Framework EDI Reference. Encoding Mechanism
UUEncode

UUEncode is an encoding mechanism that converts 8-bit binary characters to ASCII printable characters.  The encoding mechanism is similar to the Base64 mechanism, only without the translation table.  UUEncode determines the encoding character by adding 32 to the encoded decimal value, so that the resulting value falls into the printable characters section of the ASCII table.

The procedure for encoding is as follows:

1. The data is subdivided into 3-byte groups forming a 24-bit stream.
   
   Example .  The 3-byte word "The" has the following 24-bit stream (yellow).
   
   

   Text	T								h								e
   Byte Hex	0x54								0x68								0x65
   Bit Stream	0	1	0	1	0	1	0	0	0	1	1	0	1	0	0	0	0	1	1	0	0	1	0	1

   
   
2. The 24-bit stream is further subdivided into 6 bits.
   
   Example .  The 24-bit stream for the word "The" is subdivided as follows:
   
   

   Text	T								h								e
   Byte Hex	0x54								0x68								0x65
   Bit Stream	0	1	0	1	0	1	0	0	0	1	1	0	1	0	0	0	0	1	1	0	0	1	0	1
   6-Bit Group	0	1	0	1	0	1	0	0	0	1	1	0	1	0	0	0	0	1	1	0	0	1	0	1
   6-Bit Value	21						6						33						37

   
   
3. The value 32 is added to the decimal value of each of the 6-bit stream.  The result is the character represented in the ASCII table with corresponding decimal value.
   
   Example .  The 6-bit values are added with 32:
   
   
   • The value 21 + 32 is 53 which is "V".
   • The value 6 + 32 is 38
   • The value 33 + 32 is 65
   • The value 37 + 32 is 69
     
     

   Text	T								h								e
   Byte Hex	0x54								0x68								0x65
   Bit Stream	0	1	0	1	0	1	0	0	0	1	1	0	1	0	0	0	0	1	1	0	0	1	0	1
   6-Bit Group	0	1	0	1	0	1	0	0	0	1	1	0	1	0	0	0	0	1	1	0	0	1	0	1
   6-Bit Value	21 + 32 = 53						6 + 32 = 38						33 + 32 = 65						37 + 32 = 69
   Encoding	5						&						A						E

   
   The resulting encoding for the word "The" is "5&AE".
   

Example

The following shows the UUEncode encoding transformation of the string "The car".  The encoded result is "5&AE(&-A<@".  The actual encoded byte stream is shown in the last row.

Text	T								h								e								SP								c								a								r								NULL
Byte Hex	0x54								0x68								0x65								0x20								0x63								0x61								0x72								0x00
Bit Stream	0	1	0	1	0	1	0	0	0	1	1	0	1	0	0	0	0	1	1	0	0	1	0	1	0	0	1	0	0	0	0	0	0	1	1	0	0	0	1	1	0	1	1	0	0	0	0	1	0	1	1	1	0	0	1	0	0	0	0	0	0	0	0	0
6-Bit Group	0	1	0	1	0	1	0	0	0	1	1	0	1	0	0	0	0	1	1	0	0	1	0	1	0	0	1	0	0	0	0	0	0	1	1	0	0	0	1	1	0	1	1	0	0	0	0	1	0	1	1	1	0	0	1	0	0	0	0	0	0	0	0	0
6-Bit Value	21						6						33						37						8						6						13						33						28						32						0
+32	53						38						65						69						40						38						45						65						60						64
Encoding	5						&						A						E						(						&						-						A						<						@
Byte Stream	0x2B						0x26						0x41						0x45						0x28						0x26						0x2D						0x41						0x3C						0x40