Skip to main content

Base64EncodeFile

Function Base64EncodeFile( const aFileName : string) : string

Example​

procedure ScriptEvent(var Value: variant);
begin
  Value := Base64EncodeFile('C:\VeloxExamples\fictional-input.bin');
end;

Usage​

Base64EncodeFile reads a complete file and returns its bytes as unwrapped standard Base64 text.

Parameters

NameTypeDescription
aFileNamestring, constPath of the file to read using the executing Velox process's identity and execution context.

Returns

The complete file content encoded with the standard Base64 alphabet and = padding. An empty file returns an empty string.

Behaviour

  • The file is opened for reading and its entire content is encoded as binary bytes.
  • No character-set conversion, compression or content-type detection occurs.
  • Output uses standard Base64 with no inserted CR/LF wrapping.
  • The source file is not intentionally modified.

Errors

Missing files, invalid paths, access denial, sharing violations, files that are too large for available memory and other stream/encoding exceptions propagate to the script.

Usage notes

Check file size before encoding untrusted or potentially large paths. Base64 does not prove that the source was complete or unmodified; use an appropriate hash, MAC or signature when the consuming protocol requires integrity.

Additional Technical Info​

Base64EncodeFile reads the complete contents of a named file and returns those bytes as standard Base64 text without line wrapping.

The example uses a fictional local path, is source-reviewed and was not executed by the documentation workflow.

Implementation

Velox creates a TMemoryStream and a TBase64Encoding configured with line length 0, loads the complete file into the stream, and passes the stream's memory pointer and size to EncodeBytesToString. Both objects are released in a finally block.

Edge cases and quirks

  • Relative paths resolve in the current execution context and may behave differently in Designer and service processes. Prefer a controlled absolute or configured path.
  • The source can change between path validation and loading, and another process can change it while this helper runs subject to Windows sharing rules.
  • A zero-byte file yields an empty string, which is also the result of encoding a zero-length in-memory value.
  • Standard output is not automatically suitable for a URL component because it can contain +, / and =.

Side effects

Reads a file and consumes a file handle temporarily. Access is performed as the executing Velox process account.

Performance and concurrency

This is not streaming: the entire file and the resulting Base64 string are held in memory. Base64 output is about one third larger than the input before string-storage overhead. Independent files can be read concurrently, while behaviour for a file being written concurrently depends on the other process's sharing mode.

Related entries

External references

Created 2026-07-15