— A Text function that retrieves a copy of a
portion of the internal text buffer
retrieves a copy of a portion of the internal text
buffer of a Text widget. The function copies a specified number of characters
from a given start position in the internal text buffer into a buffer provided
by the application. A NULL terminator is placed at the end of the copied data.
The size of the required buffer depends on the maximum number of bytes per
character ( MB_CUR_MAX
) for the current locale. MB_CUR_MAX
macro defined in stdlib.h
. The buffer should be large enough to contain
the substring to be copied and a NULL terminator. Use the following equation
to calculate the size of buffer the application should provide:
buffer_size = (num_chars* MB_CUR_MAX) + 1
- Specifies the Text widget ID.
- Specifies the beginning character position from which the data will be
retrieved. This is an integer number of characters from the beginning of
the text buffer. The first character position is 0 (zero).
- Specifies the number of characters to be copied into the provided
- Specifies the size of the supplied buffer in bytes. This size should
account for a NULL terminator.
- Specifies the character buffer into which the internal text buffer will be
For a complete definition of Text and its associated resources, see
- The function was successful.
- The function failed because it was unable to copy the specified number of
characters into the buffer provided. The buffer size may be insufficient.
The contents of buffer are undefined.
- The requested number of characters extended beyond the internal buffer.
The function copied characters between start and the end of the
widget's buffer and terminated the string with a NULL terminator; fewer
than num_chars characters were copied.
(3) and XmTextGetSubstringWcs