jq Parse JSON Shell Script

APIs return JSON; ops search for jq in bash shell scripts to extract one field without Python. This template validates JSON, pulls nested keys, and loops array results from a file or curl.

What this script does

Validates input with jq empty
Extracts scalar with jq -r '.key'
Iterates array with jq -c '.items[]'
Reads from file or stdin
Example with nested .data.status

Prerequisites

jq package installed
UTF-8 JSON input
Quote jq filters in scripts

Step 1: Save the script

sudo nano /usr/local/bin/parse-json.sh
sudo chmod +x /usr/local/bin/parse-json.sh

Step 2: Full script (scroll to read)

parse-json.sh

#!/usr/bin/env bash
set -euo pipefail

FILE="${1:-}"
FILTER="${JQ_FILTER:-.data.status}"

json_in(){
  if [[ -n "$FILE" && "$FILE" != "-" ]]; then
    cat "$FILE"
  else
    cat
  fi
}

data=$(json_in)
if ! echo "$data" | jq empty 2>/dev/null; then
  echo "invalid JSON" >&2
  exit 1
fi

value=$(echo "$data" | jq -r "$FILTER" 2>/dev/null || true)
echo "filter=$FILTER value=$value"

# example: list names from array .items[].name
if echo "$data" | jq -e '.items|type=="array"' >/dev/null 2>&1; then
  echo "--- items ---"
  echo "$data" | jq -r '.items[] | [.id, .name] | @tsv' | head -20
fi

Scroll inside the box to read the full script.

Step 3: Configure settings

curl POST: curl POST JSON
Health checks: API health script
Avoid piping untrusted huge JSON without limits

Step 4: Test manually

echo '{"data":{"status":"ok"}}' | ./parse-json.sh

./parse-json.sh /tmp/response.json

Parse JSON with jq in Bash Shell Script Linux (curl API Logs)