src/cmd/page/gs.c - plan9 - Git at Google

 /*
  * gs interface for page.
  * ps.c and pdf.c both use these routines.
  * a caveat: if you run more than one gs, only the last
  * one gets killed by killgs
  */
 #include <u.h>
 #include <libc.h>
 #include <draw.h>
 #include <event.h>
 #include <bio.h>
 #include "page.h"

 static int gspid;	/* globals for atexit */
 static int gsfd;
 static void	killgs(void);

 static void
 killgs(void)
 {
 	char tmpfile[100];

 	close(gsfd);
 	postnote(PNGROUP, getpid(), "die");

 	/*
 	 * from ghostscript's use.txt:
 	 * ``Ghostscript currently doesn't do a very good job of deleting temporary
 	 * files when it exits; you may have to delete them manually from time to
 	 * time.''
 	 */
 	sprint(tmpfile, "/tmp/gs_%.5da", (gspid+300000)%100000);
 	if(chatty) fprint(2, "remove %s...\n", tmpfile);
 	remove(tmpfile);
 	sleep(100);
 	postnote(PNPROC, gspid, "die yankee pig dog");
 }

 int
 spawnwriter(GSInfo *g, Biobuf *b)
 {
 	char buf[4096];
 	int n;
 	int fd;

 	switch(fork()){
 	case -1:	return -1;
 	case 0:	break;
 	default:	return 0;
 	}

 	Bseek(b, 0, 0);
 	fd = g->gsfd;
 	while((n = Bread(b, buf, sizeof buf)) > 0)
 		write(fd, buf, n);
 	fprint(fd, "(/fd/3) (w) file dup (THIS IS NOT AN INFERNO BITMAP\\n) writestring flushfile\n");
 	_exits(0);
 	return -1;
 }

 int
 spawnreader(int fd)
 {
 	int n, pfd[2];
 	char buf[1024];

 	if(pipe(pfd)<0)
 		return -1;
 	switch(fork()){
 	case -1:
 		return -1;
 	case 0:
 		break;
 	default:
 		close(pfd[0]);
 		return pfd[1];
 	}

 	close(pfd[1]);
 	switch(fork()){
 	case -1:
 		wexits("fork failed");
 	case 0:
 		while((n=read(fd, buf, sizeof buf)) > 0) {
 			write(1, buf, n);
 			write(pfd[0], buf, n);
 		}
 		break;
 	default:
 		while((n=read(pfd[0], buf, sizeof buf)) > 0) {
 			write(1, buf, n);
 			write(fd, buf, n);
 		}
 		break;
 	}
 	postnote(PNGROUP, getpid(), "i'm die-ing");
 	_exits(0);
 	return -1;
 }

 void
 spawnmonitor(int fd)
 {
 	char buf[4096];
 	char *xbuf;
 	int n;
 	int out;
 	int first;

 	switch(rfork(RFFDG|RFNOTEG|RFPROC)){
 	case -1:
 	default:
 		return;

 	case 0:
 		break;
 	}

 	out = open("/dev/cons", OWRITE);
 	if(out < 0)
 		out = 2;

 	xbuf = buf;	/* for ease of acid */
 	first = 1;
 	while((n = read(fd, xbuf, sizeof buf)) > 0){
 		if(first){
 			first = 0;
 			fprint(2, "Ghostscript Error:\n");
 		}
 		write(out, xbuf, n);
 		alarm(500);
 	}
 	_exits(0);
 }

 int
 spawngs(GSInfo *g)
 {
 	char *args[16];
 	char tb[32], gb[32];
 	int i, nargs;
 	int devnull;
 	int stdinout[2];
 	int dataout[2];
 	int errout[2];

