TkGetUid(3) Tk Library Procedures TkGetUid(3)

NAME
       TkGetUid, TkUid - convert from string to unique identifier

SYNOPSIS
       ##iinncclluuddee <>

       TkUid
       TTkkGGeettUUiidd(string)

AARRGGUUMMEENNTTSS
       char         *string            (in)      String  for  which the corre-
                                                 sponding unique identifier is
                                                 desired.



DESCRIPTION
       TTkkGGeettUUiidd  returns  the  unique  identifier  corresponding  to  string.
       Unique identifiers are similar to atoms in Lisp, and are used in Tk  to
       speed  up  comparisons and searches.  A unique identifier (type TkUid)
       is a string pointer and may be used anywhere that a  variable  of  type
       ``char  *''  could be used.  However, there is guaranteed to be exactly
       one unique identifier for any given  string  value.   If  TTkkGGeettUUiidd  is
       called twice, once with string a and once with string b, and if a and b
       have the same string value (strcmp(a, b) ==  0),  then  TTkkGGeettUUiidd  will
       return  exactly  the  same  TkUid value for each call (TkGetUid(a) ==
       TkGetUid(b)).  This means that variables of type TkUid  may  be  com-
       pared  directly  (x  == y) without having to call ssttrrccmmpp.  In addition,
       the return value from TTkkGGeettUUiidd will have the same string value as  its
       argument (strcmp(TkGetUid(a), a) == 0).


KKEEYYWWOORRDDSS
       atom, unique identifier



Tk                                                                TkGetUid(3)