+/*
+
+- [ ] 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>
-#define MAX_TOT_WIDTH 1024
+#include <fcntl.h>
+#include <unistd.h>
-#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 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;
+typedef struct File File;
+struct File {
+ char *name;
+ int fd;
int width;
+ int last_read;
int ttl;
- File next;
+ int pos; /* Position on the output buffer. */
+ File *next;
};
-struct options {
- char * argv0;
+typedef struct Config Config;
+struct Config {
int interval;
- File files;
-} options = {
- .argv0 = NULL,
- .interval = 1,
- .files = NULL
+ 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,
};
-typedef struct options * Options;
-
-Options opts = &options;
-int errors = 0;
-
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"
+ " SEPARATOR = string\n"
+ " INTERVAL = int (* (positive) number of seconds *)\n"
"\n",
- opts->argv0
+ argv0
);
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 = malloc((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 = malloc((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(argc, argv, ++i); break; /* TODO: Generic set_int */
+ 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(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] 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 = malloc(sizeof(struct file));
+ File *f = malloc(sizeof(struct File));
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->files;
+
+ cfg->files = f;
+ cfg->total_width += f->width;
+ cfg->file_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[], 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)
+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)
+ 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 = opts->files; f; f = f->next) {
+ for (File *f = cfg->files; f; f = f->next) {
debug(
- "[options] file = { name = %s, width = %d, ttl = %d }\n",
+ "[config] file = "
+ "{"
+ " name = %s,"
+ " pos = %d,"
+ " width = %d,"
+ " ttl = %d,"
+ " last_read = %d,"
+ " }\n",
f->name,
+ f->pos,
f->width,
- f->ttl
+ 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 = malloc(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);
+ }
}
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