To upcase all character variables in a SAS dataset, you can use a DATA step with the UPCASE() function in combination with the VARNUM() and VARNAME() functions to iterate through all variables. Here's an example:

data upcased_dataset;
    set original_dataset;
    array _char_vars _character_; /* Create an array of all character variables */
    do i = 1 to dim(_char_vars);
        _char_vars[i] = upcase(_char_vars[i]); /* Convert each variable to uppercase */
    end;
    drop i;
run;

Explanation:

• array _char_vars _character_; creates an array _char_vars that includes all character variables in the dataset.
• The do i = 1 to dim(_char_vars); loop iterates through each character variable in the array.
• _char_vars[i] = upcase(_char_vars[i]); applies the UPCASE() function to each character variable, converting it to uppercase.
• drop i; removes the temporary index variable i from the final dataset.

Replace original_dataset with the name of your dataset, and upcased_dataset will be the name of the new dataset with all character variables in uppercase.