[khatus.git] / x5 / khatus.c

#include <sys/select.h>
#include <sys/stat.h>

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <X11/Xlib.h>

#define debug(args...) {fprintf(stderr, "[debug] " args);}
#define info( args...) {fprintf(stderr, "[info] "  args);}
#define error(args...) {fprintf(stderr, "[error] " args);}
#define fatal(args...) {fprintf(stderr, "[fatal] " args); exit(EXIT_FAILURE);}
#define usage(args...) {print_usage(); fatal("[usage] " args);}

char *argv0;

/* TODO: Convert fifo list to fifo array. */
typedef struct Fifo Fifo;
struct Fifo {
	char   *name;
	int     fd;
	int     width;
	int     last_read;
	int     ttl;
	int     pos;  /* Position on the output buffer. */
	Fifo   *next;
};

typedef struct Config Config;
struct Config {
	int    interval;
	char * separator;
	Fifo * fifos;
	int    fifo_count;
	int    total_width;
	int    output_to_x_root_window;
} defaults = {
	.interval    = 1,
	.separator   = "|",
	.fifos       = NULL,
	.fifo_count  = 0,
	.total_width = 0,
	.output_to_x_root_window = 0,
};

void
fifo_print_one(Fifo *f)
{
	debug(
		"Fifo "
		"{"
			" name = %s,"
			" fd = %d,"
			" width = %d,"
			" last_read = %d,"
			" ttl = %d,"
			" pos = %d,"
			" next = %p,"
		" }\n",
		f->name,
		f->fd,
		f->width,
		f->last_read,
		f->ttl,
		f->pos,
		f->next
	);
}

void
fifo_print_all(Fifo *head)
{
	for (Fifo *f = head; f; f = f->next) {
		fifo_print_one(f);
	}
}

void
config_print(Config *c)
{
	debug(
		"Config "
		"{"
			" interval = %d,"
			" separator = %s,"
			" fifo_count = %d,"
			" total_width = %d,"
			" fifos = ..."
		" }\n",
		c->interval,
		c->separator,
		c->fifo_count,
		c->total_width
	);
	fifo_print_all(c->fifos);
}

int
is_pos_num(char *s)
{
	while (*s != '\0')
		if (!isdigit(*(s++)))
			return 0;
	return 1;
}

void
print_usage()
{
	assert(argv0);
	fprintf(
		stderr,
		"\n"
		"Usage: %s [OPTION ...] SPEC [SPEC ...]\n"
		"\n"
		"  SPEC       = FILE_PATH DATA_WIDTH DATA_TTL\n"
		"  FILE_PATH  = string\n"
		"  DATA_WIDTH = int  (* (positive) number of characters *)\n"
		"  DATA_TTL   = int  (* (positive) number of seconds *)\n"
		"  OPTION     = -i INTERVAL\n"
		"             | -s SEPARATOR\n"
		"  SEPARATOR  = string\n"
		"  INTERVAL   = int  (* (positive) number of seconds *)\n"
		"\n",
		argv0
	);
	fprintf(
		stderr,
		"Example: %s -i 1 /dev/shm/khatus/khatus_sensor_x 4 10\n"
		"\n",
		argv0
	);
}

void opts_parse_any(Config *, int, char *[], int);  /* For mutually-recursive calls. */

void
parse_opts_opt_i(Config *cfg, int argc, char *argv[], int i)
{
	if (i < argc) {
		char *param = argv[i++];

		if (is_pos_num(param)) {
			cfg->interval = atoi(param);
			opts_parse_any(cfg, argc, argv, i);
		} else {
			usage("Option -i parameter is invalid: \"%s\"\n", param);
		}
	} else {
		usage("Option -i parameter is missing.\n");
	}
}

void
parse_opts_opt_s(Config *cfg, int argc, char *argv[], int i)
{
	if (i < argc) {
		cfg->separator = calloc((strlen(argv[i]) + 1), sizeof(char));
		strcpy(cfg->separator, argv[i]);
		opts_parse_any(cfg, argc, argv, ++i);
	} else {
		usage("Option -s parameter is missing.\n");
	}
}

void
parse_opts_opt(Config *cfg, int argc, char *argv[], int i)
{
	switch (argv[i][1]) {
		case 'i': parse_opts_opt_i(cfg, argc, argv, ++i); break;  /* TODO: Generic set_int */
		case 's': parse_opts_opt_s(cfg, argc, argv, ++i); break;  /* TODO: Generic set_str */
		case 'x': {
			cfg->output_to_x_root_window = 1;
			opts_parse_any(cfg, argc, argv, ++i);
			break;
		}
		default : usage("Option \"%s\" is invalid\n", argv[i]);
	}
}

