sputerr - put error message on screen
Sputerr displays an error message on the screen. form(C-3) uses
sputerr internally to display error messages. If the user edit
routine returns an error message, form calls sputerr to display
the user edit routine's message. Form leaves the cursor at the
current field and waits for further data entry.
After displaying the error message, sputerr clears the input
queue used by snextkey. Any pending operations inserted into the
input queue by snextkey are removed.
Sputerr is provided to allow the user edit routine to issue a
warning message and allow the operator to continue with data
entry. If sputerr is used to issue a warning message, the user
edit routine should return a NULL pointer. Form continues on to
the next data entry field as if there were no error.
The user edit routine should normally return an error message if
there is an error with data in a field. The sputerr function
should be used only in the rare occurrence when the data entered
is correct, but a warning should be given. The warning message
displayed by sputerr stays on the screen until the next data
entry field is completed or until the current record is
completed. The warning message can also be overwritten by another
Chapter 3, Form Programming Guide
If the errmsg parameter points to an empty string or if it
contains unprintable characters, then the error message is not
displayed but is replaced instead with a diagnostic message. This
also happens when a bad pointer is returned by user_edit.
Sputerr is only available in user edit routines.