2 * Copyright (C) 2013-2014 Jo-Philipp Wich <jow@openwrt.org>
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.
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.
25 #include <json-c/json.h>
28 #include <libubox/list.h>
36 struct json_object
*jsobj
;
37 struct list_head list
;
41 print_usage(char *app
)
45 " # %s [-i <file> | -s \"json...\"] {-t <pattern> | -e <pattern>}\n"
46 " -q Quiet, no errors are printed\n"
47 " -h, --help Print this help\n"
48 " -i path Specify a JSON file to parse\n"
49 " -s \"json\" Specify a JSON string to parse\n"
50 " -l limit Specify max number of results to show\n"
51 " -F separator Specify a field separator when using export\n"
52 " -t <pattern> Print the type of values matched by pattern\n"
53 " -e <pattern> Print the values matched by pattern\n"
54 " -e VAR=<pat> Serialize matched value for shell \"eval\"\n\n"
56 " Patterns are JsonPath: http://goessner.net/articles/JsonPath/\n"
57 " This tool implements $, @, [], * and the union operator ','\n"
58 " plus the usual expressions and literals.\n"
59 " It does not support the recursive child search operator '..' or\n"
60 " the '?()' and '()' filter expressions as those would require a\n"
61 " complete JavaScript engine to support them.\n\n"
63 " Display the first IPv4 address on lan:\n"
64 " # ifstatus lan | %s -e '@[\"ipv4-address\"][0].address'\n\n"
65 " Extract the release string from the board information:\n"
66 " # ubus call system board | %s -e '@.release.description'\n\n"
67 " Find all interfaces which are up:\n"
68 " # ubus call network.interface dump | \\\n"
69 " %s -e '@.interface[@.up=true].interface'\n\n"
70 " Export br-lan traffic counters for shell eval:\n"
71 " # devstatus br-lan | %s -e 'RX=@.statistics.rx_bytes' \\\n"
72 " -e 'TX=@.statistics.tx_bytes'\n",
73 app
, app
, app
, app
, app
);
76 static struct json_object
*
77 parse_json(FILE *fd
, const char *source
, const char **error
)
81 struct json_object
*obj
= NULL
;
82 struct json_tokener
*tok
= json_tokener_new();
83 enum json_tokener_error err
= json_tokener_continue
;
90 obj
= json_tokener_parse_ex(tok
, source
, strlen(source
));
91 err
= json_tokener_get_error(tok
);
95 while ((len
= fread(buf
, 1, sizeof(buf
), fd
)) > 0)
97 obj
= json_tokener_parse_ex(tok
, buf
, len
);
98 err
= json_tokener_get_error(tok
);
100 if (!err
|| err
!= json_tokener_continue
)
105 json_tokener_free(tok
);
109 if (err
== json_tokener_continue
)
110 err
= json_tokener_error_parse_eof
;
112 *error
= json_tokener_error_desc(err
);
120 print_string(const char *s
)
138 print_separator(const char *sep
, int *sc
, int sl
)
142 switch (sep
[(*sc
- 1) % sl
])
157 printf("%c", sep
[(*sc
- 1) % sl
]);
165 export_value(struct list_head
*matches
, const char *prefix
, const char *sep
,
169 int sc
= 0, sl
= strlen(sep
);
170 struct match_item
*item
;
172 if (list_empty(matches
))
177 printf("export %s=", prefix
);
179 list_for_each_entry(item
, matches
, list
)
184 switch (json_object_get_type(item
->jsobj
))
186 case json_type_object
:
187 ; /* a label can only be part of a statement */
188 json_object_object_foreach(item
->jsobj
, key
, val
)
193 print_separator(sep
, &sc
, sl
);
198 case json_type_array
:
199 for (n
= 0, len
= json_object_array_length(item
->jsobj
);
202 print_separator(sep
, &sc
, sl
);
207 case json_type_boolean
:
208 print_separator(sep
, &sc
, sl
);
