1 /*
2  * gs interface for page.
3  * ps.c and pdf.c both use these routines.
4  * a caveat: if you run more than one gs, only the last
5  * one gets killed by killgs
6  */
7 #include <u.h>
8 #include <libc.h>
9 #include <draw.h>
10 #include <thread.h>
11 #include <bio.h>
12 #include <cursor.h>
13 #include "page.h"
14 
15 static int gspid;	/* globals for atexit */
16 static int gsfd;
17 static void	killgs(void);
18 
19 static void
20 killgs(void)
21 {
22 	char tmpfile[100];
23 
24 	close(gsfd);
25 	postnote(PNGROUP, getpid(), "die");
26 
27 	/*
28 	 * from ghostscript's use.txt:
29 	 * ``Ghostscript currently doesn't do a very good job of deleting temporary
30 	 * files when it exits; you may have to delete them manually from time to
31 	 * time.''
32 	 */
33 	sprint(tmpfile, "/tmp/gs_%.5da", (gspid+300000)%100000);
34 	if(chatty) fprint(2, "remove %s...\n", tmpfile);
35 	remove(tmpfile);
36 	sleep(100);
37 	postnote(PNPROC, gspid, "die yankee pig dog");
38 }
39 
40 void
41 spawnreader(void *cp)
42 {
43 	int n, fd, pfd[2];
44 	char buf[1024];
45 
46 	recv(cp, &fd);
47 
48 	if(pipe(pfd)<0)
49 		wexits("pipe failed");
50 
51 	send(cp, &pfd[1]);
52 
53 	while((n=read(pfd[0], buf, sizeof buf)) > 0) {
54 		write(1, buf, n);
55 		write(fd, buf, n);
56 	}
57 
58 	close(pfd[0]);
59 	threadexits(0);
60 }
61 
62 void
63 spawnmonitor(void *cp)
64 {
65 	char buf[4096];
66 	char *xbuf;
67 	int fd;
68 	int n;
69 	int out;
70 	int first;
71 
72 	recv(cp, &fd);
73 
74 	out = open("/dev/tty", OWRITE);
75 	if(out < 0)
76 		out = 2;
77 
78 	xbuf = buf;	/* for ease of acid */
79 	first = 1;
80 	while((n = read(fd, xbuf, sizeof buf)) > 0){
81 		if(first){
82 			first = 0;
83 			fprint(2, "Ghostscript Error:\n");
84 		}
85 		write(out, xbuf, n);
86 		alarm(500);
87 	}
88 	threadexits(0);
89 }
90 
91 int
92 spawngs(GSInfo *g, char *safer)
93 {
94 	Channel *cp;
95 	char *args[16];
96 	char tb[32], gb[32];
97 	int i, nargs;
98 	int devnull;
99 	int stdinp[2];
100 	int stdoutp[2];
101 	int dataout[2];
102 	int errout[2];
103 
104 	/*
105 	 * spawn gs
106 	 *
107  	 * gs's standard input is fed from stdinout.
108 	 * gs output written to fd-2 (i.e. output we generate intentionally) is fed to stdinout.
109 	 * gs output written to fd 1 (i.e. ouptut gs generates on error) is fed to errout.
110 	 * gs data output is written to fd 3, which is dataout.
111 	 */
112 	if(pipe(stdinp)<0 || pipe(stdoutp)<0 || pipe(dataout)<0 || pipe(errout)<0)
113 		return -1;
114 
115 	nargs = 0;
116 	args[nargs++] = "gs";
117 	args[nargs++] = "-dNOPAUSE";
118 	args[nargs++] = "-dNOPROMPT";
119 	args[nargs++] = "-dDELAYSAFER";
120 	args[nargs++] = "-dQUIET";
121 	args[nargs++] = "-sDEVICE=bmp16m";
122 	args[nargs++] = "-sOutputFile=/dev/fd/3";
123 	args[nargs++] = "-r100";
124 	sprint(tb, "-dTextAlphaBits=%d", textbits);
125 	sprint(gb, "-dGraphicsAlphaBits=%d", gfxbits);
126 	if(textbits)
127 		args[nargs++] = tb;
128 	if(gfxbits)
129 		args[nargs++] = gb;
130 	args[nargs] = nil;
131 
132 	gspid = fork();
133 	if(gspid == 0) {
134 		close(stdinp[1]);
135 		close(stdoutp[0]);
136 		close(dataout[0]);
137 		close(errout[0]);
138 
139 		/*
140 		 * Horrible problem: we want to dup fd's 0-4 below,
141 		 * but some of the source fd's might have those small numbers.
142 		 * So we need to reallocate those.  In order to not step on
143 		 * anything else, we'll dup the fd's to higher ones using
144 		 * dup(x, -1), but we need to use up the lower ones first.
