3 #P = start of string Q = start of substr R = end of substr S = end of string
13 $SIG{__WARN__} = sub {
14 if ($_[0] =~ /^substr outside of string/) {
16 } elsif ($_[0] =~ /^Attempt to use reference as lvalue in substr/) {
18 } elsif ($_[0] =~ /^Use of uninitialized value/) {
27 run_tests() unless caller;
33 $FATAL_MSG = qr/^substr outside of string/;
35 is(substr($a,0,3), 'abc'); # P=Q R S
36 is(substr($a,3,3), 'def'); # P Q R S
37 is(substr($a,6,999), 'xyz'); # P Q S R
38 $b = substr($a,999,999) ; # warn # P R Q S
40 eval{substr($a,999,999) = "" ; };# P R Q S
41 like ($@, $FATAL_MSG);
42 is(substr($a,0,-6), 'abc'); # P=Q R S
43 is(substr($a,-3,1), 'x'); # P Q R S
44 sub{$b = shift}->(substr($a,999,999));
45 is ($w--, 1, 'boundless lvalue substr only warns on fetch');
47 substr($a,3,3) = 'XYZ';
51 substr($a,0,0) = 'ab';
53 substr($a,0,0) = '12345678';
54 is($a, '12345678abcXYZxyz' );
55 substr($a,-3,3) = 'def';
56 is($a, '12345678abcXYZdef');
57 substr($a,-3,3) = '<';
58 is($a, '12345678abcXYZ<' );
59 substr($a,-1,1) = '12345678';
60 is($a, '12345678abcXYZ12345678' );
64 is(substr($a,6), 'xyz' ); # P Q R=S
65 is(substr($a,-3), 'xyz' ); # P Q R=S
66 $b = substr($a,999,999) ; # warning # P R=S Q
68 eval{substr($a,999,999) = "" ; } ; # P R=S Q
70 is(substr($a,0), 'abcdefxyz'); # P=Q R=S
71 is(substr($a,9), ''); # P Q=R=S
72 is(substr($a,-11), 'abcdefxyz'); # Q P R=S
73 is(substr($a,-9), 'abcdefxyz'); # P=Q R=S
77 $b = substr($a,-7, 1) ; # warn # Q R P S
79 eval{substr($a,-7, 1) = "" ; }; # Q R P S
81 $b = substr($a,-7,-6) ; # warn # Q R P S
83 eval{substr($a,-7,-6) = "" ; }; # Q R P S
85 is(substr($a,-5,-7), ''); # R P=Q S
86 is(substr($a, 2,-7), ''); # R P Q S
87 is(substr($a,-3,-7), ''); # R P Q S
88 is(substr($a, 2,-5), ''); # P=R Q S
89 is(substr($a,-3,-5), ''); # P=R Q S
90 is(substr($a, 2,-4), ''); # P R Q S
91 is(substr($a,-3,-4), ''); # P R Q S
92 is(substr($a, 5,-6), ''); # R P Q=S
93 is(substr($a, 5,-5), ''); # P=R Q S
94 is(substr($a, 5,-3), ''); # P R Q=S
95 $b = substr($a, 7,-7) ; # warn # R P S Q
97 eval{substr($a, 7,-7) = "" ; }; # R P S Q
99 $b = substr($a, 7,-5) ; # warn # P=R S Q
101 eval{substr($a, 7,-5) = "" ; }; # P=R S Q
102 like($@, $FATAL_MSG);
103 $b = substr($a, 7,-3) ; # warn # P Q S Q
105 eval{substr($a, 7,-3) = "" ; }; # P Q S Q
106 like($@, $FATAL_MSG);
107 $b = substr($a, 7, 0) ; # warn # P S Q=R
109 eval{substr($a, 7, 0) = "" ; }; # P S Q=R
110 like($@, $FATAL_MSG);
112 is(substr($a,-7,2), ''); # Q P=R S
113 is(substr($a,-7,4), '54'); # Q P R S
114 is(substr($a,-7,7), '54321');# Q P R=S
115 is(substr($a,-7,9), '54321');# Q P S R
116 is(substr($a,-5,0), ''); # P=Q=R S
117 is(substr($a,-5,3), '543');# P=Q R S
118 is(substr($a,-5,5), '54321');# P=Q R=S