void
parse_opts_spec(Config *cfg, int argc, char *argv[], int i)
{
	if ((i + 3) > argc)
		usage("[spec] Parameter(s) missing for fifo \"%s\".\n", argv[i]);

	char *n = argv[i++];
	char *w = argv[i++];
	char *t = argv[i++];

	if (!is_pos_num(w))
		usage("[spec] Invalid width: \"%s\", for fifo \"%s\"\n", w, n);
	if (!is_pos_num(t))
		usage("[spec] Invalid TTL: \"%s\", for fifo \"%s\"\n", t, n);
	Fifo *f = calloc(1, sizeof(struct Fifo));
	if (f) {
		f->name      = n;
		f->fd        = -1;
		f->width     = atoi(w);
		f->ttl       = atoi(t);
		f->last_read = 0;
		f->pos       = cfg->total_width;
		f->next      = cfg->fifos;

		cfg->fifos        = f;
		cfg->total_width += f->width;
		cfg->fifo_count++;
	} else {
		fatal("[memory] Allocation failure.");
	}
	opts_parse_any(cfg, argc, argv, i);
}

void
opts_parse_any(Config *cfg, int argc, char *argv[], int i)
{
	if (i < argc) {
		switch (argv[i][0]) {
			case '-': parse_opts_opt(cfg, argc, argv, i); break;
			default : parse_opts_spec(cfg, argc, argv, i);
		}
	}
}

void
opts_parse(Config *cfg, int argc, char *argv[])
{
	opts_parse_any(cfg, argc, argv, 1);

	Fifo *last = cfg->fifos;
	cfg->fifos = NULL;
	for (Fifo *f = last; f; ) {
		Fifo *next = f->next;
		f->next = cfg->fifos;
		cfg->fifos = f;
		f = next;
	}
}

void
read_one(Fifo *f, char *buf)
{
	ssize_t current;
	ssize_t total;
	char *b;
	char c;

	current = 0;
	total = 0;
	c = '\0';
	b = buf + f->pos;
	memset(b, ' ', f->width);
	while ((current = read(f->fd, &c, 1)) && c != '\n' && c != '\0' && total++ < f->width)
		*b++ = c;
	if (current == -1)
		error("Failed to read: \"%s\". Error: %s\n", f->name, strerror(errno));
	/* TODO Record timestamp read */
	close(f->fd);
	f->fd = -1;
}

void
read_all(Config *cfg, char *buf)
{
	fd_set fds;
	int maxfd = -1;
	int ready;
	struct stat st;

	FD_ZERO(&fds);
	/* TODO: Check TTL */
	for (Fifo *f = cfg->fifos; f; f = f->next) {
		/* TODO: Create the FIFO if it doesn't already exist. */
		if (lstat(f->name, &st) < 0)
			fatal("Cannot stat \"%s\". Error: %s\n", f->name, strerror(errno));
		if (!(st.st_mode & S_IFIFO))
			fatal("\"%s\" is not a FIFO\n", f->name);
		debug("opening: %s\n", f->name);
		if (f->fd < 0)
			f->fd = open(f->name, O_RDONLY | O_NONBLOCK);
		if (f->fd == -1)
			/* TODO: Consider backing off retries for failed fifos. */
			fatal("Failed to open \"%s\"\n", f->name);
		if (f->fd > maxfd)
			maxfd = f->fd;
		FD_SET(f->fd, &fds);
	}
	debug("selecting...\n");
	ready = select(maxfd + 1, &fds, NULL, NULL, NULL);
	debug("ready: %d\n", ready);
	assert(ready != 0);
	if (ready < 0)
		fatal("%s", strerror(errno));
	for (Fifo *f = cfg->fifos; f; f = f->next) {
		if (FD_ISSET(f->fd, &fds)) {
			debug("reading: %s\n", f->name);
			read_one(f, buf);
		}
	}
}

int
main(int argc, char *argv[])
{
	int width;
	int nfifos = 0;
	int seplen;
	int prefix = 0;
	char *buf;
	Config *cfg = &defaults;
	Display *display = NULL;

	argv0 = argv[0];

	opts_parse(cfg, argc, argv);
	debug("argv0 = %s\n", argv0);
	config_print(cfg);
	if (cfg->fifos == NULL)
		usage("No fifo specs were given!\n");

	width  = cfg->total_width;
	seplen = strlen(cfg->separator);

