[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);}

#define ERRMSG "ERROR"

static const char errmsg[] = ERRMSG;
static const int  errlen   = sizeof(ERRMSG) - 1;

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':
			/* TODO: Generic set_int */
			parse_opts_opt_i(cfg, argc, argv, ++i);
			break;
		case 's':
			/* TODO: Generic set_str */
			parse_opts_opt_s(cfg, argc, argv, ++i);
			break;
		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
fifo_read_error(Fifo *f, char *buf)
{
	char *b;
	int i;

	b = buf + f->pos;
	/* Copy as much of the error message as possible.
	 * EXCLUDING the reminating \0. */
	for (i = 0; i < errlen && i < f->width; i++)
		b[i] = errmsg[i];
	/* Any remaining slots: */
	for (; i < f->width; i++)
		b[i] = '_';
}

void
fifo_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;
	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));
		fifo_read_error(f, buf);
	} else
		while (total++ < f->width)
			*b++ = ' ';
	/* TODO Record timestamp read */
	close(f->fd);
	f->fd = -1;
}

void
fifo_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) {
			error("Cannot stat \"%s\". Error: %s\n", f->name, strerror(errno));
			fifo_read_error(f, buf);
			continue;
		}
		if (!(st.st_mode & S_IFIFO)) {
			error("\"%s\" is not a FIFO\n", f->name);
			fifo_read_error(f, buf);
			continue;
		}
		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. */
			error("Failed to open \"%s\"\n", f->name);
			fifo_read_error(f, buf);
			continue;
		}
		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);
			fifo_read_one(f, buf);
		}
	}
}

int
main(int argc, char *argv[])
{
	int width  = 0;
	int nfifos = 0;
	int seplen = 0;
	int prefix = 0;
	int errors = 0;
	char *buf;
	Config cfg0 = defaults;
	Config *cfg = &cfg0;
	Display *display = NULL;
	struct stat st;

	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");

	/* 1st pass to check file existence and type */
	for (Fifo *f = cfg->fifos; f; f = f->next) {
		if (lstat(f->name, &st) < 0) {
			error("Cannot stat \"%s\". Error: %s\n", f->name, strerror(errno));
			errors++;
			continue;
		}
		if (!(st.st_mode & S_IFIFO)) {
			error("\"%s\" is not a FIFO\n", f->name);
			errors++;
			continue;
		}
	}
	if (errors)
		fatal("Encountered errors with the given file paths. See log.\n");

