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