Commit ad95012

nsxivad95012

Add reuseable abstraction over fork/exec/dup2 (#211)

Author: N-R-K
Date: 2022-02-20 15:54 +0000
Committer: GitHub · 2022-02-20 15:54 +0000
Parent: 3cf4fc5
Commit: ad95012be993664e062e7724155c54a482a51315

+113 −45

3 files changed

Browse files Patch

−Context 3+

M main.c +24 −45
M nsxiv.h +13 −0
M util.c +76 −0

M main.c View

M nsxiv.h View

M util.c View

		@@ -240,29 +240,22 @@ void close_info(void)
240	240
241	241		void open_info(void)
242	242		{
243		−	int pfd[2];
	243	+	spawn_t pfd;
244	244		char w[12], h[12];
	245	+	char *argv[5];
245	246
246	247		if (info.f.err \|\| info.fd >= 0 \|\| win.bar.h == 0)
247	248		return;
248	249		win.bar.l.buf[0] = '\0';
249		−	if (pipe(pfd) < 0)
250		−	return;
251		−	if ((info.pid = fork()) == 0) {
252		−	close(pfd[0]);
253		−	dup2(pfd[1], 1);
254		−	snprintf(w, sizeof(w), "%d", img.w);
255		−	snprintf(h, sizeof(h), "%d", img.h);
256		−	execl(info.f.cmd, info.f.cmd, files[fileidx].name, w, h, NULL);
257		−	error(EXIT_FAILURE, errno, "exec: %s", info.f.cmd);
258		−	}
259		−	close(pfd[1]);
260		−	if (info.pid < 0) {
261		−	close(pfd[0]);
262		−	} else {
263		−	fcntl(pfd[0], F_SETFL, O_NONBLOCK);
264		−	info.fd = pfd[0];
	250	+	snprintf(w, sizeof(w), "%d", img.w);
	251	+	snprintf(h, sizeof(h), "%d", img.h);
	252	+	construct_argv(argv, ARRLEN(argv), info.f.cmd, files[fileidx].name, w, h, NULL);
	253	+	pfd = spawn(info.f.cmd, argv, X_READ);
	254	+	if (pfd.readfd >= 0) {
	255	+	fcntl(pfd.readfd, F_SETFL, O_NONBLOCK);
	256	+	info.fd = pfd.readfd;
265	257		info.i = info.lastsep = 0;
	258	+	info.pid = pfd.pid;
266	259		}
267	260		}
268	261
		@@ -510,15 +503,16 @@ void handle_key_handler(bool init)
510	503
511	504		static bool run_key_handler(const char *key, unsigned int mask)
512	505		{
513		−	pid_t pid;
514	506		FILE *pfs;
515	507		bool marked = mode == MODE_THUMB && markcnt > 0;
516	508		bool changed = false;
517		−	int f, i, pfd[2];
	509	+	int f, i;
518	510		int fcnt = marked ? markcnt : 1;
519	511		char kstr[32];
520	512		struct stat *oldst, st;
521	513		XEvent dump;
	514	+	char *argv[3];
	515	+	spawn_t pfd;
522	516
523	517		if (keyhandler.f.err) {
524	518		if (!keyhandler.warned) {
		@@ -530,41 +524,27 @@ static bool run_key_handler(const char *key, unsigned int mask)
530	524		if (key == NULL)
531	525		return false;
532	526
533		−	if (pipe(pfd) < 0) {
534		−	error(0, errno, "pipe");
535		−	return false;
536		−	}
537		−	if ((pfs = fdopen(pfd[1], "w")) == NULL) {
538		−	error(0, errno, "open pipe");
539		−	close(pfd[0]), close(pfd[1]);
540		−	return false;
541		−	}
542		−	oldst = emalloc(fcnt * sizeof(*oldst));
543		−
544	527		close_info();
545	528		strncpy(win.bar.l.buf, "Running key handler...", win.bar.l.size);
546	529		win_draw(&win);
547	530		win_set_cursor(&win, CURSOR_WATCH);
	531	+	setenv("NSXIV_USING_NULL", options->using_null ? "1" : "0", 1);
548	532
549	533		snprintf(kstr, sizeof(kstr), "%s%s%s%s",
550	534		mask & ControlMask ? "C-" : "",
551	535		mask & Mod1Mask ? "M-" : "",
552	536		mask & ShiftMask ? "S-" : "", key);
553		−	setenv("NSXIV_USING_NULL", options->using_null ? "1" : "0", 1);
554		−
555		−	if ((pid = fork()) == 0) {
556		−	close(pfd[1]);
557		−	dup2(pfd[0], 0);
558		−	execl(keyhandler.f.cmd, keyhandler.f.cmd, kstr, NULL);
559		−	error(EXIT_FAILURE, errno, "exec: %s", keyhandler.f.cmd);
560		−	}
561		−	close(pfd[0]);
562		−	if (pid < 0) {
563		−	error(0, errno, "fork");
564		−	fclose(pfs);
565		−	goto end;
	537	+	construct_argv(argv, ARRLEN(argv), keyhandler.f.cmd, kstr, NULL);
	538	+	pfd = spawn(keyhandler.f.cmd, argv, X_WRITE);
	539	+	if (pfd.writefd < 0)
	540	+	return false;
	541	+	if ((pfs = fdopen(pfd.writefd, "w")) == NULL) {
	542	+	close(pfd.writefd);
	543	+	error(0, errno, "open pipe");
	544	+	return false;
566	545		}
567	546
	547	+	oldst = emalloc(fcnt * sizeof(*oldst));
568	548		for (f = i = 0; f < fcnt; i++) {
569	549		if ((marked && (files[i].flags & FF_MARK)) \|\| (!marked && i == fileidx)) {
570	550		stat(files[i].path, &oldst[f]);
		@@ -573,7 +553,7 @@ static bool run_key_handler(const char *key, unsigned int mask)
573	553		}
574	554		}
575	555		fclose(pfs);
576		−	while (waitpid(pid, NULL, 0) == -1 && errno == EINTR);
	556	+	while (waitpid(pfd.pid, NULL, 0) == -1 && errno == EINTR);
577	557
578	558		for (f = i = 0; f < fcnt; i++) {
579	559		if ((marked && (files[i].flags & FF_MARK)) \|\| (!marked && i == fileidx)) {
		@@ -592,7 +572,6 @@ static bool run_key_handler(const char *key, unsigned int mask)
592	572		/* drop user input events that occurred while running the key handler */
593	573		while (XCheckIfEvent(win.env.dpy, &dump, is_input_ev, NULL));
594	574
595		−	end:
596	575		if (mode == MODE_IMAGE) {
597	576		if (changed) {
598	577		img_close(&img, true);

