libcurl初体验

2020-04-30 | 0 评论 | 0 浏览

背景

curl是c下面涉及到ssl的http上传下载库的第一选择。官方提供了一些示例，因此上手非常的容易。

官方示例

例子	描述
10-at-a-time	Download many files in parallel, in the same thread.
altsvc	HTTP with Alt-Svc support
anyauthput	HTTP PUT upload with authentiction using "any" method. libcurl picks the one the server supports/wants.
asiohiper (C++)	demonstrate the use of multi socket interface with boost::asio
cacertinmem	CA cert in memory with OpenSSL to get a HTTPS page.
certinfo	Extract lots of TLS certificate info.
chkspeed	Show transfer timing info after download completes.
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.
curlgtk	use the libcurl in a gtk-threaded application
curlx	demonstrates use of SSL context callback, requires OpenSSL
debug	Show how CURLOPT_DEBUGFUNCTION can be used.
ephiperfifo	multi socket API usage with epoll and timerfd
evhiperfifo	multi socket interface together with libev
externalsocket	An example demonstrating how an application can pass in a custom socket to libcurl to use. This example also handles the connect itself.
fileupload	Upload to a file:// URL
fopen	implements an fopen() abstraction allowing reading from URLs
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.
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.
ghiper	multi socket API usage together with with glib2
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.
htmltidy	Download a document and use libtidy to parse the HTML.
htmltitle (C++)	Get a web page, extract the title with libxml.
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
https	Simple HTTPS GET
imap-append	IMAP example showing how to send e-mails
imap-authzid	IMAP example showing how to retreieve e-mails from a shared mailed box
imap-copy	IMAP example showing how to copy an e-mail from one folder to another
imap-create	IMAP example showing how to create a new folder
imap-delete	IMAP example showing how to delete a folder
imap-examine	IMAP example showing how to obtain information about a folder
imap-fetch	IMAP example showing how to retreieve e-mails
imap-list	IMAP example to list the folders within a mailbox
imap-lsub	IMAP example to list the subscribed folders
imap-multi	IMAP example using the multi interface
imap-noop	IMAP example showing how to perform a noop
imap-search	IMAP example showing how to search for new e-mails
imap-ssl	IMAP example using SSL
imap-store	IMAP example showing how to modify the properties of an e-mail
imap-tls	IMAP example using TLS
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-poll	single download with the multi interface's curl_multi_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 example that uses pthreads to fetch several files at once
opensslthreadlock	one way to set the necessary OpenSSL locking callbacks if you want to do multi-threaded transfers with HTTPS/FTPS with libcurl built to use OpenSSL.
parseurl	Basic URL API use.
persistent	re-using handles to do HTTP persistent connections
pop3-authzid	POP3 example showing how to retrieve e-mails from a shared mailbox
pop3-dele	POP3 example showing how to delete e-mails
pop3-list	POP3 example to list the contents of a mailbox
pop3-multi	POP3 example using the multi interface
pop3-noop	POP3 example showing how to perform a noop
pop3-retr	POP3 example showing how to retrieve e-mails
pop3-ssl	POP3 example using SSL
pop3-stat	POP3 example showing how to obtain message statistics
pop3-tls	POP3 example using TLS
pop3-top	POP3 example showing how to retrieve only the headers of an e-mail
pop3-uidl	POP3 example to list the contents of a mailbox by unique ID
post-callback	Issue an HTTP POST and provide the data through the read callback.
postinmemory	Make a 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.
resolve	Use CURLOPT_RESOLVE to feed custom IP addresses for given host name + port number combinations.
rtsp	A basic RTSP transfer
sampleconv	This is a simple example showing how a program on a non-ASCII platform would invoke callbacks to do its own codeset conversions instead of using the built-in iconv functions in libcurl.
sendrecv	An example of 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 e-mail on behalf of another user with SMTP
smtp-expn	SMTP example showing how to expand an e-mail mailing list
smtp-mail	Send e-mail with SMTP
smtp-mime	SMTP example showing how to send mime e-mails
smtp-multi	SMTP example using the multi interface
smtp-ssl	SMTP example using SSL
smtp-tls	SMTP example using TLS
smtp-vrfy	SMTP example showing how to verify an e-mail 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-shared-conn	Multi-threaded transfers sharing a single connection pool
threaded-ssl	Show the required mutex callback setups for GnuTLS and OpenSSL when using libcurl multi-threaded.
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.
xmlstream	Stream-parse a document using the streaming Expat parser.