cequal string string: This command compares two strings for equality. It returns 1 if string1 and string2 are the identical and 0 if they are not. This command is a short-cut for string compare and avoids the problems with string expressions being treated unintentionally as numbers.
This command is UTF-aware and will also work on binary data.
Now in the core as string equal
Category Command in Tclx extension