[khatus.git] / x5 / khatus.c

#include <fcntl.h>
#include <unistd.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <X11/Xlib.h>

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.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 file list to file array. */
typedef struct File File;
struct File {
	char   *name;
	int     fd;
	int     width;
	int     last_read;
	int     ttl;
	int     pos;  /* Position on the output buffer. */
	File   *next;
};

typedef struct Config Config;
struct Config {
	int    interval;
	char * separator;
	File * files;
	int    file_count;
	int    total_width;
	int    output_to_x_root_window;
} defaults = {
	.interval    = 1,
	.separator   = "|",
	.files       = NULL,
	.file_count  = 0,
	.total_width = 0,
	.output_to_x_root_window = 0,
};

void
file_print_one(File *f)
{
	debug(
		"File "
		"{"
			" 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
file_print_all(File *head)
{
	for (File *f = head; f; f = f->next) {
		file_print_one(f);
	}
}

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

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 file \"%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 file \"%s\"\n", w, n);
	if (!is_pos_num(t))
		usage("[spec] Invalid TTL: \"%s\", for file \"%s\"\n", t, n);
	File *f = calloc(1, sizeof(struct File));
	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->files;

		cfg->files        = f;
		cfg->total_width += f->width;
		cfg->file_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[], int i)
{
	opts_parse_any(cfg, argc, argv, 1);

	File *last = cfg->files;
	cfg->files = NULL;
	for (File *f = last; f; ) {
		File *next = f->next;
		f->next = cfg->files;
		cfg->files = f;
		f = next;
	}
}

void
read_one(File *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;
	int ready;
	struct stat st;

	FD_ZERO(&fds);
	/* TODO: Check TTL */
	for (File *f = cfg->files; 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 files. */
			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 (File *f = cfg->files; 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 nfiles = 0;
	int seplen;
	int prefix = 0;
	char *buf;
	Config *cfg = &defaults;
	Display *display;

	argv0 = argv[0];

	opts_parse(cfg, argc, argv, 1);
	debug("argv0 = %s\n", argv0);
	config_print(cfg);
	if (cfg->files == NULL)
		usage("No file specs were given!\n");

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

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