1 |
# Demonstrations for users. Could go in docs. |
2 |
|
3 |
#### GetValue scope and shopt --unset dynamic_scope |
4 |
|
5 |
f() { |
6 |
echo "sh x=$x" |
7 |
} |
8 |
|
9 |
proc p { |
10 |
echo "oil x=$x" |
11 |
} |
12 |
|
13 |
demo() { |
14 |
local x=dynamic |
15 |
f |
16 |
p |
17 |
|
18 |
shopt --unset dynamic_scope |
19 |
f |
20 |
} |
21 |
|
22 |
x=global |
23 |
demo |
24 |
echo x=$x |
25 |
|
26 |
## STDOUT: |
27 |
sh x=dynamic |
28 |
oil x=global |
29 |
sh x=global |
30 |
x=global |
31 |
## END |
32 |
|
33 |
|
34 |
#### SetValue scope and shopt --unset dynamic_scope |
35 |
f() { |
36 |
x=f |
37 |
} |
38 |
|
39 |
proc p { |
40 |
x=p |
41 |
} |
42 |
|
43 |
demo() { |
44 |
local x=stack |
45 |
echo x=$x |
46 |
echo --- |
47 |
|
48 |
f |
49 |
echo f x=$x |
50 |
|
51 |
x=stack |
52 |
p |
53 |
echo p x=$x |
54 |
|
55 |
shopt --unset dynamic_scope |
56 |
x=stack |
57 |
f |
58 |
echo funset x=$x |
59 |
} |
60 |
|
61 |
x=global |
62 |
demo |
63 |
|
64 |
echo --- |
65 |
echo x=$x |
66 |
|
67 |
## STDOUT: |
68 |
x=stack |
69 |
--- |
70 |
f x=f |
71 |
p x=stack |
72 |
funset x=stack |
73 |
--- |
74 |
x=global |
75 |
## END |
76 |
|
77 |
#### read scope (setref) |
78 |
set -o errexit |
79 |
|
80 |
read-x() { |
81 |
echo dynamic-scope | read x |
82 |
} |
83 |
demo() { |
84 |
local x=42 |
85 |
echo x_before=$x |
86 |
read-x |
87 |
echo x_after=$x |
88 |
} |
89 |
demo |
90 |
echo x=$x |
91 |
|
92 |
echo --- |
93 |
|
94 |
# Now 'read x' creates a local variable |
95 |
shopt --unset dynamic_scope |
96 |
demo |
97 |
echo x=$x |
98 |
|
99 |
## STDOUT: |
100 |
x_before=42 |
101 |
x_after=dynamic-scope |
102 |
x= |
103 |
--- |
104 |
x_before=42 |
105 |
x_after=42 |
106 |
x= |
107 |
## END |
108 |
|
109 |
#### printf -v x respects dynamic_scope |
110 |
set -o errexit |
111 |
|
112 |
set-x() { |
113 |
printf -v x "%s" dynamic-scope |
114 |
} |
115 |
demo() { |
116 |
local x=42 |
117 |
echo x=$x |
118 |
set-x |
119 |
echo x=$x |
120 |
} |
121 |
demo |
122 |
echo x=$x |
123 |
|
124 |
echo --- |
125 |
|
126 |
shopt --unset dynamic_scope # should NOT affect read |
127 |
demo |
128 |
echo x=$x |
129 |
|
130 |
## STDOUT: |
131 |
x=42 |
132 |
x=dynamic-scope |
133 |
x= |
134 |
--- |
135 |
x=42 |
136 |
x=42 |
137 |
x= |
138 |
## END |
139 |
|
140 |
#### printf -v a[i] respects dynamic_scope |
141 |
set -o errexit |
142 |
shopt --set eval_unsafe_arith |
143 |
|
144 |
set-item() { |
145 |
printf -v 'a[1]' "%s" dynamic-scope |
146 |
} |
147 |
demo() { |
148 |
local -a a=(41 42 43) |
149 |
echo "a[1]=${a[1]}" |
150 |
set-item |
151 |
echo "a[1]=${a[1]}" |
152 |
} |
153 |
demo |
154 |
echo "a[1]=${a[1]}" |
155 |
|
156 |
echo --- |
157 |
|
158 |
shopt --unset dynamic_scope # should NOT affect read |
159 |
demo |
160 |
echo "a[1]=${a[1]}" |
161 |
|
162 |
## STDOUT: |
163 |
a[1]=42 |
164 |
a[1]=dynamic-scope |
165 |
a[1]= |
166 |
--- |
167 |
a[1]=42 |
168 |
a[1]=42 |
