curl / libcurl / API / Examples

libcurl - small example snippets

A collection of smaller stand-alone applications using the libcurl API in different ways to show how to use it for different Internet transfer scenarios.

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You can also see a list of all libcurl easy options and which example source codes that use them.

All examples are written in C, unless specifically mentioned.

Index of examples

10-at-a-time Download many files in parallel, in the same thread.
address-scope HTTP GET to an IPv6 address with specific scope
altsvc HTTP with Alt-Svc support
anyauthput HTTP PUT upload with authentication using "any" method. libcurl picks the one the server supports/wants.
cacertinmem CA cert in memory with OpenSSL to get an HTTPS page.
certinfo Extract lots of TLS certificate info.
chkspeed Show transfer timing info after download completes.
connect-to Use CURLOPT_CONNECT_TO to connect to "wrong" hostname
cookie_interface Import and export cookies with COOKIELIST.
crawler Web crawler based on curl and libxml2 to stress-test curl with hundreds of concurrent connections to various servers.
debug Show how CURLOPT_DEBUGFUNCTION can be used.
default-scheme Change default scheme when none is provided in the URL
ephiperfifo multi socket API usage with epoll and timerfd
evhiperfifo multi socket interface together with libev
externalsocket Pass in a custom socket for libcurl to use.
fileupload Upload to a file:// URL
ftp-wildcard FTP wildcard pattern matching
ftpget Get a single file from an FTP server.
ftpgetinfo Checks a single file's size and mtime from an FTP server.
ftpgetresp Similar to ftpget.c but also stores the received response-lines in a separate file using our own callback!
ftpsget Get a single file from an FTPS server.
ftpupload Performs an FTP upload and renames the file just after a successful transfer.
ftpuploadfrommem FTP upload a file from memory
ftpuploadresume Upload to FTP, resuming failed transfers. Active mode.
getinfo Use getinfo to get content-type after completed transfer.
getinmemory Shows how the write callback function can be used to download data into a chunk of memory instead of storing it in a file.
getredirect Show how to extract Location: header and URL to redirect to.
getreferrer Show how to extract referrer header.
ghiper multi socket API usage together with glib2
headerapi Extract headers post transfer with the header API
hiperfifo multi socket API usage with libevent 2
href_extractor Uses the "Streaming HTML parser" to extract the href pieces in a streaming manner from a downloaded HTML.
hsts-preload Preload domains to HSTS
htmltidy Download a document and use libtidy to parse the HTML.
htmltitle (C++)Get a web page, extract the title with libxml.
http-options Issue an HTTP 'OPTIONS *' request
http-post simple HTTP POST using the easy interface
http2-download Multiplexed HTTP/2 downloads over a single connection
http2-pushinmemory HTTP/2 server push. Receive all data in memory.
http2-serverpush HTTP/2 server push
http2-upload Multiplexed HTTP/2 uploads over a single connection
http3 Very simple HTTP/3 GET
http3-present Checks if HTTP/3 support is present in libcurl.
httpcustomheader HTTP request with custom modified, removed and added headers
httpput HTTP PUT with easy interface and read callback
httpput-postfields HTTP PUT using CURLOPT_POSTFIELDS
https Simple HTTPS GET
imap-append Send email with IMAP
imap-authzid Retrieve emails from a shared IMAP mailbox
imap-copy Copy an email from one IMAP folder to another
imap-create Create a new IMAP folder
imap-delete Delete an IMAP folder
imap-examine Obtain information about an IMAP folder
imap-fetch Retrieve IMAP emails
imap-list List the folders within an IMAP mailbox
imap-lsub List the subscribed IMAP folders
imap-multi Get IMAP email with the multi interface
imap-noop Perform an IMAP noop
imap-search Search for new IMAP emails
imap-ssl IMAP with implicit SSL
imap-store Modify the properties of an email over IMAP
imap-tls IMAP using TLS
