form_field_buffer(3X) form_field_buffer(3X)
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:
o Buffer 0 is the displayed value of the field.
o Other numbered buffers may be allocated by applications through the nbuf argument of (see form_field_new(3X)) but are not manipu-
lated by the forms library.
The function field_buffer returns a pointer to the contents of the given numbered buffer:
o The buffer contents always have the same length, and are padded with trailing spaces as needed to ensure this length is the same.
o The buffer may contain leading spaces, depending on how it was set.
o The buffer contents are set with set_field_buffer, or as a side effect of any editing operations on the corresponding field.
o Editing operations are based on the window which displays the field, rather than a string. The window contains only printable char-
acters, and is filled with blanks. If you want the raw data, you must write your own routine that copies the value out of the buf-
fer and removes the leading and trailing spaces.
o 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).
E_BAD_ARGUMENT
Routine detected an incorrect or out-of-range argument.
SEE ALSO
curses(3X) and related pages whose names begin "form_" for detailed descriptions of the entry points.
NOTES
The header file <form.h> automatically includes the header file
When configured for wide characters, field_buffer returns a pointer to temporary storage (allocated and freed by the library). The appli-
cation should not attempt to modify the data. It will be freed on the next call to field_buffer to return the same buffer. <curses.h>.
PORTABILITY
These routines emulate the System V forms library. They were not supported on Version 7 or BSD versions.
AUTHORS
Juergen Pfeifer. Manual pages and adaptation for new curses by Eric S. Raymond.
form_field_buffer(3X)
