curl and mbstring php 7.1 installation on ubuntu 17.04

You need to add PHP ppa first, update, and install

sudo add-apt-repository ppa:ondrej/phpsudo apt-get updatesudo apt install php7.1-curl

php ubuntu curl php-7.1

While it seems strange that you are not able to find php-curl, you should search for php curl package version available on your system:

sudo apt updatesudo apt search ^php

Between the results, it should display something like this (the output was taken from Ubuntu 17.10, yours will be different):

php7.1-curl/artful-updates,artful-security 7.1.15-0ubuntu0.17.10.1 amd64      CURL module for PHP

then, you just install it as usual:

sudo apt install php7.1-curl

happy coding!

CodeHunter