	/* 1st pass to make space for separators */
	for (Fifo *f = cfg->fifos; f; f = f->next) {
		f->pos += prefix;
		prefix += seplen;
		nfifos++;
	}
	width += (seplen * (nfifos - 1));
	buf = calloc(1, width + 1);
	if (buf == NULL)
		fatal("[memory] Failed to allocate buffer of %d bytes", width);
	memset(buf, ' ', width);
	buf[width] = '\0';
	/* 2nd pass to set the separators */
	for (Fifo *f = cfg->fifos; f; f = f->next) {
		if (f->pos) {  /* Skip the first, left-most */
			/* Copying only seplen ensures we omit the '\0' byte. */
			strncpy(buf + (f->pos - seplen), cfg->separator, seplen);
		}
	}

	if (cfg->output_to_x_root_window && !(display = XOpenDisplay(NULL)))
		fatal("XOpenDisplay failed with: %p\n", display);
	/* TODO: nanosleep and nano time diff */
	for (;;) {
		/* TODO: Check TTL and maybe blank-out */
		/* TODO: How to trigger TTL check? On select? Alarm signal? */
		/* TODO: Set timeout on read_all based on diff of last time of
		 *       read_all and desired time of next TTL check.
		 * */
		read_all(cfg, buf);
		if (cfg->output_to_x_root_window) {
			if (XStoreName(display, DefaultRootWindow(display), buf) < 0)
				fatal("XStoreName failed.\n");
			XFlush(display);
		} else {
			puts(buf);
			fflush(stdout);
		}
	}

