main.c

   1 /*
   2  * Copyright (C) 2013-2014 Jo-Philipp Wich <jow@openwrt.org>
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include <stdio.h>
  18 #include <stdbool.h>
  19 #include <unistd.h>
  20 #include <errno.h>
  21
  22 #ifdef JSONC
  23         #include <json.h>
  24 #else
  25         #include <json-c/json.h>
  26 #endif
  27
  28 #include <libubox/list.h>
  29
  30 #include "lexer.h"
  31 #include "parser.h"
  32 #include "matcher.h"
  33
  34
  35 struct match_item {
  36         struct json_object *jsobj;
  37         struct list_head list;
  38 };
  39
  40 static struct json_object *
  41 parse_json(FILE *fd, const char *source, const char **error)
  42 {
  43         int len;
  44         char buf[256];
  45         struct json_object *obj = NULL;
  46         struct json_tokener *tok = json_tokener_new();
  47         enum json_tokener_error err = json_tokener_continue;
  48
  49         if (!tok)
  50                 return NULL;
  51
  52         if (source)
  53         {
  54                 obj = json_tokener_parse_ex(tok, source, strlen(source));
  55                 err = json_tokener_get_error(tok);
  56         }
  57         else
  58         {
  59                 while ((len = fread(buf, 1, sizeof(buf), fd)) > 0)
  60                 {
  61                         obj = json_tokener_parse_ex(tok, buf, len);
  62                         err = json_tokener_get_error(tok);
  63
  64                         if (!err || err != json_tokener_continue)
  65                                 break;
  66                 }
  67         }
  68
  69         json_tokener_free(tok);
  70
  71         if (err)
  72         {
  73                 if (err == json_tokener_continue)
  74                         err = json_tokener_error_parse_eof;
  75
  76                 *error = json_tokener_error_desc(err);
  77                 return NULL;
  78         }
  79
  80         return obj;
  81 }
  82
  83 static void
  84 print_string(const char *s)
  85 {
  86         const char *p;
  87
  88         printf("'");
  89
  90         for (p = s; *p; p++)
  91         {
  92                 if (*p == '\'')
  93                         printf("'\"'\"'");
  94                 else
  95                         printf("%c", *p);
  96         }
  97
  98         printf("'");
  99 }
 100
 101 static void
 102 print_separator(const char *sep, int *sc, int sl)
 103 {
 104         if (*sc > 0)
 105         {
 106                 switch (sep[(*sc - 1) % sl])
 107                 {
 108                 case '"':
 109                         printf("'\"'");
 110                         break;
 111
 112                 case '\'':
 113                         printf("\"'\"");
 114                         break;
 115
 116                 case ' ':
 117                         printf("\\ ");
 118                         break;
 119
 120                 default:
 121                         printf("%c", sep[(*sc - 1) % sl]);
 122                 }
 123         }
 124
 125         (*sc)++;
 126 }
 127
 128 static void
 129 export_value(struct list_head *matches, const char *prefix, const char *sep)
 130 {
 131         int n, len;
 132         int sc = 0, sl = strlen(sep);
 133         struct match_item *item;
 134
 135         if (list_empty(matches))
 136                 return;
 137
 138         if (prefix)
 139         {
 140                 printf("export %s=", prefix);
 141
 142                 list_for_each_entry(item, matches, list)
 143                 {
 144                         switch (json_object_get_type(item->jsobj))
 145                         {
 146                         case json_type_object:
 147                                 ; /* a label can only be part of a statement */
 148                                 json_object_object_foreach(item->jsobj, key, val)
 149                                 {
 150                                         if (!val)
 151                                                 continue;
 152
 153                                         print_separator(sep, &sc, sl);
 154                                         print_string(key);
 155                                 }
 156                                 break;
 157
 158                         case json_type_array:
 159                                 for (n = 0, len = json_object_array_length(item->jsobj);
 160                                      n < len; n++)
 161                                 {
 162                                         print_separator(sep, &sc, sl);
 163                                         printf("%d", n);
 164                                 }
 165                                 break;
 166
 167                         case json_type_boolean:
 168                                 print_separator(sep, &sc, sl);
 169                                 printf("%d", json_object_get_boolean(item->jsobj));
 170                                 break;
 171
 172                         case json_type_int:
 173                                 print_separator(sep, &sc, sl);
 174                                 printf("%d", json_object_get_int(item->jsobj));
 175                                 break;
 176
 177                         case json_type_double:
 178                                 print_separator(sep, &sc, sl);
 179                                 printf("%f", json_object_get_double(item->jsobj));
 180                                 break;
 181
 182                         case json_type_string:
 183                                 print_separator(sep, &sc, sl);
 184                                 print_string(json_object_get_string(item->jsobj));
 185                                 break;
 186
 187                         case json_type_null:
 188                                 break;
 189                         }
 190                 }
 191
 192                 printf("; ");
 193         }
 194         else
 195         {
 196                 list_for_each_entry(item, matches, list)
 197                 {
 198                         switch (json_object_get_type(item->jsobj))
 199                         {
 200                         case json_type_object:
 201                         case json_type_array:
 202                         case json_type_boolean:
 203                         case json_type_int:
 204                         case json_type_double:
 205                                 printf("%s\n", json_object_to_json_string(item->jsobj));
 206                                 break;
 207
 208                         case json_type_string:
 209                                 printf("%s\n", json_object_get_string(item->jsobj));
 210                                 break;
 211
