X-Git-Url: http://git.openwrt.org/?a=blobdiff_plain;f=main.c;h=85a53f4af40e4d02429ee2fdfda597780b7e1f96;hb=dea067ad67d977c247c300c06676a06adf21e0c7;hp=0f1a39b30c507e5a775e6dfa538e74716645e165;hpb=cdc760c58077f44fc40adbbe41e1556a67c1b9a9;p=project%2Fjsonpath.git

diff --git a/main.c b/main.c
index 0f1a39b..85a53f4 100644
--- a/main.c
+++ b/main.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013-2014 Jo-Philipp Wich <jow@openwrt.org>
+ * Copyright (C) 2013-2014 Jo-Philipp Wich <jo@mein.io>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -16,6 +16,7 @@
 
 #include <stdio.h>
 #include <stdbool.h>
+#include <stdint.h>
 #include <unistd.h>
 #include <errno.h>
 
@@ -37,6 +38,42 @@ struct match_item {
 	struct list_head list;
 };
 
+static void
+print_usage(char *app)
+{
+	printf(
+	"== Usage ==\n\n"
+	"  # %s [-i <file> | -s \"json...\"] {-t <pattern> | -e <pattern>}\n"
+	"  -q		Quiet, no errors are printed\n"
+	"  -h, --help	Print this help\n"
+	"  -i path	Specify a JSON file to parse\n"
+	"  -s \"json\"	Specify a JSON string to parse\n"
+	"  -l limit	Specify max number of results to show\n"
+	"  -F separator	Specify a field separator when using export\n"
+	"  -t <pattern>	Print the type of values matched by pattern\n"
+	"  -e <pattern>	Print the values matched by pattern\n"
+	"  -e VAR=<pat>	Serialize matched value for shell \"eval\"\n\n"
+	"== Patterns ==\n\n"
+	"  Patterns are JsonPath: http://goessner.net/articles/JsonPath/\n"
+	"  This tool implements $, @, [], * and the union operator ','\n"
+	"  plus the usual expressions and literals.\n"
+	"  It does not support the recursive child search operator '..' or\n"
+	"  the '?()' and '()' filter expressions as those would require a\n"
+	"  complete JavaScript engine to support them.\n\n"
+	"== Examples ==\n\n"
+	"  Display the first IPv4 address on lan:\n"
+	"  # ifstatus lan | %s -e '@[\"ipv4-address\"][0].address'\n\n"
+	"  Extract the release string from the board information:\n"
+	"  # ubus call system board | %s -e '@.release.description'\n\n"
+	"  Find all interfaces which are up:\n"
+	"  # ubus call network.interface dump | \\\n"
+	"  	%s -e '@.interface[@.up=true].interface'\n\n"
+	"  Export br-lan traffic counters for shell eval:\n"
+	"  # devstatus br-lan | %s -e 'RX=@.statistics.rx_bytes' \\\n"
+	"	-e 'TX=@.statistics.tx_bytes'\n",
+		app, app, app, app, app);
+}
+
 static struct json_object *
 parse_json(FILE *fd, const char *source, const char **error)
 {
@@ -175,7 +212,7 @@ export_value(struct list_head *matches, const char *prefix, const char *sep,
 
 			case json_type_int:
 				print_separator(sep, &sc, sl);
-				printf("%d", json_object_get_int(item->jsobj));
+				printf("%" PRId64, json_object_get_int64(item->jsobj));
 				break;
 
 			case json_type_double:
@@ -382,10 +419,20 @@ int main(int argc, char **argv)
 	struct json_object *jsobj = NULL;
 	const char *jserr = NULL, *source = NULL, *separator = " ";
 
-	while ((opt = getopt(argc, argv, "i:s:e:t:F:l:q")) != -1)
+	if (argc == 1)
+	{
+		print_usage(argv[0]);
+		goto out;
+	}
+
+	while ((opt = getopt(argc, argv, "hi:s:e:t:F:l:q")) != -1)
 	{
 		switch (opt)
 		{
+		case 'h':
+			print_usage(argv[0]);
+			goto out;
+
 		case 'i':
 			input = fopen(optarg, "r");
 
@@ -444,7 +491,7 @@ out:
 	if (jsobj)
 		json_object_put(jsobj);
 
-	if (input != stdin)
+	if (input && input != stdin)
 		fclose(input);
 
 	return rv;