167 UTL_ENCODE

The UTL_ENCODE package provides functions that encode RAW data into a standard encoded format so that the data can be transported between hosts. You can use UTL_ENCODE functions to encode the body of email text. The package also contains the decode counterpart functions of the encode functions. The functions follow published standards for encoding to accommodate non-Oracle utilities on the sending or receiving ends.

This chapter contains the following topic:

Summary of UTL_ENCODE Subprograms

Summary of UTL_ENCODE Subprograms

Table 167-1 UTL_ENCODE Package Subprograms

Subprogram	Description
BASE64_DECODE Function	Reads the base 64-encoded `RAW` input string and decodes it to its original `RAW` value
BASE64_ENCODE Function	Encodes the binary representation of the `RAW` value into base 64 elements and returns it in the form of a `RAW` string
MIMEHEADER_DECODE Function	Decodes a string from mime header format
MIMEHEADER_ENCODE Function	Encodes a string into mime header format
QUOTED_PRINTABLE_DECODE Function	Reads the `varchar2` quoted printable format input string and decodes it to the corresponding `RAW` string
QUOTED_PRINTABLE_ENCODE Function	Reads the `RAW` input string and encodes it to the corresponding quoted printable format string
TEXT_DECODE Function	Decodes a character set sensitive text string
TEXT_ENCODE Function	Encodes a character set sensitive text string
UUDECODE Function	Reads the `RAW` uuencode format input string and decodes it to the corresponding `RAW` string
UUENCODE Function	Reads the `RAW` input string and encodes it to the corresponding uuencode format string

BASE64_DECODE Function

This function reads the base 64-encoded RAW input string and decodes it to its original RAW value.

Syntax

UTL_ENCODE.BASE64_DECODE (
   r  IN RAW) 
RETURN RAW;

Pragmas

pragma RESTRICT_REFERENCES(base64_decode, WNDS, RNDS, WNPS, RNPS);

Parameters

Table 167-2 BASE64_DECODE Function Parameters

Parameter	Description
`r`	The RAW string containing base 64-encoded data. There are no defaults or optional parameters.

Return Values

Table 167-3 BASE64_DECODE Function Return Values

Return	Description
`RAW`	Contains the decoded string

BASE64_ENCODE Function

This function encodes the binary representation of the RAW value into base 64 elements and returns it in the form of a RAW string.

Syntax

UTL_ENCODE.BASE64_ENCODE (
   r  IN RAW) 
RETURN RAW;

Pragmas

pragma RESTRICT_REFERENCES(base64_encode, WNDS, RNDS, WNPS, RNPS);

Parameters

Table 167-4 BASE64_ENCODE Function Parameters

Parameter	Description
`r`	The RAW value to be encoded. There are no defaults or optional parameters.

Return Values

Table 167-5 BASE64_ENCODE Function Return Values

Return	Description
`RAW`	Contains the encoded base 64 elements

MIMEHEADER_DECODE Function

This function accepts as input an "encoded word" of the form:

=?<charset>?<encoding>?<encoded text>?= 
=?ISO-8859-1?Q?Here is some encoded text?=

The <encoded text> is encapsulated in mime header tags which give the MIMEHEADER_DECODE function information about how to decode the string. The mime header metadata tags are stripped from the input string and the <encoded text> is converted to the base database character set as follows:

If this is a UTF16 platform, convert the encoded text from UTF16 to ASCII
If this is an EBCDIC platform, convert the encoded text from EBCDIC to ASCII
If this is an ASCII or UTF8 platform, no conversion needed

The string is decoded using either quoted-printable or base64 decoding, as specified by the <encoding> metadata tag in the encoded word. The resulting converted and decoded text is returned to the caller as a VARCHAR2 string.

Syntax

UTL_ENCODE.MIMEHEADER_DECODE (
   buf    IN   VARCHAR2 CHARACTER SET ANY_CS) 
  RETURN data VARCHAR2 CHARACTER SET buf%CHARSET;

Parameters

Table 167-6 MIMEHEADER_DECODE Function Parameters

Parameter	Description
`buf`	The encoded text data with mime header format tags.

Return Values

Table 167-7 MIMEHEADER_DECODE Function Return Values

Return	Description
`data`	The encoded text data with mime header format tags

Examples

v2:=utl_encode.mimeheader_decode('=?ISO-8859-1?Q?Here is some encoded text?=');

MIMEHEADER_ENCODE Function

This function accepts as input an "encoded word" of the form:

=?<charset>?<encoding>?<encoded text>?= 
=?ISO-8859-1?Q?Here is some text?=

The buf input parameter is the text to be encoded and becomes the <encoded text>.