 212                         case json_type_null:
 213                                 break;
 214                         }
 215                 }
 216         }
 217 }
 218
 219 static void
 220 export_type(struct list_head *matches, const char *prefix)
 221 {
 222         bool first = true;
 223         struct match_item *item;
 224         const char *types[] = {
 225                 "null",
 226                 "boolean",
 227                 "double",
 228                 "int",
 229                 "object",
 230                 "array",
 231                 "string"
 232         };
 233
 234         if (list_empty(matches))
 235                 return;
 236
 237         if (prefix)
 238                 printf("export %s=", prefix);
 239
 240         list_for_each_entry(item, matches, list)
 241         {
 242                 if (!first)
 243                         printf("\\ ");
 244
 245                 printf("%s", types[json_object_get_type(item->jsobj)]);
 246                 first = false;
 247         }
 248
 249         if (prefix)
 250                 printf("; ");
 251         else
 252                 printf("\n");
 253 }
 254
 255 static void
 256 match_cb(struct json_object *res, void *priv)
 257 {
 258         struct list_head *h = priv;
 259         struct match_item *i = calloc(1, sizeof(*i));
 260
 261         if (i)
 262         {
 263                 i->jsobj = res;
 264                 list_add_tail(&i->list, h);
 265         }
 266 }
 267
 268 static void
 269 print_error(struct jp_state *state, char *expr)
 270 {
 271         int i;
 272         bool first = true;
 273
 274         fprintf(stderr, "Syntax error: ");
 275
 276         switch (state->error_code)
 277         {
 278         case -4:
 279                 fprintf(stderr, "Unexpected character\n");
 280                 break;
 281
 282         case -3:
 283                 fprintf(stderr, "String or label literal too long\n");
 284                 break;
 285
 286         case -2:
 287                 fprintf(stderr, "Invalid escape sequence\n");
 288                 break;
 289
 290         case -1:
 291                 fprintf(stderr, "Unterminated string\n");
 292                 break;
 293
 294         default:
 295                 for (i = 0; i < sizeof(state->error_code) * 8; i++)
 296                 {
 297                         if (state->error_code & (1 << i))
 298                         {
 299                                 fprintf(stderr,
 300                                         first ? "Expecting %s" : " or %s", tokennames[i]);
 301
 302                                 first = false;
 303                         }
 304                 }
 305
 306                 fprintf(stderr, "\n");
 307                 break;
 308         }
 309
 310         fprintf(stderr, "In expression %s\n", expr);
 311         fprintf(stderr, "Near here ----");
 312
 313         for (i = 0; i < state->error_pos; i++)
 314                 fprintf(stderr, "-");
 315
 316         fprintf(stderr, "^\n");
 317 }
 318
 319 static bool
 320 filter_json(int opt, struct json_object *jsobj, char *expr, const char *sep)
 321 {
 322         struct jp_state *state;
 323         const char *prefix = NULL;
 324         struct list_head matches;
 325         struct match_item *item, *tmp;
 326         struct json_object *res = NULL;
 327
 328         state = jp_parse(expr);
 329
 330         if (!state)
 331         {
 332                 fprintf(stderr, "Out of memory\n");
 333                 goto out;
 334         }
 335         else if (state->error_code)
 336         {
 337                 print_error(state, expr);
 338                 goto out;
 339         }
 340
 341         INIT_LIST_HEAD(&matches);
 342
 343         res = jp_match(state->path, jsobj, match_cb, &matches);
 344         prefix = (state->path->type == T_LABEL) ? state->path->str : NULL;
 345
 346         switch (opt)
 347         {
 348         case 't':
 349                 export_type(&matches, prefix);
 350                 break;
 351
 352         default:
 353                 export_value(&matches, prefix, sep);
 354                 break;
 355         }
 356
 357         list_for_each_entry_safe(item, tmp, &matches, list)
 358                 free(item);
 359
 360 out:
 361         if (state)
 362                 jp_free(state);
 363
 364         return !!res;
 365 }
 366
 367 int main(int argc, char **argv)
 368 {
 369         int opt, rv = 0;
 370         FILE *input = stdin;
 371         struct json_object *jsobj = NULL;
 372         const char *jserr = NULL, *source = NULL, *separator = " ";
 373
 374         while ((opt = getopt(argc, argv, "i:s:e:t:F:q")) != -1)
 375         {
 376                 switch (opt)
 377                 {
 378                 case 'i':
 379                         input = fopen(optarg, "r");
 380
 381                         if (!input)
 382                         {
 383                                 fprintf(stderr, "Failed to open %s: %s\n",
 384                                                 optarg, strerror(errno));
 385
 386                                 rv = 125;
 387                                 goto out;
 388                         }
 389
 390                         break;
 391
 392                 case 's':
 393                         source = optarg;
 394                         break;
 395
 396                 case 'F':
 397                         if (optarg && *optarg)
 398                                 separator = optarg;
 399                         break;
 400
 401                 case 't':
 402                 case 'e':
 403                         if (!jsobj)
 404                         {
 405                                 jsobj = parse_json(input, source, &jserr);
 406
 407                                 if (!jsobj)
 408                                 {
 409                                         fprintf(stderr, "Failed to parse json data: %s\n",
 410                                                 jserr);
 411
 412                                         rv = 126;
 413                                         goto out;
 414                                 }
 415                         }
 416
 417                         if (!filter_json(opt, jsobj, optarg, separator))
 418                                 rv = 1;
 419
 420                         break;
 421
 422                 case 'q':
 423                         fclose(stderr);
 424                         break;
 425                 }
 426         }
 427
 428 out:
 429         if (jsobj)
 430                 json_object_put(jsobj);
 431
 432         if (input != stdin)
 433                 fclose(input);
 434
 435         return rv;
 436 }