145 		 */
146 		while((devnull = open("/dev/null", ORDWR)) < 5)
147 			;
148 
149 		stdinp[0] = dup(stdinp[0], -1);
150 		stdoutp[1] = dup(stdoutp[1], -1);
151 		errout[1] = dup(errout[1], -1);
152 		dataout[1] = dup(dataout[1], -1);
153 
154 		dup(stdinp[0], 0);
155 		dup(errout[1], 1);
156 		dup(devnull, 2);	/* never anything useful */
157 		dup(dataout[1], 3);
158 		dup(stdoutp[1], 4);
159 		for(i=5; i<20; i++)
160 			close(i);
161 		execvp("gs", args);
162 		wexits("exec");
163 	}
164 	close(stdinp[0]);
165 	close(stdoutp[1]);
166 	close(errout[1]);
167 	close(dataout[1]);
168 	atexit(killgs);
169 
170 	cp = chancreate(sizeof(int), 0);
171 	if(teegs) {
172 		proccreate(spawnreader, cp, mainstacksize);
173 		send(cp, &stdoutp[0]);
174 		recv(cp, &stdoutp[0]);
175 	}
176 
177 	gsfd = g->gsfd = stdinp[1];
178 	g->gspid = gspid;
179 	g->g.fd = dataout[0];
180 	g->g.name = "gs pipe";
181 	g->g.type = Ibmp;
182 
183 	proccreate(spawnmonitor, cp, mainstacksize);
184 	send(cp, &errout[0]);
185 	chanfree(cp);
186 
187 	Binit(&g->gsrd, stdoutp[0], OREAD);
188 
189 	gscmd(g, "/PAGEDIDSHOWPAGE false def\n");
190 	gscmd(g, "/showpage { /PAGEDIDSHOWPAGE true def showpage } bind def\n");
191 	gscmd(g, "/PAGEFLUSH { PAGEDIDSHOWPAGE not {showpage} if /PAGEDIDSHOWPAGE false def } def\n");
192 
193 	gscmd(g, "/PAGEOUT (/dev/fd/4) (w) file def\n");
194 	if(!strcmp(safer, "-dSAFER"))
195 		gscmd(g, ".setsafe\n");
196 	gscmd(g, "/PAGE== { PAGEOUT exch write==only PAGEOUT (\\n) writestring PAGEOUT flushfile } def\n");
197 	waitgs(g);
198 
199 	return 0;
200 }
201 
202 int
203 gscmd(GSInfo *gs, char *fmt, ...)
204 {
205 	char buf[1024];
206 	int n;
207 
208 	va_list v;
209 	va_start(v, fmt);
210 	n = vseprint(buf, buf+sizeof buf, fmt, v) - buf;
211 	if(n <= 0)
212 		return n;
213 
214 	if(chatty) {
215 		fprint(2, "cmd: ");
216 		write(2, buf, n);
217 	}
218 
219 	if(write(gs->gsfd, buf, n) != 0)
220 		return -1;
221 
222 	return n;
223 }
224 
225 /*
226  * set the dimensions of the bitmap we expect to get back from GS.
227  */
228 void
229 setdim(GSInfo *gs, Rectangle bbox, int ppi, int landscape)
230 {
231 	Rectangle pbox;
232 
233 	if(chatty)
234 		fprint(2, "setdim: bbox=%R\n", bbox);
235 
236 	if(ppi)
237 		gs->ppi = ppi;
238 
239 	gscmd(gs, "mark\n");
240 	if(ppi)
241 		gscmd(gs, "/HWResolution [%d %d]\n", ppi, ppi);
242 
243 	if(!Dx(bbox))
244 		bbox = Rect(0, 0, 612, 792);	/* 8½×11 */
245 
246 	switch(landscape){
247 	case 0:
248 		pbox = bbox;
249 		break;
250 	default:
251 		pbox = Rect(bbox.min.y, bbox.min.x, bbox.max.y, bbox.max.x);
252 		break;
253 	}
254 	gscmd(gs, "/PageSize [%d %d]\n", Dx(pbox), Dy(pbox));
255 	gscmd(gs, "/Margins [%d %d]\n", -pbox.min.x, -pbox.min.y);
256 	gscmd(gs, "currentdevice putdeviceprops pop\n");
257 	gscmd(gs, "/#copies 1 store\n");
258 
259 	if(!eqpt(bbox.min, ZP))
260 		gscmd(gs, "%d %d translate\n", -bbox.min.x, -bbox.min.y);
261 
262 	switch(landscape){
263 	case 0:
264 		break;
265 	case 1:
266 		gscmd(gs, "%d 0 translate\n", Dy(bbox));
267 		gscmd(gs, "90 rotate\n");
268 		break;
269 	}
270 
271 	waitgs(gs);
272 }
273 
274 void
275 waitgs(GSInfo *gs)
276 {
277 	/* we figure out that gs is done by telling it to
278 	 * print something and waiting until it does.
279 	 */
280 	char *p;
281 	Biobuf *b = &gs->gsrd;
282 	uchar buf[1024];
283 	int n;
284 
285 //	gscmd(gs, "(\\n**bstack\\n) print flush\n");
286 //	gscmd(gs, "stack flush\n");
287 //	gscmd(gs, "(**estack\\n) print flush\n");
288 	gscmd(gs, "(\\n//GO.SYSIN DD\\n) PAGE==\n");
289 
290 	alarm(300*1000);
291 	for(;;) {
292 		p = Brdline(b, '\n');
293 		if(p == nil) {
294 			n = Bbuffered(b);
295 			if(n <= 0)
296 				break;
297 			if(n > sizeof buf)
298 				n = sizeof buf;
299 			Bread(b, buf, n);
300 			continue;
301 		}
302 		p[Blinelen(b)-1] = 0;
303 		if(chatty) fprint(2, "p: ");
304 		if(chatty) write(2, p, Blinelen(b)-1);
305 		if(chatty) fprint(2, "\n");
306 		if(strstr(p, "Error:")) {
307 			alarm(0);
308 			fprint(2, "ghostscript error: %s\n", p);
309 			wexits("gs error");
310 		}
311 
312 		if(strstr(p, "//GO.SYSIN DD")) {
313 			break;
314 		}
315 	}
316 	alarm(0);
317 }