Hosting Operations

Read-only

Inspect Response Headers

You need to inspect server and security headers quickly.

Command

curl -sI https://example.com

Before you run this

System impact: Read-only. Low when scoped to the shown target.

When not to use it: Do not use headers alone to validate page content or application behavior.

Expected output

HTTP status and response headers.

System impact

Read-only. Nothing changes. The command prints response headers only.

Recovery / rollback: no state is changed.

When to use it

Use this to check redirects, server headers, cache headers, and security headers.

When not to use it

Do not use headers alone to validate page content or application behavior.

Watch this command run

Command transcript

This sanitized transcript shows the commands and output shape without exposing host details.

demo@lab:~$

$ curl -sI https://example.com

HTTP/2 200
server: lab-nginx
x-content-type-options: nosniff

$ curl -sI https://example.com | grep -i "x-content-type-options\|server"

server: lab-nginx
x-content-type-options: nosniff

$ curl -I http://example.com

HTTP/1.1 301 Moved Permanently
Location: https://example.com/

View commands shown

These are the commands shown in the sanitized transcript.

Commands shown

curl -sI https://example.com
curl -sI https://example.com | grep -i "x-content-type-options\|server"
curl -I http://example.com

next steps

Related commands

Hosting Operations Read-only

Check HTTP to HTTPS Redirect

HTTPS worked. The plain HTTP redirect still mattered.

curl -I http://example.com

Hosting Operations Can be slow

Find HTML Pages Missing from the Sitemap

A page can exist in the build but never make it into the sitemap.

find public -name '*.html' -print | sed 's#^public#https://example.com#' | while read -r url; do grep -q "$url" public/sitemap.xml || echo "$url"; done

Hosting Operations Can be slow

Find Feed Links Missing from the Sitemap

Your feed can advertise URLs that the sitemap never lists.

grep -o '<link>https://example.com/[^<]*</link>' public/feed.xml | sed 's#<link>##;s#</link>##' | while read -r url; do grep -q "$url" public/sitemap.xml || echo "$url"; done

Hosting Operations Read-only

Check the Current Release Symlink

The deploy finished. The symlink told me what was actually live.

readlink -f /srv/www/example.com/current

Web Server Rescue Read-only

Your Site Is Not Down. DNS Might Be Lying.

The browser said the site was gone. The server was answering fine.

curl --resolve example.com:443:203.0.113.10 https://example.com/

Study mapping

Use this as independent command practice: read the notes, predict the output, then compare it with the example before using a real shell.