main.c

   1 /*
   2  * Copyright (C) 2013 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 "lexer.h"
  29 #include "parser.h"
  30 #include "matcher.h"
  31
  32 static struct json_object *
  33 parse_json(FILE *fd, const char *source, const char **error)
  34 {
  35         int len;
  36         char buf[256];
  37         struct json_object *obj = NULL;
  38         struct json_tokener *tok = json_tokener_new();
  39         enum json_tokener_error err = json_tokener_continue;
  40
  41         if (!tok)
  42                 return NULL;
  43
  44         if (source)
  45         {
  46                 obj = json_tokener_parse_ex(tok, source, strlen(source));
  47                 err = json_tokener_get_error(tok);
  48         }
  49         else
  50         {
  51                 while ((len = fread(buf, 1, sizeof(buf), fd)) > 0)
  52                 {
  53                         obj = json_tokener_parse_ex(tok, buf, len);
  54                         err = json_tokener_get_error(tok);
  55
  56                         if (!err || err != json_tokener_continue)
  57                                 break;
  58                 }
  59         }
  60
  61         json_tokener_free(tok);
  62
  63         if (err)
  64         {
  65                 if (err == json_tokener_continue)
  66                         err = json_tokener_error_parse_eof;
  67
  68                 *error = json_tokener_error_desc(err);
  69                 return NULL;
  70         }
  71
  72         return obj;
  73 }
  74
  75 static void
  76 print_string(const char *s)
  77 {
  78         const char *p;
  79
  80         printf("'");
  81
  82         for (p = s; *p; p++)
  83         {
  84                 if (*p == '\'')
  85                         printf("'\"'\"'");
  86                 else
  87                         printf("%c", *p);
  88         }
  89
  90         printf("'");
  91 }
  92
  93 static void
  94 export_value(struct json_object *jsobj, const char *prefix)
  95 {
  96         int n, len;
  97         bool first = true;
  98
  99         if (prefix)
 100         {
 101                 switch (json_object_get_type(jsobj))
 102                 {
 103                 case json_type_object:
 104                         printf("export %s=", prefix);
 105                         json_object_object_foreach(jsobj, key, val)
 106                         {
 107                                 if (!val)
 108                                         continue;
 109
 110                                 if (!first)
 111                                         printf("\\ ");
 112
 113                                 print_string(key);
 114                                 first = false;
 115                         }
 116                         printf("; ");
 117                         break;
 118
 119                 case json_type_array:
 120                         printf("export %s=", prefix);
 121                         for (n = 0, len = json_object_array_length(jsobj); n < len; n++)
 122                         {
 123                                 if (!first)
 124                                         printf("\\ ");
 125
 126                                 printf("%d", n);
 127                                 first = false;
 128                         }
 129                         printf("; ");
 130                         break;
 131
 132                 case json_type_boolean:
 133                         printf("export %s=%d; ", prefix, json_object_get_boolean(jsobj));
 134                         break;
 135
 136                 case json_type_int:
 137                         printf("export %s=%d; ", prefix, json_object_get_int(jsobj));
 138                         break;
 139
 140                 case json_type_double:
 141                         printf("export %s=%f; ", prefix, json_object_get_double(jsobj));
 142                         break;
 143
 144                 case json_type_string:
 145                         printf("export %s=", prefix);
 146                         print_string(json_object_get_string(jsobj));
 147                         printf("; ");
 148                         break;
 149
 150                 case json_type_null:
 151                         break;
 152                 }
 153         }
 154         else
 155         {
 156                 printf("%s\n", json_object_to_json_string(jsobj));
 157         }
 158 }
 159
 160 static void
 161 export_type(struct json_object *jsobj, const char *prefix)
 162 {
 163         const char *types[] = {
 164                 "null",
 165                 "boolean",
 166                 "double",
 167                 "int",
 168                 "object",
 169                 "array",
 170                 "string"
 171         };
 172
 173         if (prefix)
 174                 printf("export %s=%s; ", prefix, types[json_object_get_type(jsobj)]);
 175         else
 176                 printf("%s\n", types[json_object_get_type(jsobj)]);
 177 }
 178
 179 static bool
 180 filter_json(int opt, struct json_object *jsobj, char *expr)
 181 {
 182         struct jp_state *state;
 183         struct json_object *res = NULL;
 184         const char *prefix = NULL;
 185
 186         state = jp_parse(expr);
 187
 188         if (!state || state->error)
 189         {
 190                 fprintf(stderr, "In expression '%s': %s\n",
 191                         expr, state ? state->error : "Out of memory");
 192
 193                 goto out;
 194         }
 195
 196         res = jp_match(state->path, jsobj);
 197
 198         if (res)
 199         {
 200                 prefix = (state->path->type == T_LABEL) ? state->path->str : NULL;
 201
 202                 switch (opt)
 203                 {
 204                 case 't':
 205                         export_type(res, prefix);
 206                         break;
 207
 208                 default:
 209                         export_value(res, prefix);
 210                         break;
 211                 }
 212         }
 213
 214 out:
 215         if (state)
 216                 jp_free(state);
 217
 218         return !!res;
 219 }
 220
 221 int main(int argc, char **argv)
 222 {
 223         int opt, rv = 0;
 224         FILE *input = stdin;
 225         struct json_object *jsobj = NULL;
 226         const char *jserr = NULL, *source = NULL;
 227
 228         while ((opt = getopt(argc, argv, "i:s:e:t:q")) != -1)
 229         {
 230                 switch (opt)
 231                 {
 232                 case 'i':
 233                         input = fopen(optarg, "r");
 234
 235                         if (!input)
 236                         {
 237                                 fprintf(stderr, "Failed to open %s: %s\n",
 238                                                 optarg, strerror(errno));
 239
 240                                 rv = 125;
 241                                 goto out;
 242                         }
 243
 244                         break;
 245
 246                 case 's':
 247                         source = optarg;
 248                         break;
 249
 250                 case 't':
 251                 case 'e':
 252                         if (!jsobj)
 253                         {
 254                                 jsobj = parse_json(input, source, &jserr);
 255
 256                                 if (!jsobj)
 257                                 {
 258                                         fprintf(stderr, "Failed to parse json data: %s\n",
 259                                                 jserr);
 260
 261                                         rv = 126;
 262                                         goto out;
 263                                 }
 264                         }
 265
 266                         if (!filter_json(opt, jsobj, optarg))
 267                                 rv = 1;
 268
 269                         break;
 270
 271                 case 'q':
 272                         fclose(stderr);
 273                         break;
 274                 }
 275         }
 276
 277 out:
 278         if (jsobj)
 279                 json_object_put(jsobj);
 280
 281         if (input != stdin)
 282                 fclose(input);
 283
 284         return rv;
 285 }