CURL 7.78 released: tool to transfer data from or to a server

curl is a tool to transfer data from or to a server, using one of the supported protocols (HTTP, HTTPS, FTP, FTPS, SCP, SFTP, TFTP, DICT, TELNET, LDAP or FILE). The command is designed to work without user interaction.
curl offers proxy support, user authentication, FTP uploading, HTTP posting, SSL connections, cookies, file transfer resume, Metalink, and many other features.

CURL 7.78 released.

Changelog

Changes:

• curl_url_set: reject spaces in URLs w/o CURLU_ALLOW_SPACE
• CURLE_SETOPT_OPTION_SYNTAX: new error name for wrong setopt syntax
• hostip: make ‘localhost’ return fixed values
• mbedtls: add support for cert and key blob options
• metalink: remove all support for it
• mqtt: add support for username and password

Bugfixes:

• –socks4[a]: clarify where the host name is resolved
• ares: always store IPv6 addresses first
• asyn-ares: remove check for ‘data’ in Curl_resolver_cancel
• bearssl: explicitly initialize all fields of Curl_ssl
• bearssl: remove incorrect const on variable that is modified
• build: fix compiler warnings when CURL_DISABLE_VERBOSE_STRINGS
• c-hyper: abort CONNECT response reading early on non 2xx responses
• c-hyper: add support for transfer-encoding in the request
• c-hyper: bail on too long response headers
• c-hyper: clear NTLM auth buffer when request is issued
• c-hyper: convert HYPERE_INVALID_PEER_MESSAGE to CURLE_UNSUPPORTED_PROTOCOL
• c-hyper: fix NTLM on closed connection tested with test159
• c-hyper: fix the uploaded field in progress callbacks
• c-hyper: handle NULL from hyper_buf_copy()
• c-hyper: support CURLINFO_STARTTRANSFER_TIME
• c-hyper: support CURLOPT_HEADER
• ccsidcurl: fix the compile errors

More…

Download

How to use curl

Basic GET

GET a single resource via its URI

The default operation is a GET:

curl http://api.example.com:8080/statuses/1234

GET multiple resources where IDs are in a range

Use square brackets with a dashed range:

curl http://api.example.com:8080/items/[1230-1234]

GET multiple resources where IDs aren’t in a range

Use curly braces with comma-delimited strings:

curl http://api.example.com:8080/products/{abc,def,ghi}/status

Using HTTP Headers

Accept only the application/json content-type

Use the header option: -H or –header

curl -H 'Accept: application/json' http://api.example.com:8080/items/1234

Add multiple headers

Use multiple -H options:

curl -H ‘Accept: application/json’ -H ‘Accept-Encoding: gzip’ http://api.example.com:8080/products/a1b2c3ef/status

Note: the output from this is likely to be unreadable because it’s gzipped!

More likely you’d use this with ETags:

curl -H ‘Accept: application/json’ -H ‘If-None-Match: “1cc044-172-3d9aee80″‘ http://api.example.com:8080/products/a1b2c3ef/status

Show the network and HTTP “conversation”

Use the verbose option: -v or –verbose

curl -v -H http://api.example.com

POST and PUT

POST data to a URI

To send data to the server, you use either POST or PUT, depending on what the API requires. To do a POST, you simply use the -d (–data)  with some content:

curl -d "name=Ted" http://api.example.com:8080/customers

Note that this uses application/x-www-form-urlencoded as the Content-Type, i.e.,as if it was submitted by an HTML Form. You can use multiple -d options, which will be combined, e.g., these two commands produce the same content:

curl -d “first=Ted” -d “last=Young” http://api.example.com:8080/customers
curl -d “first=Ted&last=Young” http://api.example.com:8080/customers

If you want to send JSON, you’ll need to specify the Content-Type explicitly using the -H (header) option:

curl -d '{"name": "Ted"}' -H 'Content-Type: application/json' http://api.example.com:8080/items

PUT data to a URI

If you need to use the PUT method, you’ll need to override the method with the -X (–request) option:

curl -X PUT -d ‘{“name”: “Ted”}’ -H ‘Content-Type: application/json’ http://api.example.com:8080/items/1234