feat: Added a custom json extractor

lib/json.sh

@@ -0,0 +1,68 @@
+#!/usr/bin/env bash
+
+# generic JSON parser in pure bash and awk.
+# reads JSON from stdin and outputs a flattened list of key-value pairs.
+# example input: {"plugins": {"my_plugin": {"version": "1.0", "arr": [1, 2]}}}
+# example output:
+  # plugins.my_plugin.version="1.0"
+  # plugins.my_plugin.arr[0]=1
+  # plugins.my_plugin.arr[1]=2
+
+# pardon my french
+parse_json() {
+    # Tokenize the JSON using grep
+    grep -oE '"([^"\\]|\\.)*"|true|false|null|[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?|[{}[\]:,]' | \
+    awk '
+    BEGIN { 
+        depth=0; 
+        key="" 
+    }
+    {
+        token = $0
+        if (token == "{") {
+            depth++
+            is_key[depth] = 1
+            array_idx[depth] = ""
+        } else if (token == "}") {
+            delete path[depth]
+            delete array_idx[depth]
+            depth--
+        } else if (token == "[") {
+            depth++
+            is_key[depth] = 0
+            array_idx[depth] = 0
+        } else if (token == "]") {
+            delete array_idx[depth]
+            delete path[depth]
+            depth--
+        } else if (token == ":") {
+            is_key[depth] = 0
+        } else if (token == ",") {
+            if (array_idx[depth] != "") {
+                array_idx[depth]++
+            } else {
+                is_key[depth] = 1
+            }
+        } else {
+            if (is_key[depth] == 1) {
+                # Remove quotes from the key
+                gsub(/^"|"$/, "", token)
+                path[depth] = token
+            } else {
+                # It is a value
+                p = ""
+                for (i=1; i<=depth; i++) {
+                    if (array_idx[i] != "") {
+                        p = p "[" array_idx[i] "]"
+                    } else if (path[i] != "") {
+                        p = p "." path[i]
+                    }
+                }
+                # Remove leading dot
+                sub(/^\./, "", p)
+                print p "=" token
+            }
+        }
+    }
+    '
+}