119 is(substr($a,-5,7), '54321');# P=Q S R
120 is(substr($a,-3,0), ''); # P Q=R S
121 is(substr($a,-3,3), '321');# P Q R=S
122 is(substr($a,-2,3), '21'); # P Q S R
123 is(substr($a,0,-5), ''); # P=Q=R S
124 is(substr($a,2,-3), ''); # P Q=R S
125 is(substr($a,0,0), ''); # P=Q=R S
126 is(substr($a,0,5), '54321');# P=Q R=S
127 is(substr($a,0,7), '54321');# P=Q S R
128 is(substr($a,2,0), ''); # P Q=R S
129 is(substr($a,2,3), '321'); # P Q R=S
130 is(substr($a,5,0), ''); # P Q=R=S
131 is(substr($a,5,2), ''); # P Q=S R
132 is(substr($a,-7,-5), ''); # Q P=R S
133 is(substr($a,-7,-2), '543');# Q P R S
134 is(substr($a,-5,-5), ''); # P=Q=R S
135 is(substr($a,-5,-2), '543');# P=Q R S
136 is(substr($a,-3,-3), ''); # P Q=R S
137 is(substr($a,-3,-1), '32');# P Q R S
141 is(substr($a,-2,2), ''); # Q P=R=S
142 is(substr($a,0,0), ''); # P=Q=R=S
143 is(substr($a,0,1), ''); # P=Q=S R
144 is(substr($a,-2,3), ''); # Q P=S R
145 is(substr($a,-2), ''); # Q P=R=S
146 is(substr($a,0), ''); # P=Q=R=S
149 is(substr($a,0,-1), ''); # R P=Q=S
150 $b = substr($a,-2, 0) ; # warn # Q=R P=S
152 eval{substr($a,-2, 0) = "" ; }; # Q=R P=S
153 like($@, $FATAL_MSG);
155 $b = substr($a,-2, 1) ; # warn # Q R P=S
157 eval{substr($a,-2, 1) = "" ; }; # Q R P=S
158 like($@, $FATAL_MSG);
160 $b = substr($a,-2,-1) ; # warn # Q R P=S
162 eval{substr($a,-2,-1) = "" ; }; # Q R P=S
163 like($@, $FATAL_MSG);
165 $b = substr($a,-2,-2) ; # warn # Q=R P=S
167 eval{substr($a,-2,-2) = "" ; }; # Q=R P=S
168 like($@, $FATAL_MSG);
170 $b = substr($a, 1,-2) ; # warn # R P=S Q
172 eval{substr($a, 1,-2) = "" ; }; # R P=S Q
173 like($@, $FATAL_MSG);
175 $b = substr($a, 1, 1) ; # warn # P=S Q R
177 eval{substr($a, 1, 1) = "" ; }; # P=S Q R
178 like($@, $FATAL_MSG);
180 $b = substr($a, 1, 0) ;# warn # P=S Q=R
182 eval{substr($a, 1, 0) = "" ; }; # P=S Q=R
183 like($@, $FATAL_MSG);
185 $b = substr($a,1) ; # warning # P=R=S Q
187 eval{substr($a,1) = "" ; }; # P=R=S Q
188 like($@, $FATAL_MSG);
190 $b = substr($a,-7,-6) ; # warn # Q R P S
192 eval{substr($a,-7,-6) = "" ; }; # Q R P S
193 like($@, $FATAL_MSG);
202 substr($a,0,2) = 'pq';
204 substr($a,2,0) = 'r';
206 substr($a,8,0) = 'asd';
207 is($a, 'pqrcvbnmasd');
208 substr($a,0,2) = 'iop';
209 is($a, 'ioprcvbnmasd');
210 substr($a,0,5) = 'fgh';
211 is($a, 'fghvbnmasd');
212 substr($a,3,5) = 'jkl';
214 substr($a,3,2) = '1234';
215 is($a, 'fgh1234lsd');
218 # with lexicals (and in re-entered scopes)
223 substr($txt, -1) = "X";
227 substr($txt, 0, 1) = "X";
233 # coercion of references
236 substr($s, 0, 1) = 'Foo';
237 is (substr($s,0,7), "FooRRAY");
242 # check no spurious warnings
245 # check new 4 arg replacement syntax
248 is(substr($a, 0, 3, ""), "abc");
250 is(substr($a, 0, 0, "abc"), "");
