Understanding Window Specific URL Curl Output with Bash

Understanding cURL Output in bash

cURL is a popular command-line tool used for transferring data to or from a server. It is widely used for testing APIs, downloading files, and accessing web content. When executed, cURL generates output that can provide valuable information about the request and response. In this article, we will explore how to interpret cURL output in bash, focusing on the SSL and version information.

cURL Output Format

By default, cURL output is sent to the console. The output consists of several sections, including the request line, headers, and body. The request line includes the HTTP method, URL, and protocol version. The headers contain information about the request and response, such as the content type, status code, and transfer encoding. The body contains the data transferred between the client and server.

Retrieving Raw Text from Pastebin using cURL

Suppose you want to retrieve a raw text file hosted on Pastebin. You can use cURL to download the content and save it to a local file. Here's an example command:

In this command, the -s option tells cURL to run silently, without displaying progress meters or error messages. The -S option ensures that cURL displays error messages, even with the -s option. The -L option tells cURL to follow redirects. The -o option specifies the output file name.

Interpreting SSL Information

When you run a cURL command with the -v option, cURL displays detailed information about the SSL handshake. Here's an example:

The SSL information includes the SSL version, cipher, and certificate information. Here's an example output:

In this example, the SSL version is TLSv1.3, and the cipher is TLS_AES_256_GCM_SHA384. The server certificate information includes the certificate issuer, validity period, and fingerprint.

Interpreting Version Information

When you run a cURL command with the --version option, cURL displays version information. Here's an example:

The version information includes the cURL version number, compiler flags, and feature support. Here's an example output:

In this example, the cURL version is 7.79.1, and it was compiled with OpenSSL 1.1.1k, zlib 1.2.11, and other libraries. The feature support includes HTTPS-proxy, HTTP2, and Kerberos.

• cURL is a command-line tool for transferring data to or from a server.
• cURL output includes the request line, headers, and body.
• The -sSL options tell cURL to run silently, follow redirects, and verify SSL certificates.
• The -v option displays detailed information about the SSL handshake.
• The --version option displays version information and feature support.

References

• cURL Manual Page
• cURL on Wikipedia
• Pastebin