 	/*
 	 * spawn gs
 	 *
  	 * gs's standard input is fed from stdinout.
 	 * gs output written to fd-2 (i.e. output we generate intentionally) is fed to stdinout.
 	 * gs output written to fd 1 (i.e. ouptut gs generates on error) is fed to errout.
 	 * gs data output is written to fd 3, which is dataout.
 	 */
 	if(pipe(stdinout) < 0 || pipe(dataout)<0 || pipe(errout)<0)
 		return -1;

 	nargs = 0;
 	args[nargs++] = "gs";
 	args[nargs++] = "-dNOPAUSE";
 	args[nargs++] = "-dSAFER";
 	args[nargs++] = "-sDEVICE=plan9";
 	args[nargs++] = "-sOutputFile=/fd/3";
 	args[nargs++] = "-dQUIET";
 	args[nargs++] = "-r100";
 	sprint(tb, "-dTextAlphaBits=%d", textbits);
 	sprint(gb, "-dGraphicsAlphaBits=%d", gfxbits);
 	if(textbits)
 		args[nargs++] = tb;
 	if(gfxbits)
 		args[nargs++] = gb;
 	args[nargs++] = "-";
 	args[nargs] = nil;

 	gspid = fork();
 	if(gspid == 0) {
 		close(stdinout[1]);
 		close(dataout[1]);
 		close(errout[1]);

 		/*
 		 * Horrible problem: we want to dup fd's 0-4 below,
 		 * but some of the source fd's might have those small numbers.
 		 * So we need to reallocate those.  In order to not step on
 		 * anything else, we'll dup the fd's to higher ones using
 		 * dup(x, -1), but we need to use up the lower ones first.
 		 */
 		while((devnull = open("/dev/null", ORDWR)) < 5)
 			;

 		stdinout[0] = dup(stdinout[0], -1);
 		errout[0] = dup(errout[0], -1);
 		dataout[0] = dup(dataout[0], -1);

 		dup(stdinout[0], 0);
 		dup(errout[0], 1);
 		dup(devnull, 2);	/* never anything useful */
 		dup(dataout[0], 3);
 		dup(stdinout[0], 4);
 		for(i=5; i<20; i++)
 			close(i);
 		exec("/bin/gs", args);
 		wexits("exec");
 	}
 	close(stdinout[0]);
 	close(errout[0]);
 	close(dataout[0]);
 	atexit(killgs);

 	if(teegs)
 		stdinout[1] = spawnreader(stdinout[1]);

 	gsfd = g->gsfd = stdinout[1];
 	g->gsdfd = dataout[1];
 	g->gspid = gspid;

 	spawnmonitor(errout[1]);
 	Binit(&g->gsrd, g->gsfd, OREAD);

 	gscmd(g, "/PAGEOUT (/fd/4) (w) file def\n");
 	gscmd(g, "/PAGE== { PAGEOUT exch write==only PAGEOUT (\\n) writestring PAGEOUT flushfile } def\n");
 	waitgs(g);

 	return 0;
 }

 int
 gscmd(GSInfo *gs, char *fmt, ...)
 {
 	char buf[1024];
 	int n;

 	va_list v;
 	va_start(v, fmt);
 	n = vseprint(buf, buf+sizeof buf, fmt, v) - buf;
 	if(n <= 0)
 		return n;

 	if(chatty) {
 		fprint(2, "cmd: ");
 		write(2, buf, n);
 	}

 	if(write(gs->gsfd, buf, n) != 0)
 		return -1;

 	return n;
 }

 /*
  * set the dimensions of the bitmap we expect to get back from GS.
  */
 void
 setdim(GSInfo *gs, Rectangle bbox, int ppi, int landscape)
 {
 	Rectangle pbox;

 	if(chatty)
 		fprint(2, "setdim: bbox=%R\n", bbox);

 	if(ppi)
 		gs->ppi = ppi;

 	gscmd(gs, "mark\n");
 	if(ppi)
 		gscmd(gs, "/HWResolution [%d %d]\n", ppi, ppi);

