cli: additional flags and cleanup

	* add -q flag to suppress error messages
	* add -t flag to test type of result
	* clean up exit codes to indicate success;
		- 0 if all -t and -e expression yielded a result
		- 1 if at least one -t or -e expression didn't match
		- 125 when failed to open input file
		- 126 when failed to parse json input
		- 127 when the farser fails due to oom

1 files changed, 113 insertions, 59 deletions

diff --git a/main.c b/main.c
index 05e445c..7d530fa 100644
--- a/main.c
+++ b/main.c
@@ -15,6 +15,7 @@
  */
 
 #include <stdio.h>
+#include <stdbool.h>
 #include <unistd.h>
 #include <errno.h>
 
@@ -29,7 +30,7 @@
 #include "matcher.h"
 
 static struct json_object *
-parse_json(FILE *fd)
+parse_json(FILE *fd, const char **error)
 {
 	int len;
 	char buf[256];
@@ -51,7 +52,16 @@ parse_json(FILE *fd)
 
 	json_tokener_free(tok);
 
-	return err ? NULL : obj;
+	if (err)
+	{
+		if (err == json_tokener_continue)
+			err = json_tokener_error_parse_eof;
+
+		*error = json_tokener_error_desc(err);
+		return NULL;
+	}
+
+	return obj;
 }
 
 static void
@@ -73,37 +83,18 @@ print_string(const char *s)
 }
 
 static void
-export_json(struct json_object *jsobj, char *expr)
+export_value(struct json_object *jsobj, const char *prefix)
 {
-	bool first;
-	struct jp_state *state;
-	struct json_object *res;
-	const char *prefix;
-
-	state = jp_parse(expr);
-
-	if (!state || state->error)
-	{
-		fprintf(stderr, "In expression '%s': %s\n",
-		        expr, state ? state->error : "Out of memory");
-
-		goto out;
-	}
-
-	res = jp_match(state->path, jsobj);
+	int n, len;
+	bool first = true;
 
-	if (state->path->type == T_LABEL)
+	if (prefix)
 	{
-		prefix = state->path->str;
-
-		switch (json_object_get_type(res))
+		switch (json_object_get_type(jsobj))
 		{
 		case json_type_object:
-			printf("export %s_TYPE=object; ", prefix);
-
-			first = true;
-			printf("export %s_KEYS=", prefix);
-			json_object_object_foreach(res, key, val)
+			printf("export %s=", prefix);
+			json_object_object_foreach(jsobj, key, val)
 			{
 				if (!val)
 					continue;
@@ -115,68 +106,118 @@ export_json(struct json_object *jsobj, char *expr)
 				first = false;
 			}
 			printf("; ");
-
-			//printf("export %s=", prefix);
-			//print_string(json_object_to_json_string(res));
-			//printf("; ");
-
 			break;
 
 		case json_type_array:
-			printf("export %s_TYPE=array; ", prefix);
-			printf("export %s_LENGTH=%d; ",
-			       prefix, json_object_array_length(res));
+			printf("export %s=", prefix);
+			for (n = 0, len = json_object_array_length(jsobj); n < len; n++)
+			{
+				if (!first)
+					printf("\\ ");
 
-			//printf("export %s=", prefix);
-			//print_string(json_object_to_json_string(res));
-			//printf("; ");
+				printf("%d", n);
+				first = false;
+			}
+			printf("; ");
 			break;
 
 		case json_type_boolean:
-			printf("export %s_TYPE=bool; ", prefix);
-			printf("export %s=%d; ", prefix, json_object_get_boolean(res));
+			printf("export %s=%d; ", prefix, json_object_get_boolean(jsobj));
 			break;
 
 		case json_type_int:
-			printf("export %s_TYPE=int; ", prefix);
-			printf("export %s=%d; ", prefix, json_object_get_int(res));
+			printf("export %s=%d; ", prefix, json_object_get_int(jsobj));
 			break;
 
 		case json_type_double:
-			printf("export %s_TYPE=double; ", prefix);
-			printf("export %s=%f; ", prefix, json_object_get_double(res));
+			printf("export %s=%f; ", prefix, json_object_get_double(jsobj));
 			break;
 
 		case json_type_string:
-			printf("export %s_TYPE=string; ", prefix);
 			printf("export %s=", prefix);
-			print_string(json_object_get_string(res));
+			print_string(json_object_get_string(jsobj));
 			printf("; ");
 			break;
 
 		case json_type_null:
-			printf("unset %s %s_TYPE %s_LENGTH %s_KEYS; ",
-				   prefix, prefix, prefix, prefix);
 			break;
 		}
 	}
 	else
 	{
-		printf("%s\n", json_object_to_json_string(res));
+		printf("%s\n", json_object_to_json_string(jsobj));
+	}
+}
+
+static void
+export_type(struct json_object *jsobj, const char *prefix)
+{
+	const char *types[] = {
+		"null",
+		"boolean",
+		"double",
+		"int",
+		"object",
+		"array",
+		"string"
+	};
+
+	if (prefix)
+		printf("export %s=%s; ", prefix, types[json_object_get_type(jsobj)]);
+	else
+		printf("%s\n", types[json_object_get_type(jsobj)]);
+}
+
+static bool
+filter_json(int opt, struct json_object *jsobj, char *expr)
+{
+	struct jp_state *state;
+	struct json_object *res = NULL;
+	const char *prefix = NULL;
+
+	state = jp_parse(expr);
+
+	if (!state || state->error)
+	{
+		fprintf(stderr, "In expression '%s': %s\n",
+		        expr, state ? state->error : "Out of memory");
+
+		goto out;
+	}
+
+	res = jp_match(state->path, jsobj);
+
+	if (res)
+	{
+		prefix = (state->path->type == T_LABEL) ? state->path->str : NULL;
+
+		switch (opt)
+		{
+		case 't':
+			export_type(res, prefix);
+			break;
+
+		default:
+			export_value(res, prefix);
+			break;
+		}
 	}
 
 out:
 	if (state)
 		jp_free(state);
+
+	return !!res;
 }
 
 int main(int argc, char **argv)
 {
-	int opt;
+	int opt, rv = 0;
 	FILE *input = stdin;
 	struct json_object *jsobj = NULL;
+	const char *jserr = NULL;
 
-	while ((opt = getopt(argc, argv, "i:e:")) != -1)
+	while ((opt = getopt(argc, argv, "i:e:t:q")) != -1)
 	{
 		switch (opt)
 		{
@@ -188,32 +229,45 @@ int main(int argc, char **argv)
 				fprintf(stderr, "Failed to open %s: %s\n",
 						optarg, strerror(errno));
 
-				exit(1);
+				rv = 125;
+				goto out;
 			}
 
 			break;
 
+		case 't':
 		case 'e':
 			if (!jsobj)
 			{
-				jsobj = parse_json(input);
+				jsobj = parse_json(input, &jserr);
 
 				if (!jsobj)
 				{
-					fprintf(stderr, "Failed to parse json data\n");
-					exit(2);
+					fprintf(stderr, "Failed to parse json data: %s\n",
+					        jserr);
+
+					rv = 126;
+					goto out;
 				}
 			}
 
-			export_json(jsobj, optarg);
+			if (!filter_json(opt, jsobj, optarg))
+				rv = 1;
+
+			break;
+
+		case 'q':
+			fclose(stderr);
 			break;
 		}
 	}
 
+out:
 	if (jsobj)
 		json_object_put(jsobj);
 
-	fclose(input);
+	if (input != stdin)
+		fclose(input);
 
-	return 0;
+	return rv;
 }