169 |
a[1]= |
170 |
## END |
171 |
|
172 |
#### ${undef=a} and shopt --unset dynamic_scope |
173 |
|
174 |
set-x() { |
175 |
: ${x=new} |
176 |
} |
177 |
demo() { |
178 |
local x |
179 |
echo x=$x |
180 |
set-x |
181 |
echo x=$x |
182 |
} |
183 |
|
184 |
demo |
185 |
echo x=$x |
186 |
|
187 |
echo --- |
188 |
|
189 |
# Now this IS affected? |
190 |
shopt --unset dynamic_scope |
191 |
demo |
192 |
echo x=$x |
193 |
## STDOUT: |
194 |
x= |
195 |
x=new |
196 |
x= |
197 |
--- |
198 |
x= |
199 |
x= |
200 |
x= |
201 |
## END |
202 |
|
203 |
#### declare -p respects it |
204 |
__g=G |
205 |
show-vars() { |
206 |
local __x=X |
207 |
declare -p | grep '__' |
208 |
echo status=$? |
209 |
|
210 |
echo - |
211 |
declare -p __y | grep '__' |
212 |
echo status=$? |
213 |
} |
214 |
|
215 |
demo() { |
216 |
local __y=Y |
217 |
|
218 |
show-vars |
219 |
echo --- |
220 |
shopt --unset dynamic_scope |
221 |
show-vars |
222 |
} |
223 |
|
224 |
demo |
225 |
|
226 |
## STDOUT: |
227 |
declare -- __g=G |
228 |
declare -- __x=X |
229 |
declare -- __y=Y |
230 |
status=0 |
231 |
- |
232 |
declare -- __y=Y |
233 |
status=0 |
234 |
--- |
235 |
declare -- __g=G |
236 |
declare -- __x=X |
237 |
status=0 |
238 |
- |
239 |
status=1 |
240 |
## END |
241 |
|
242 |
|
243 |
#### OshLanguageSetValue constructs |
244 |
|
245 |
f() { |
246 |
(( x = 42 )) |
247 |
} |
248 |
demo() { |
249 |
f |
250 |
echo x=$x |
251 |
} |
252 |
|
253 |
demo |
254 |
|
255 |
echo --- |
256 |
|
257 |
shopt --unset dynamic_scope |
258 |
|
259 |
unset x |
260 |
|
261 |
demo |
262 |
|
263 |
echo --- global |
264 |
echo x=$x |
265 |
## STDOUT: |
266 |
x=42 |
267 |
--- |
268 |
x= |
269 |
--- global |
270 |
x= |
271 |
## END |
272 |
|
273 |
|
274 |
#### shell assignments 'neutered' inside 'proc' |
275 |
|
276 |
# They can't mutate globals or anything higher on the stack |
277 |
|
278 |
proc p { |
279 |
g=PROC |
280 |
export e=PROC |
281 |
} |
282 |
|
283 |
f() { |
284 |
g=SH |
285 |
export e=SH |
286 |
} |
287 |
|
288 |
e=E |
289 |
g=G |
290 |
p |
291 |
echo e=$e g=$g |
292 |
|
293 |
p |
294 |
echo e=$e g=$g |
295 |
|
296 |
f |
297 |
echo e=$e g=$g |
298 |
|
299 |
## STDOUT: |
300 |
e=E g=G |
301 |
e=E g=G |
302 |
e=SH g=SH |
303 |
## END |
304 |
|
305 |
#### setglobal still allows setting globals |
306 |
|
307 |
proc p { |
308 |
setglobal new_global = 'p' |
309 |
setglobal g = 'p' |
310 |
} |
311 |
|
312 |
var g = 'G' |
313 |
|
314 |
p |
315 |
|
316 |
echo g=$g new_global=$new_global |
317 |
## STDOUT: |
318 |
g=p new_global=p |
319 |
## END |
320 |
|
321 |
#### setref with :out param |
322 |
|
323 |
proc set-it(:s, val) { |
324 |
#pp cell __s |
325 |
setref s = "foo-$val" |
326 |
} |
327 |
|
328 |
proc demo { |
329 |
# TODO: Our bad implementation causes a recursion problem here because we use |
330 |
# the name 's'. |
331 |
if true; then |
332 |
var s = 'abc' |
333 |
set-it :s SS |
334 |
echo $s |
