Xmstringisvoid a compound string function that provides information on the existence of non-zero-length text components, tab components, or separator components "xmstringisvoid" "compound string functions" "xmstringisvoid"
#include <Xm/Xm.h> Boolean XmStringIsVoid( XmString s1);
XmStringIsVoid returns a Boolean value indicating whether or not string s1 is void.
Specifies the compound string
Returns True if any non-zero-length text components, tab components, or separator components exist in s1. That is, the function returns True if the string has no text, tabs, or separators. If s1 contains the NULL string, the function returns True.