 	if(!Dx(bbox))
 		bbox = Rect(0, 0, 612, 792);	/* 8½×11 */

 	switch(landscape){
 	case 0:
 		pbox = bbox;
 		break;
 	case 1:
 		pbox = Rect(bbox.min.y, bbox.min.x, bbox.max.y, bbox.max.x);
 		break;
 	}
 	gscmd(gs, "/PageSize [%d %d]\n", Dx(pbox), Dy(pbox));
 	gscmd(gs, "/Margins [%d %d]\n", -pbox.min.x, -pbox.min.y);
 	gscmd(gs, "currentdevice putdeviceprops pop\n");
 	gscmd(gs, "/#copies 1 store\n");

 	if(!eqpt(bbox.min, ZP))
 		gscmd(gs, "%d %d translate\n", -bbox.min.x, -bbox.min.y);

 	switch(landscape){
 	case 0:
 		break;
 	case 1:
 		gscmd(gs, "%d 0 translate\n", Dy(bbox));
 		gscmd(gs, "90 rotate\n");
 		break;
 	}

 	waitgs(gs);
 }

 void
 waitgs(GSInfo *gs)
 {
 	/* we figure out that gs is done by telling it to
 	 * print something and waiting until it does.
 	 */
 	char *p;
 	Biobuf *b = &gs->gsrd;
 	uchar buf[1024];
 	int n;

 //	gscmd(gs, "(\\n**bstack\\n) print flush\n");
 //	gscmd(gs, "stack flush\n");
 //	gscmd(gs, "(**estack\\n) print flush\n");
 	gscmd(gs, "(\\n//GO.SYSIN DD\\n) PAGE==\n");

 	alarm(300*1000);
 	for(;;) {
 		p = Brdline(b, '\n');
 		if(p == nil) {
 			n = Bbuffered(b);
 			if(n <= 0)
 				break;
 			if(n > sizeof buf)
 				n = sizeof buf;
 			Bread(b, buf, n);
 			continue;
 		}
 		p[Blinelen(b)-1] = 0;
 		if(chatty) fprint(2, "p: ");
 		if(chatty) write(2, p, Blinelen(b)-1);
 		if(chatty) fprint(2, "\n");
 		if(strstr(p, "Error:")) {
 			alarm(0);
 			fprint(2, "ghostscript error: %s\n", p);
 			wexits("gs error");
 		}

 		if(strstr(p, "//GO.SYSIN DD")) {
 			break;
 		}
 	}
 	alarm(0);
 }
	/*
	* gs interface for page.
	* ps.c and pdf.c both use these routines.
	* a caveat: if you run more than one gs, only the last
	* one gets killed by killgs
	*/
	#include <u.h>
	#include <libc.h>
	#include <draw.h>
	#include <event.h>
	#include <bio.h>
	#include "page.h"

	static int gspid; /* globals for atexit */
	static int gsfd;
	static void killgs(void);

	static void
	killgs(void)
	{
	char tmpfile[100];

	close(gsfd);
	postnote(PNGROUP, getpid(), "die");

	/*
	* from ghostscript's use.txt:
	* ``Ghostscript currently doesn't do a very good job of deleting temporary
	* files when it exits; you may have to delete them manually from time to
	* time.''
	*/
	sprint(tmpfile, "/tmp/gs_%.5da", (gspid+300000)%100000);
	if(chatty) fprint(2, "remove %s...\n", tmpfile);
	remove(tmpfile);
	sleep(100);
	postnote(PNPROC, gspid, "die yankee pig dog");
	}

	int
	spawnwriter(GSInfo g, Biobuf b)
	{
	char buf[4096];
	int n;
	int fd;

	switch(fork()){
	case -1: return -1;
	case 0: break;
	default: return 0;
	}

	Bseek(b, 0, 0);
	fd = g->gsfd;
	while((n = Bread(b, buf, sizeof buf)) > 0)
	write(fd, buf, n);
	fprint(fd, "(/fd/3) (w) file dup (THIS IS NOT AN INFERNO BITMAP\\n) writestring flushfile\n");
	_exits(0);
	return -1;
	}

