Get final URL after curl is redirected

Question

I need to get the final URL after a page redirect preferably with curl or wget.

For example http://google.com may redirect to http://www.google.com

Answer 1

curl can only follow http redirects. To also follow meta refresh directives and javascript redirects, you need a full-blown browser like headless chrome:

#!/bin/bash
real_url () {
    printf 'location.href\nquit\n' | \
    chromium-browser --headless --disable-gpu --disable-software-rasterizer \
    --disable-dev-shm-usage --no-sandbox --repl "$@" 2> /dev/null \
    | tr -d '>>> ' | jq -r '.result.value'
}

If you don't have chrome installed, you can use it from a docker container:

#!/bin/bash
real_url () {
    printf 'location.href\nquit\n' | \
    docker run -i --rm --user "$(id -u "$USER")" --volume "$(pwd)":/usr/src/app \
    zenika/alpine-chrome --no-sandbox --repl "$@" 2> /dev/null \
    | tr -d '>>> ' | jq -r '.result.value'
}

Like so:

$ real_url http://dx.doi.org/10.1016/j.pgeola.2020.06.005 
https://www.sciencedirect.com/science/article/abs/pii/S0016787820300638?via%3Dihub