252 is(substr($a, 3, -1, ""), "xy");
255 is(substr($a, 3, undef, "xy"), "");
261 is(substr($a, 3, 9999999, ""), "xyz");
263 eval{substr($a, -99, 0, "") };
264 like($@, $FATAL_MSG);
265 eval{substr($a, 99, 3, "") };
266 like($@, $FATAL_MSG);
268 substr($a, 0, length($a), "foo");
272 # using 4 arg substr as lvalue is a compile time error
273 eval 'substr($a,0,0,"") = "abc"';
274 like ($@, qr/Can't modify substr/);
278 is(sub { shift }->(substr($a, 0, 4, "xxxx")), 'abcd');
289 my $x = substr("a\x{263a}b",0);
295 substr($x,0,1) = "abcd";
296 is($x, "abcd\x{263a}");
300 is($x, "\x{263a}dcba");
303 $z = "21\x{263a}" . $z;
305 is($z, "21\x{263a}10");
308 # replacement should work on magical values
311 tie $data{'a'}, 'Tie::StdScalar'; # makes $data{'a'} magical
312 $data{a} = "firstlast";
313 is(substr($data{'a'}, 0, 5, ""), "first");
314 is($data{'a'}, "last");
318 # The following two originally from Ignasi Roca.
321 substr($x, 0, 1) = "\x{100}"; # Ignasi had \x{FF}
323 is($x, "\x{100}\xF2\xF3");
324 is(substr($x, 0, 1), "\x{100}");
325 is(substr($x, 1, 1), "\x{F2}");
326 is(substr($x, 2, 1), "\x{F3}");
329 substr($x, 0, 1) = "\x{100}\x{FF}"; # Ignasi had \x{FF}
331 is($x, "\x{100}\x{FF}\xF2\xF3");
332 is(substr($x, 0, 1), "\x{100}");
333 is(substr($x, 1, 1), "\x{FF}");
334 is(substr($x, 2, 1), "\x{F2}");
335 is(substr($x, 3, 1), "\x{F3}");
337 # more utf8 lval exercise
340 substr($x, 0, 2) = "\x{100}\xFF";
342 is($x, "\x{100}\xFF\xF3");
343 is(substr($x, 0, 1), "\x{100}");
344 is(substr($x, 1, 1), "\x{FF}");
345 is(substr($x, 2, 1), "\x{F3}");
348 substr($x, 1, 1) = "\x{100}\xFF";
350 is($x, "\xF1\x{100}\xFF\xF3");
351 is(substr($x, 0, 1), "\x{F1}");
352 is(substr($x, 1, 1), "\x{100}");
353 is(substr($x, 2, 1), "\x{FF}");
354 is(substr($x, 3, 1), "\x{F3}");
357 substr($x, 2, 1) = "\x{100}\xFF";
359 is($x, "\xF1\xF2\x{100}\xFF");
360 is(substr($x, 0, 1), "\x{F1}");
361 is(substr($x, 1, 1), "\x{F2}");
362 is(substr($x, 2, 1), "\x{100}");
363 is(substr($x, 3, 1), "\x{FF}");
366 substr($x, 3, 1) = "\x{100}\xFF";
368 is($x, "\xF1\xF2\xF3\x{100}\xFF");
369 is(substr($x, 0, 1), "\x{F1}");
370 is(substr($x, 1, 1), "\x{F2}");
371 is(substr($x, 2, 1), "\x{F3}");
372 is(substr($x, 3, 1), "\x{100}");
373 is(substr($x, 4, 1), "\x{FF}");
376 substr($x, -1, 1) = "\x{100}\xFF";
378 is($x, "\xF1\xF2\x{100}\xFF");
379 is(substr($x, 0, 1), "\x{F1}");
380 is(substr($x, 1, 1), "\x{F2}");
381 is(substr($x, 2, 1), "\x{100}");
382 is(substr($x, 3, 1), "\x{FF}");
385 substr($x, -1, 0) = "\x{100}\xFF";
387 is($x, "\xF1\xF2\x{100}\xFF\xF3");
388 is(substr($x, 0, 1), "\x{F1}");
389 is(substr($x, 1, 1), "\x{F2}");
390 is(substr($x, 2, 1), "\x{100}");
391 is(substr($x, 3, 1), "\x{FF}");
