base64-decode-stream

Arguments: instream outstream &key count (error-p t)

This operator was added in an update released around December 1, 2006. You must have that update to use this operator. See sys:update-allegro for information on updating Allegro CL. The keyword arguments were added in a later update.

base64-decode-stream reads bytes from instream, does base64 decoding on them, and writes the decoded bytes to outstream. Non-base64 characters are ignored. Invalid base64 encodings will result in an error being generated. instream is read until base64 terminating characters are seen or until end-of-file. If end-of-file is seen at an improper place (such as in the middle of a base64 chunk) an error will be generated.

If the count keyword argument is supplied, it must be an integer indicating the maximum number of bytes to read from instream. If count is not supplied, or is nil (the default), the instream will be read until base64 terminating bytes are seen, or until end-of-file.

If the error-p keyword argument is true (the default), then errors during base64 decoding (such as unexpected end of input, or invalid encodings) will result in an error being generated. If error-p is nil, base64 decoding will simply stop processing and return.

Notes: instream must be a stream capable of being read in an octet-oriented manner (i.e, it must be a stream for which read-byte will succeed). In particular, instream cannot be a string stream. Likewise, outstream must be a stream capable of being written in an octet-oriented manner.

See Base64 Support in miscellaneous.htm for information on Base64 and Base64 support in Allegro CL.

See also: base64-encode-stream documentation.

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Documentation for Allegro CL version 8.0. This page is new in the 8.0 release.
Created 2007.4.30.