This function queries the length of an atom represented by the specified atom.

#define INCL_WINATOM /* Or use INCL_WIN, INCL_PM, */
#include <os2.h>

HATOMTBL    hatomtblAtomTbl;  /*  Atom-table handle. */
ATOM        atom;             /*  Atom whose associated character-string length is to be returned. */
ULONG       ulretlen;         /*  String length. */

ulretlen = WinQueryAtomLength(hatomtblAtomTbl,
             atom);