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

	/* 2nd 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';
	/* 3rd 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 */
	/* TODO: Handle signals */
	for (;;) {
		/* TODO: Check TTL and maybe blank-out */
		/* TODO: How to trigger TTL check? On select? Alarm signal? */
		/* TODO: Set timeout on fifo_read_all based on diff of last time of
		 *       fifo_read_all and desired time of next TTL check.
		 * */
		fifo_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
e6c523cd SK	21	#define ERRMSG "ERROR"
	22
	23	static const char errmsg[] = ERRMSG;
	24	static const int errlen = sizeof(ERRMSG) - 1;
	25
4d66492f	26	char *argv0;
9b5ebc12	27
1872c5c1 SK	28	/* TODO: Convert fifo list to fifo array. */
	29	typedef struct Fifo Fifo;
	30	struct Fifo {
4d66492f SK	31	char *name;
4d66492f SK	32	int fd;
9b5ebc12	33	int width;
4d66492f	34	int last_read;
9b5ebc12	35	int ttl;
4d66492f	36	int pos; /* Position on the output buffer. */
1872c5c1	37	Fifo *next;
9b5ebc12 SK	38	};
9b5ebc12 SK	39
4d66492f SK	40	typedef struct Config Config;
4d66492f SK	41	struct Config {
9b5ebc12	42	int interval;
4d66492f	43	char * separator;
1872c5c1 SK	44	Fifo * fifos;
1872c5c1 SK	45	int fifo_count;
4d66492f	46	int total_width;
fabb8771	47	int output_to_x_root_window;
4d66492f SK	48	} defaults = {
	49	.interval = 1,
	50	.separator = "\|",
1872c5c1 SK	51	.fifos = NULL,
1872c5c1 SK	52	.fifo_count = 0,
4d66492f	53	.total_width = 0,
fabb8771	54	.output_to_x_root_window = 0,
9b5ebc12 SK	55	};
9b5ebc12 SK	56
77c76070	57	void
1872c5c1	58	fifo_print_one(Fifo *f)
77c76070 SK	59	{
77c76070 SK	60	debug(
1872c5c1	61	"Fifo "
77c76070 SK	62	"{"
	63	" name = %s,"
	64	" fd = %d,"
	65	" width = %d,"
	66	" last_read = %d,"
	67	" ttl = %d,"
	68	" pos = %d,"
	69	" next = %p,"
	70	" }\n",
	71	f->name,
	72	f->fd,
	73	f->width,
	74	f->last_read,
	75	f->ttl,
	76	f->pos,
	77	f->next
	78	);
	79	}
	80
	81	void
1872c5c1	82	fifo_print_all(Fifo *head)
77c76070	83	{
1872c5c1 SK	84	for (Fifo *f = head; f; f = f->next) {
1872c5c1 SK	85	fifo_print_one(f);
77c76070 SK	86	}
	87	}
	88
	89	void
	90	config_print(Config *c)
	91	{
	92	debug(
	93	"Config "
	94	"{"
	95	" interval = %d,"
	96	" separator = %s,"
1872c5c1	97	" fifo_count = %d,"
77c76070	98	" total_width = %d,"
1872c5c1	99	" fifos = ..."
77c76070 SK	100	" }\n",
	101	c->interval,
	102	c->separator,
1872c5c1	103	c->fifo_count,
77c76070 SK	104	c->total_width
77c76070 SK	105	);
1872c5c1	106	fifo_print_all(c->fifos);
77c76070	107	}
9b5ebc12 SK	108
	109	int
	110	is_pos_num(char *s)
	111	{
	112	while (*s != '\0')
	113	if (!isdigit(*(s++)))
	114	return 0;
	115	return 1;
	116	}
	117
	118	void
	119	print_usage()
	120	{
4d66492f	121	assert(argv0);
9b5ebc12 SK	122	fprintf(
	123	stderr,
	124	"\n"
4d66492f	125	"Usage: %s [OPTION ...] SPEC [SPEC ...]\n"
9b5ebc12	126	"\n"
4d66492f SK	127	" SPEC = FILE_PATH DATA_WIDTH DATA_TTL\n"
	128	" FILE_PATH = string\n"
	129	" DATA_WIDTH = int (* (positive) number of characters *)\n"
	130	" DATA_TTL = int (* (positive) number of seconds *)\n"
	131	" OPTION = -i INTERVAL\n"
	132	" \| -s SEPARATOR\n"
