[khatus.git] / x5 / khatus.c

/*

- [ ] Switch from regular files to named pipes
	- [ ] poll with select

*/

#include <assert.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <fcntl.h>
#include <unistd.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;

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;
	char * timefmt;
	File * files;
	int    file_count;
	int    total_width;
} defaults = {
	.interval    = 1,
	.separator   = "|",
	.timefmt     = "%Y-%m-%d %H:%M:%S",
	.files       = NULL,
	.file_count  = 0,
	.total_width = 0,
};


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_t(Config *cfg, int argc, char *argv[], int i)
{
	if (i < argc) {
		cfg->timefmt = calloc((strlen(argv[i]) + 1), sizeof(char));
		strcpy(cfg->timefmt, argv[i]);
		opts_parse_any(cfg, argc, argv, ++i);
	} else {
		usage("Option -t 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 't': parse_opts_opt_t(cfg, argc, argv, ++i); break;  /* TODO: Generic set_str */
		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_all(Config *cfg, char *buf)
{
	/* TODO: stat then check TTL */
	for (File *f = cfg->files; f; f = f->next) {
		if (f->fd < 0)
			f->fd = open(f->name, O_RDONLY);
		if (f->fd == -1) {
			/* TODO: Consider backing off retries for failed files. */
			fatal("Failed to open \"%s\"\n", f->name);
		} else {
			lseek(f->fd, 0, 0);
			ssize_t n = read(f->fd, buf + f->pos, f->width);
			int lasti = n + f->pos - 1;
			char lastc = buf[lasti];
			if (lastc == '\n')
				buf[lasti] = ' ';
		}
	}
}

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

	argv0 = argv[0];

	opts_parse(cfg, argc, argv, 1);
	debug("argv0 = %s\n", argv0);
	debug("[config] interval    = %d\n", cfg->interval);
	debug("[config] separator   = %s\n", cfg->separator);
	debug("[config] file_count  = %d\n", cfg->file_count);
	debug("[config] total_width = %d\n", cfg->total_width);
	if (cfg->files == NULL)
		usage("No file specs were given!\n");
	for (File *f = cfg->files; f; f = f->next) {
		debug(
			"[config] file = "
			"{"
				" name = %s,"
				" pos = %d,"
				" width = %d,"
				" ttl = %d,"
				" last_read = %d,"
			" }\n",
			f->name,
			f->pos,
			f->width,
			f->ttl,
			f->last_read
		);
	}

	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 */
			strcpy(buf + (f->pos - seplen), cfg->separator);
		}
	}