The <encoding> value is either "Q" or "B" for quoted-printable encode or base64 encoding respectively. The ENCODING input parameter accepts as valid values UTL_ENCODE.QUOTED_PRINTABLE or UTL_ENCODE.BASE64 or NULL. If NULL, quoted-printable encoding is selected as a default value.

The <charset> value is specified as the input parameter encode_charset. If NULL, the database character set is selected as a default value.

The mimeheader encoding process includes conversion of the buf input string to the character set specified by the encode_charset parameter. The converted string is encoded to either quoted-printable or base64 encoded format. The mime header tags are appended and prepended.

Finally, the string is converted to the base character set of the database:

If this is a UTF16 platform, convert the encoded text to UTF16
If this is an EBCDIC platform, convert the encoded text to EBCDIC
If this is an ASCII or UTF8 platform, no conversion needed.

Syntax

UTL_ENCODE.MIMEHEADER_ENCODE (
   buf            IN  VARCHAR2 CHARACTER SET ANY_CS, 
   encode_charset IN  VARCHAR2 DEFAULT NULL, 
   encoding       IN  PLS_INTEGER DEFAULT NULL) 
 RETURN string VARCHAR2 CHARACTER SET buf%CHARSET;

Parameters

Table 167-8 MIMEHEADER_ENCODE Function Parameters

Parameter	Description
`buf`	The text data.
`encode_charset`	The target character set.
`encoding`	The encoding format. Valid values are `UTL_ENCODE`.`BASE64`, `UTL_ENCODE`.`QUOTED_PRINTABLE` and `NULL`

Return Values

Table 167-9 MIMEHEADER_ENCODE Function Return Values

Return	Description
`string`	A `VARCHAR2` encoded string with mime header format tags.

QUOTED_PRINTABLE_DECODE Function

This function reads the varchar2 quoted printable format input string and decodes it to the corresponding RAW string.

Syntax

UTL_ENCODE.QUOTED_PRINTABLE_DECODE (
   r  IN RAW)
RETURN RAW;

Pragmas

pragma RESTRICT_REFERENCES(quoted_printable_decode, WNDS, RNDS, WNPS, RNPS);

Parameters

Table 167-10 QUOTED_PRINTABLE_DECODE Function Parameters

Parameters	Description
`r`	The RAW string containing a quoted printable data string. There are no defaults or optional parameters.

Return Values

Table 167-11 QUOTED_PRINTABLE_DECODE Function Return Values

Return	Description
`RAW`	The decoded string

QUOTED_PRINTABLE_ENCODE Function

This function reads the RAW input string and encodes it to the corresponding quoted printable format string.

Syntax

UTL_ENCODE.QUOTED_PRINTABLE_ENCODE (
   r  IN RAW)
RETURN RAW;

Pragmas

pragma RESTRICT_REFERENCES(quoted_printable_encode, WNDS, RNDS,WNPS, RNPS);

Parameters

Table 167-12 QUOTED_PRINTABLE_ENCODE Function Parameters

Parameter	Description
`r`	The RAW string. There are no defaults or optional parameters.

Return Values

Table 167-13 QUOTED_PRINTABLE_ENCODE Function Return Values

Return	Description
`RAW`	Contains the quoted printable string

TEXT_DECODE Function

This function converts the input text to the target character set as specified by the encode_charset parameter, if not NULL. The encoded text is converted to the base character set of database, as follows:

If this is a UTF16 platform, convert the encoded text from UTF16 to ASCII
If this is an EBCDIC platform, convert the encoded text from EBCDIC to ASCII
If this is an ASCII or UTF8 platform, no conversion needed

You can decode from either quoted-printable or base64 format, with regard to each encoding parameter. If NULL, quoted-printable is selected as a default decoding format. If encode_charset is not NULL, you convert the string from the specified character set to the database character set. The resulting decoded and converted text string is returned to the caller.

