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- * @Id: form_field_buffer.3x,v 1.12 2005/05/15 15:59:55 tom Exp @
+ * @Id: form_field_buffer.3x,v 1.16 2010/07/31 16:09:36 tom Exp @
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</PRE>
<H2>DESCRIPTION</H2><PRE>
The function <STRONG>set_field_buffer</STRONG> 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 <STRONG>nbuf</STRONG> argument
- of (see <STRONG><A HREF="form_field_new.3x.html">form_field_new(3x)</A></STRONG>) but are not manipulated by the
- forms library. The function <STRONG>field_buffer</STRONG> returns the
- address of the buffer. Please note that this buffer has
- always the length of the buffer, that means that it may
- typically contain trailing spaces. If you entered leading
- spaces the buffer may also contain them. 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 trail-
- ing spaces. Please note also, that subsequent operations
- on the form will probably change the content of the
- buffer. So do not use it for long term storage of the
- entered form data.
+ the given field to contain a given string:
+
+ - Buffer 0 is the displayed value of the field.
+
+ - Other numbered buffers may be allocated by applica-
+ tions through the <STRONG>nbuf</STRONG> argument of (see
+ <STRONG><A HREF="form_field_new.3x.html">form_field_new(3x)</A></STRONG>) but are not manipulated by the
+ forms library.
+
+ The function <STRONG>field_buffer</STRONG> returns a pointer to the con-
+ tents 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 <STRONG>set_field_buffer</STRONG>,
+ or as a side effect of any editing operations on the
+ corresponding field.
+
+ - Editing operations are based on the <EM>window</EM> which
+ displays the field, rather than a <EM>string</EM>. The win-
+ dow 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 trail-
+ ing 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 <STRONG>set_field_status</STRONG> sets the associated status
flag of <EM>field</EM>; <STRONG>field_status</STRONG> gets the current value. The
</PRE>
<H2>RETURN VALUE</H2><PRE>
- The <STRONG>field_buffer</STRONG> function returns NULL on error.
+ The <STRONG>field_buffer</STRONG> function returns NULL on error. It sets
+ errno according to their success:
+
+ <STRONG>E_OK</STRONG> The routine succeeded.
+
+ <STRONG>E_BAD_ARGUMENT</STRONG>
+ Routine detected an incorrect or out-of-range argu-
+ ment.
The <STRONG>field_status</STRONG> function returns <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG>.
When configured for wide-characters, <STRONG>field_buffer</STRONG> 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
- <STRONG>field_buffer</STRONG> to return the same buffer. <STRONG><curses.h></STRONG>.
+ the data. It will be freed on the next call to <STRONG>field_buf-</STRONG>
+ <STRONG>fer</STRONG> to return the same buffer. <STRONG><curses.h></STRONG>.
</PRE>
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