	int
	spawnreader(int fd)
	{
	int n, pfd[2];
	char buf[1024];

	if(pipe(pfd)<0)
	return -1;
	switch(fork()){
	case -1:
	return -1;
	case 0:
	break;
	default:
	close(pfd[0]);
	return pfd[1];
	}

	close(pfd[1]);
	switch(fork()){
	case -1:
	wexits("fork failed");
	case 0:
	while((n=read(fd, buf, sizeof buf)) > 0) {
	write(1, buf, n);
	write(pfd[0], buf, n);
	}
	break;
	default:
	while((n=read(pfd[0], buf, sizeof buf)) > 0) {
	write(1, buf, n);
	write(fd, buf, n);
	}
	break;
	}
	postnote(PNGROUP, getpid(), "i'm die-ing");
	_exits(0);
	return -1;
	}

	void
	spawnmonitor(int fd)
	{
	char buf[4096];
	char *xbuf;
	int n;
	int out;
	int first;

	switch(rfork(RFFDG\|RFNOTEG\|RFPROC)){
	case -1:
	default:
	return;

	case 0:
	break;
	}

	out = open("/dev/cons", OWRITE);
	if(out < 0)
	out = 2;

	xbuf = buf; /* for ease of acid */
	first = 1;
	while((n = read(fd, xbuf, sizeof buf)) > 0){
	if(first){
	first = 0;
	fprint(2, "Ghostscript Error:\n");
	}
	write(out, xbuf, n);
	alarm(500);
	}
	_exits(0);
	}

	int
	spawngs(GSInfo *g)
	{
	char *args[16];
	char tb[32], gb[32];
	int i, nargs;
	int devnull;
	int stdinout[2];
	int dataout[2];
	int errout[2];

	/*
	* spawn gs
	*
	* gs's standard input is fed from stdinout.
	* gs output written to fd-2 (i.e. output we generate intentionally) is fed to stdinout.
	* gs output written to fd 1 (i.e. ouptut gs generates on error) is fed to errout.
	* gs data output is written to fd 3, which is dataout.
	*/
	if(pipe(stdinout) < 0 \|\| pipe(dataout)<0 \|\| pipe(errout)<0)
	return -1;

	nargs = 0;
	args[nargs++] = "gs";
	args[nargs++] = "-dNOPAUSE";
	args[nargs++] = "-dSAFER";
	args[nargs++] = "-sDEVICE=plan9";
	args[nargs++] = "-sOutputFile=/fd/3";
	args[nargs++] = "-dQUIET";
	args[nargs++] = "-r100";
	sprint(tb, "-dTextAlphaBits=%d", textbits);
	sprint(gb, "-dGraphicsAlphaBits=%d", gfxbits);
	if(textbits)
	args[nargs++] = tb;
	if(gfxbits)
	args[nargs++] = gb;
	args[nargs++] = "-";
	args[nargs] = nil;

	gspid = fork();
	if(gspid == 0) {
	close(stdinout[1]);
	close(dataout[1]);
	close(errout[1]);

	/*
	* Horrible problem: we want to dup fd's 0-4 below,
	* but some of the source fd's might have those small numbers.
	* So we need to reallocate those. In order to not step on
	* anything else, we'll dup the fd's to higher ones using
	* dup(x, -1), but we need to use up the lower ones first.
	*/
	while((devnull = open("/dev/null", ORDWR)) < 5)
	;

	stdinout[0] = dup(stdinout[0], -1);
	errout[0] = dup(errout[0], -1);
	dataout[0] = dup(dataout[0], -1);

	dup(stdinout[0], 0);
	dup(errout[0], 1);
	dup(devnull, 2); /* never anything useful */
	dup(dataout[0], 3);
	dup(stdinout[0], 4);
	for(i=5; i<20; i++)
	close(i);
	exec("/bin/gs", args);
	wexits("exec");
	}
	close(stdinout[0]);
	close(errout[0]);
	close(dataout[0]);
	atexit(killgs);

