Tk_GetUid, Tk_Uid — convert from string to unique identifier
#include <tk.h>
Tk_Uid
Tk_GetUid(string)
- char *string (in)
- String for which the corresponding unique identifier is
desired.
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).
atom, unique identifier
Copyright © 1990 The Regents of the University of
California.
Copyright © 1994-1996 Sun Microsystems, Inc.