x5/khatus.c

   1 #include <assert.h>
   2 #include <ctype.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6
   7 #define  MAX_TOT_WIDTH  1024
   8
   9 #define debug(   args...) {fprintf(stderr, "[debug] " args);}
  10 #define error(   args...) {fprintf(stderr, "[error] " args); errors++;}
  11 #define fatal(n, args...) {fprintf(stderr, "[fatal] " args); exit(n);}
  12 #define usage(   args...) {print_usage(); fatal(1, "[usage] " args);}
  13
  14
  15 typedef struct file * File;
  16
  17 struct file {
  18         char *  name;
  19         int     width;
  20         int     ttl;
  21         File    next;
  22 };
  23
  24 struct options {
  25         char * argv0;
  26         int    interval;
  27         File   files;
  28 } options = {
  29         .argv0    = NULL,
  30         .interval = 1,
  31         .files    = NULL
  32 };
  33
  34 typedef struct options * Options;
  35
  36 Options opts   = &options;
  37 int     errors = 0;
  38
  39
  40 int
  41 is_pos_num(char *s)
  42 {
  43         while (*s != '\0')
  44                 if (!isdigit(*(s++)))
  45                         return 0;
  46         return 1;
  47 }
  48
  49 void
  50 print_usage()
  51 {
  52         assert(opts->argv0);
  53         fprintf(
  54                 stderr,
  55                 "\n"
  56                 "Usage: %s [OPTIONS ...] SPEC [SPEC ...]\n"
  57                 "\n"
  58                 "\tSPEC       = FILE_PATH DATA_WIDTH DATA_TTL\n"
  59                 "\tFILE_PATH  = string\n"
  60                 "\tDATA_WIDTH = int  (* (positive) number of characters *)\n"
  61                 "\tDATA_TTL   = int  (* (positive) number of seconds *)\n"
  62                 "\tOPTION     = -i INTERVAL\n"
  63                 "\tINTERVAL   = int  (* (positive) number of seconds *)\n"
  64                 "\n",
  65                 opts->argv0
  66         );
  67         fprintf(
  68                 stderr,
  69                 "Example: %s -i 1 /dev/shm/khatus/khatus_sensor_x 4 10\n"
  70                 "\n",
  71                 opts->argv0
  72         );
  73 }
  74
  75 void parse_opts(int, char *[], int);  /* For mutually-recursive calls. */
  76
  77 void
  78 parse_opts_opt_i(int argc, char *argv[], int i)
  79 {
  80         if (i < argc) {
  81                 char *param = argv[i++];
  82
  83                 if (is_pos_num(param)) {
  84                         opts->interval = atoi(param);
  85                         parse_opts(argc, argv, i);
  86                 } else {
  87                         usage("Option -i parameter is invalid: \"%s\"\n", param);
  88                 }
  89         } else {
  90                 usage("Option -i parameter is missing.\n");
  91         }
  92 }
  93
  94 void
  95 parse_opts_opt(int argc, char *argv[], int i)
  96 {
  97         switch (argv[i][1]) {
  98                 case 'i': parse_opts_opt_i(argc, argv, ++i); break;  /* TODO: Generic set_int */
  99                 default : usage("Option \"%s\" is invalid\n", argv[i]);
 100         }
 101 }
 102
 103 void
 104 parse_opts_spec(int argc, char *argv[], int i)
 105 {
 106         if ((i + 3) > argc)
 107                 usage("[spec] Parameter(s) missing for file \"%s\".\n", argv[i]);
 108
 109         char *n = argv[i++];
 110         char *w = argv[i++];
 111         char *t = argv[i++];
 112
 113         if (!is_pos_num(w))
 114                 usage("[spec] Invalid width: \"%s\", for file \"%s\"\n", w, n);
 115         if (!is_pos_num(t))
 116                 usage("[spec] Invalid TTL: \"%s\", for file \"%s\"\n", t, n);
 117         File f = malloc(sizeof(struct file));
 118         if (f) {
 119                 f->name     = n;
 120                 f->width    = atoi(w);
 121                 f->ttl      = atoi(t);
 122                 f->next     = opts->files;
 123                 opts->files = f;
 124         } else {
 125                 fatal(2, "[memory] Allocation failure.");
 126         }
 127         parse_opts(argc, argv, i);
 128 }
 129
 130 void
 131 parse_opts(int argc, char *argv[], int i)
 132 {
 133         if (i < argc) {
 134                 switch (argv[i][0]) {
 135                         case '-': parse_opts_opt(argc, argv, i); break;
 136                         default : parse_opts_spec(argc, argv, i);
 137                 }
 138         }
 139 }
 140
 141 int
 142 main(int argc, char **argv)
 143 {
 144         opts->argv0 = argv[0];
 145         parse_opts(argc, argv, 1);
 146         assert(!errors);
 147         debug("[options] argv0 = %s\n", opts->argv0);
 148         debug("[options] interval = %d\n", opts->interval);
 149         if (opts->files == NULL)
 150                 usage("No file specs were given!\n");
 151         for (File f = opts->files; f; f = f->next) {
 152                 debug(
 153                         "[options] file = { name = %s, width = %d, ttl = %d }\n",
 154                         f->name,
 155                         f->width,
 156                         f->ttl
 157                 );
 158         }
 159 }