335 |
fi |
336 |
|
337 |
var t = 'def' |
338 |
set-it :t TT |
339 |
echo $t |
340 |
} |
341 |
|
342 |
demo |
343 |
|
344 |
## STDOUT: |
345 |
foo-SS |
346 |
foo-TT |
347 |
## END |
348 |
|
349 |
#### setref with conflicting variable name |
350 |
|
351 |
proc set-it(:s, val) { |
352 |
#pp cell __s |
353 |
|
354 |
# This breaks it! |
355 |
var oops = '' |
356 |
setref s = "foo-$val" |
357 |
} |
358 |
|
359 |
proc demo { |
360 |
var oops = '' |
361 |
set-it :oops zz |
362 |
echo oops=$oops |
363 |
} |
364 |
|
365 |
demo |
366 |
|
367 |
## STDOUT: |
368 |
oops=foo-zz |
369 |
## END |
370 |
|
371 |
|
372 |
#### setref of regular param is a fatal error |
373 |
proc set-it(:s, val) { |
374 |
setref val = 'oops' |
375 |
} |
376 |
|
377 |
var s = 'abc' |
378 |
set-it :s SS |
379 |
echo $s |
380 |
|
381 |
## status: 1 |
382 |
## STDOUT: |
383 |
## END |
384 |
|
385 |
#### setref equivalent without pgen2 syntax, using open proc |
386 |
|
387 |
# This is kind of what we compile to. Ref params get an extra __ prefix? then |
388 |
# that means you can't really READ them either? I think that's OK. |
389 |
|
390 |
# At call time, param binding time: |
391 |
# If the PARAM has a colon prefix: |
392 |
# Assert that the ARG has a colon prefix. Don't remove it. |
393 |
# Set the cell.nameref flag. |
394 |
# |
395 |
# At Setref time: |
396 |
# Check that it's cell.nameref. |
397 |
# Add extra : to lvalue.{Named,Indexed,Keyed} and perform it. |
398 |
# |
399 |
# The __ avoids the nameref cycle check. |
400 |
# And we probably disallow reading from the ref. That's OK. The caller can |
401 |
# pass it in as a regular value! |
402 |
|
403 |
proc set-it { |
404 |
local -n __s=$1 # nameref flag needed with setref |
405 |
local val=$2 |
406 |
|
407 |
# well this part requires pgen2 |
408 |
setref s = "foo-$val" |
409 |
} |
410 |
|
411 |
var s = 'abc' |
412 |
var t = 'def' |
413 |
set-it s SS |
414 |
set-it t TT # no colon here |
415 |
echo $s |
416 |
echo $t |
417 |
|
418 |
## STDOUT: |
419 |
foo-SS |
420 |
foo-TT |
421 |
## END |
422 |
|
423 |
#### setref a, b = 'one', 'two' |
424 |
|
425 |
proc p(x, :a, :b) { |
426 |
setref a, b = "${x}1", "${x}2" |
427 |
} |
428 |
|
429 |
p foo :c :d |
430 |
echo c=$c d=$d |
431 |
## STDOUT: |
432 |
c=foo1 d=foo2 |
433 |
## END |
434 |
|
435 |
#### setref a[i] |
436 |
|
437 |
# You can do this in bash/mksh. See nameref! |
438 |
|
439 |
proc set1(:a, item) { |
440 |
setref a[1] = item |
441 |
} |
442 |
|
443 |
var a = %(one two three) |
444 |
var myarray = %(a b c) |
445 |
|
446 |
set1 :a zzz |
447 |
set1 :myarray z |
448 |
|
449 |
shopt --set oil:basic |
450 |
#write -- @a |
451 |
write -- @myarray |
452 |
|
453 |
## STDOUT: |
454 |
a |
455 |
z |
456 |
c |
457 |
## END |
458 |
|
459 |
#### unset inside proc uses local scope |
460 |
shopt --set parse_brace |
461 |
|
462 |
f() { |
463 |
unset x |
464 |
} |
465 |
|
466 |
proc p() { |
