Question

is the output of the dprint_r() function (introduced by devel module) visible only if I’m logged in drupal system (as administrator user) ?

thanks

Answer 1

Looking at the function definition, you will find:

/**
 * Pretty-print a variable to the browser (no krumo).
 * Displays only for users with proper permissions. If
 * you want a string returned instead of a print, use the 2nd param.
 */
function dprint_r($input, $return = FALSE, $name = NULL, $function = 'print_r', $check= TRUE) {
  if (user_access('access devel information')) {
    // Snipped main function code ...
  }
}

So it will only produce output for users with the access devel information permission. If you assigned this permission to no role, only user 1 will get to see the output.