+#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 <time.h>
+#include <unistd.h>
+
+#include <X11/Xlib.h>
+
+#include "bsdtimespec.h"
-#define MAX_TOT_WIDTH 1024
+#define debug(args...) if (cfg->log_level >= Debug) {fprintf(stderr, "[debug] " args); fflush(stderr);}
+#define info( args...) if (cfg->log_level >= Info ) {fprintf(stderr, "[info] " args); fflush(stderr);}
+#define error(args...) if (cfg->log_level >= Error) {fprintf(stderr, "[error] " args); fflush(stderr);}
+#define fatal(args...) {fprintf(stderr, "[fatal] " args); exit(EXIT_FAILURE);}
+#define usage(args...) {print_usage(); fatal("[usage] " args);}
-#define debug( args...) {fprintf(stderr, "[debug] " args);}
-#define error( args...) {fprintf(stderr, "[error] " args); errors++;}
-#define fatal(n, args...) {fprintf(stderr, "[fatal] " args); exit(n);}
-#define usage( args...) {print_usage(); fatal(1, "[usage] " args);}
+#define ERRMSG "ERROR"
+static const char errmsg[] = ERRMSG;
+static const int errlen = sizeof(ERRMSG) - 1;
-typedef struct file * File;
+char *argv0;
-struct file {
- char * name;
+typedef enum LogLevel {
+ Nothing,
+ Error,
+ Info,
+ Debug
+} LogLevel;
+
+/* TODO: Convert fifo list to fifo array. */
+typedef struct Fifo Fifo;
+struct Fifo {
+ char *name;
+ int fd;
int width;
+ int last_read;
int ttl;
- File next;
+ int pos; /* Position on the output buffer. */
+ Fifo *next;
};
-struct options {
- char * argv0;
+typedef struct Config Config;
+struct Config {
int interval;
- File files;
-} options = {
- .argv0 = NULL,
- .interval = 1,
- .files = NULL
+ char * separator;
+ Fifo * fifos;
+ int fifo_count;
+ int total_width;
+ int output_to_x_root_window;
+ LogLevel log_level;
+} defaults = {
+ .interval = 1,
+ .separator = "|",
+ .fifos = NULL,
+ .fifo_count = 0,
+ .total_width = 0,
+ .output_to_x_root_window = 0,
+ .log_level = Info,
};
-typedef struct options * Options;
+void
+fifo_print_one(Fifo *f, Config *cfg)
+{
+ info(
+ "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
+ );
+}
-Options opts = &options;
-int errors = 0;
+void
+fifo_print_all(Fifo *head, Config *cfg)
+{
+ for (Fifo *f = head; f; f = f->next) {
+ fifo_print_one(f, cfg);
+ }
+}
+void
+config_print(Config *cfg)
+{
+ info(
+ "Config "
+ "{"
+ " interval = %d,"
+ " separator = %s,"
+ " fifo_count = %d,"
+ " total_width = %d,"
+ " log_level = %d,"
+ " fifos = ..."
+ " }\n",
+ cfg->interval,
+ cfg->separator,
+ cfg->fifo_count,
+ cfg->total_width,
+ cfg->log_level
+ );
+ fifo_print_all(cfg->fifos, cfg);
+}
int
is_pos_num(char *s)
void
print_usage()
{
- assert(opts->argv0);
+ assert(argv0);
fprintf(
stderr,
"\n"
- "Usage: %s [OPTIONS ...] SPEC [SPEC ...]\n"
+ "Usage: %s [OPTION ...] SPEC [SPEC ...]\n"
"\n"
- "\tSPEC = FILE_PATH DATA_WIDTH DATA_TTL\n"
- "\tFILE_PATH = string\n"
- "\tDATA_WIDTH = int (* (positive) number of characters *)\n"
- "\tDATA_TTL = int (* (positive) number of seconds *)\n"
- "\tOPTION = -i INTERVAL\n"
- "\tINTERVAL = int (* (positive) number of seconds *)\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"
+ " | -x (* Output to X root window *)\n"
+ " | -l LOG_LEVEL\n"
+ " SEPARATOR = string\n"
+ " INTERVAL = int (* (positive) number of seconds *)\n"
+ " LOG_LEVEL = int (* %d through %d *)\n"
"\n",
- opts->argv0
+ argv0,
+ Nothing,
+ Debug
);
fprintf(
stderr,
"Example: %s -i 1 /dev/shm/khatus/khatus_sensor_x 4 10\n"
"\n",
- opts->argv0
+ argv0
);
}
-void parse_opts(int, char *[], int); /* For mutually-recursive calls. */
+void opts_parse_any(Config *, int, char *[], int); /* For mutually-recursive calls. */
void
-parse_opts_opt_i(int argc, char *argv[], int i)
+parse_opts_opt_i(Config *cfg, int argc, char *argv[], int i)
{
if (i < argc) {
char *param = argv[i++];
if (is_pos_num(param)) {
- opts->interval = atoi(param);
- parse_opts(argc, argv, i);
+ cfg->interval = atoi(param);
+ opts_parse_any(cfg, argc, argv, i);
} else {
usage("Option -i parameter is invalid: \"%s\"\n", param);
}
}
void
-parse_opts_opt(int argc, char *argv[], int i)
+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_l(Config *cfg, int argc, char *argv[], int i)
+{
+ int log_level;
+
+ if (i < argc) {
+ char *param = argv[i++];
+
+ if (is_pos_num(param)) {
+ log_level = atoi(param);