	return EXIT_SUCCESS;
}
Commit	Line	Data
77c76070	1	#include <sys/select.h>
bec93767	2	#include <sys/stat.h>
4d66492f	3
9b5ebc12 SK	4	#include <assert.h>
9b5ebc12 SK	5	#include <ctype.h>
77c76070	6	#include <errno.h>
c5d1af8c	7	#include <fcntl.h>
9b5ebc12 SK	8	#include <stdio.h>
	9	#include <stdlib.h>
	10	#include <string.h>
c5d1af8c SK	11	#include <unistd.h>
	12
	13	#include <X11/Xlib.h>
9b5ebc12	14
4d66492f SK	15	#define debug(args...) {fprintf(stderr, "[debug] " args);}
	16	#define info( args...) {fprintf(stderr, "[info] " args);}
	17	#define error(args...) {fprintf(stderr, "[error] " args);}
	18	#define fatal(args...) {fprintf(stderr, "[fatal] " args); exit(EXIT_FAILURE);}
	19	#define usage(args...) {print_usage(); fatal("[usage] " args);}
9b5ebc12	20
4d66492f	21	char *argv0;
9b5ebc12	22
1872c5c1 SK	23	/* TODO: Convert fifo list to fifo array. */
	24	typedef struct Fifo Fifo;
	25	struct Fifo {
4d66492f SK	26	char *name;
4d66492f SK	27	int fd;
9b5ebc12	28	int width;
4d66492f	29	int last_read;
9b5ebc12	30	int ttl;
4d66492f	31	int pos; /* Position on the output buffer. */
1872c5c1	32	Fifo *next;
9b5ebc12 SK	33	};
9b5ebc12 SK	34
4d66492f SK	35	typedef struct Config Config;
4d66492f SK	36	struct Config {
9b5ebc12	37	int interval;
4d66492f	38	char * separator;
1872c5c1 SK	39	Fifo * fifos;
1872c5c1 SK	40	int fifo_count;
4d66492f	41	int total_width;
fabb8771	42	int output_to_x_root_window;
4d66492f SK	43	} defaults = {
	44	.interval = 1,
	45	.separator = "\|",
1872c5c1 SK	46	.fifos = NULL,
1872c5c1 SK	47	.fifo_count = 0,
4d66492f	48	.total_width = 0,
fabb8771	49	.output_to_x_root_window = 0,
9b5ebc12 SK	50	};
9b5ebc12 SK	51
77c76070	52	void
1872c5c1	53	fifo_print_one(Fifo *f)
77c76070 SK	54	{
77c76070 SK	55	debug(
1872c5c1	56	"Fifo "
77c76070 SK	57	"{"
	58	" name = %s,"
	59	" fd = %d,"
	60	" width = %d,"
	61	" last_read = %d,"
	62	" ttl = %d,"
	63	" pos = %d,"
	64	" next = %p,"
	65	" }\n",
	66	f->name,
	67	f->fd,
	68	f->width,
	69	f->last_read,
	70	f->ttl,
	71	f->pos,
	72	f->next
	73	);
	74	}
	75
	76	void
1872c5c1	77	fifo_print_all(Fifo *head)
77c76070	78	{
1872c5c1 SK	79	for (Fifo *f = head; f; f = f->next) {
1872c5c1 SK	80	fifo_print_one(f);
77c76070 SK	81	}
	82	}
	83
	84	void
	85	config_print(Config *c)
	86	{
	87	debug(
	88	"Config "
	89	"{"
	90	" interval = %d,"
	91	" separator = %s,"
1872c5c1	92	" fifo_count = %d,"
77c76070	93	" total_width = %d,"
1872c5c1	94	" fifos = ..."
77c76070 SK	95	" }\n",
	96	c->interval,
	97	c->separator,
1872c5c1	98	c->fifo_count,
77c76070 SK	99	c->total_width
77c76070 SK	100	);
1872c5c1	101	fifo_print_all(c->fifos);
77c76070	102	}
9b5ebc12 SK	103
	104	int
	105	is_pos_num(char *s)
	106	{
	107	while (*s != '\0')
	108	if (!isdigit(*(s++)))
	109	return 0;
	110	return 1;
	111	}
	112
	113	void
	114	print_usage()
	115	{
4d66492f	116	assert(argv0);
9b5ebc12 SK	117	fprintf(
	118	stderr,
	119	"\n"
4d66492f	120	"Usage: %s [OPTION ...] SPEC [SPEC ...]\n"
9b5ebc12	121	"\n"
4d66492f SK	122	" SPEC = FILE_PATH DATA_WIDTH DATA_TTL\n"
	123	" FILE_PATH = string\n"
	124	" DATA_WIDTH = int (* (positive) number of characters *)\n"
	125	" DATA_TTL = int (* (positive) number of seconds *)\n"
	126	" OPTION = -i INTERVAL\n"
	127	" \| -s SEPARATOR\n"
	128	" SEPARATOR = string\n"
	129	" INTERVAL = int (* (positive) number of seconds *)\n"
9b5ebc12	130	"\n",
4d66492f	131	argv0
9b5ebc12 SK	132	);
	133	fprintf(
	134	stderr,
	135	"Example: %s -i 1 /dev/shm/khatus/khatus_sensor_x 4 10\n"
	136	"\n",
4d66492f	137	argv0
9b5ebc12 SK	138	);
	139	}
	140
4d66492f	141	void opts_parse_any(Config , int, char [], int); /* For mutually-recursive calls. */
9b5ebc12 SK	142
9b5ebc12 SK	143	void