	if(teegs)
	stdinout[1] = spawnreader(stdinout[1]);

	gsfd = g->gsfd = stdinout[1];
	g->gsdfd = dataout[1];
	g->gspid = gspid;

	spawnmonitor(errout[1]);
	Binit(&g->gsrd, g->gsfd, OREAD);

	gscmd(g, "/PAGEOUT (/fd/4) (w) file def\n");
	gscmd(g, "/PAGE== { PAGEOUT exch write==only PAGEOUT (\\n) writestring PAGEOUT flushfile } def\n");
	waitgs(g);

	return 0;
	}

	int
	gscmd(GSInfo gs, char fmt, ...)
	{
	char buf[1024];
	int n;

	va_list v;
	va_start(v, fmt);
	n = vseprint(buf, buf+sizeof buf, fmt, v) - buf;
	if(n <= 0)
	return n;

	if(chatty) {
	fprint(2, "cmd: ");
	write(2, buf, n);
	}

	if(write(gs->gsfd, buf, n) != 0)
	return -1;

	return n;
	}

	/*
	* set the dimensions of the bitmap we expect to get back from GS.
	*/
	void
	setdim(GSInfo *gs, Rectangle bbox, int ppi, int landscape)
	{
	Rectangle pbox;

	if(chatty)
	fprint(2, "setdim: bbox=%R\n", bbox);

	if(ppi)
	gs->ppi = ppi;

	gscmd(gs, "mark\n");
	if(ppi)
	gscmd(gs, "/HWResolution [%d %d]\n", ppi, ppi);

	if(!Dx(bbox))
	bbox = Rect(0, 0, 612, 792); /* 8½×11 */

	switch(landscape){
	case 0:
	pbox = bbox;
	break;
	case 1:
	pbox = Rect(bbox.min.y, bbox.min.x, bbox.max.y, bbox.max.x);
	break;
	}
	gscmd(gs, "/PageSize [%d %d]\n", Dx(pbox), Dy(pbox));
	gscmd(gs, "/Margins [%d %d]\n", -pbox.min.x, -pbox.min.y);
	gscmd(gs, "currentdevice putdeviceprops pop\n");
	gscmd(gs, "/#copies 1 store\n");

	if(!eqpt(bbox.min, ZP))
	gscmd(gs, "%d %d translate\n", -bbox.min.x, -bbox.min.y);

	switch(landscape){
	case 0:
	break;
	case 1:
	gscmd(gs, "%d 0 translate\n", Dy(bbox));
	gscmd(gs, "90 rotate\n");
	break;
	}

	waitgs(gs);
	}

	void
	waitgs(GSInfo *gs)
	{
	/* we figure out that gs is done by telling it to
	* print something and waiting until it does.
	*/
	char *p;
	Biobuf *b = &gs->gsrd;
	uchar buf[1024];
	int n;

	// gscmd(gs, "(\\n**bstack\\n) print flush\n");
	// gscmd(gs, "stack flush\n");
	// gscmd(gs, "(**estack\\n) print flush\n");
	gscmd(gs, "(\\n//GO.SYSIN DD\\n) PAGE==\n");

	alarm(300*1000);
	for(;;) {
	p = Brdline(b, '\n');
	if(p == nil) {
	n = Bbuffered(b);
	if(n <= 0)
	break;
	if(n > sizeof buf)
	n = sizeof buf;
	Bread(b, buf, n);
	continue;
	}
	p[Blinelen(b)-1] = 0;
	if(chatty) fprint(2, "p: ");
	if(chatty) write(2, p, Blinelen(b)-1);
	if(chatty) fprint(2, "\n");
	if(strstr(p, "Error:")) {
	alarm(0);
	fprint(2, "ghostscript error: %s\n", p);
	wexits("gs error");
	}

	if(strstr(p, "//GO.SYSIN DD")) {
	break;
	}
	}
	alarm(0);
	}