CURL

cURL is a command-line tool for getting or sending data including files using URL syntax. cURL supports a range of common network protocols, currently including HTTP, HTTPS, FTP, FTPS, SCP, SFTP, TFTP, LDAP, DAP, DICT, TELNET, FILE, IMAP, POP3, SMTP and RTSP.

brew install curl
apt install curl

Examples

• curl --help
• curl -vvv https://google.com
• curl --insecure https://yourdomain.com
• curl https://google.com/file_to_download -o output_file_name
• curl -sS https://google.com

-s --silent Avoid showing progress bar

-S --show-error

• curl -sSL

-L, --location follow redirects

• curl -u YOUR_USERNAME:YOUR_PASSWORD https://yourpasswordprotectedpage.com/
• Save your cookies and reuse them:

curl --user user:pass --cookie-jar ./somefile_with_your_cookies https://xyz.com/a

curl --cookie ./omefile_with_your_cookiese https://xyz.com/b

• curl --header 'X-JFrog-Art-Api: 1234567890'
• curl --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/notification_settings
• curl -Is https://yourdomain.com/ | head -1

• -m, --max-time

• Upload a file:

curl -u YOUR_USERNAME:YOUR_PASSWORD -T FILE_TO_UPLOAD https://yourpasswordprotectedpage.com/your_destionation

-T, --upload-file <file>

• Display HTTP response headers:

curl -sD - -o /dev/null http://example.com

-s Avoid showing progress bar

-D Dump headers to a file, but - sends it to stdout

-o /dev/null Ignore response body

• curl -XDELETE localhost:9200/index/type/documentID (Invoke-WebRequest -method DELETE http://localhost:9200/_all)

Offers the same features to fetch remote banner information from HTTP servers:

curl -s -I 192.168.0.15 | grep -e "Server: "

Other options:

-k, --insecure To accept self signed certificate
-L, --location

Advance usage

• Use cURL to measure request and response times: https://stackoverflow.com/a/22625150

curl -o /dev/null -s -w 'Total: %{time_total}s\n' https://www.google.com

Errors

• curl: (52) Empty reply from server
• CURL Error (7): couldn't connect to host

Related terms

• JSON
• opensearch-cli curl
• Elasticsearch curl URLs
• Python requests library
• Scraping

See also

• wget, cURL, links, lynx, elinks, w3m, httpie, opensearch-cli curl, --no-check-certificate, wget --help
• telnet, netcat, nc, nc -l, ncat, socat, ngrok
• iwr (Invoke-WebRequest) PowerShell functionality
• lynx, links (browser), lynx (browser), Elinks (browser) command line browsers

http://man7.org/linux/man-pages/man1/curl.1.html

https://docs.gitlab.com/ee/api/notification_settings.html#global-notification-settings

https://stackoverflow.com/questions/3252851/how-to-display-request-headers-with-command-line-curl