	133	" SEPARATOR = string\n"
	134	" INTERVAL = int (* (positive) number of seconds *)\n"
9b5ebc12	135	"\n",
4d66492f	136	argv0
9b5ebc12 SK	137	);
	138	fprintf(
	139	stderr,
	140	"Example: %s -i 1 /dev/shm/khatus/khatus_sensor_x 4 10\n"
	141	"\n",
4d66492f	142	argv0
9b5ebc12 SK	143	);
	144	}
	145
4d66492f	146	void opts_parse_any(Config , int, char [], int); /* For mutually-recursive calls. */
9b5ebc12 SK	147
9b5ebc12 SK	148	void
4d66492f	149	parse_opts_opt_i(Config cfg, int argc, char argv[], int i)
9b5ebc12 SK	150	{
	151	if (i < argc) {
	152	char *param = argv[i++];
	153
	154	if (is_pos_num(param)) {
4d66492f SK	155	cfg->interval = atoi(param);
4d66492f SK	156	opts_parse_any(cfg, argc, argv, i);
9b5ebc12 SK	157	} else {
	158	usage("Option -i parameter is invalid: \"%s\"\n", param);
	159	}
	160	} else {
	161	usage("Option -i parameter is missing.\n");
	162	}
	163	}
	164
	165	void
4d66492f SK	166	parse_opts_opt_s(Config cfg, int argc, char argv[], int i)
	167	{
	168	if (i < argc) {
3c836bfd	169	cfg->separator = calloc((strlen(argv[i]) + 1), sizeof(char));
4d66492f SK	170	strcpy(cfg->separator, argv[i]);
	171	opts_parse_any(cfg, argc, argv, ++i);
	172	} else {
	173	usage("Option -s parameter is missing.\n");
	174	}
	175	}
	176
4d66492f SK	177	void
4d66492f SK	178	parse_opts_opt(Config cfg, int argc, char argv[], int i)
9b5ebc12 SK	179	{
9b5ebc12 SK	180	switch (argv[i][1]) {
fb8745ba SK	181	case 'i':
	182	/* TODO: Generic set_int */
	183	parse_opts_opt_i(cfg, argc, argv, ++i);
	184	break;
	185	case 's':
	186	/* TODO: Generic set_str */
	187	parse_opts_opt_s(cfg, argc, argv, ++i);
	188	break;
	189	case 'x':
fabb8771 SK	190	cfg->output_to_x_root_window = 1;
	191	opts_parse_any(cfg, argc, argv, ++i);
	192	break;
fb8745ba SK	193	default :
fb8745ba SK	194	usage("Option \"%s\" is invalid\n", argv[i]);
9b5ebc12 SK	195	}
	196	}
	197
	198	void
4d66492f	199	parse_opts_spec(Config cfg, int argc, char argv[], int i)
9b5ebc12 SK	200	{
9b5ebc12 SK	201	if ((i + 3) > argc)
1872c5c1	202	usage("[spec] Parameter(s) missing for fifo \"%s\".\n", argv[i]);
9b5ebc12 SK	203
	204	char *n = argv[i++];
	205	char *w = argv[i++];
	206	char *t = argv[i++];
	207
	208	if (!is_pos_num(w))
1872c5c1	209	usage("[spec] Invalid width: \"%s\", for fifo \"%s\"\n", w, n);
9b5ebc12	210	if (!is_pos_num(t))
1872c5c1 SK	211	usage("[spec] Invalid TTL: \"%s\", for fifo \"%s\"\n", t, n);
1872c5c1 SK	212	Fifo *f = calloc(1, sizeof(struct Fifo));
9b5ebc12	213	if (f) {
4d66492f SK	214	f->name = n;
	215	f->fd = -1;
	216	f->width = atoi(w);
	217	f->ttl = atoi(t);
	218	f->last_read = 0;
	219	f->pos = cfg->total_width;
1872c5c1	220	f->next = cfg->fifos;
4d66492f	221
1872c5c1	222	cfg->fifos = f;
4d66492f	223	cfg->total_width += f->width;
1872c5c1	224	cfg->fifo_count++;
9b5ebc12	225	} else {
4d66492f	226	fatal("[memory] Allocation failure.");
9b5ebc12	227	}
4d66492f	228	opts_parse_any(cfg, argc, argv, i);
9b5ebc12 SK	229	}
	230
	231	void
4d66492f	232	opts_parse_any(Config cfg, int argc, char argv[], int i)
9b5ebc12 SK	233	{
	234	if (i < argc) {
	235	switch (argv[i][0]) {
fb8745ba SK	236	case '-':
