How to handle location header
When a permanent redirect is encountered, the location header is used to indicate the new URL. The location header is used in the response to a GET request. The permanent redirect is indicated by the HTTP status code 301.
curl does not follow redirects by default, so you need to tell it to do so, like so:
Long form:
curl --location <URL>
Short form:
curl -L <URL>
Example:
curl -L https://pxy.fi/4/wall
curl 'https://pxy.fi/4/wall' -si|grep location
location: https://releases.llvm.org/4.0.0/tools/clang/docs/DiagnosticsReference.html#wall
And if you want to get the final URL:
curl -I -L 'https://pxy.fi/4/wall'
HTTP/2 302
date: Mon, 10 Apr 2023 18:50:14 GMT
content-length: 0
location: https://releases.llvm.org/4.0.0/tools/clang/docs/DiagnosticsReference.html#wall
x-request-id: 9b2a6981cd62b009e75f3029abd056de
access-control-allow-origin: *
access-control-allow-methods: OPTIONS, GET, DELETE, POST, PUT, HEAD, PATCH
access-control-allow-headers: Authorization, Origin, X-Requested-With, Content-Type, Accept, User-Agent
x-openwhisk-activation-id: 7fe44f20f111402ba44f20f111302b80
cache-control: no-store, no-cache, private
cf-cache-status: DYNAMIC
server: cloudflare
cf-ray: 7b5d2ca2598ab704-AMS
strict-transport-security: max-age=63072000; includeSubDomains; preload
x-frame-options: DENY
x-content-type-options: nosniff
x-xss-protection: 1; mode=block
HTTP/2 200
server: nginx/1.4.6 (Ubuntu)
content-type: text/html
last-modified: Thu, 27 Apr 2017 06:46:52 GMT
etag: "590193dc-ce6aa"
via: 1.1 varnish, 1.1 varnish
accept-ranges: bytes
date: Mon, 10 Apr 2023 18:50:15 GMT
age: 18
x-served-by: cache-lga21921-LGA, cache-cph2320059-CPH
x-cache: MISS, HIT
x-cache-hits: 0, 1
x-timer: S1681152615.139322,VS0,VE1
strict-transport-security: max-age=300
content-length: 845482
And a brief note:
Use the -L, –location option to tell it to do that. When following redirects is enabled, curl will follow up to 50 redirects by default. You can change this number with the –max-redirs option.