392 is(substr($x, 4, 1), "\x{F3}");
395 substr($x, 0, -1) = "\x{100}\xFF";
397 is($x, "\x{100}\xFF\xF3");
398 is(substr($x, 0, 1), "\x{100}");
399 is(substr($x, 1, 1), "\x{FF}");
400 is(substr($x, 2, 1), "\x{F3}");
403 substr($x, 0, -2) = "\x{100}\xFF";
405 is($x, "\x{100}\xFF\xF2\xF3");
406 is(substr($x, 0, 1), "\x{100}");
407 is(substr($x, 1, 1), "\x{FF}");
408 is(substr($x, 2, 1), "\x{F2}");
409 is(substr($x, 3, 1), "\x{F3}");
412 substr($x, 0, -3) = "\x{100}\xFF";
414 is($x, "\x{100}\xFF\xF1\xF2\xF3");
415 is(substr($x, 0, 1), "\x{100}");
416 is(substr($x, 1, 1), "\x{FF}");
417 is(substr($x, 2, 1), "\x{F1}");
418 is(substr($x, 3, 1), "\x{F2}");
419 is(substr($x, 4, 1), "\x{F3}");
422 substr($x, 1, -1) = "\x{100}\xFF";
424 is($x, "\xF1\x{100}\xFF\xF3");
425 is(substr($x, 0, 1), "\x{F1}");
426 is(substr($x, 1, 1), "\x{100}");
427 is(substr($x, 2, 1), "\x{FF}");
428 is(substr($x, 3, 1), "\x{F3}");
431 substr($x, -1, -1) = "\x{100}\xFF";
433 is($x, "\xF1\xF2\x{100}\xFF\xF3");
434 is(substr($x, 0, 1), "\x{F1}");
435 is(substr($x, 1, 1), "\x{F2}");
436 is(substr($x, 2, 1), "\x{100}");
437 is(substr($x, 3, 1), "\x{FF}");
438 is(substr($x, 4, 1), "\x{F3}");
440 # And tests for already-UTF8 one
442 $x = "\x{101}\x{F2}\x{F3}";
443 substr($x, 0, 1) = "\x{100}";
445 is($x, "\x{100}\xF2\xF3");
446 is(substr($x, 0, 1), "\x{100}");
447 is(substr($x, 1, 1), "\x{F2}");
448 is(substr($x, 2, 1), "\x{F3}");
450 $x = "\x{101}\x{F2}\x{F3}";
451 substr($x, 0, 1) = "\x{100}\x{FF}";
453 is($x, "\x{100}\x{FF}\xF2\xF3");
454 is(substr($x, 0, 1), "\x{100}");
455 is(substr($x, 1, 1), "\x{FF}");
456 is(substr($x, 2, 1), "\x{F2}");
457 is(substr($x, 3, 1), "\x{F3}");
459 $x = "\x{101}\x{F2}\x{F3}";
460 substr($x, 0, 2) = "\x{100}\xFF";
462 is($x, "\x{100}\xFF\xF3");
463 is(substr($x, 0, 1), "\x{100}");
464 is(substr($x, 1, 1), "\x{FF}");
465 is(substr($x, 2, 1), "\x{F3}");
467 $x = "\x{101}\x{F2}\x{F3}";
468 substr($x, 1, 1) = "\x{100}\xFF";
470 is($x, "\x{101}\x{100}\xFF\xF3");
471 is(substr($x, 0, 1), "\x{101}");
472 is(substr($x, 1, 1), "\x{100}");
473 is(substr($x, 2, 1), "\x{FF}");
474 is(substr($x, 3, 1), "\x{F3}");
476 $x = "\x{101}\x{F2}\x{F3}";
477 substr($x, 2, 1) = "\x{100}\xFF";
479 is($x, "\x{101}\xF2\x{100}\xFF");
480 is(substr($x, 0, 1), "\x{101}");
481 is(substr($x, 1, 1), "\x{F2}");
482 is(substr($x, 2, 1), "\x{100}");
483 is(substr($x, 3, 1), "\x{FF}");
485 $x = "\x{101}\x{F2}\x{F3}";
486 substr($x, 3, 1) = "\x{100}\xFF";
488 is($x, "\x{101}\x{F2}\x{F3}\x{100}\xFF");
489 is(substr($x, 0, 1), "\x{101}");
490 is(substr($x, 1, 1), "\x{F2}");
491 is(substr($x, 2, 1), "\x{F3}");
492 is(substr($x, 3, 1), "\x{100}");
493 is(substr($x, 4, 1), "\x{FF}");
495 $x = "\x{101}\x{F2}\x{F3}";
496 substr($x, -1, 1) = "\x{100}\xFF";
