1 |
# Demonstrations for users. Could go in docs. |
2 |
|
3 |
#### GetValue scope and shopt --unset dynamic_scope |
4 |
shopt --set parse_proc |
5 |
|
6 |
f() { |
7 |
echo "sh x=$x" |
8 |
} |
9 |
|
10 |
proc p { |
11 |
echo "oil x=$x" |
12 |
} |
13 |
|
14 |
demo() { |
15 |
local x=dynamic |
16 |
f |
17 |
p |
18 |
|
19 |
shopt --unset dynamic_scope |
20 |
f |
21 |
} |
22 |
|
23 |
x=global |
24 |
demo |
25 |
echo x=$x |
26 |
|
27 |
## STDOUT: |
28 |
sh x=dynamic |
29 |
oil x=global |
30 |
sh x=global |
31 |
x=global |
32 |
## END |
33 |
|
34 |
|
35 |
#### SetValue scope and shopt --unset dynamic_scope |
36 |
shopt --set parse_proc |
37 |
|
38 |
f() { |
39 |
x=f |
40 |
} |
41 |
|
42 |
proc p { |
43 |
x=p |
44 |
} |
45 |
|
46 |
demo() { |
47 |
local x=stack |
48 |
echo x=$x |
49 |
echo --- |
50 |
|
51 |
f |
52 |
echo f x=$x |
53 |
|
54 |
x=stack |
55 |
p |
56 |
echo p x=$x |
57 |
|
58 |
shopt --unset dynamic_scope |
59 |
x=stack |
60 |
f |
61 |
echo funset x=$x |
62 |
} |
63 |
|
64 |
x=global |
65 |
demo |
66 |
|
67 |
echo --- |
68 |
echo x=$x |
69 |
|
70 |
## STDOUT: |
71 |
x=stack |
72 |
--- |
73 |
f x=f |
74 |
p x=stack |
75 |
funset x=stack |
76 |
--- |
77 |
x=global |
78 |
## END |
79 |
|
80 |
#### read scope (setref) |
81 |
set -o errexit |
82 |
|
83 |
read-x() { |
84 |
echo dynamic-scope | read x |
85 |
} |
86 |
demo() { |
87 |
local x=42 |
88 |
echo x_before=$x |
89 |
read-x |
90 |
echo x_after=$x |
91 |
} |
92 |
demo |
93 |
echo x=$x |
94 |
|
95 |
echo --- |
96 |
|
97 |
# Now 'read x' creates a local variable |
98 |
shopt --unset dynamic_scope |
99 |
demo |
100 |
echo x=$x |
101 |
|
102 |
## STDOUT: |
103 |
x_before=42 |
104 |
x_after=dynamic-scope |
105 |
x= |
106 |
--- |
107 |
x_before=42 |
108 |
x_after=42 |
109 |
x= |
110 |
## END |
111 |
|
112 |
#### printf -v x respects dynamic_scope |
113 |
set -o errexit |
114 |
|
115 |
set-x() { |
116 |
printf -v x "%s" dynamic-scope |
117 |
} |
118 |
demo() { |
119 |
local x=42 |
120 |
echo x=$x |
121 |
set-x |
122 |
echo x=$x |
123 |
} |
124 |
demo |
125 |
echo x=$x |
126 |
|
127 |
echo --- |
128 |
|
129 |
shopt --unset dynamic_scope # should NOT affect read |
130 |
demo |
131 |
echo x=$x |
132 |
|
133 |
## STDOUT: |
134 |
x=42 |
135 |
x=dynamic-scope |
136 |
x= |
137 |
--- |
138 |
x=42 |
139 |
x=42 |
140 |
x= |
141 |
## END |
142 |
|
143 |
#### printf -v a[i] respects dynamic_scope |
144 |
set -o errexit |
145 |
|
146 |
set-item() { |
147 |
printf -v 'a[1]' "%s" dynamic-scope |
148 |
} |
149 |
demo() { |
150 |
local -a a=(41 42 43) |
151 |
echo "a[1]=${a[1]}" |
152 |
set-item |
153 |
echo "a[1]=${a[1]}" |
154 |
} |
155 |
demo |
156 |
echo "a[1]=${a[1]}" |
157 |
|
158 |
echo --- |
159 |
|
160 |
shopt --unset dynamic_scope # should NOT affect read |
161 |
demo |
162 |
echo "a[1]=${a[1]}" |
163 |
|
164 |
## STDOUT: |
165 |
a[1]=42 |
166 |
a[1]=dynamic-scope |
167 |
a[1]= |
168 |
--- |
169 |
a[1]=42 |
170 |
a[1]=42 |
171 |
a[1]= |
172 |
## END |
173 |
|
174 |
#### ${undef=a} and shopt --unset dynamic_scope |
175 |
|
176 |
set-x() { |
177 |
