uuencode
More info
- Creator
- Mary Ann Horton
- Released
- 1980
- Type
- Binary-to-text encoding
The encoding that turned binary files into printable characters so they could survive email and Usenet, until MIME and Base64 took over.
Mary Ann Horton wrote uuencode at Berkeley in 1980 to move binaries over UUCP, which could only be trusted with seven-bit printable ASCII. Three bytes became four characters, each line started with a length character, and the whole thing was wrapped in begin 644 filename and end. Files grew by about a third.
Through the 80s and 90s this was how pictures and programs moved around Usenet: split into numbered parts that the reader stitched together and fed to uudecode. The character set included spaces and symbols that IBM's EBCDIC gateways on BITNET mangled, which produced the xxencode variant. MIME picked Base64 in 1992, and uuencode became something you recognise mainly by the wall of lines starting with M.