209 printf("%d", json_object_get_boolean(item
->jsobj
));
213 print_separator(sep
, &sc
, sl
);
214 printf("%d", json_object_get_int(item
->jsobj
));
217 case json_type_double
:
218 print_separator(sep
, &sc
, sl
);
219 printf("%f", json_object_get_double(item
->jsobj
));
222 case json_type_string
:
223 print_separator(sep
, &sc
, sl
);
224 print_string(json_object_get_string(item
->jsobj
));
236 list_for_each_entry(item
, matches
, list
)
241 switch (json_object_get_type(item
->jsobj
))
243 case json_type_object
:
244 case json_type_array
:
245 case json_type_boolean
:
247 case json_type_double
:
248 printf("%s\n", json_object_to_json_string(item
->jsobj
));
251 case json_type_string
:
252 printf("%s\n", json_object_get_string(item
->jsobj
));
263 export_type(struct list_head
*matches
, const char *prefix
, int limit
)
266 struct match_item
*item
;
267 const char *types
[] = {
277 if (list_empty(matches
))
281 printf("export %s=", prefix
);
283 list_for_each_entry(item
, matches
, list
)
291 printf("%s", types
[json_object_get_type(item
->jsobj
)]);
302 match_cb(struct json_object
*res
, void *priv
)
304 struct list_head
*h
= priv
;
305 struct match_item
*i
= calloc(1, sizeof(*i
));
310 list_add_tail(&i
->list
, h
);
315 print_error(struct jp_state
*state
, char *expr
)
320 fprintf(stderr
, "Syntax error: ");
322 switch (state
->error_code
)
325 fprintf(stderr
, "Unexpected character\n");
329 fprintf(stderr
, "String or label literal too long\n");
333 fprintf(stderr
, "Invalid escape sequence\n");
337 fprintf(stderr
, "Unterminated string\n");
341 for (i
= 0; i
< sizeof(state
->error_code
) * 8; i
++)
343 if (state
->error_code
& (1 << i
))
346 first
? "Expecting %s" : " or %s", tokennames
[i
]);
352 fprintf(stderr
, "\n");
356 fprintf(stderr
, "In expression %s\n", expr
);
357 fprintf(stderr
, "Near here ----");
359 for (i
= 0; i
< state
->error_pos
; i
++)
360 fprintf(stderr
, "-");
362 fprintf(stderr
, "^\n");
366 filter_json(int opt
, struct json_object
*jsobj
, char *expr
, const char *sep
,
369 struct jp_state
*state
;
370 const char *prefix
= NULL
;
371 struct list_head matches
;
372 struct match_item
*item
, *tmp
;
373 struct json_object
*res
= NULL
;
375 state
= jp_parse(expr
);
379 fprintf(stderr
, "Out of memory\n");
382 else if (state
->error_code
)
384 print_error(state
, expr
);
388 INIT_LIST_HEAD(&matches
);
390 res
= jp_match(state
->path
, jsobj
, match_cb
, &matches
);
391 prefix
= (state
->path
->type
== T_LABEL
) ? state
->path
->str
: NULL
;
396 export_type(&matches
, prefix
, limit
);
400 export_value(&matches
, prefix
, sep
, limit
);
404 list_for_each_entry_safe(item
, tmp
, &matches
, list
)
414 int main(int argc
, char **argv
)
416 int opt
, rv
= 0, limit
= 0x7FFFFFFF;
418 struct json_object
*jsobj
= NULL
;
419 const char *jserr
= NULL
, *source
= NULL
, *separator
= " ";
423 print_usage(argv
[0]);
427 while ((opt
= getopt(argc
, argv
, "hi:s:e:t:F:l:q")) != -1)
432 print_usage(argv
[0]);
436 input
= fopen(optarg
, "r");
440 fprintf(stderr
, "Failed to open %s: %s\n",
441 optarg
, strerror(errno
));
454 if (optarg
&& *optarg
)
459 limit
= atoi(optarg
);
466 jsobj
= parse_json(input
, source
, &jserr
);
470 fprintf(stderr
, "Failed to parse json data: %s\n",
478 if (!filter_json(opt
, jsobj
, optarg
, separator
, limit
))
491 json_object_put(jsobj
);
493 if (input
&& input
!= stdin
)