3d81cad810e65dc9318e6f059089b249d2f5e5b0
1 #include <sys/select.h>
16 #include "bsdtimespec.h"
18 #define debug(args...) if (cfg->log_level >= Debug) {fprintf(stderr, "[debug] " args); fflush(stderr);}
19 #define info( args...) if (cfg->log_level >= Info ) {fprintf(stderr, "[info] " args); fflush(stderr);}
20 #define error(args...) if (cfg->log_level >= Error) {fprintf(stderr, "[error] " args); fflush(stderr);}
21 #define fatal(args...) {fprintf(stderr, "[fatal] " args); exit(EXIT_FAILURE);}
22 #define usage(args...) {print_usage(); fatal("[usage] " args);}
24 #define ERRMSG "ERROR"
26 static const char errmsg
[] = ERRMSG
;
27 static const int errlen
= sizeof(ERRMSG
) - 1;
31 typedef enum LogLevel
{
38 /* TODO: Convert fifo list to fifo array. */
39 typedef struct Fifo Fifo
;
46 int pos
; /* Position on the output buffer. */
50 typedef struct Config Config
;
57 int output_to_x_root_window
;
65 .output_to_x_root_window
= 0,
70 fifo_print_one(Fifo
*f
, Config
*cfg
)
94 fifo_print_all(Fifo
*head
, Config
*cfg
)
96 for (Fifo
*f
= head
; f
; f
= f
->next
) {
97 fifo_print_one(f
, cfg
);
102 config_print(Config
*cfg
)
120 fifo_print_all(cfg
->fifos
, cfg
);
127 if (!isdigit(*(s
++)))
139 "Usage: %s [OPTION ...] SPEC [SPEC ...]\n"
141 " SPEC = FILE_PATH DATA_WIDTH DATA_TTL\n"
142 " FILE_PATH = string\n"
143 " DATA_WIDTH = int (* (positive) number of characters *)\n"
144 " DATA_TTL = int (* (positive) number of seconds *)\n"
145 " OPTION = -i INTERVAL\n"
147 " | -x (* Output to X root window *)\n"
149 " SEPARATOR = string\n"
150 " INTERVAL = int (* (positive) number of seconds *)\n"
151 " LOG_LEVEL = int (* %d through %d *)\n"
159 "Example: %s -i 1 /dev/shm/khatus/khatus_sensor_x 4 10\n"
165 void opts_parse_any(Config
*, int, char *[], int); /* For mutually-recursive calls. */
168 parse_opts_opt_i(Config
*cfg
, int argc
, char *argv
[], int i
)
173 usage("Option -i parameter is missing.\n");
175 if (!is_pos_num(param
))
176 usage("Option -i parameter is invalid: \"%s\"\n", param
);
177 cfg
->interval
= atoi(param
);
178 opts_parse_any(cfg
, argc
, argv
, i
);
182 parse_opts_opt_s(Config
*cfg
, int argc
, char *argv
[], int i
)
185 usage("Option -s parameter is missing.\n");
186 cfg
->separator
= calloc((strlen(argv
[i
]) + 1), sizeof(char));
187 strcpy(cfg
->separator
, argv
[i
]);
188 opts_parse_any(cfg
, argc
, argv
, ++i
);
192 parse_opts_opt_l(Config
*cfg
, int argc
, char *argv
[], int i
)
198 usage("Option -l parameter is missing.\n");
200 if (!is_pos_num(param
))
201 usage("Option -l parameter is invalid: \"%s\"\n", param
);
202 log_level
= atoi(param
);
203 if (log_level
> Debug
)
204 usage("Option -l value (%d) exceeds maximum (%d)\n", log_level
, Debug
);
205 cfg
->log_level
= log_level
;
206 opts_parse_any(cfg
, argc
, argv
, i
);
210 parse_opts_opt(Config
*cfg
, int argc
, char *argv
[], int i
)
212 switch (argv
[i
][1]) {
214 /* TODO: Generic set_int */
215 parse_opts_opt_i(cfg
, argc
, argv
, ++i
);
218 /* TODO: Generic set_str */
219 parse_opts_opt_s(cfg
, argc
, argv
, ++i
);
222 cfg
