %= PL;
217 72197f89 2014-10-21 rsc 	p = lbuff;
218 72197f89 2014-10-21 rsc 	while (*p)
219 72197f89 2014-10-21 rsc 		*p++ = '\0';
220 72197f89 2014-10-21 rsc 	line = lbuff;
221 72197f89 2014-10-21 rsc 	lp = 0;
222 72197f89 2014-10-21 rsc 	if (page[lno])
223 72197f89 2014-10-21 rsc 		strcpy(line, page[lno]);
224 72197f89 2014-10-21 rsc }
225 72197f89 2014-10-21 rsc 
226 72197f89 2014-10-21 rsc void
227 72197f89 2014-10-21 rsc emit(char *s, int lineno)
228 72197f89 2014-10-21 rsc {
229 72197f89 2014-10-21 rsc 	int ncp;
230 72197f89 2014-10-21 rsc 	char *p;
231 72197f89 2014-10-21 rsc 	static int cline = 0;
232 72197f89 2014-10-21 rsc 
233 72197f89 2014-10-21 rsc 	if (*s) {
234 72197f89 2014-10-21 rsc 		while (cline < lineno - 1) {
235 72197f89 2014-10-21 rsc 			Bputc(&bout, '\n');
236 72197f89 2014-10-21 rsc 			pcp = 0;
237 72197f89 2014-10-21 rsc 			cline += 2;
238 72197f89 2014-10-21 rsc 		}
239 72197f89 2014-10-21 rsc 		if (cline != lineno) {
240 72197f89 2014-10-21 rsc 			Bputc(&bout, ESC);
241 72197f89 2014-10-21 rsc 			Bputc(&bout, '9');
242 72197f89 2014-10-21 rsc 			cline++;
243 72197f89 2014-10-21 rsc 		}
244 72197f89 2014-10-21 rsc 		if (pcp)
245 72197f89 2014-10-21 rsc 			Bputc(&bout, '\r');
246 72197f89 2014-10-21 rsc 		pcp = 0;
247 72197f89 2014-10-21 rsc 		p = s;
248 72197f89 2014-10-21 rsc 		while (*p) {
249 72197f89 2014-10-21 rsc 			ncp = pcp;
250 72197f89 2014-10-21 rsc 			while (*p++ == ' ')
251 72197f89 2014-10-21 rsc 				if ((++ncp & 7) == 0 && !xflag) {
252 72197f89 2014-10-21 rsc 					pcp = ncp;
253 72197f89 2014-10-21 rsc 					Bputc(&bout, '\t');
254 72197f89 2014-10-21 rsc 				}
255 72197f89 2014-10-21 rsc 			if (!*--p)
256 72197f89 2014-10-21 rsc 				break;
257 72197f89 2014-10-21 rsc 			while (pcp < ncp) {
258 72197f89 2014-10-21 rsc 				Bputc(&bout, ' ');
259 72197f89 2014-10-21 rsc 				pcp++;
260 72197f89 2014-10-21 rsc 			}
261 72197f89 2014-10-21 rsc 			Bputc(&bout, *p);
262 72197f89 2014-10-21 rsc 			if (*p++ == '\b')
263 72197f89 2014-10-21 rsc 				pcp--;
264 72197f89 2014-10-21 rsc 			else
265 72197f89 2014-10-21 rsc 				pcp++;
266 72197f89 2014-10-21 rsc 		}
267 72197f89 2014-10-21 rsc 	}
268 72197f89 2014-10-21 rsc }
269 72197f89 2014-10-21 rsc 
270 72197f89 2014-10-21 rsc void
271 72197f89 2014-10-21 rsc incr(void)
272 72197f89 2014-10-21 rsc {
273 72197f89 2014-10-21 rsc 	int lno;
274 72197f89 2014-10-21 rsc 
275 72197f89 2014-10-21 rsc 	store(ll++);
276 72197f89 2014-10-21 rsc 	if (ll > llh)
277 72197f89 2014-10-21 rsc 		llh = ll;
278 72197f89 2014-10-21 rsc 	lno = ll % PL;
279 72197f89 2014-10-21 rsc 	if (ll >= mustwr && page[lno]) {
280 72197f89 2014-10-21 rsc 		emit(page[lno], ll - PL);
281 72197f89 2014-10-21 rsc 		mustwr++;
282 72197f89 2014-10-21 rsc 		free(page[lno]);
283 72197f89 2014-10-21 rsc 		page[lno] = nil;
284 72197f89 2014-10-21 rsc 	}
285 72197f89 2014-10-21 rsc 	fetch(ll);
286 72197f89 2014-10-21 rsc }
287 72197f89 2014-10-21 rsc 
288 72197f89 2014-10-21 rsc void
289 72197f89 2014-10-21 rsc decr(void)
290 72197f89 2014-10-21 rsc {
291 72197f89 2014-10-21 rsc 	if (ll > mustwr - PL) {
292 72197f89 2014-10-21 rsc 		store(ll--);
293 72197f89 2014-10-21 rsc 		fetch(ll);
294 72197f89 2014-10-21 rsc 	}
295 72197f89 2014-10-21 rsc }