gnutls_base64_decode2 - Linux


gnutls_base64_decode2 is a command-line utility for decoding base64-encoded strings. It employs GnuTLS, a robust cryptographic library, to securely decode base64 strings. This makes it ideal for tasks involving data privacy, authentication, and information security.


gnutls_base64_decode2 [options] [file]


  • -b, –breaklines: Output the decoded data with line breaks after every 76 characters.
  • -h, –help: Display help and usage information.
  • -n, –no-crlf: Remove CR (carriage return) characters from the decoded data.
  • -o, –outfile : Specify an output file to save the decoded data.
  • -p, –prefix : Prefix the decoded data with the specified text.
  • -q, –quiet: Suppress output and only display errors.
  • -s, –suffix : Append the decoded data with the specified text.


Example 1: Simple Base64 Decoding

gnutls_base64_decode2 encoded_string

Example 2: Decoding from a File and Saving to Another File

gnutls_base64_decode2 -o decoded_file encoded_file

Example 3: Line Breaks and Custom Prefix/Suffix

gnutls_base64_decode2 -b -p "decoded: " -s " (base64)" encoded_string

Common Issues

  • Incorrectly Encoded Input: Ensure the input string is a valid base64 encoding.
  • Output File Permission Errors: Verify that you have write permissions to the output file path.
  • Malformed Input: If the input string contains invalid characters or is not properly formatted, the decoding will fail.


gnutls_base64_decode2 can be integrated with scripts or other commands to automate decoding tasks. For instance, you can use it to:

cat encoded_file | gnutls_base64_decode2 | tail -n +2

This command would remove the header line from the encoded file and decode the rest.

Related Commands

  • base64: A generic base64 utility without GnuTLS integration.
  • openssl base64: Another base64 decoding tool using the OpenSSL library.