498 is($x, "\x{101}\xF2\x{100}\xFF");
499 is(substr($x, 0, 1), "\x{101}");
500 is(substr($x, 1, 1), "\x{F2}");
501 is(substr($x, 2, 1), "\x{100}");
502 is(substr($x, 3, 1), "\x{FF}");
504 $x = "\x{101}\x{F2}\x{F3}";
505 substr($x, -1, 0) = "\x{100}\xFF";
507 is($x, "\x{101}\xF2\x{100}\xFF\xF3");
508 is(substr($x, 0, 1), "\x{101}");
509 is(substr($x, 1, 1), "\x{F2}");
510 is(substr($x, 2, 1), "\x{100}");
511 is(substr($x, 3, 1), "\x{FF}");
512 is(substr($x, 4, 1), "\x{F3}");
514 $x = "\x{101}\x{F2}\x{F3}";
515 substr($x, 0, -1) = "\x{100}\xFF";
517 is($x, "\x{100}\xFF\xF3");
518 is(substr($x, 0, 1), "\x{100}");
519 is(substr($x, 1, 1), "\x{FF}");
520 is(substr($x, 2, 1), "\x{F3}");
522 $x = "\x{101}\x{F2}\x{F3}";
523 substr($x, 0, -2) = "\x{100}\xFF";
525 is($x, "\x{100}\xFF\xF2\xF3");
526 is(substr($x, 0, 1), "\x{100}");
527 is(substr($x, 1, 1), "\x{FF}");
528 is(substr($x, 2, 1), "\x{F2}");
529 is(substr($x, 3, 1), "\x{F3}");
531 $x = "\x{101}\x{F2}\x{F3}";
532 substr($x, 0, -3) = "\x{100}\xFF";
534 is($x, "\x{100}\xFF\x{101}\x{F2}\x{F3}");
535 is(substr($x, 0, 1), "\x{100}");
536 is(substr($x, 1, 1), "\x{FF}");
537 is(substr($x, 2, 1), "\x{101}");
538 is(substr($x, 3, 1), "\x{F2}");
539 is(substr($x, 4, 1), "\x{F3}");
541 $x = "\x{101}\x{F2}\x{F3}";
542 substr($x, 1, -1) = "\x{100}\xFF";
544 is($x, "\x{101}\x{100}\xFF\xF3");
545 is(substr($x, 0, 1), "\x{101}");
546 is(substr($x, 1, 1), "\x{100}");
547 is(substr($x, 2, 1), "\x{FF}");
548 is(substr($x, 3, 1), "\x{F3}");
550 $x = "\x{101}\x{F2}\x{F3}";
551 substr($x, -1, -1) = "\x{100}\xFF";
553 is($x, "\x{101}\xF2\x{100}\xFF\xF3");
554 is(substr($x, 0, 1), "\x{101}");
555 is(substr($x, 1, 1), "\x{F2}");
556 is(substr($x, 2, 1), "\x{100}");
557 is(substr($x, 3, 1), "\x{FF}");
558 is(substr($x, 4, 1), "\x{F3}");
560 substr($x = "ab", 0, 0, "\x{100}\x{200}");
561 is($x, "\x{100}\x{200}ab");
563 substr($x = "\x{100}\x{200}", 0, 0, "ab");
564 is($x, "ab\x{100}\x{200}");
566 substr($x = "ab", 1, 0, "\x{100}\x{200}");
567 is($x, "a\x{100}\x{200}b");
569 substr($x = "\x{100}\x{200}", 1, 0, "ab");
570 is($x, "\x{100}ab\x{200}");
572 substr($x = "ab", 2, 0, "\x{100}\x{200}");
573 is($x, "ab\x{100}\x{200}");
575 substr($x = "\x{100}\x{200}", 2, 0, "ab");
576 is($x, "\x{100}\x{200}ab");
578 substr($x = "\xFFb", 0, 0, "\x{100}\x{200}");
579 is($x, "\x{100}\x{200}\xFFb");
581 substr($x = "\x{100}\x{200}", 0, 0, "\xFFb");
582 is($x, "\xFFb\x{100}\x{200}");
584 substr($x = "\xFFb", 1, 0, "\x{100}\x{200}");
585 is($x, "\xFF\x{100}\x{200}b");
587 substr($x = "\x{100}\x{200}", 1, 0, "\xFFb");
588 is($x, "\x{100}\xFFb\x{200}");
590 substr($x = "\xFFb", 2, 0, "\x{100}\x{200}");
591 is($x, "\xFFb\x{100}\x{200}");