467 |
unset x |
468 |
} |
469 |
|
470 |
proc p2() { |
471 |
shopt --set dynamic_scope { # turn it back on |
472 |
unset x |
473 |
} |
474 |
} |
475 |
|
476 |
x=foo |
477 |
f |
478 |
echo f x=$x |
479 |
|
480 |
x=bar |
481 |
p |
482 |
echo p x=$x |
483 |
|
484 |
x=spam |
485 |
p2 |
486 |
echo p2 x=$x |
487 |
|
488 |
## STDOUT: |
489 |
f x= |
490 |
p x=bar |
491 |
p2 x= |
492 |
## END |
493 |
|
494 |
#### unset composes when you turn on dynamic scope |
495 |
shopt -s oil:all |
496 |
|
497 |
proc unset-two { |
498 |
shopt --set dynamic_scope { |
499 |
unset $1 |
500 |
unset $2 |
501 |
} |
502 |
} |
503 |
|
504 |
demo() { |
505 |
local x=X |
506 |
local y=Y |
507 |
|
508 |
echo "x=$x y=$y" |
509 |
|
510 |
unset-two x y |
511 |
|
512 |
shopt --unset nounset |
513 |
echo "x=$x y=$y" |
514 |
} |
515 |
|
516 |
demo |
517 |
## STDOUT: |
518 |
x=X y=Y |
519 |
x= y= |
520 |
## END |
521 |
|
522 |
#### Temp Bindings |
523 |
myfunc() { |
524 |
echo myfunc FOO=$FOO |
525 |
} |
526 |
proc myproc() { |
527 |
echo myproc FOO=$FOO |
528 |
} |
529 |
|
530 |
FOO=bar myfunc |
531 |
FOO=bar myproc |
532 |
FOO=bar echo inline FOO=$FOO |
533 |
FOO=bar printenv.py FOO |
534 |
|
535 |
## STDOUT: |
536 |
myfunc FOO=bar |
537 |
myproc FOO= |
538 |
inline FOO= |
539 |
bar |
540 |
## END |
541 |
|
542 |
#### cd blocks don't introduce new scopes |
543 |
shopt --set oil:basic |
544 |
|
545 |
var x = 42 |
546 |
cd / { |
547 |
var y, z = 0, 1 |
548 |
echo $x $y $z |
549 |
setvar y = 43 |
550 |
} |
551 |
setvar z = 44 |
552 |
echo $x $y $z |
553 |
|
554 |
## STDOUT: |
555 |
42 0 1 |
556 |
42 43 44 |
557 |
## END |
558 |
|
559 |
#### IFS=: myproc exports when it doesn't need to |
560 |
shopt --set parse_brace |
561 |
|
562 |
s='xzx zxz' |
563 |
|
564 |
myfunc() { |
565 |
echo myfunc IFS="$IFS" |
566 |
argv.py $s |
567 |
} |
568 |
|
569 |
proc myproc() { |
570 |
echo myproc IFS="$IFS" |
571 |
argv.py $s |
572 |
} |
573 |
|
574 |
IFS=: $REPO_ROOT/spec/bin/printenv.py IFS |
575 |
|
576 |
# default value |
577 |
echo "$IFS" | od -A n -t x1 |
578 |
|
579 |
IFS=' z' |
580 |
echo IFS="$IFS" |
581 |
|
582 |
IFS=' x' myfunc |
583 |
|
584 |
# Problem: $IFS in procs only finds GLOBAL values. But when actually |
585 |
# splitting, $IFS is a 'shvar' which respects DYNAMIC scope. |
586 |
# - TODO: shvar_get('IFS') |
587 |
|
588 |
IFS=' x' myproc |
589 |
|
590 |
# Oil solution to the problem |
591 |
shvar IFS=' x' { |
592 |
myproc |
593 |
} |
594 |
|
595 |
## STDOUT: |
596 |
: |
597 |
20 09 0a 0a |
598 |
IFS= z |
599 |
myfunc IFS= x |
600 |
['', 'z', 'z', 'z'] |
601 |
myproc IFS= z |
602 |
['', 'z', 'z', 'z'] |
603 |
myproc IFS= x |
604 |
['', 'z', 'z', 'z'] |
605 |
## END |
606 |
|
607 |
#### shvar usage |
608 |
shopt --set oil:basic |
609 |
shopt --unset errexit |
610 |
|
611 |
# no block |
612 |
shvar |
613 |
echo status=$? |
614 |
|
615 |
shvar { # no arg |
616 |
true |
617 |