Syntax

UTL_ENCODE.TEXT_DECODE(
   buf            IN  VARCHAR2 CHARACTER SET ANY_CS, 
   encode_charset IN  VARCHAR2 DEFAULT NULL, 
   encoding       IN  PLS_INTEGER DEFAULT NULL) 
 RETURN string VARCHAR2 CHARACTER SET buf%CHARSET;

Parameters

Table 167-14 TEXT_DECODE Function Parameters

Parameter	Description
`buf`	The encoded text data.
`encode_charset`	The source character set.
`encoding`	The encoding format. Valid values are `UTL_ENCODE`.`BASE64`, `UTL_ENCODE`.`QUOTED_PRINTABLE` and `NULL.`

Return Values

Table 167-15 QUOTED_PRINTABLE_ENCODE Function Return Values

Return	Description
`string`	A `VARCHAR2` decoded text string.

Examples

v2:=UTL_ENCODE.TEXT_DECODE( 
      'Here is some text', 
       WE8ISO8859P1, 
       UTL_ENCODE.BASE64);

TEXT_ENCODE Function

This function converts the input text to the target character set as specified by the encode_charset parameter, if not NULL. The text is encoded to either base64 or quoted-printable format, as specified by the encoding parameter. Quoted-printable is selected as a default if ENCODING is NULL.

The encoded text is converted to the base character set of the database:

If this is a UTF16 platform, convert the encoded text to UTF16
If this is an EBCDIC platform, convert the encoded text to EBCDIC
If this is an ASCII or UTF8 platform, no conversion needed

The resulting encoded and converted text string is returned to the caller.

Syntax

UTL_ENCODE.TEXT_ENCODE (
   buf            IN  VARCHAR2 CHARACTER SET ANY_CS, 
   encode_charset IN  VARCHAR2 DEFAULT NULL, 
   encoding       IN  PLS_INTEGER DEFAULT NULL) 
 RETURN string VARCHAR2 CHARACTER SET buf%CHARSET;

Parameters

Table 167-16 TEXT_ENCODE Function Parameters

Parameter	Description
`buf`	The text data.
`encode_charset`	The target character set.
`encoding`	The encoding format. Valid values are `UTL_ENCODE`.`BASE64`, `UTL_ENCODE`.`QUOTED_PRINTABLE` and `NULL`

Return Values

Table 167-17 TEXT_ENCODE Function Return Values

Return	Description
`string`	A `VARCHAR2` encoded string with mime header format tags.

Examples

v2:=utl_encode.text_encode( 
   'Here is some text', 
   'WE8ISO8859P1', 
    UTL_ENCODE.BASE64);

UUDECODE Function

This function reads the RAW uuencode format input string and decodes it to the corresponding RAW string. See "UUENCODE Function" for discussion of the cumulative nature of UUENCODE and UUDECODE for data streams.

Syntax

UTL_ENCODE.UUDECODE (
   r  IN RAW) 
RETURN RAW;

Pragmas

pragma RESTRICT_REFERENCES(uudecode, WNDS, RNDS, WNPS, RNPS);

Parameters

Table 167-18 UUDECODE Function Parameters

Parameter	Description
`r`	The RAW string containing the uuencoded data string. There are no defaults or optional parameters.

Return Values

Table 167-19 UUDECODE Function Return Values

Return	Description
`RAW`	The decoded `RAW` string

UUENCODE Function

This function reads the RAW input string and encodes it to the corresponding uuencode format string. The output of this function is cumulative, in that it can be used to encode large data streams, by splitting the data stream into acceptably sized RAW values, encoded, and concatenated into a single encoded string.

Syntax

UTL_ENCODE.UUENCODE (
   r          IN RAW,
   type       IN PLS_INTEGER DEFAULT 1,
   filename   IN VARCHAR2 DEFAULT NULL,
   permission IN VARCHAR2 DEFAULT NULL) RETURN RAW;

Pragmas

pragma RESTRICT_REFERENCES(uuencode, WNDS, RNDS, WNPS, RNPS);

Parameters

Table 167-20 UUENCODE Function Parameters

Parameter	Description
`r`	`RAW` string
`type`	Optional number parameter containing the type of uuencoded output. Options: complete—a defined PL/SQL constant with a value of `1`. (default) header_piece ...middle_piece ...end_piece
`filename`	Optional `varchar2` parameter containing the uuencode filename; the default is `uuencode.txt`
`permission`	Optional `varchar2` parameter containing the permission mode; the default is `0` (a text string zero).

Return Values

Table 167-21 UUENCODE Function Return Values

Return	Description
`RAW`	Contains the uuencode format string