593 substr($x = "\x{100}\x{200}", 2, 0, "\xFFb");
594 is($x, "\x{100}\x{200}\xFFb");
600 $r[$_] = \ substr $s, $_, 1 for (0, 1);
601 is(join("", map { $$_ } @r), "ab");
607 substr($_[0],0,1) ^= substr($_[0],1,1) ^=
608 substr($_[0],0,1) ^= substr($_[0],1,1);
610 my $x = my $y = 'AB'; ss $x; ss $y;
616 my $x = "0123456789\x{500}";
617 my $y = substr $x, 4;
618 is(substr($x, 7, 1), "7");
621 # multiple assignments to lvalue [perl #24346]
624 for (substr($x,1,3)) {
632 $_ = "\xF1\xF2\xF3\xF4\xF5\xF6";
633 is($_, "\xF1\xF2\xF3\xF4\xF5\xF6");
634 is($x, "a\xF1\xF2\xF3\xF4\xF5\xF6ef");
645 $x .= "frompswiggle";
646 is $_, "XXfrompswiggle";
649 for (substr($x,1,-1)) {
654 $x .= "frompswiggle";
655 is $_, "XXffrompswiggl";
658 for (substr($x,-5,3)) {
660 $_ = 'XX'; # now $_ is substr($x, -4, 2)
663 $x .= "frompswiggle";
667 for (substr($x,-5)) {
669 $_ = 'XX'; # now substr($x, -2)
672 $x .= "frompswiggle";
676 for (substr($x,-5,-1)) {
678 $_ = 'XX'; # now substr($x, -3, -1)
681 $x .= "frompswiggle";
686 # Also part of perl #24346; scalar(substr...) should not affect lvalueness
689 sub { $_[0] = 'dea' }->( scalar substr $str, 3, 2 );
690 is $str, 'abcdeaf', 'scalar does not affect lvalueness of substr';
693 # [perl #24200] string corruption with lvalue sub
696 sub bar: lvalue { substr $krunch, 0 }
699 $krunch = '123456789';
700 is(bar, '123456789');
705 my $text = "0123456789\xED ";
706 utf8::upgrade($text);
709 my $a = substr($text, $pos, $pos);
710 is(substr($text,$pos,1), $pos);
714 # [perl #34976] incorrect caching of utf8 substr length
716 my $a = "abcd\x{100}";
717 is(substr($a,1,2), 'bc');
718 is(substr($a,1,1), 'b');
721 # [perl #62646] offsets exceeding 32 bits on 64-bit system
723 skip("32-bit system", 24) unless ~0 > 0xffffffff;
731 $r = substr($a, 0xffffffff, 1);
736 $r = substr($a, 0xffffffff+1, 1);
741 ok( !eval { $r = substr($s=$a, 0xffffffff, 1, "_"); 1 } );
747 ok( !eval { $r = substr($s=$a, 0xffffffff+1, 1, "_"); 1 } );
756 # [perl #77692] UTF8 cache not being reset when TARG is reused
758 local ${^UTF8CACHE} = -1;
761 my $dummy = length(substr("\x{100}",0,$i));
764 }, 'UTF8 cache is reset when TARG is reused [perl #77692]';
768 use open qw( :utf8 :std );
772 substr $t, 0, 0, *ワルド;
773 is($t, "*main::ワルド", "substr works on UTF-8 globs");
776 substr $t, 0, 9, *ザ::ワルド;
777 is($t, "*ザ::ワルド!", "substr works on a UTF-8 glob + stash");
782 my $y = \substr *foo, 0, 0;
783 is ref \$x, 'GLOB', '\substr does not coerce its glob arg just yet';
785 $y = \substr *foo, 0, 0;
786 is ref \$x, 'REF', '\substr does not coerce its ref arg just yet';
789 # Test that UTF8-ness of magic var changing does not confuse substr lvalue
791 # We use overloading for our magic var, but a typeglob would work, too.
