plucky (3) set_field_status.3form.gz

NAME

       form_field_buffer - field buffer control

SYNOPSIS

       #include <form.h>

       int set_field_buffer(FIELD *field, int buf, const char *value);
       char *field_buffer(const FIELD *field, int buffer);

       int set_field_status(FIELD *field, bool status);
       bool field_status(const FIELD *field);

       int set_max_field(FIELD *field, int max);

DESCRIPTION

       The function set_field_buffer sets the numbered buffer of the given field to contain a given string:

          •   Buffer 0 is the displayed value of the field.

          •   Other  numbered  buffers  may  be  allocated  by  applications  through  the nbuf argument of (see
              field_new(3FORM)) but are not manipulated by the forms library.

       The function field_buffer returns a pointer to the contents of the given numbered buffer:

          •   The buffer contents always have the same length, and are padded with trailing spaces as needed  to
              ensure this length is the same.

          •   The buffer may contain leading spaces, depending on how it was set.

          •   The  buffer  contents are set with set_field_buffer, or as a side effect of any editing operations
              on the corresponding field.

          •   Editing operations are based on the window which displays the field, rather than  a  string.   The
              window  contains  only printable characters, and is filled with blanks.  If you want the raw data,
              you must write your own routine that copies the value out of the buffer and  removes  the  leading
              and trailing spaces.

          •   Because  editing  operations  change  the  content  of the buffer to correspond to the window, you
              should not rely on using buffers for long-term storage of form data.

       The function set_field_status sets the associated status flag of field;  field_status  gets  the  current
       value.  The status flag is set to a nonzero value whenever the field changes.

       The  function  set_max_field  sets  the maximum size for a dynamic field.  An argument of 0 turns off any
       maximum size threshold for that field.

RETURN VALUE

       The field_buffer function returns NULL on error.  It sets errno according to their success:

       E_OK The routine succeeded.

       E_BAD_ARGUMENT
            Routine detected an incorrect or out-of-range argument.

       The field_status function returns TRUE or FALSE.

       The remaining routines return one of the following:

       E_OK The routine succeeded.

       E_SYSTEM_ERROR
            System error occurred (see errno(3)).

       E_BAD_ARGUMENT
            Routine detected an incorrect or out-of-range argument.

NOTES

       When configured for wide characters, field_buffer returns a pointer to temporary storage  (allocated  and
       freed  by  the library).  The application should not attempt to modify the data.  It will be freed on the
       next call to field_buffer to return the same buffer.

PORTABILITY

       These routines emulate the System V forms library.  They were not supported on Version 7 or BSD versions.

       The set_max_field function checks for an ncurses extension O_INPUT_FIELD which allows a dynamic field  to
       shrink if the new limit is smaller than the current field size.

AUTHORS

       Juergen Pfeifer.  Manual pages and adaptation for new curses by Eric S. Raymond.

SEE ALSO

       ncurses(3NCURSES)  and  related  pages  whose  names begin “form_” for detailed descriptions of the entry
       points.