The following example converts all characters in character_set to uppercase.
char character_set[] = {'a', '5', '$', 'z'};
int i;
for( i=0; i<4; i++ )
lr_output_message("%c ", toupper(character_set[i]));
Example: Output:
Action.c(7): A
Action.c(7): 5
Action.c(7): $
Action.c(7): Z