A two to three hour libcurl video tutorial

agenda.md

This is going to become a live-stream video "class" done by Daniel in November 2023. Also recorded for Youtube of course.

The exact date/time is pending. This is the tentative agenda. What are you missing from here?

Mastering libcurl

• The project
• Getting libcurl
• API and ABI
• Architecture
• Transfers
• Basics
• Using
• Share API
• TLS
• Proxies
• HTTP
• HTTP header API
• URL API
• WebSocket
• Future

getting it

• installing
• building
• debugging
• free support
• paid support

API and ABI

• compatibility
• versions
• the API is for C
• header files
• compiling libcurl programs

Architecture

• C89
• backends
• everything is non-blocking

transfers

• content ignorant
• URLs
• callbacks
• different versions/installs

libcurl basics

• global init
• easy handles
• options
• easy perform
• multi handles
• multi perform
• multi_socket

Using libcurl

• verbose debug function tracing
• curl_version / curl_version_info
• persistent connections
• multiplexing
• Downloads
  • Storing downloads
  • Compression
  • Multiple downloads
  • Maximum file size
  • Resuming and ranges
• Uploads
  • Multiple uploads
• Transfer controls
  • Stop slow transfers
  • Rate limiting
• Connections
  • Name resolve tricks
  • Connection timeout
  • Network interface
  • Local port number
  • Keep alive
• Timeouts
• .netrc
• return codes
• SCP and SFTP
• Reading email
• Sending email
• --libcurl
• post transfer meta-data
• caches
• some words on threads
• error handling with libcurl

Share API

• sharing data between easy handles

TLS

• ciphers
• enable TLS
• verifying server certificates custom checks
• client certificates
• on TLS backends
• SSLKEYLOGFILE

Proxies

• Proxy type
• HTTP proxy
• SOCKS proxy (tor)
• Authentication
• HTTPS proxy
• Proxy environment variables
• Proxy headers

HTTP

• Authentication
• Ranges
• HTTP versions
• Conditionals
• HTTP POST data with callback
• Multipart formpost
• Redirects
• Modify the HTTP request
• HTTP PUT
• Cookies
• Alternative Services
• HSTS
• HTTP/2
• HTTP/3

HTTP header API

• get specific header field after transfer
• iterate over many headers

URL API

• Parse a URL
• extract components
• update components
• URL encoding/decoding
• IDN encoding/decoding
• redirects

WebSocket

• just a quickie, I did a separate websocket video recently https://youtu.be/NLIhd0wYO24

Feedback from Mastodon/email to get into the presentation:

• handling libcurl in threads
• practical tips on real-world error handling, as often this is hand-waved away during tutorials and blog posts
• when scripting curl becomes so cumbersome that switching to writing libcurl apps makes more sense instead
• best companion libs to write async libcurl apps