form_driver —
form library
Curses Form Library (libform, -lform)
#include <form.h>
int
  
  form_driver(FORM
    *form, int
    request);
The form_driver() is the heart of the forms library, it
  takes commands in the request parameter that is either a
  request to the driver to perform some action or is a character to be inserted
  into the current field. The form driver will attempt to insert any printable
  character passed to it into the current field. This may or may not succeed
  depending on the state of the current field. If the character passed is not
  printable then the driver attempts to process it as a driver request. If the
  character passed is not a valid request then the driver will return an unknown
  command error.
The forms driver recognizes the following requests:
  - REQ_NEXT_PAGE
- Change to the next page in the form.
- REQ_PREV_PAGE
- Change to the previous page in the form.
- REQ_FIRST_PAGE
- Select the first page in the form.
- REQ_LAST_PAGE
- Go to the last page in the form.
- REQ_NEXT_FIELD
- Move to the next field in the form field array.
- REQ_PREV_FIELD
- Move to the previous field in the form field array.
- REQ_FIRST_FIELD
- Go to the first field in the form field array.
- REQ_LAST_FIELD
- Go to the last field in the form field array.
- REQ_SNEXT_FIELD
- Move to the next sorted field on the form.
- REQ_SPREV_FIELD
- Move to the previous sorted field on the form.
- REQ_SFIRST_FIELD
- Go to the first field in the sorted list.
- REQ_SLAST_FIELD
- Move to the last field in the sorted list.
- REQ_LEFT_FIELD
- Go one field to the left on the form page.
- REQ_RIGHT_FIELD
- Go one field to the right on the form page.
- REQ_UP_FIELD
- Go up one field on the form page.
- REQ_DOWN_FIELD
- Go down one field on the form page.
- REQ_NEXT_CHAR
- Move one char to the right within the field
- REQ_PREV_CHAR
- Move one char to the left within the current field.
- REQ_NEXT_LINE
- Go down one line in the current field.
- REQ_PREV_LINE
- Go up one line in the current field.
- REQ_NEXT_WORD
- Go forward one word in the current field
- REQ_PREV_WORD
- Go backward one word in the current field.
- REQ_BEG_FIELD
- Move the cursor to the beginning of the current field.
- REQ_END_FIELD
- Move the cursor to the end of the current field.
- REQ_BEG_LINE
- Move the cursor to the beginning of the line in the current field.
- REQ_END_LINE
- Move the cursor to the end of the line.
- REQ_LEFT_CHAR
- Move the cursor left one character
- REQ_RIGHT_CHAR
- Move the cursor right one character
- REQ_UP_CHAR
- Move the cursor up one line.
- REQ_DOWN_CHAR
- Move the cursor down one line.
- REQ_NEW_LINE
- Insert a new line at the current cursor position.
- REQ_INS_CHAR
- Insert a blank character at the current cursor position
- REQ_INS_LINE
- Open a blank line at the current cursor position.
- REQ_DEL_CHAR
- Delete the character at the current cursor position.
- REQ_DEL_PREV
- Delete the character to the left of the current cursor position.
- REQ_DEL_LINE
- Delete the current line.
- REQ_DEL_WORD
- Delete the word at the current cursor position.
- REQ_CLR_EOL
- Clear the field from the current cursor position to the end of the current
      line.
- REQ_CLR_EOF
- Clear the field from the current cursor position to the end of the
    field.
- REQ_CLR_FIELD
- Clear the field.
- REQ_OVL_MODE
- Enter overlay mode, characters added to the field will replace the ones
      already there.
- REQ_INS_MODE
- Enter insert mode, characters will be inserted at the current cursor
      position. Any characters to the right of the cursor will be moved right to
      accommodate the new characters.
- REQ_SCR_FLINE
- Scroll the field forward one line.
- REQ_SCR_BLINE
- Scroll the field backward one line.
- REQ_SCR_FPAGE
- Scroll the field forward one field page.
- REQ_SCR_BPAGE
- Scroll the field backward one field page.
- REQ_SCR_FHPAGE
- Scroll the field forward half one field page.
- REQ_SCR_BHPAGE
- Scroll the field backward half one field page.
- REQ_SCR_FCHAR
- Scroll the field horizontally forward one character
- REQ_SCR_BCHAR
- Scroll the field horizontally backward one character
- REQ_SCR_HFLINE
- Scroll the field horizontally forward one field line.
- REQ_SCR_HBLINE
- Scroll the field horizontally backward one field line.
- REQ_SCR_HFHALF
- Scroll the field horizontally forward half a field line.
- REQ_SCR_HBHALF
- Scroll the field horizontally backward half a field line.
- REQ_VALIDATION
- Request the contents of the current field be validated using any field
      validation function that has been set for the field. Normally, the field
      is validated before the current field changes. This request allows the
      current field to be validated.
- REQ_PREV_CHOICE
- Select the previous choice in an enumerated type field.
- REQ_NEXT_CHOICE
- Select the next choice in an enumerated type field.
Functions returning pointers will returnNULL if an
  error is detected. The functions that return an int will return one of the
  following error values:
  - E_OK
- The function was successful.
- E_REQUEST_DENIED
- The forms driver request could not be fulfilled
- E_UNKNOWN_COMMAND
- The passed character is not a printable character and is not a valid forms
      driver request.
- E_BAD_ARGUMENT
- A bad argument was passed to the forms driver.
- E_INVALID_FIELD
- The form passed to the driver has no valid attached fields.
- E_NOT_POSTED
- The given form is not currently posted to the screen.
- E_BAD_STATE
- The forms driver was called from within an init or term function.
- E_INVALID_FIELD
- The character passed to the forms driver fails the character validation
      for the current field.
Field sorting is done by location of the field on the form page, the fields are
  sorted by position starting with the top-most, left-most field and progressing
  left to right. For the purposes of sorting, the fields top left corner is used
  as the sort criteria. The header<form.h> automatically
  includes both <curses.h> and
  <eti.h>.