793 use overload '""' => sub { ++our $count; $_[0][0] }
795 my $refee = bless ["\x{100}a"], o::;
796 my $substr = \substr $refee, -2; # UTF8 flag still off for $$substr.
797 $$substr = "b"; # UTF8 flag turns on when setsubstr
798 is $refee, "b", # magic stringifies $$substr.
799 'substr lvalue assignment when stringification turns on UTF8ness';
801 # Test that changing UTF8-ness does not confuse 4-arg substr.
802 $refee = bless [], "\x{100}a";
803 # stringify without returning on UTF8 flag on $refee:
804 my $string = $refee; $string = "$string";
805 substr $refee, 0, 0, "\xff";
806 is $refee, "\xff$string",
807 '4-arg substr with target UTF8ness turning on when stringified';
808 $refee = bless [], "\x{100}";
809 () = "$refee"; # UTF8 flag now on
810 bless $refee, "\xff";
811 $string = $refee; $string = "$string";
812 substr $refee, 0, 0, "\xff";
813 is $refee, "\xff$string",
814 '4-arg substr with target UTF8ness turning off when stringified';
817 $refee = bless ["foo"], o::;
819 substr $refee, 0, 0, "";
820 is $o::count, 1, '4-arg substr calls overloading once on the target';
821 $refee = bless ["\x{100}"], o::;
822 () = "$refee"; # turn UTF8 flag on
824 () = substr $refee, 0;
825 is $o::count, 1, 'rvalue substr calls overloading once on utf8 target';
828 ${\substr $refee, 0} = bless ["\x{100}"], o::;
829 is $o::count, 1, 'assigning utf8 overload to substr lvalue calls ovld 1ce';
831 # [perl #7678] core dump with substr reference and localisation
832 {$b="abcde"; local $k; *k=\substr($b, 2, 1);}
834 # [perl #128260] assertion failure with \substr %h, \substr @h
838 is ${\substr %h, 0}, scalar %h, '\substr %h';
839 is ${\substr @a, 0}, scalar @a, '\substr @a';
842 } # sub run_tests - put tests above this line that can run in threads
846 { package Class; DESTROY { ++$destroyed; } }
852 $x = bless({}, 'Class');
854 is($destroyed, 1, 'Timely scalar destruction with lvalue substr');
859 my ($word, $replace) = @_;
860 my $ref = \substr($word, 0, 1);
862 if ($replace eq "b") {
863 $result_3363 = $word;
868 a_3363($_, "v") for "test";
870 is($result_3363, "best", "ref-to-substr retains lvalue-ness under recursion [perl #3363]");
874 fresh_perl_is('$0 = "/usr/bin/perl"; substr($0, 0, 0, $0)', '', {}, "(perl #129340) substr() with source in target");
877 # [perl #130624] - heap-use-after-free, observable under asan
881 my $z = substr $x, 0, 1, $y;
882 is $z, "\xE9", "RT#130624: heap-use-after-free in 4-arg substr (ret)";
883 is $x, "\x{100}zzzz", "RT#130624: heap-use-after-free in 4-arg substr (targ)";
889 substr($#ta, 0, 2) = 23;
892 substr($#ta, 0, 2) =~ s/\A..\z/23/s;
895 substr($#ta, 0, 2, 23);
897 sub ta_tindex :lvalue { $#ta }
902 substr(ta_tindex(), 0, 2) = 23;
905 substr(ta_tindex(), 0, 2) =~ s/\A..\z/23/s;
908 substr(ta_tindex(), 0, 2, 23);
913 use feature 'refaliasing';
914 no warnings 'experimental::refaliasing';
916 \$h{foo} = \(my $bar = "baz");
917 substr delete $h{foo}, 1, 1, o=>;
918 is $bar, boz => 'first arg to 4-arg substr is loose lvalue context';