Tcl Source Code

and
.QW \e\fIn\fR
sequences are handled for each substitution using the information
from the corresponding match.
.TP
\fB\-command\fR
.VS 8.7
Changes the handling of \fIsubSpec\fR so that it is not treated
as a template for a substitution string and the substrings
.QW &
and
.QW \e\fIn\fR
no longer have special meaning. Instead \fIsubSpec\fR must be a

command prefix, that is, a non-empty list.  The substring of \fIstring\fR
that matches \fIexp\fR, and then each substring that matches each
capturing sub-RE within \fIexp\fR are appended as additional elements
to that list. (The items appended to the list are much like what
\fBregexp\fR \fB-inline\fR would return).  The completed list is then
evaluated as a Tcl command, and the result of that command is the

substitution string.  Any error or exception from command evaluation
becomes an error or exception from the \fBregsub\fR command.
.RS
.PP
If \fB\-all\fR is not also given, the command callback will be invoked at most
once (exactly when the regular expression matches). If \fB\-all\fR is given,
the command callback will be invoked for each matched location, in sequence.
The exact location indices that matched are not made available to the script.
.PP

Tcl_RegsubObjCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    int idx, result, cflags, all, wlen, wsublen, numMatches, offset;
    int start, end, subStart, subEnd, match, command, numParts;
    Tcl_RegExp regExpr;
    Tcl_RegExpInfo info;
    Tcl_Obj *resultPtr, *subPtr, *objPtr, *startIndex = NULL;

    Tcl_UniChar ch, *wsrc, *wfirstChar, *wstring, *wsubspec, *wend;

    static const char *const options[] = {
	"-all",		"-command",	"-expanded",	"-line",
	"-linestop",	"-lineanchor",	"-nocase",	"-start",
	"--",		NULL
    };

	 * In command-prefix mode, the substitutions are added as quoted
	 * arguments to the subSpec to form a command, that is then executed
	 * and the result used as the string to substitute in. Actually,
	 * everything is passed through Tcl_EvalObjv, as that's much faster.
	 */

	if (command) {
	    Tcl_Obj **args = NULL, **parts;
	    int numArgs;

	    Tcl_ListObjGetElements(interp, subPtr, &numParts, &parts);
	    numArgs = numParts + info.nsubs + 1;
	    args = ckalloc(sizeof(Tcl_Obj*) * numArgs);
	    memcpy(args, parts, sizeof(Tcl_Obj*) * numParts);


	    for (idx = 0 ; idx <= info.nsubs ; idx++) {
		subStart = info.matches[idx].start;
		subEnd = info.matches[idx].end;
		if ((subStart >= 0) && (subEnd >= 0)) {
		    args[idx + numParts] = Tcl_NewUnicodeObj(
			    wstring + offset + subStart, subEnd - subStart);

	     * At this point, we're locally holding the references to the
	     * argument words we added for this time round the loop, and the
	     * subPtr is holding the references to the words that the user
	     * supplied directly. None are zero-refcount, which is important
	     * because Tcl_EvalObjv is "hairy monster" in terms of refcount
	     * handling, being able to optionally add references to any of its
	     * argument words. We'll drop the local refs immediately
	     * afterwards; subPtr is handled in the main exit stanza.
	     */

	    result = Tcl_EvalObjv(interp, numArgs, args, 0);
	    for (idx = 0 ; idx <= info.nsubs ; idx++) {
		TclDecrRefCount(args[idx + numParts]);
	    }
	    ckfree(args);
	    if (result != TCL_OK) {
		if (result == TCL_ERROR) {
		    Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
			    "\n    (%s substitution computation script)",
			    options[REGSUB_COMMAND]));
		}
		goto done;

  done:
    if (objPtr && (objv[1] == objv[0])) {
	Tcl_DecrRefCount(objPtr);
    }
    if (subPtr && (objv[2] == objv[0])) {
	Tcl_DecrRefCount(subPtr);
    }



    if (resultPtr) {
	Tcl_DecrRefCount(resultPtr);
    }
    return result;
}

/*