rtrim

Library: ib_udf

Changed in: 1.5, 1.5.2, 2.0

Better alternative: Internal function TRIM()

Description

Returns the input string with any trailing space characters removed. In new code, you are advised to use the internal function TRIM() instead, as it is both more powerful and more versatile.

Result type: VARCHAR(n)

Syntax (unchanged)

rtrim (str)

Declaration

DECLARE EXTERNAL FUNCTION rtrim
  CSTRING(255) NULL
   RETURNS CSTRING(255) FREE_IT
  ENTRY_POINT 'IB_UDF_rtrim' MODULE_NAME 'ib_udf'

The above declaration is from the file ib_udf2.sql. The NULL after the argument is an optional addition that became available in Firebird 2. If the argument is declared with the NULL keyword, the engine will pass a NULL argument value unchanged to the function. This leads to a NULL result, which is correct. Without the NULL keyword (your only option in pre-2.0 versions), NULL is passed to the function as an empty string and the result is an empty string as well.

For more information about passing NULLs to UDFs, see the note at the end of this book.

Notes:

• Depending on how you declare it (see CSTRING note), this function can accept and return strings of up to 32767 characters.
• Before Firebird 2.0, the result type was CHAR(n).
• In Firebird 1.5.1 and below, the default declaration used CSTRING(80) instead of CSTRING(255).
• In Firebird 1.0.x, this function returned NULL if the input string was either empty or NULL.