Complete Stock List are one of the market data product for both exchange, we may not be able to get it for free.

However, if you make use of some hacking technique, you may be able to retrieve the list

HKEX

wget https://www.hkex.com.hk/eng/market/sec_tradinfo/isincode/documents/isino.xls

SGX

curl 'https://sgx-premium.wealthmsi.com/sgx/search' -H 'Cookie: _gat=1; _ga=GA1.1.275393693.1483093908' -H 'currency: sgd' -H 'Origin: https://sgx-premium.wealthmsi.com' -H 'Accept-Encoding: gzip, deflate, br' -H 'Accept-Language: en-US,en;q=0.8,fr;q=0.6,zh-TW;q=0.4' -H 'User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/55.0.2883.87 Chrome/55.0.2883.87 Safari/537.36' -H 'Content-Type: application/json' -H 'Accept: application/json, text/javascript, */*; q=0.01' -H 'cache-control: no-cache' -H 'X-Requested-With: XMLHttpRequest' -H 'Connection: keep-alive' -H 'Referer: https://sgx-premium.wealthmsi.com/index.html' --data-binary '{"criteria":[]}' --compressed > sgx_stock.json