->output_to_x_root_window
= 1;
223 opts_parse_any(cfg
, argc
, argv
, ++i
);
226 /* TODO: Generic set_int */
227 parse_opts_opt_l(cfg
, argc
, argv
, ++i
);
230 usage("Option \"%s\" is invalid\n", argv
[i
]);
235 parse_opts_spec(Config
*cfg
, int argc
, char *argv
[], int i
)
238 usage("[spec] Parameter(s) missing for fifo \"%s\".\n", argv
[i
]);
245 usage("[spec] Invalid width: \"%s\", for fifo \"%s\"\n", w
, n
);
247 usage("[spec] Invalid TTL: \"%s\", for fifo \"%s\"\n", t
, n
);
248 Fifo
*f
= calloc(1, sizeof(struct Fifo
));
255 f
->pos
= cfg
->total_width
;
256 f
->next
= cfg
->fifos
;
259 cfg
->total_width
+= f
->width
;
262 fatal("[memory] Allocation failure.");
264 opts_parse_any(cfg
, argc
, argv
, i
);
268 opts_parse_any(Config
*cfg
, int argc
, char *argv
[], int i
)
271 switch (argv
[i
][0]) {
273 parse_opts_opt(cfg
, argc
, argv
, i
);
276 parse_opts_spec(cfg
, argc
, argv
, i
);
282 opts_parse(Config
*cfg
, int argc
, char *argv
[])
284 opts_parse_any(cfg
, argc
, argv
, 1);
286 Fifo
*last
= cfg
->fifos
;
288 for (Fifo
*f
= last
; f
; ) {
289 Fifo
*next
= f
->next
;
290 f
->next
= cfg
->fifos
;
297 fifo_read_error(Fifo
*f
, char *buf
)
303 /* Copy as much of the error message as possible.
304 * EXCLUDING the reminating \0. */
305 for (i
= 0; i
< errlen
&& i
< f
->width
; i
++)
307 /* Any remaining slots: */
308 for (; i
< f
->width
; i
++)
313 fifo_read_one(Fifo
*f
, char *buf
, Config
*cfg
)
324 while ((current
= read(f
->fd
, &c
, 1)) && c
!= '\n' && c
!= '\0' && total
++ < f
->width
)
327 error("Failed to read: \"%s\". Error: %s\n", f
->name
, strerror(errno
));
328 fifo_read_error(f
, buf
);
330 while (total
++ < f
->width
)
332 /* TODO Record timestamp read */
338 fifo_read_all(Config
*cfg
, char *buf
)
346 for (Fifo
*f
= cfg
->fifos
; f
; f
= f
->next
) {
347 /* TODO: Create the FIFO if it doesn't already exist. */
348 if (lstat(f
->name
, &st
) < 0) {
349 error("Cannot stat \"%s\". Error: %s\n", f
->name
, strerror(errno
));
350 fifo_read_error(f
, buf
);
353 if (!(st
.st_mode
& S_IFIFO
)) {
354 error("\"%s\" is not a FIFO\n", f
->name
);
355 fifo_read_error(f
, buf
);
358 debug("opening: %s\n", f
->name
);
360 f
->fd
= open(f
->name
, O_RDONLY
| O_NONBLOCK
);
362 /* TODO: Consider backing off retries for failed fifos. */
363 error("Failed to open \"%s\"\n", f
->name
);
364 fifo_read_error(f
, buf
);
371 debug("selecting...\n");
372 ready
= select(maxfd
+ 1, &fds
, NULL
, NULL
, NULL
);
373 debug("ready: %d\n", ready
);
376 fatal("%s", strerror(errno
));
377 for (Fifo
*f
= cfg
->fifos
; f
; f
= f
->next
) {
378 if (FD_ISSET(f
->fd
, &fds
)) {
379 debug("reading: %s\n", f
->name
);
380 fifo_read_one(f
, buf
, cfg
);
386 snooze(struct timespec
*t
, Config
*cfg
)
388 struct timespec remainder
;
391 result
= nanosleep(t
, &remainder
);
394 if (errno
== EINTR
) {
396 "nanosleep interrupted. Remainder: "
397 "{ tv_sec = %ld, tv_nsec = %ld }",
398 remainder
.tv_sec
, remainder
.tv_nsec
);
399 /* No big deal if we occasionally sleep less,
400 * so not attempting to correct after an interruption.
