-/*
-
-- [ ] Switch from regular files to named pipes
- - [ ] poll with select
-
-*/
+#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 <fcntl.h>
+#include <time.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);}
+#include <X11/Xlib.h>
+
+#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 struct File File;
-struct File {
+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;
int pos; /* Position on the output buffer. */
- File *next;
+ Fifo *next;
};
typedef struct Config Config;
struct Config {
int interval;
char * separator;
- char * timefmt;
- File * files;
- int file_count;
+ Fifo * fifos;
+ int fifo_count;
int total_width;
+ int output_to_x_root_window;
+ LogLevel log_level;
} defaults = {
.interval = 1,
.separator = "|",
- .timefmt = "%Y-%m-%d %H:%M:%S",
- .files = NULL,
- .file_count = 0,
+ .fifos = NULL,
+ .fifo_count = 0,
.total_width = 0,
+ .output_to_x_root_window = 0,
+ .log_level = Info,
};
+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
+ );
+}
+
+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)
" 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,
parse_opts_opt_s(Config *cfg, int argc, char *argv[], int i)
{
if (i < argc) {
- cfg->separator = malloc((strlen(argv[i]) + 1) * sizeof(char));
+ cfg->separator = calloc((strlen(argv[i]) + 1), sizeof(char));
strcpy(cfg->separator, argv[i]);
opts_parse_any(cfg, argc, argv, ++i);
} else {
}
void
-parse_opts_opt_t(Config *cfg, int argc, char *argv[], int i)
+parse_opts_opt_l(Config *cfg, int argc, char *argv[], int i)
{
+ int log_level;
+
if (i < argc) {
- cfg->timefmt = malloc((strlen(argv[i]) + 1) * sizeof(char));
- strcpy(cfg->timefmt, argv[i]);
- opts_parse_any(cfg, argc, argv, ++i);
+ 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 -t parameter is missing.\n");
+ usage("Option -l parameter is missing.\n");
}
}
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]);
+ 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]);
}
}
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->fd = -1;
f->ttl = atoi(t);
f->last_read = 0;
f->pos = cfg->total_width;
- f->next = cfg->files;
+ f->next = cfg->fifos;
- cfg->files = f;
+ cfg->fifos = f;
cfg->total_width += f->width;
- cfg->file_count++;
+ cfg->fifo_count++;
} else {
fatal("[memory] Allocation failure.");
}
{
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
-opts_parse(Config *cfg, int argc, char *argv[], int i)
+opts_parse(Config *cfg, int argc, char *argv[])
{
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;
+ 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
-read_all(Config *cfg, char *buf)
+fifo_read_error(Fifo *f, char *buf)
{
- /* TODO: stat then check TTL */
- for (File *f = cfg->files; f; f = f->next) {
+ 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);
+ 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);
+ /* 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 {
- 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] = ' ';
+ fatal("nanosleep: %s\n", strerror(errno));
}
}
}
int
main(int argc, char *argv[])
{
- int width;
- int nfiles = 0;
- int seplen;
+ int width = 0;
+ int nfifos = 0;
+ int seplen = 0;
int prefix = 0;
+ int errors = 0;
char *buf;
- Config *cfg = &defaults;
+ 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, 1);
+ opts_parse(cfg, argc, argv);
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
- );
+ 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 */
- for (File *f = cfg->files; f; f = f->next) {
+ /* 2nd pass to make space for separators */
+ for (Fifo *f = cfg->fifos; f; f = f->next) {
f->pos += prefix;
prefix += seplen;
- nfiles++;
+ nfifos++;
}
- width += (seplen * (nfiles - 1));
- buf = malloc(width + 1);
+ 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';
- /* 2nd pass to set the separators */
- for (File *f = cfg->files; f; f = f->next) {
+ /* 3rd pass to set the separators */
+ for (Fifo *f = cfg->fifos; f; f = f->next) {
if (f->pos) { /* Skip the first, left-most */
- strcpy(buf + (f->pos - seplen), cfg->separator);
+ /* Copying only seplen ensures we omit the '\0' byte. */
+ strncpy(buf + (f->pos - seplen), cfg->separator, seplen);
}
}
- /* TODO: nanosleep and nano time diff */
+ if (cfg->output_to_x_root_window && !(display = XOpenDisplay(NULL)))
+ fatal("XOpenDisplay failed with: %p\n", display);
+ /* TODO: Handle signals */
for (;;) {
- read_all(cfg, buf);
- printf("%s\n", buf);
- sleep(cfg->interval);
+ 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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