From b3cf44567d9a01f8bdba85ddcf5df2f3d070d55d Mon Sep 17 00:00:00 2001
From: Matthias Kruk <matthias.kruk@miraclelinux.com>
Date: Fri, 28 May 2021 21:12:16 +0900
Subject: [PATCH] include/json: Add functions for manipulating JSON arrays

Handling JSON arrays in shell scripts can be painful without jq. This
commit adds a number of convenience functions that wrap jq to make
array handling easier. The follow fuctions are added:
 - json_array_head(): Returns the first element of a JSON array
 - json_array_tail(): Returns a new JSON array without the first element
 - json_array_to_lines(): Returns all elements of a JSON array, one per line
---
 include/json.sh | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/include/json.sh b/include/json.sh
index 341a240..789f5a5 100644
--- a/include/json.sh
+++ b/include/json.sh
@@ -105,3 +105,47 @@ json_array() {
 
 	return 0
 }
+
+json_array_head() {
+	local array="$1"
+
+	local head
+
+	if ! head=$(jq -e -r '.[0]' <<< "$array"); then
+		return 1
+	fi
+
+	echo "$head"
+	return 0
+}
+
+json_array_tail() {
+	local array="$1"
+
+	local tail
+	local element
+	local new
+
+	tail=()
+
+	while read -r element; do
+		tail+=("$element")
+	done < <(jq -r '.[1:][]' <<< "$array")
+
+	if ! new=$(json_array "${tail[@]}"); then
+		return 1
+	fi
+
+	echo "$new"
+	return 0
+}
+
+json_array_to_lines() {
+	local array="$1"
+
+        if ! jq -r '.[]' <<< "$array"; then
+		return 1
+	fi
+
+	return 0
+}
-- 
2.47.3