4d66492f	144	parse_opts_opt_i(Config cfg, int argc, char argv[], int i)
9b5ebc12 SK	145	{
	146	if (i < argc) {
	147	char *param = argv[i++];
	148
	149	if (is_pos_num(param)) {
4d66492f SK	150	cfg->interval = atoi(param);
4d66492f SK	151	opts_parse_any(cfg, argc, argv, i);
9b5ebc12 SK	152	} else {
	153	usage("Option -i parameter is invalid: \"%s\"\n", param);
	154	}
	155	} else {
	156	usage("Option -i parameter is missing.\n");
	157	}
	158	}
	159
	160	void
4d66492f SK	161	parse_opts_opt_s(Config cfg, int argc, char argv[], int i)
	162	{
	163	if (i < argc) {
3c836bfd	164	cfg->separator = calloc((strlen(argv[i]) + 1), sizeof(char));
4d66492f SK	165	strcpy(cfg->separator, argv[i]);
	166	opts_parse_any(cfg, argc, argv, ++i);
	167	} else {
	168	usage("Option -s parameter is missing.\n");
	169	}
	170	}
	171
4d66492f SK	172	void
4d66492f SK	173	parse_opts_opt(Config cfg, int argc, char argv[], int i)
9b5ebc12 SK	174	{
9b5ebc12 SK	175	switch (argv[i][1]) {
4d66492f SK	176	case 'i': parse_opts_opt_i(cfg, argc, argv, ++i); break; /* TODO: Generic set_int */
4d66492f SK	177	case 's': parse_opts_opt_s(cfg, argc, argv, ++i); break; /* TODO: Generic set_str */
fabb8771 SK	178	case 'x': {
	179	cfg->output_to_x_root_window = 1;
	180	opts_parse_any(cfg, argc, argv, ++i);
	181	break;
	182	}
9b5ebc12 SK	183	default : usage("Option \"%s\" is invalid\n", argv[i]);
	184	}
	185	}
	186
	187	void
4d66492f	188	parse_opts_spec(Config cfg, int argc, char argv[], int i)
9b5ebc12 SK	189	{
9b5ebc12 SK	190	if ((i + 3) > argc)
1872c5c1	191	usage("[spec] Parameter(s) missing for fifo \"%s\".\n", argv[i]);
9b5ebc12 SK	192
	193	char *n = argv[i++];
	194	char *w = argv[i++];
	195	char *t = argv[i++];
	196
	197	if (!is_pos_num(w))
1872c5c1	198	usage("[spec] Invalid width: \"%s\", for fifo \"%s\"\n", w, n);
9b5ebc12	199	if (!is_pos_num(t))
1872c5c1 SK	200	usage("[spec] Invalid TTL: \"%s\", for fifo \"%s\"\n", t, n);
1872c5c1 SK	201	Fifo *f = calloc(1, sizeof(struct Fifo));
9b5ebc12	202	if (f) {
4d66492f SK	203	f->name = n;
	204	f->fd = -1;
	205	f->width = atoi(w);
	206	f->ttl = atoi(t);
	207	f->last_read = 0;
	208	f->pos = cfg->total_width;
1872c5c1	209	f->next = cfg->fifos;
4d66492f	210
1872c5c1	211	cfg->fifos = f;
4d66492f	212	cfg->total_width += f->width;
1872c5c1	213	cfg->fifo_count++;
9b5ebc12	214	} else {
4d66492f	215	fatal("[memory] Allocation failure.");
9b5ebc12	216	}
4d66492f	217	opts_parse_any(cfg, argc, argv, i);
9b5ebc12 SK	218	}
	219
	220	void
4d66492f	221	opts_parse_any(Config cfg, int argc, char argv[], int i)
9b5ebc12 SK	222	{
	223	if (i < argc) {
	224	switch (argv[i][0]) {
4d66492f SK	225	case '-': parse_opts_opt(cfg, argc, argv, i); break;
	226	default : parse_opts_spec(cfg, argc, argv, i);
	227	}
	228	}
	229	}
	230
	231	void
5400b86f	232	opts_parse(Config cfg, int argc, char argv[])
4d66492f SK	233	{
	234	opts_parse_any(cfg, argc, argv, 1);
	235
1872c5c1 SK	236	Fifo *last = cfg->fifos;
	237	cfg->fifos = NULL;
	238	for (Fifo *f = last; f; ) {
	239	Fifo *next = f->next;
	240	f->next = cfg->fifos;
	241	cfg->fifos = f;
4d66492f SK	242	f = next;
	243	}
	244	}
	245
77c76070	246	void
1872c5c1	247	read_one(Fifo f, char buf)
77c76070	248	{
3efcce25 SK	249	ssize_t current;
3efcce25 SK	250	ssize_t total;
77c76070	251	char *b;
3efcce25	252	char c;
77c76070	253
3efcce25 SK	254	current = 0;
	255	total = 0;
	256	c = '\0';
77c76070 SK	257	b = buf + f->pos;
77c76070 SK	258	memset(b, ' ', f->width);
3efcce25 SK	259	while ((current = read(f->fd, &c, 1)) && c != '\n' && c != '\0' && total++ < f->width)
	260	*b++ = c;
	261	if (current == -1)
	262	error("Failed to read: \"%s\". Error: %s\n", f->name, strerror(errno));
6c29392d	263	/* TODO Record timestamp read */