	/* TODO: nanosleep and nano time diff */
	for (;;) {
		read_all(cfg, buf);
		printf("%s\n", buf);
		sleep(cfg->interval);
	}
}
Commit	Line	Data
4d66492f SK	1	/*
	2
	3	- [ ] Switch from regular files to named pipes
	4	- [ ] poll with select
	5
	6	*/
	7
9b5ebc12 SK	8	#include <assert.h>
	9	#include <ctype.h>
	10	#include <stdio.h>
	11	#include <stdlib.h>
	12	#include <string.h>
	13
4d66492f SK	14	#include <fcntl.h>
4d66492f SK	15	#include <unistd.h>
9b5ebc12	16
4d66492f SK	17	#define debug(args...) {fprintf(stderr, "[debug] " args);}
	18	#define info( args...) {fprintf(stderr, "[info] " args);}
	19	#define error(args...) {fprintf(stderr, "[error] " args);}
	20	#define fatal(args...) {fprintf(stderr, "[fatal] " args); exit(EXIT_FAILURE);}
	21	#define usage(args...) {print_usage(); fatal("[usage] " args);}
9b5ebc12	22
4d66492f	23	char *argv0;
9b5ebc12	24
4d66492f SK	25	typedef struct File File;
	26	struct File {
	27	char *name;
	28	int fd;
9b5ebc12	29	int width;
4d66492f	30	int last_read;
9b5ebc12	31	int ttl;
4d66492f SK	32	int pos; /* Position on the output buffer. */
4d66492f SK	33	File *next;
9b5ebc12 SK	34	};
9b5ebc12 SK	35
4d66492f SK	36	typedef struct Config Config;
4d66492f SK	37	struct Config {
9b5ebc12	38	int interval;
4d66492f SK	39	char * separator;
	40	char * timefmt;
	41	File * files;
	42	int file_count;
	43	int total_width;
	44	} defaults = {
	45	.interval = 1,
	46	.separator = "\|",
	47	.timefmt = "%Y-%m-%d %H:%M:%S",
	48	.files = NULL,
	49	.file_count = 0,
	50	.total_width = 0,
9b5ebc12 SK	51	};
9b5ebc12 SK	52
9b5ebc12 SK	53
	54	int
	55	is_pos_num(char *s)
	56	{
	57	while (*s != '\0')
	58	if (!isdigit(*(s++)))
	59	return 0;
	60	return 1;
	61	}
	62
	63	void
	64	print_usage()
	65	{
4d66492f	66	assert(argv0);
9b5ebc12 SK	67	fprintf(
	68	stderr,
	69	"\n"
4d66492f	70	"Usage: %s [OPTION ...] SPEC [SPEC ...]\n"
9b5ebc12	71	"\n"
4d66492f SK	72	" SPEC = FILE_PATH DATA_WIDTH DATA_TTL\n"
	73	" FILE_PATH = string\n"
	74	" DATA_WIDTH = int (* (positive) number of characters *)\n"
	75	" DATA_TTL = int (* (positive) number of seconds *)\n"
	76	" OPTION = -i INTERVAL\n"
	77	" \| -s SEPARATOR\n"
	78	" SEPARATOR = string\n"
	79	" INTERVAL = int (* (positive) number of seconds *)\n"
9b5ebc12	80	"\n",
4d66492f	81	argv0
9b5ebc12 SK	82	);
	83	fprintf(
	84	stderr,
	85	"Example: %s -i 1 /dev/shm/khatus/khatus_sensor_x 4 10\n"
	86	"\n",
4d66492f	87	argv0
9b5ebc12 SK	88	);
	89	}
	90
4d66492f	91	void opts_parse_any(Config , int, char [], int); /* For mutually-recursive calls. */
9b5ebc12 SK	92
9b5ebc12 SK	93	void
4d66492f	94	parse_opts_opt_i(Config cfg, int argc, char argv[], int i)
9b5ebc12 SK	95	{
	96	if (i < argc) {
	97	char *param = argv[i++];
	98
	99	if (is_pos_num(param)) {
4d66492f SK	100	cfg->interval = atoi(param);
4d66492f SK	101	opts_parse_any(cfg, argc, argv, i);
9b5ebc12 SK	102	} else {
	103	usage("Option -i parameter is invalid: \"%s\"\n", param);
	104	}
	105	} else {
	106	usage("Option -i parameter is missing.\n");
	107	}
	108	}
	109
	110	void
4d66492f SK	111	parse_opts_opt_s(Config cfg, int argc, char argv[], int i)
	112	{
	113	if (i < argc) {
3c836bfd	114	cfg->separator = calloc((strlen(argv[i]) + 1), sizeof(char));
4d66492f SK	115	strcpy(cfg->separator, argv[i]);
	116	opts_parse_any(cfg, argc, argv, ++i);
	117	} else {
	118	usage("Option -s parameter is missing.\n");
	119	}
	120	}
	121
	122	void
	123	parse_opts_opt_t(Config cfg, int argc, char argv[], int i)
	124	{
	125	if (i < argc) {
3c836bfd	126	cfg->timefmt = calloc((strlen(argv[i]) + 1), sizeof(char));
4d66492f SK	127	strcpy(cfg->timefmt, argv[i]);
	128	opts_parse_any(cfg, argc, argv, ++i);
	129	} else {
	130	usage("Option -t parameter is missing.\n");
	131	}
	132	}
	133
	134	void
	135	parse_opts_opt(Config cfg, int argc, char argv[], int i)
9b5ebc12 SK	136	{
9b5ebc12 SK	137	switch (argv[i][1]) {
4d66492f SK	138	case 'i': parse_opts_opt_i(cfg, argc, argv, ++i); break; /* TODO: Generic set_int */
	139	case 's': parse_opts_opt_s(cfg, argc, argv, ++i); break; /* TODO: Generic set_str */
	140	case 't': parse_opts_opt_t(cfg, argc, argv, ++i); break; /* TODO: Generic set_str */
