Tcl Source Code

static int
StringFirstCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{

    int start = 0;

    if (objc < 3 || objc > 4) {
	Tcl_WrongNumArgs(interp, 1, objv,
		"needleString haystackString ?startIndex?");
	return TCL_ERROR;
    }












    if (objc == 4) {




	int size = Tcl_GetCharLength(objv[2]);

	if (TCL_OK != TclGetIntForIndexM(interp, objv[3], size - 1, &start)) {

	    return TCL_ERROR;
	}








	if (start < 0) {

	    start = 0;






	}
	if (start >= size) {


	    Tcl_SetObjResult(interp, Tcl_NewIntObj(-1));




	    return TCL_OK;


	}





    }


















    Tcl_SetObjResult(interp, Tcl_NewIntObj(TclStringFind(objv[1],
	    objv[2], start)));
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * StringLastCmd --

	}
    doneStringMap:
	TRACE_WITH_OBJ(("%.20s %.20s %.20s => ",
		O2S(value2Ptr), O2S(value3Ptr), O2S(valuePtr)), objResultPtr);
	NEXT_INST_V(1, 3, 1);

    case INST_STR_FIND:
#if 1
	match = TclStringFind(OBJ_UNDER_TOS, OBJ_AT_TOS, 0);
#else
	ustring1 = Tcl_GetUnicodeFromObj(OBJ_AT_TOS, &length);	/* Haystack */
	ustring2 = Tcl_GetUnicodeFromObj(OBJ_UNDER_TOS, &length2);/* Needle */

	match = -1;
	if (length2 > 0 && length2 <= length) {
	    end = ustring1 + length - length2 + 1;
	    for (p=ustring1 ; p<end ; p++) {
		if ((*p == *ustring2) &&
			memcmp(ustring2,p,sizeof(Tcl_UniChar)*length2) == 0) {
		    match = p - ustring1;
		    break;
		}
	    }
	}
#endif

	TRACE(("%.20s %.20s => %d\n",
		O2S(OBJ_UNDER_TOS), O2S(OBJ_AT_TOS), match));
	TclNewIntObj(objResultPtr, match);
	NEXT_INST_F(1, 2, 1);

    case INST_STR_FIND_LAST:

			    Tcl_Obj *const *objv, int objc, int subIdx,
			    Tcl_Obj *bad, Tcl_Obj *fix);
MODULE_SCOPE void *	TclStackRealloc(Tcl_Interp *interp, void *ptr,
			    int numBytes);
MODULE_SCOPE int	TclStringCatObjv(Tcl_Interp *interp, int inPlace,
			    int objc, Tcl_Obj *const objv[],
			    Tcl_Obj **objPtrPtr);
MODULE_SCOPE int	TclStringFind(Tcl_Obj *needle, Tcl_Obj *haystack,
			    unsigned int start);
MODULE_SCOPE int	TclStringMatch(const char *str, int strLen,
			    const char *pattern, int ptnLen, int flags);
MODULE_SCOPE int	TclStringMatchObj(Tcl_Obj *stringObj,
			    Tcl_Obj *patternObj, int flags);
MODULE_SCOPE Tcl_Obj *	TclStringObjReverse(Tcl_Obj *objPtr);
MODULE_SCOPE void	TclSubstCompile(Tcl_Interp *interp, const char *bytes,
			    int numBytes, int flags, int line,

		dst += more;
	    }
	}
    }
    *objPtrPtr = objResultPtr;
    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * TclStringFind --
 *
 *	Implements the [string first] operation.
 *
 * Results:
 *	If needle is found as a substring of haystack, the index of the
 *	first instance of such a find is returned.  If needle is not present
 *	as a substring of haystack, -1 is returned.
 *
 * Side effects:
 *	needle and haystack may have their Tcl_ObjType changed.
 *
 *---------------------------------------------------------------------------
 */

int
TclStringFind(
    Tcl_Obj *needle,
    Tcl_Obj *haystack,
    unsigned int start)
{
    int lh, ln = Tcl_GetCharLength(needle);

    if (ln == 0) {
	/*
	 * 	We don't find empty substrings.  Bizarre!
	 *
	 * 	TODO: When we one day make this a true substring
	 * 	finder, change this to "return 0"
	 */
	return -1;
    }

    if (TclIsPureByteArray(needle) && TclIsPureByteArray(haystack)) {
	unsigned char *end, *try, *bh;
	unsigned char *bn = Tcl_GetByteArrayFromObj(needle, &ln);

	bh = Tcl_GetByteArrayFromObj(haystack, &lh);
	end = bh + lh;

	try = bh + start;
	while (try + ln <= end) {
	    try = memchr(try, bn[0], end - try);

	    if (try == NULL) {
		return -1;
	    }
	    if (0 == memcmp(try+1, bn+1, ln-1)) {
		return (try - bh);
	    }
	    try++;
	}
	return -1;
    }

    lh = Tcl_GetCharLength(haystack);
    if (haystack->bytes && (lh == haystack->length)) {
	/* haystack is all single-byte chars */

	if (needle->bytes && (ln == needle->length)) {
	    /* needle is also all single-byte chars */
	    char *found = strstr(haystack->bytes + start, needle->bytes);

	    if (found) {
		return (found - haystack->bytes);
	    } else {
		return -1;
	    }
	} else {
	    /*
	     * Cannot find substring with a multi-byte char inside
	     * a string with no multi-byte chars.
	     */
	    return -1;
	}
    } else {
	Tcl_UniChar *try, *end, *uh;
	Tcl_UniChar *un = Tcl_GetUnicodeFromObj(needle, &ln);

	uh = Tcl_GetUnicodeFromObj(haystack, &lh);
	end = uh + lh;

	try = uh + start;
	while (try + ln <= end) {
	    if ((*try == *un)
		    && (0 == memcmp(try+1, un+1, (ln-1)*sizeof(Tcl_UniChar)))) {
		return (try - uh);
	    }
	    try++;
	}
	return -1;
    }
}

/*
 *---------------------------------------------------------------------------
 *
 * TclStringObjReverse --
 *
 *	Implements the [string reverse] operation.