Implement a mostly-functional query language for JSON.

TODO.txt

@@ -28,8 +28,9 @@ Milestone: v0.3.0
     [x] Built on HTTP client API
     [ ] http man page
 [~] Simple command line tool for working with JSON
-    [x] Should pretty-print Json
+    [x] Pretty-print Json
-    [ ] Query fields for use in shell scripts.
+    [x] Query fields for use in shell scripts.
+    [ ] Encode user-provided JSON strings
     [ ] json man page
 
 [ ] Move configuration to database

tools/src/http.c

@@ -83,7 +83,7 @@ main(int argc, char **argv)
                 if (!method)
                 {
                     fprintf(stderr, "Unknown request method: %s\n", optarg);
-                    return -1;
+                    return 1;
                 }
                 break;
             case 'H':
@@ -107,21 +107,21 @@ main(int argc, char **argv)
                 break;
             default:
                 usage(argv[0]);
-                return -1;
+                return 1;
         }
     }
 
     if (argc - optind < 1)
     {
         usage(argv[0]);
-        return -1;
+        return 1;
     }
 
     uri = UriParse(argv[optind]);
     if (!uri)
     {
         fprintf(stderr, "Failed to parse URI: %s\n", argv[optind]);
-        return -1;
+        return 1;
     }
 
     if (!uri->port)
@@ -140,7 +140,7 @@ main(int argc, char **argv)
     {
         fprintf(stderr, "Unknown protocol: %s\n", uri->proto);
         UriFree(uri);
-        return -1;
+        return 1;
     }
 
     if (strcmp(uri->proto, "https") == 0)
@@ -154,7 +154,7 @@ main(int argc, char **argv)
     {
         fprintf(stderr, "Failed to connect.\n");
         UriFree(uri);
-        return -1;
+        return 1;
     }
 
     while (HashMapIterate(requestHeaders, &key, (void **) &val))
@@ -180,7 +180,7 @@ main(int argc, char **argv)
         fprintf(stderr, "Failed to send request.\n");
         HttpClientContextFree(cx);
         UriFree(uri);
-        return -1;
+        return 1;
     }
 
     if (flags & FLAG_HEADERS)

tools/src/json.c

@@ -22,7 +22,12 @@
  * SOFTWARE.
  */
 #include <stdio.h>
+#include <string.h>
+#include <getopt.h>
 
+#include <Array.h>
+#include <HashMap.h>
+#include <Memory.h>
 #include <Json.h>
 
 int
@@ -38,8 +43,131 @@ main(int argc, char **argv)
         return 1;
     }
 
-    JsonEncode(json, stdout, JSON_PRETTY);
+    if (argc > 1)
-    printf("\n");
+    {
+        char *select = argv[1];
+        char *key;
+        JsonValue *val = JsonValueObject(json);
 
+        key = strtok(select, "->");
+
+        while (key)
+        {
+            char keyName[128];
+            size_t arrInd;
+            int expectArr = 0;
+            int func = 0;
+
+            expectArr = (sscanf(key, "%127[^[][%lu]", keyName, &arrInd) == 2);
+
+            if (keyName[0] == '@')
+            {
+                if (strcmp(keyName + 1, "length") == 0)
+                {
+                    switch (JsonValueType(val))
+                    {
+                        case JSON_ARRAY:
+                            val = JsonValueInteger(ArraySize(JsonValueAsArray(val)));
+                            break;
+                        case JSON_STRING:
+                            val = JsonValueInteger(strlen(JsonValueAsString(val)));
+                            break;
+                        default:
+                            val = NULL;
+                            break;
+                    }
+                }
+                else if (JsonValueType(val) == JSON_OBJECT && strcmp(keyName + 1, "keys") == 0)
+                {
+                    HashMap *obj = JsonValueAsObject(val);
+                    Array *arr = ArrayCreate();
+                    char *k;
+                    void *v;
+
+                    while (HashMapIterate(obj, &k, &v))
+                    {
+                        ArrayAdd(arr, JsonValueString(k));
+                    }
+
+                    val = JsonValueArray(arr);
+                }
+                else if (JsonValueType(val) == JSON_STRING && strcmp(keyName + 1, "decode") == 0)
+                {
+                    printf("%s", JsonValueAsString(val));
+                    val = NULL;
+                    break;
+                }
+                else
+                {
+                    val = NULL;
+                    break;
+                }
+
+                func = 1;
+            }
+            else if (keyName[0] == '!')
+            {
+                if (JsonValueType(val) == JSON_OBJECT)
+                {
+                    HashMap *obj = JsonValueAsObject(val);
+
+                    JsonValueFree(HashMapDelete(obj, keyName + 1));
+                }
+                else if (JsonValueType(val) == JSON_ARRAY)
+                {
+                    size_t i;
+
+                    sscanf(keyName + 1, "%lu", &i);
+                    JsonValueFree(ArrayDelete(JsonValueAsArray(val), i));
+                }
+                else
+                {
+                    val = NULL;
+                    break;
+                }
+
+                func = 1;
+            }
+
+            if (!func)
+            {
+                if (JsonValueType(val) == JSON_OBJECT)
+                {
+                    val = HashMapGet(JsonValueAsObject(val), keyName);
+                }
+                else
+                {
+                    val = NULL;
+                    break;
+                }
+            }
+
+            if (expectArr && JsonValueType(val) == JSON_ARRAY)
+            {
+                val = ArrayGet(JsonValueAsArray(val), arrInd);
+            }
+
+            if (!val)
+            {
+                break;
+            }
+
+            key = strtok(NULL, "->");
+        }
+
+        if (val)
+        {
+            JsonEncodeValue(val, stdout, JSON_PRETTY);
+        }
+
+        printf("\n");
+    }
+    else
+    {
+        JsonEncode(json, stdout, JSON_PRETTY);
+        JsonFree(json);
+    }
+
+    MemoryFreeAll();
     return 0;
 }