XmTextGetSubstring - A Text function that
retrieves a copy of a portion of the internal text buffer
int XmTextGetSubstring (widget, start, num_chars, buffer_size, buffer)
XmTextGetSubstring 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 is a 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
- 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.
- Specifies the number of characters to be copied into the
- 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 copied.
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.