	237	parse_opts_opt(cfg, argc, argv, i);
	238	break;
	239	default :
	240	parse_opts_spec(cfg, argc, argv, i);
4d66492f SK	241	}
	242	}
	243	}
	244
	245	void
5400b86f	246	opts_parse(Config cfg, int argc, char argv[])
4d66492f SK	247	{
	248	opts_parse_any(cfg, argc, argv, 1);
	249
1872c5c1 SK	250	Fifo *last = cfg->fifos;
	251	cfg->fifos = NULL;
	252	for (Fifo *f = last; f; ) {
	253	Fifo *next = f->next;
	254	f->next = cfg->fifos;
	255	cfg->fifos = f;
4d66492f SK	256	f = next;
	257	}
	258	}
	259
e6c523cd	260	void
69b75a40	261	fifo_read_error(Fifo f, char buf)
e6c523cd SK	262	{
	263	char *b;
	264	int i;
	265
	266	b = buf + f->pos;
	267	/* Copy as much of the error message as possible.
	268	* EXCLUDING the reminating \0. */
	269	for (i = 0; i < errlen && i < f->width; i++)
	270	b[i] = errmsg[i];
	271	/* Any remaining slots: */
	272	for (; i < f->width; i++)
	273	b[i] = '_';
	274	}
	275
77c76070	276	void
69b75a40	277	fifo_read_one(Fifo f, char buf)
77c76070	278	{
3efcce25 SK	279	ssize_t current;
3efcce25 SK	280	ssize_t total;
77c76070	281	char *b;
3efcce25	282	char c;
77c76070	283
3efcce25 SK	284	current = 0;
	285	total = 0;
	286	c = '\0';
77c76070	287	b = buf + f->pos;
3efcce25 SK	288	while ((current = read(f->fd, &c, 1)) && c != '\n' && c != '\0' && total++ < f->width)
3efcce25 SK	289	*b++ = c;
e6c523cd	290	if (current == -1) {
3efcce25	291	error("Failed to read: \"%s\". Error: %s\n", f->name, strerror(errno));
69b75a40	292	fifo_read_error(f, buf);
7fb02106 SK	293	} else
	294	while (total++ < f->width)
	295	*b++ = ' ';
6c29392d	296	/* TODO Record timestamp read */
77c76070 SK	297	close(f->fd);
	298	f->fd = -1;
	299	}
	300
4d66492f	301	void
69b75a40	302	fifo_read_all(Config cfg, char buf)
4d66492f	303	{
77c76070	304	fd_set fds;
bfab34f8	305	int maxfd = -1;
77c76070	306	int ready;
bec93767	307	struct stat st;
77c76070 SK	308
77c76070 SK	309	FD_ZERO(&fds);
bec93767	310	/* TODO: Check TTL */
1872c5c1	311	for (Fifo *f = cfg->fifos; f; f = f->next) {
bec93767	312	/* TODO: Create the FIFO if it doesn't already exist. */
e6c523cd SK	313	if (lstat(f->name, &st) < 0) {
e6c523cd SK	314	error("Cannot stat \"%s\". Error: %s\n", f->name, strerror(errno));
69b75a40	315	fifo_read_error(f, buf);
e6c523cd SK	316	continue;
	317	}
	318	if (!(st.st_mode & S_IFIFO)) {
	319	error("\"%s\" is not a FIFO\n", f->name);
69b75a40	320	fifo_read_error(f, buf);
e6c523cd SK	321	continue;
e6c523cd SK	322	}
77c76070	323	debug("opening: %s\n", f->name);
4d66492f	324	if (f->fd < 0)
77c76070	325	f->fd = open(f->name, O_RDONLY \| O_NONBLOCK);
e6c523cd	326	if (f->fd == -1) {
1872c5c1	327	/* TODO: Consider backing off retries for failed fifos. */
e6c523cd	328	error("Failed to open \"%s\"\n", f->name);
69b75a40	329	fifo_read_error(f, buf);
e6c523cd SK	330	continue;
e6c523cd SK	331	}
77c76070 SK	332	if (f->fd > maxfd)
	333	maxfd = f->fd;
	334	FD_SET(f->fd, &fds);
	335	}
	336	debug("selecting...\n");
	337	ready = select(maxfd + 1, &fds, NULL, NULL, NULL);
	338	debug("ready: %d\n", ready);
	339	assert(ready != 0);
	340	if (ready < 0)
	341	fatal("%s", strerror(errno));
1872c5c1	342	for (Fifo *f = cfg->fifos; f; f = f->next) {
