Tcl Source Code

.AP Tcl_Interp *interp in
Interpreter that contains \fIvarName\fR.
Also used by \fBTcl_LinkVar\fR to return error messages.
.AP "const char" *varName in
Name of global variable.
.AP void *addr in
Address of C variable that is to be linked to \fIvarName\fR.





.AP int type in
Type of C variable for \fBTcl_LinkVar\fR or type of array element for
\fBTcl_LinkArray\fR.  Must be one of \fBTCL_LINK_INT\fR,
\fBTCL_LINK_UINT\fR, \fBTCL_LINK_CHAR\fR, \fBTCL_LINK_UCHAR\fR,
\fBTCL_LINK_SHORT\fR, \fBTCL_LINK_USHORT\fR, \fBTCL_LINK_LONG\fR,
\fBTCL_LINK_ULONG\fR, \fBTCL_LINK_WIDE_INT\fR,
\fBTCL_LINK_WIDE_UINT\fR, \fBTCL_LINK_FLOAT\fR, \fBTCL_LINK_DOUBLE\fR,
\fBTCL_LINK_BOOLEAN\fR, or one of the extra ones listed below.
.sp
In \fBTcl_LinkVar\fR, the additional linked type \fBTCL_LINK_STRING\fR may be
used.
.sp
.VS "TIP 312"
In \fBTcl_LinkArray\fR, the additional linked types \fBTCL_LINK_CHARS\fR and
\fBTCL_LINK_BYTES\fR may be used.  \fBTCL_LINK_ALLOC\fR may also be OR'ed in
to tell Tcl to manage the storage for the array in the variable (that is, the
C variable is technically a pointer to an array, not the array itself).
.VE "TIP 312"
.sp
All the above for both functions may be
optionally OR'ed with \fBTCL_LINK_READ_ONLY\fR to make the Tcl
variable read-only.
.AP int size in
.VS "TIP 312"

while setting up the link (e.g. because \fIvarName\fR is the
name of array) then \fBTCL_ERROR\fR is returned and the interpreter's result
contains an error message.
.PP
.VS "TIP 312"
\fBTcl_LinkArray\fR is similar, but for arrays of fixed size (given by
the \fIsize\fR argument). When asked to allocate the backing C array
storage (via the \fBTCL_LINK_ALLOC\fR bit), it writes the address that
it allocated to the Tcl interpreter result in addition to storing the
location of the array in the C variable pointed to by \fIaddr\fR.
.VE "TIP 312"
.PP
The \fItype\fR argument specifies the type of the C variable,
or the type of the elements of the C array,
and must have one of the following values, optionally OR'ed with
\fBTCL_LINK_READ_ONLY\fR:
.TP

    Tcl_Interp *interp,		/* Interpreter in which varName exists. */
    const char *varName,	/* Name of a global variable in interp. */
    void *addr,			/* Address of a C variable to be linked to
				 * varName. If NULL then the necessary space
				 * will be allocated and returned as the
				 * interpreter result. */
    int type,			/* Type of C variable: TCL_LINK_INT, etc. Also
				 * may have TCL_LINK_READ_ONLY and
				 * TCL_LINK_ALLOC OR'ed in. */
    int size)			/* Size of C variable array, >1 if array */
{
    Tcl_Obj *objPtr;
    Link *linkPtr;
    int code;

    if (size < 1) {