| 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 | } |