} |
618 |
echo status=$? |
619 |
|
620 |
shvar foo { # should be name=value |
621 |
true |
622 |
} |
623 |
echo status=$? |
624 |
## STDOUT: |
625 |
status=2 |
626 |
status=2 |
627 |
status=2 |
628 |
## END |
629 |
|
630 |
#### shvar global |
631 |
shopt --set oil:basic |
632 |
shopt --unset nounset |
633 |
|
634 |
echo _ESCAPER=$_ESCAPER |
635 |
echo _DIALECT=$_DIALECT |
636 |
|
637 |
shvar _ESCAPER=html _DIALECT=ninja { |
638 |
echo block _ESCAPER=$_ESCAPER |
639 |
echo block _DIALECT=$_DIALECT |
640 |
} |
641 |
|
642 |
echo _ESCAPER=$_ESCAPER |
643 |
echo _DIALECT=$_DIALECT |
644 |
|
645 |
# Now set them |
646 |
_ESCAPER=foo |
647 |
_DIALECT=bar |
648 |
|
649 |
echo ___ |
650 |
|
651 |
echo _ESCAPER=$_ESCAPER |
652 |
echo _DIALECT=$_DIALECT |
653 |
|
654 |
shvar _ESCAPER=html _DIALECT=ninja { |
655 |
echo block _ESCAPER=$_ESCAPER |
656 |
echo block _DIALECT=$_DIALECT |
657 |
|
658 |
shvar _ESCAPER=nested { |
659 |
echo nested _ESCAPER=$_ESCAPER |
660 |
echo nested _DIALECT=$_DIALECT |
661 |
} |
662 |
} |
663 |
|
664 |
echo _ESCAPER=$_ESCAPER |
665 |
echo _DIALECT=$_DIALECT |
666 |
|
667 |
## STDOUT: |
668 |
_ESCAPER= |
669 |
_DIALECT= |
670 |
block _ESCAPER=html |
671 |
block _DIALECT=ninja |
672 |
_ESCAPER= |
673 |
_DIALECT= |
674 |
___ |
675 |
_ESCAPER=foo |
676 |
_DIALECT=bar |
677 |
block _ESCAPER=html |
678 |
block _DIALECT=ninja |
679 |
nested _ESCAPER=nested |
680 |
nested _DIALECT=ninja |
681 |
_ESCAPER=foo |
682 |
_DIALECT=bar |
683 |
## END |
684 |
|
685 |
#### shvar local |
686 |
shopt --set oil:basic # blocks |
687 |
shopt --unset simple_word_eval # test word splitting |
688 |
|
689 |
proc foo { |
690 |
shvar IFS=x MYTEMP=foo { |
691 |
echo IFS="$IFS" |
692 |
argv.py $s |
693 |
echo MYTEMP=${MYTEMP:-undef} |
694 |
} |
695 |
} |
696 |
var s = 'a b c' |
697 |
argv.py $s |
698 |
foo |
699 |
argv.py $s |
700 |
echo MYTEMP=${MYTEMP:-undef} |
701 |
## STDOUT: |
702 |
['a', 'b', 'c'] |
703 |
IFS=x |
704 |
['a b c'] |
705 |
MYTEMP=foo |
706 |
['a', 'b', 'c'] |
707 |
MYTEMP=undef |
708 |
## END |
709 |
|
710 |
#### shvar IFS |
711 |
shopt --set oil:basic |
712 |
|
713 |
proc myproc() { |
714 |
echo "$IFS" | od -A n -t x1 |
715 |
|
716 |
local mylocal=x |
717 |
shvar IFS=w { |
718 |
echo inside IFS="$IFS" |
719 |
echo mylocal="$mylocal" # I do NOT want a new scope! |
720 |
} |
721 |
echo "$IFS" | od -A n -t x1 |
722 |
} |
723 |
|
724 |
myproc |
725 |
## STDOUT: |
726 |
20 09 0a 0a |
727 |
inside IFS=w |
728 |
mylocal=x |
729 |
20 09 0a 0a |
730 |
## END |
731 |
|
732 |
#### shvar_get() |
733 |
|
734 |
s='xzx zxz' |
735 |
|
736 |
proc myproc { |
737 |
echo wrong IFS="$IFS" # NOT what's used |
738 |
echo shvar IFS=$shvar_get('IFS') # what IS used: dynamic scope |
739 |
argv.py $s |
740 |
} |
741 |
|
742 |
IFS=x |
743 |
IFS=z myproc |
744 |
## STDOUT: |
745 |
wrong IFS=x |
746 |
shvar IFS=z |
747 |
['x', 'x ', 'x'] |
748 |
## END |