403 fatal("nanosleep: %s\n", strerror(errno
));
409 main(int argc
, char *argv
[])
417 Config cfg0
= defaults
;
419 Display
*display
= NULL
;
422 t0
, /* time stamp. before reading fifos */
423 t1
, /* time stamp. after reading fifos */
424 ti
, /* time interval desired (t1 - t0) */
425 td
, /* time interval measured (t1 - t0) */
426 tc
; /* time interval correction (ti - td) when td < ti */
430 opts_parse(cfg
, argc
, argv
);
431 debug("argv0 = %s\n", argv0
);
434 /* TODO: Support interval < 1. i.e. implement timespec_of_float */
435 ti
.tv_sec
= cfg
->interval
;
438 if (cfg
->fifos
== NULL
)
439 usage("No fifo specs were given!\n");
441 /* 1st pass to check file existence and type */
442 for (Fifo
*f
= cfg
->fifos
; f
; f
= f
->next
) {
443 if (lstat(f
->name
, &st
) < 0) {
444 error("Cannot stat \"%s\". Error: %s\n", f
->name
, strerror(errno
));
448 if (!(st
.st_mode
& S_IFIFO
)) {
449 error("\"%s\" is not a FIFO\n", f
->name
);
455 fatal("Encountered errors with the given file paths. See log.\n");
457 width
= cfg
->total_width
;
458 seplen
= strlen(cfg
->separator
);
460 /* 2nd pass to make space for separators */
461 for (Fifo
*f
= cfg
->fifos
; f
; f
= f
->next
) {
466 width
+= (seplen
* (nfifos
- 1));
467 buf
= calloc(1, width
+ 1);
469 fatal("[memory] Failed to allocate buffer of %d bytes", width
);
470 memset(buf
, ' ', width
);
472 /* 3rd pass to set the separators */
473 for (Fifo
*f
= cfg
->fifos
; f
; f
= f
->next
) {
474 if (f
->pos
) { /* Skip the first, left-most */
475 /* Copying only seplen ensures we omit the '\0' byte. */
476 strncpy(buf
+ (f
->pos
- seplen
), cfg
->separator
, seplen
);
480 if (cfg
->output_to_x_root_window
&& !(display
= XOpenDisplay(NULL
)))
481 fatal("XOpenDisplay failed with: %p\n", display
);
482 /* TODO: Handle signals */
484 clock_gettime(CLOCK_MONOTONIC
, &t0
); // FIXME: check errors
485 /* TODO: Cache expiration. i.e. use the TTL */
486 /* TODO: How to trigger TTL check? On select? Alarm signal? */
487 /* TODO: Set timeout on fifo_read_all based on diff of last time of
488 * fifo_read_all and desired time of next TTL check.
490 /* TODO: How long to wait on IO? Max TTL? */
491 fifo_read_all(cfg
, buf
);
492 if (cfg
->output_to_x_root_window
) {
493 if (XStoreName(display
, DefaultRootWindow(display
), buf
) < 0)
494 fatal("XStoreName failed.\n");
500 clock_gettime(CLOCK_MONOTONIC
, &t1
); // FIXME: check errors
501 timespecsub(&t1
, &t0
, &td
);
502 debug("td {tv_sec = %ld, tv_nsec = %ld}\n", td
.tv_sec
, td
.tv_nsec
);
503 if (timespeccmp(&td
, &ti
, <)) {
504 /* Pushback on data producers by refusing to read the
505 * pipe more frequently than the interval.
507 timespecsub(&ti
, &td
, &tc
);
508 debug("snooze YES\n");
511 debug("snooze NO\n");
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