		@@ -342,6 +342,17 @@ typedef struct {
342	342		int stlen;
343	343		} r_dir_t;
344	344
	345	+	typedef struct {
	346	+	int readfd;
	347	+	int writefd;
	348	+	pid_t pid;
	349	+	} spawn_t;
	350	+
	351	+	enum {
	352	+	X_READ = (1 << 0),
	353	+	X_WRITE = (1 << 1)
	354	+	};
	355	+
345	356		extern const char *progname;
346	357
347	358		void* emalloc(size_t);
		@@ -353,6 +364,8 @@ int r_opendir(r_dir_t, const char, bool);
353	364		int r_closedir(r_dir_t*);
354	365		char* r_readdir(r_dir_t*, bool);
355	366		int r_mkdir(char*);
	367	+	void construct_argv(char**, unsigned int, ...);
	368	+	spawn_t spawn(const char, char const [], unsigned int);
356	369
357	370
358	371		/* window.c */

		@@ -211,3 +211,79 @@ int r_mkdir(char *path)
211	211		}
212	212		return 0;
213	213		}
	214	+
	215	+	void construct_argv(char **argv, unsigned int len, ...)
	216	+	{
	217	+	unsigned int i;
	218	+	va_list args;
	219	+
	220	+	va_start(args, len);
	221	+	for (i = 0; i < len; ++i)
	222	+	argv[i] = va_arg(args, char *);
	223	+	va_end(args);
	224	+	if (argv[len-1] != NULL)
	225	+	error(EXIT_FAILURE, 0, "argv not NULL terminated");
	226	+	}
	227	+
	228	+	spawn_t spawn(const char cmd, char const argv[], unsigned int flags)
	229	+	{
	230	+	pid_t pid;
	231	+	spawn_t status = { -1, -1, -1 };
	232	+	int pfd_read[2] = { -1, -1 };
	233	+	int pfd_write[2] = { -1, -1 };
	234	+	const bool r = flags & X_READ;
	235	+	const bool w = flags & X_WRITE;
	236	+
	237	+	if (cmd == NULL \|\| argv == NULL \|\| flags == 0)
	238	+	return status;
	239	+
	240	+	if (r && pipe(pfd_read) < 0) {
	241	+	error(0, errno, "pipe: %s", cmd);
	242	+	return status;
	243	+	}
	244	+
	245	+	if (w && pipe(pfd_write) < 0) {
	246	+	if (r) {
	247	+	close(pfd_read[0]);
	248	+	close(pfd_read[1]);
	249	+	}
	250	+	error(0, errno, "pipe: %s", cmd);
	251	+	return status;
	252	+	}
	253	+
	254	+	if ((pid = fork()) == 0) {
	255	+	bool err = (r && dup2(pfd_read[1], 1) < 0) \|\| (w && dup2(pfd_write[0], 0) < 0);
	256	+	if (r) {
	257	+	close(pfd_read[0]);
	258	+	close(pfd_read[1]);
	259	+	}
	260	+	if (w) {
	261	+	close(pfd_write[0]);
	262	+	close(pfd_write[1]);
	263	+	}
	264	+
	265	+	if (err)
	266	+	error(EXIT_FAILURE, errno, "dup2: %s", cmd);
	267	+	execv(cmd, argv);
	268	+	error(EXIT_FAILURE, errno, "exec: %s", cmd);
	269	+	}
	270	+
	271	+	if (r)
	272	+	close(pfd_read[1]);
	273	+	if (w)
	274	+	close(pfd_write[0]);
	275	+
	276	+	if (pid < 0) {
	277	+	if (r)
	278	+	close(pfd_read[0]);
	279	+	if (w)
	280	+	close(pfd_write[1]);
	281	+	error(0, errno, "fork: %s", cmd);
	282	+	return status;
	283	+	}
	284	+
	285	+	status.pid = pid;
	286	+	status.readfd = pfd_read[0];
	287	+	status.writefd = pfd_write[1];
	288	+	return status;
	289	+	}

nsxiv/ad95012

Add reuseable abstraction over fork/exec/dup2 (#211)

nsxivad95012