77c76070 SK	264	close(f->fd);
	265	f->fd = -1;
	266	}
	267
4d66492f SK	268	void
	269	read_all(Config cfg, char buf)
	270	{
77c76070	271	fd_set fds;
bfab34f8	272	int maxfd = -1;
77c76070	273	int ready;
bec93767	274	struct stat st;
77c76070 SK	275
77c76070 SK	276	FD_ZERO(&fds);
bec93767	277	/* TODO: Check TTL */
1872c5c1	278	for (Fifo *f = cfg->fifos; f; f = f->next) {
bec93767 SK	279	/* TODO: Create the FIFO if it doesn't already exist. */
	280	if (lstat(f->name, &st) < 0)
	281	fatal("Cannot stat \"%s\". Error: %s\n", f->name, strerror(errno));
	282	if (!(st.st_mode & S_IFIFO))
	283	fatal("\"%s\" is not a FIFO\n", f->name);
77c76070	284	debug("opening: %s\n", f->name);
4d66492f	285	if (f->fd < 0)
77c76070 SK	286	f->fd = open(f->name, O_RDONLY \| O_NONBLOCK);
77c76070 SK	287	if (f->fd == -1)
1872c5c1	288	/* TODO: Consider backing off retries for failed fifos. */
4d66492f	289	fatal("Failed to open \"%s\"\n", f->name);
77c76070 SK	290	if (f->fd > maxfd)
	291	maxfd = f->fd;
	292	FD_SET(f->fd, &fds);
	293	}
	294	debug("selecting...\n");
	295	ready = select(maxfd + 1, &fds, NULL, NULL, NULL);
	296	debug("ready: %d\n", ready);
	297	assert(ready != 0);
	298	if (ready < 0)
	299	fatal("%s", strerror(errno));
1872c5c1	300	for (Fifo *f = cfg->fifos; f; f = f->next) {
77c76070 SK	301	if (FD_ISSET(f->fd, &fds)) {
	302	debug("reading: %s\n", f->name);
	303	read_one(f, buf);
9b5ebc12 SK	304	}
	305	}
	306	}
	307
	308	int
4d66492f	309	main(int argc, char *argv[])
9b5ebc12	310	{
4d66492f	311	int width;
1872c5c1	312	int nfifos = 0;
4d66492f SK	313	int seplen;
	314	int prefix = 0;
	315	char *buf;
	316	Config *cfg = &defaults;
bfab34f8	317	Display *display = NULL;
4d66492f SK	318
	319	argv0 = argv[0];
	320
5400b86f	321	opts_parse(cfg, argc, argv);
4d66492f	322	debug("argv0 = %s\n", argv0);
77c76070	323	config_print(cfg);
1872c5c1 SK	324	if (cfg->fifos == NULL)
1872c5c1 SK	325	usage("No fifo specs were given!\n");
4d66492f SK	326
	327	width = cfg->total_width;
	328	seplen = strlen(cfg->separator);
	329
	330	/* 1st pass to make space for separators */
1872c5c1	331	for (Fifo *f = cfg->fifos; f; f = f->next) {
4d66492f SK	332	f->pos += prefix;
4d66492f SK	333	prefix += seplen;
1872c5c1	334	nfifos++;
4d66492f	335	}
1872c5c1	336	width += (seplen * (nfifos - 1));
3c836bfd	337	buf = calloc(1, width + 1);
4d66492f SK	338	if (buf == NULL)
	339	fatal("[memory] Failed to allocate buffer of %d bytes", width);
	340	memset(buf, ' ', width);
	341	buf[width] = '\0';
	342	/* 2nd pass to set the separators */
1872c5c1	343	for (Fifo *f = cfg->fifos; f; f = f->next) {
4d66492f	344	if (f->pos) { /* Skip the first, left-most */
77c76070 SK	345	/* Copying only seplen ensures we omit the '\0' byte. */
77c76070 SK	346	strncpy(buf + (f->pos - seplen), cfg->separator, seplen);
4d66492f SK	347	}
	348	}
	349
fabb8771 SK	350	if (cfg->output_to_x_root_window && !(display = XOpenDisplay(NULL)))
fabb8771 SK	351	fatal("XOpenDisplay failed with: %p\n", display);
4d66492f SK	352	/* TODO: nanosleep and nano time diff */
4d66492f SK	353	for (;;) {
6c29392d SK	354	/* TODO: Check TTL and maybe blank-out */
6c29392d SK	355	/* TODO: How to trigger TTL check? On select? Alarm signal? */
fabb8771 SK	356	/* TODO: Set timeout on read_all based on diff of last time of
	357	* read_all and desired time of next TTL check.
	358	* */
4d66492f	359	read_all(cfg, buf);
fabb8771 SK	360	if (cfg->output_to_x_root_window) {
	361	if (XStoreName(display, DefaultRootWindow(display), buf) < 0)
	362	fatal("XStoreName failed.\n");
	363	XFlush(display);
	364	} else {
	365	puts(buf);
	366	fflush(stdout);
	367	}
4d66492f	368	}
3d7e82a8 SK	369
3d7e82a8 SK	370	return EXIT_SUCCESS;
9b5ebc12	371	}