77c76070 SK	343	if (FD_ISSET(f->fd, &fds)) {
77c76070 SK	344	debug("reading: %s\n", f->name);
69b75a40	345	fifo_read_one(f, buf);
9b5ebc12 SK	346	}
	347	}
	348	}
	349
	350	int
4d66492f	351	main(int argc, char *argv[])
9b5ebc12	352	{
f277f405	353	int width = 0;
1872c5c1	354	int nfifos = 0;
f277f405	355	int seplen = 0;
4d66492f	356	int prefix = 0;
e6c523cd	357	int errors = 0;
4d66492f	358	char *buf;
a6d4c9c3 SK	359	Config cfg0 = defaults;
a6d4c9c3 SK	360	Config *cfg = &cfg0;
bfab34f8	361	Display *display = NULL;
e6c523cd	362	struct stat st;
4d66492f SK	363
	364	argv0 = argv[0];
	365
5400b86f	366	opts_parse(cfg, argc, argv);
4d66492f	367	debug("argv0 = %s\n", argv0);
77c76070	368	config_print(cfg);
1872c5c1 SK	369	if (cfg->fifos == NULL)
1872c5c1 SK	370	usage("No fifo specs were given!\n");
4d66492f	371
e6c523cd SK	372	/* 1st pass to check file existence and type */
	373	for (Fifo *f = cfg->fifos; f; f = f->next) {
	374	if (lstat(f->name, &st) < 0) {
	375	error("Cannot stat \"%s\". Error: %s\n", f->name, strerror(errno));
	376	errors++;
	377	continue;
	378	}
	379	if (!(st.st_mode & S_IFIFO)) {
	380	error("\"%s\" is not a FIFO\n", f->name);
	381	errors++;
	382	continue;
	383	}
	384	}
	385	if (errors)
	386	fatal("Encountered errors with the given file paths. See log.\n");
	387
4d66492f SK	388	width = cfg->total_width;
	389	seplen = strlen(cfg->separator);
	390
e6c523cd	391	/* 2nd pass to make space for separators */
1872c5c1	392	for (Fifo *f = cfg->fifos; f; f = f->next) {
4d66492f SK	393	f->pos += prefix;
4d66492f SK	394	prefix += seplen;
1872c5c1	395	nfifos++;
4d66492f	396	}
1872c5c1	397	width += (seplen * (nfifos - 1));
3c836bfd	398	buf = calloc(1, width + 1);
4d66492f SK	399	if (buf == NULL)
	400	fatal("[memory] Failed to allocate buffer of %d bytes", width);
	401	memset(buf, ' ', width);
	402	buf[width] = '\0';
e6c523cd	403	/* 3rd pass to set the separators */
1872c5c1	404	for (Fifo *f = cfg->fifos; f; f = f->next) {
4d66492f	405	if (f->pos) { /* Skip the first, left-most */
77c76070 SK	406	/* Copying only seplen ensures we omit the '\0' byte. */
77c76070 SK	407	strncpy(buf + (f->pos - seplen), cfg->separator, seplen);
4d66492f SK	408	}
	409	}
	410
fabb8771 SK	411	if (cfg->output_to_x_root_window && !(display = XOpenDisplay(NULL)))
fabb8771 SK	412	fatal("XOpenDisplay failed with: %p\n", display);
4d66492f	413	/* TODO: nanosleep and nano time diff */
805f0d22	414	/* TODO: Handle signals */
4d66492f	415	for (;;) {
6c29392d SK	416	/* TODO: Check TTL and maybe blank-out */
6c29392d SK	417	/* TODO: How to trigger TTL check? On select? Alarm signal? */
69b75a40 SK	418	/* TODO: Set timeout on fifo_read_all based on diff of last time of
69b75a40 SK	419	* fifo_read_all and desired time of next TTL check.
fabb8771	420	* */
69b75a40	421	fifo_read_all(cfg, buf);
fabb8771 SK	422	if (cfg->output_to_x_root_window) {
	423	if (XStoreName(display, DefaultRootWindow(display), buf) < 0)
	424	fatal("XStoreName failed.\n");
	425	XFlush(display);
	426	} else {
	427	puts(buf);
	428	fflush(stdout);
	429	}
4d66492f	430	}
3d7e82a8 SK	431
3d7e82a8 SK	432	return EXIT_SUCCESS;
9b5ebc12	433	}