#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <time.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);}
+#include "bsdtimespec.h"
+
+#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 ERRMSG "ERROR"
+
+static const char errmsg[] = ERRMSG;
+static const int errlen = sizeof(ERRMSG) - 1;
+
char *argv0;
+typedef enum LogLevel {
+ Nothing,
+ Error,
+ Info,
+ Debug
+} LogLevel;
+
/* TODO: Convert fifo list to fifo array. */
typedef struct Fifo Fifo;
struct Fifo {
int fifo_count;
int total_width;
int output_to_x_root_window;
+ LogLevel log_level;
} defaults = {
.interval = 1,
.separator = "|",
.fifo_count = 0,
.total_width = 0,
.output_to_x_root_window = 0,
+ .log_level = Info,
};
void
-fifo_print_one(Fifo *f)
+fifo_print_one(Fifo *f, Config *cfg)
{
- debug(
+ info(
"Fifo "
"{"
" name = %s,"
}
void
-fifo_print_all(Fifo *head)
+fifo_print_all(Fifo *head, Config *cfg)
{
for (Fifo *f = head; f; f = f->next) {
- fifo_print_one(f);
+ fifo_print_one(f, cfg);
}
}
void
-config_print(Config *c)
+config_print(Config *cfg)
{
- debug(
+ info(
"Config "
"{"
" interval = %d,"
" separator = %s,"
" fifo_count = %d,"
" total_width = %d,"
+ " log_level = %d,"
" fifos = ..."
" }\n",
- c->interval,
- c->separator,
- c->fifo_count,
- c->total_width
+ cfg->interval,
+ cfg->separator,
+ cfg->fifo_count,
+ cfg->total_width,
+ cfg->log_level
);
- fifo_print_all(c->fifos);
+ fifo_print_all(cfg->fifos, cfg);
}
int
" 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",
- argv0
+ argv0,
+ Nothing,
+ Debug
);
fprintf(
stderr,
}
}
+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(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': {
+ 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]);
+ case 'l':
+ /* TODO: Generic set_int */
+ parse_opts_opt_l(cfg, argc, argv, ++i);
+ break;
+ default :
+ usage("Option \"%s\" is invalid\n", argv[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);
+ case '-':
+ parse_opts_opt(cfg, argc, argv, i);
+ break;
+ default :
+ parse_opts_spec(cfg, argc, argv, i);
}
}
}
}
void
-read_one(Fifo *f, char *buf)
+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;
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)
+ 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
-read_all(Config *cfg, char *buf)
+fifo_read_all(Config *cfg, char *buf)
{
fd_set fds;
int maxfd = -1;
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)
- 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);
+ 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)
+ if (f->fd == -1) {
/* TODO: Consider backing off retries for failed fifos. */
- fatal("Failed to open \"%s\"\n", f->name);
+ 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);
for (Fifo *f = cfg->fifos; f; f = f->next) {
if (FD_ISSET(f->fd, &fds)) {
debug("reading: %s\n", f->name);
- read_one(f, buf);
+ 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[])
{
- int width;
+ int width = 0;
int nfifos = 0;
- int seplen;
+ 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);
- /* 1st pass to make space for separators */
+ /* 2nd pass to make space for separators */
for (Fifo *f = cfg->fifos; f; f = f->next) {
f->pos += prefix;
prefix += seplen;
fatal("[memory] Failed to allocate buffer of %d bytes", width);
memset(buf, ' ', width);
buf[width] = '\0';
- /* 2nd pass to set the separators */
+ /* 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. */
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 */
+ 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 read_all based on diff of last time of
- * read_all and desired time of next TTL check.
- * */
- read_all(cfg, buf);
+ /* 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");
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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