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).
- E_BAD_ARGUMENT
- Routine detected an incorrect or out-of-range argument.
SEE ALSO¶
ncurses(3NCURSES) 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 application 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.