+ if (log_level <= Debug) {
+ cfg->log_level = log_level;
+ opts_parse_any(cfg, argc, argv, i);
+ } else {
+ usage("Option -l value (%d) exceeds maximum (%d)\n", log_level, Debug);
+ }
+ } else {
+ usage("Option -l parameter is invalid: \"%s\"\n", param);
+ }
+ } else {
+ usage("Option -l 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(argc, argv, ++i); break; /* TODO: Generic set_int */
- default : usage("Option \"%s\" is invalid\n", argv[i]);
+ 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;
+ case 'l':
+ /* TODO: Generic set_int */
+ parse_opts_opt_l(cfg, argc, argv, ++i);
+ break;
+ default :
+ usage("Option \"%s\" is invalid\n", argv[i]);
}
}
void
-parse_opts_spec(int argc, char *argv[], int i)
+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]);
+ 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 file \"%s\"\n", w, n);
+ usage("[spec] Invalid width: \"%s\", for fifo \"%s\"\n", w, n);
if (!is_pos_num(t))
- usage("[spec] Invalid TTL: \"%s\", for file \"%s\"\n", t, n);
- File f = malloc(sizeof(struct file));
+ usage("[spec] Invalid TTL: \"%s\", for fifo \"%s\"\n", t, n);
+ Fifo *f = calloc(1, sizeof(struct Fifo));
if (f) {
- f->name = n;
- f->width = atoi(w);
- f->ttl = atoi(t);
- f->next = opts->files;
- opts->files = 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(2, "[memory] Allocation failure.");
+ fatal("[memory] Allocation failure.");
}
- parse_opts(argc, argv, i);
+ opts_parse_any(cfg, argc, argv, i);
}
void
-parse_opts(int argc, char *argv[], int i)
+opts_parse_any(Config *cfg, int argc, char *argv[], int i)
{
if (i < argc) {
switch (argv[i][0]) {
- case '-': parse_opts_opt(argc, argv, i); break;
- default : parse_opts_spec(argc, argv, i);
+ 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, Config *cfg)
+{
+ 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);
+ 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, cfg);
+ }
+ }
+}
+
+void
+snooze(struct timespec *t, Config *cfg)
+{
+ struct timespec remainder;
+ int result;
+
+ result = nanosleep(t, &remainder);
+
+ if (result < 0) {
+ if (errno == EINTR) {
+ info(
+ "nanosleep interrupted. Remainder: "
+ "{ tv_sec = %ld, tv_nsec = %ld }",
+ remainder.tv_sec, remainder.tv_nsec);
+ /* No big deal if we occasionally sleep less,
+ * so not attempting to correct after an interruption.
+ */
+ } else {
+ fatal("nanosleep: %s\n", strerror(errno));
}
}
}
int
-main(int argc, char **argv)
-{
- opts->argv0 = argv[0];
- parse_opts(argc, argv, 1);
- assert(!errors);
- debug("[options] argv0 = %s\n", opts->argv0);
- debug("[options] interval = %d\n", opts->interval);
- if (opts->files == NULL)
- usage("No file specs were given!\n");
- for (File f = opts->files; f; f = f->next) {
- debug(
- "[options] file = { name = %s, width = %d, ttl = %d }\n",
- f->name,
- f->width,
- f->ttl
- );
+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;
+ struct timespec
+ t0, /* time stamp. before reading fifos */
+ t1, /* time stamp. after reading fifos */
+ ti, /* time interval desired (t1 - t0) */
+ td, /* time interval measured (t1 - t0) */
+ tc; /* time interval correction (ti - td) when td < ti */
+
+ argv0 = argv[0];
+
+ opts_parse(cfg, argc, argv);
+ debug("argv0 = %s\n", argv0);
+ config_print(cfg);
+
+ /* TODO: Support interval < 1. i.e. implement timespec_of_float */
+ ti.tv_sec = cfg->interval;
+ ti.tv_nsec = 0;
+
+ 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: Handle signals */
+ for (;;) {
+ clock_gettime(CLOCK_MONOTONIC, &t0); // FIXME: check errors
+ /* TODO: Cache expiration. i.e. use the TTL */
+ /* 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.
+ */
+ /* TODO: How long to wait on IO? Max TTL? */
+ 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);
+ }
+ clock_gettime(CLOCK_MONOTONIC, &t1); // FIXME: check errors
+ timespecsub(&t1, &t0, &td);
+ debug("td {tv_sec = %ld, tv_nsec = %ld}\n", td.tv_sec, td.tv_nsec);
+ if (timespeccmp(&td, &ti, <)) {
+ /* Pushback on data producers by refusing to read the
+ * pipe more frequently than the interval.
+ */
+ timespecsub(&ti, &td, &tc);
+ debug("snooze YES\n");
+ snooze(&tc, cfg);
+ } else
+ debug("snooze NO\n");
+ }
+
+ return EXIT_SUCCESS;
}
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