: ${x=new} |
178 |
} |
179 |
demo() { |
180 |
local x |
181 |
echo x=$x |
182 |
set-x |
183 |
echo x=$x |
184 |
} |
185 |
|
186 |
demo |
187 |
echo x=$x |
188 |
|
189 |
echo --- |
190 |
|
191 |
# Now this IS affected? |
192 |
shopt --unset dynamic_scope |
193 |
demo |
194 |
echo x=$x |
195 |
## STDOUT: |
196 |
x= |
197 |
x=new |
198 |
x= |
199 |
--- |
200 |
x= |
201 |
x= |
202 |
x= |
203 |
## END |
204 |
|
205 |
#### declare -p respects it |
206 |
__g=G |
207 |
show-vars() { |
208 |
local __x=X |
209 |
declare -p | grep '__' |
210 |
echo status=$? |
211 |
|
212 |
echo - |
213 |
declare -p __y | grep '__' |
214 |
echo status=$? |
215 |
} |
216 |
|
217 |
demo() { |
218 |
local __y=Y |
219 |
|
220 |
show-vars |
221 |
echo --- |
222 |
shopt --unset dynamic_scope |
223 |
show-vars |
224 |
} |
225 |
|
226 |
demo |
227 |
|
228 |
## STDOUT: |
229 |
declare -- __g=G |
230 |
declare -- __x=X |
231 |
declare -- __y=Y |
232 |
status=0 |
233 |
- |
234 |
declare -- __y=Y |
235 |
status=0 |
236 |
--- |
237 |
declare -- __g=G |
238 |
declare -- __x=X |
239 |
status=0 |
240 |
- |
241 |
status=1 |
242 |
## END |
243 |
|
244 |
|
245 |
#### OshLanguageSetValue constructs |
246 |
|
247 |
f() { |
248 |
(( x = 42 )) |
249 |
} |
250 |
demo() { |
251 |
f |
252 |
echo x=$x |
253 |
} |
254 |
|
255 |
demo |
256 |
|
257 |
echo --- |
258 |
|
259 |
shopt --unset dynamic_scope |
260 |
|
261 |
unset x |
262 |
|
263 |
demo |
264 |
|
265 |
echo --- global |
266 |
echo x=$x |
267 |
## STDOUT: |
268 |
x=42 |
269 |
--- |
270 |
x= |
271 |
--- global |
272 |
x= |
273 |
## END |
274 |
|
275 |
|
276 |
#### shell assignments 'neutered' inside 'proc' |
277 |
shopt --set parse_proc |
278 |
|
279 |
# They can't mutate globals or anything higher on the stack |
280 |
|
281 |
proc p { |
282 |
g=PROC |
283 |
export e=PROC |
284 |
} |
285 |
|
286 |
f() { |
287 |
g=SH |
288 |
export e=SH |
289 |
} |
290 |
|
291 |
e=E |
292 |
g=G |
293 |
p |
294 |
echo e=$e g=$g |
295 |
|
296 |
p |
297 |
echo e=$e g=$g |
298 |
|
299 |
f |
300 |
echo e=$e g=$g |
301 |
|
302 |
## STDOUT: |
303 |
e=E g=G |
304 |
e=E g=G |
305 |
e=SH g=SH |
306 |
## END |
307 |
|
308 |
#### setglobal still allows setting globals |
309 |
shopt --set parse_proc |
310 |
|
311 |
proc p { |
312 |
setglobal new_global = 'p' |
313 |
setglobal g = 'p' |
314 |
} |
315 |
|
316 |
var g = 'G' |
317 |
|
318 |
p |
319 |
|
320 |
echo g=$g new_global=$new_global |
321 |
## STDOUT: |
322 |
g=p new_global=p |
323 |
## END |
324 |
|
325 |
#### setref with out Ref param |
326 |
shopt --set parse_proc |
327 |
|
328 |
proc set-it(s Ref, val) { |
329 |
# s param is rewritten to __s to avoid name conflict |
330 |
#pp cell __s |
331 |
setref s = "foo-$val" |
332 |
} |
333 |
|
334 |
proc demo { |
335 |
if true; then |
336 |
var s = 'abc' |
337 |
set-it :s SS |
338 |
echo $s |
339 |
fi |
340 |
|
341 |
var t = 'def' |
342 |
set-it :t TT |
343 |
echo $t |
344 |
} |
345 |
|
346 |
demo |
347 |
|
348 |
## STDOUT: |
349 |
foo-SS |
350 |
foo-TT |
351 |
## END |
352 |
|
353 |
#### setref with conflicting variable name |
354 |
