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Tk_GetUid(3)                                Tk Library Procedures                               Tk_GetUid(3)



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NAME
       Tk_GetUid, Tk_Uid - convert from string to unique identifier

SYNOPSIS
       #include <tk.h>

       Tk_Uid
       Tk_GetUid(string)

ARGUMENTS
       char *string (in)                         String  for  which  the  corresponding unique identifier is
                                                 desired.
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DESCRIPTION
       Tk_GetUid 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
       Tk_Uid) 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
       Tk_GetUid 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 Tk_GetUid will return exactly the same Tk_Uid value for each
       call (Tk_GetUid(a) == Tk_GetUid(b)).  This means that  variables  of  type  Tk_Uid  may  be  compared
       directly  (x  == y) without having to call strcmp.  In addition, the return value from Tk_GetUid will
       have the same string value as its argument (strcmp(Tk_GetUid(a), a) == 0).


KEYWORDS
       atom, unique identifier



Tk                                                                                              Tk_GetUid(3)