9b5ebc12 SK	141	default : usage("Option \"%s\" is invalid\n", argv[i]);
	142	}
	143	}
	144
	145	void
4d66492f	146	parse_opts_spec(Config cfg, int argc, char argv[], int i)
9b5ebc12 SK	147	{
	148	if ((i + 3) > argc)
	149	usage("[spec] Parameter(s) missing for file \"%s\".\n", argv[i]);
	150
	151	char *n = argv[i++];
	152	char *w = argv[i++];
	153	char *t = argv[i++];
	154
	155	if (!is_pos_num(w))
	156	usage("[spec] Invalid width: \"%s\", for file \"%s\"\n", w, n);
	157	if (!is_pos_num(t))
	158	usage("[spec] Invalid TTL: \"%s\", for file \"%s\"\n", t, n);
3c836bfd	159	File *f = calloc(1, sizeof(struct File));
9b5ebc12	160	if (f) {
4d66492f SK	161	f->name = n;
	162	f->fd = -1;
	163	f->width = atoi(w);
	164	f->ttl = atoi(t);
	165	f->last_read = 0;
	166	f->pos = cfg->total_width;
	167	f->next = cfg->files;
	168
	169	cfg->files = f;
	170	cfg->total_width += f->width;
	171	cfg->file_count++;
9b5ebc12	172	} else {
4d66492f	173	fatal("[memory] Allocation failure.");
9b5ebc12	174	}
4d66492f	175	opts_parse_any(cfg, argc, argv, i);
9b5ebc12 SK	176	}
	177
	178	void
4d66492f	179	opts_parse_any(Config cfg, int argc, char argv[], int i)
9b5ebc12 SK	180	{
	181	if (i < argc) {
	182	switch (argv[i][0]) {
4d66492f SK	183	case '-': parse_opts_opt(cfg, argc, argv, i); break;
	184	default : parse_opts_spec(cfg, argc, argv, i);
	185	}
	186	}
	187	}
	188
	189	void
	190	opts_parse(Config cfg, int argc, char argv[], int i)
	191	{
	192	opts_parse_any(cfg, argc, argv, 1);
	193
	194	File *last = cfg->files;
	195	cfg->files = NULL;
	196	for (File *f = last; f; ) {
	197	File *next = f->next;
	198	f->next = cfg->files;
	199	cfg->files = f;
	200	f = next;
	201	}
	202	}
	203
	204	void
	205	read_all(Config cfg, char buf)
	206	{
	207	/* TODO: stat then check TTL */
	208	for (File *f = cfg->files; f; f = f->next) {
	209	if (f->fd < 0)
	210	f->fd = open(f->name, O_RDONLY);
	211	if (f->fd == -1) {
	212	/* TODO: Consider backing off retries for failed files. */
	213	fatal("Failed to open \"%s\"\n", f->name);
	214	} else {
	215	lseek(f->fd, 0, 0);
	216	ssize_t n = read(f->fd, buf + f->pos, f->width);
	217	int lasti = n + f->pos - 1;
	218	char lastc = buf[lasti];
	219	if (lastc == '\n')
	220	buf[lasti] = ' ';
9b5ebc12 SK	221	}
	222	}
	223	}
	224
	225	int
4d66492f	226	main(int argc, char *argv[])
9b5ebc12	227	{
4d66492f SK	228	int width;
	229	int nfiles = 0;
	230	int seplen;
	231	int prefix = 0;
	232	char *buf;
	233	Config *cfg = &defaults;
	234
	235	argv0 = argv[0];
	236
	237	opts_parse(cfg, argc, argv, 1);
	238	debug("argv0 = %s\n", argv0);
	239	debug("[config] interval = %d\n", cfg->interval);
	240	debug("[config] separator = %s\n", cfg->separator);
	241	debug("[config] file_count = %d\n", cfg->file_count);
	242	debug("[config] total_width = %d\n", cfg->total_width);
	243	if (cfg->files == NULL)
9b5ebc12	244	usage("No file specs were given!\n");
4d66492f	245	for (File *f = cfg->files; f; f = f->next) {
9b5ebc12	246	debug(
4d66492f SK	247	"[config] file = "
	248	"{"
	249	" name = %s,"
	250	" pos = %d,"
	251	" width = %d,"
	252	" ttl = %d,"
	253	" last_read = %d,"
	254	" }\n",
9b5ebc12	255	f->name,
4d66492f	256	f->pos,
9b5ebc12	257	f->width,
4d66492f SK	258	f->ttl,
4d66492f SK	259	f->last_read
9b5ebc12 SK	260	);
9b5ebc12 SK	261	}
4d66492f SK	262
	263	width = cfg->total_width;
	264	seplen = strlen(cfg->separator);
	265
	266	/* 1st pass to make space for separators */
	267	for (File *f = cfg->files; f; f = f->next) {
	268	f->pos += prefix;
	269	prefix += seplen;
	270	nfiles++;
	271	}
	272	width += (seplen * (nfiles - 1));
3c836bfd	273	buf = calloc(1, width + 1);
4d66492f SK	274	if (buf == NULL)
	275	fatal("[memory] Failed to allocate buffer of %d bytes", width);
	276	memset(buf, ' ', width);
	277	buf[width] = '\0';
	278	/* 2nd pass to set the separators */
	279	for (File *f = cfg->files; f; f = f->next) {
	280	if (f->pos) { /* Skip the first, left-most */
	281	strcpy(buf + (f->pos - seplen), cfg->separator);
	282	}
	283	}
	284
	285	/* TODO: nanosleep and nano time diff */
	286	for (;;) {
	287	read_all(cfg, buf);
	288	printf("%s\n", buf);
	289	sleep(cfg->interval);
	290	}
9b5ebc12	291	}