ccollate is a command within the Tclx package.
This command compares two strings. It returns -1 if string1 is less than string2, 0 if they are equal and 1 if string1 is greater than string2.
If -local is specified, the strings are compared according to the collation environment of the current locale.
This command at one point did not work with binary or UTF data.
If locale-aware processing is not required, consider using string compare.