interface Use CURLOPT_INTERFACE to bind the outgoing socket to an interface
ipv6 HTTPS GET using IPv6 only
keepalive Use the TCP keep-alive options
localport Use CURLOPT_LOCALPORT to control local port number
maxconnects Set maximum number of persistent connections to 1.
multi-app A basic application source code using the multi interface doing two transfers in parallel.
multi-debugcallback multi interface and debug callback
multi-double multi interface code doing two parallel HTTP transfers
multi-event multi_socket API using libevent
multi-formadd using the multi interface to do a multipart formpost without blocking
multi-legacy A basic application source code using the multi interface doing two transfers in parallel without curl_multi_wait/poll.
multi-post using the multi interface to do a multipart formpost without blocking
multi-single using the multi interface to do a single download
multi-uv multi_socket API using libuv
multithread A multi-threaded program using pthreads to fetch several files at once
netrc Use credentials from .netrc
parseurl Basic URL API use.
persistent reusing handles to do HTTP persistent connections
pop3-authzid Retrieve emails from a shared POP3 mailbox
pop3-dele Delete POP3 emails
pop3-list List the contents of a POP3 mailbox
pop3-multi Get POP3 email using the multi interface
pop3-noop Perform a POP3 noop
pop3-retr Retrieve POP3 email
pop3-ssl Get POP3 email using implicit SSL
pop3-stat Obtain POP3 message statistics
pop3-tls POP3 using TLS
pop3-top POP3 example showing how to retrieve only the headers of an email
pop3-uidl List the contents of a POP3 mailbox by unique ID
post-callback Issue an HTTP POST and provide the data through the read callback.
postinmemory Make an HTTP POST with data from memory and receive response in memory.
postit2 HTTP Multipart formpost with file upload and two additional parts.
postit2-formadd HTTP Multipart formpost with file upload and two additional parts.
progressfunc Use the progress callbacks, old and/or new one depending on available libcurl version.
protofeats Outputs all protocols and features supported
range GET a range only of an HTTP resource
resolve Use CURLOPT_RESOLVE to feed custom IP addresses for given hostname + port number combinations.
rtsp-options Very simple RTSP request sending OPTIONS.
sendrecv Demonstrate curl_easy_send() and curl_easy_recv() usage.
sepheaders Simple HTTP GET that stores the headers in a separate file
sessioninfo Uses the CURLINFO_TLS_SESSION data.
sftpget Gets a file using an SFTP URL.
sftpuploadresume Upload to SFTP, resuming a previously aborted transfer.
shared-connection-cache Connection cache shared between easy handles with the share interface
simple Very simple HTTP GET
simplepost Very simple HTTP POST
simplessl Shows HTTPS usage with client certs and optional ssl engine use.
smooth-gtk-thread A multi threaded application that uses a progress bar to show status. It uses Gtk+ to make a smooth pulse.
smtp-authzid Send email on behalf of another user with SMTP
smtp-expn Expand an SMTP email mailing list
smtp-mail Send email with SMTP
smtp-mime Send SMTP mime emails
smtp-multi Send SMTP email with the multi interface
smtp-ssl Send SMTP email using implicit SSL
smtp-tls Send SMTP email using implicit TLS
smtp-vrfy Verify an SMTP email address
sslbackend Shows HTTPS usage with client certs and optional ssl engine use.
synctime Set your system time from a remote HTTP server's Date: header.
threaded-ssl Show the required mutex callback setups for GnuTLS and OpenSSL when using libcurl multi-threaded.
unixsocket Access HTTP server over unix domain socket
url2file Download a given URL into a local file named page.out.
urlapi Set working URL with CURLU *.
usercertinmem Use an in-memory user certificate and RSA key and retrieve an https page.
websocket WebSocket using CONNECT_ONLY
websocket-cb WebSocket download-only using write callback
xmlstream Stream-parse a document using the streaming Expat parser.

You also find these examples in the distribution archive, in docs/examples.