shopt --set parse_proc |
355 |
|
356 |
proc set-it(s Ref, val) { |
357 |
#pp cell __s |
358 |
|
359 |
# This breaks it! |
360 |
var oops = '' |
361 |
setref s = "foo-$val" |
362 |
} |
363 |
|
364 |
proc demo { |
365 |
var oops = '' |
366 |
set-it :oops zz |
367 |
echo oops=$oops |
368 |
} |
369 |
|
370 |
demo |
371 |
|
372 |
## STDOUT: |
373 |
oops=foo-zz |
374 |
## END |
375 |
|
376 |
|
377 |
#### setref of regular param is a fatal error |
378 |
shopt --set parse_proc |
379 |
|
380 |
proc set-it(s Ref, val) { |
381 |
setref val = 'oops' |
382 |
} |
383 |
|
384 |
var s = 'abc' |
385 |
set-it :s SS |
386 |
echo $s |
387 |
|
388 |
## status: 1 |
389 |
## STDOUT: |
390 |
## END |
391 |
|
392 |
#### setref equivalent without pgen2 syntax, using open proc |
393 |
shopt --set parse_proc |
394 |
|
395 |
# This is kind of what we compile to. Ref params get an extra __ prefix? then |
396 |
# that means you can't really READ them either? I think that's OK. |
397 |
|
398 |
# At call time, param binding time: |
399 |
# If the PARAM has a colon prefix: |
400 |
# Assert that the ARG has a colon prefix. Don't remove it. |
401 |
# Set the cell.nameref flag. |
402 |
# |
403 |
# At Setref time: |
404 |
# Check that it's cell.nameref. |
405 |
# Add extra : to lvalue.{Named,Indexed,Keyed} and perform it. |
406 |
# |
407 |
# The __ avoids the nameref cycle check. |
408 |
# And we probably disallow reading from the ref. That's OK. The caller can |
409 |
# pass it in as a regular value! |
410 |
|
411 |
proc set-it { |
412 |
local -n __s=$1 # nameref flag needed with setref |
413 |
local val=$2 |
414 |
|
415 |
# well this part requires pgen2 |
416 |
setref s = "foo-$val" |
417 |
} |
418 |
|
419 |
var s = 'abc' |
420 |
var t = 'def' |
421 |
set-it s SS |
422 |
set-it t TT # no colon here |
423 |
echo $s |
424 |
echo $t |
425 |
|
426 |
## STDOUT: |
427 |
foo-SS |
428 |
foo-TT |
429 |
## END |
430 |
|
431 |
#### setref a, b = 'one', 'two' |
432 |
shopt --set parse_proc |
433 |
|
434 |
proc p(x, a Ref, b Ref) { |
435 |
setref a, b = "${x}1", "${x}2" |
436 |
} |
437 |
|
438 |
p foo :c :d |
439 |
echo c=$c d=$d |
440 |
## STDOUT: |
441 |
c=foo1 d=foo2 |
442 |
## END |
443 |
|
444 |
#### setref a[i] |
445 |
|
446 |
# You can do this in bash/mksh. See nameref! |
447 |
|
448 |
proc set1(:a, item) { |
449 |
setref a[1] = item |
450 |
} |
451 |
|
452 |
var a = %(one two three) |
453 |
var myarray = %(a b c) |
454 |
|
455 |
set1 :a zzz |
456 |
set1 :myarray z |
457 |
|
458 |
shopt --set oil:upgrade |
459 |
#write -- @a |
460 |
write -- @myarray |
461 |
|
462 |
## STDOUT: |
463 |
a |
464 |
z |
465 |
c |
466 |
## END |
467 |
|
468 |
#### unset inside proc uses local scope |
469 |
shopt --set parse_brace |
470 |
shopt --set parse_proc |
471 |
|
472 |
f() { |
473 |
unset x |
474 |
} |
475 |
|
476 |
proc p() { |
477 |
unset x |
478 |
} |
479 |
|
480 |
proc p2() { |
481 |
shopt --set dynamic_scope { # turn it back on |
482 |
unset x |
483 |
} |
484 |
} |
485 |
|
486 |
x=foo |
487 |
f |
488 |
echo f x=$x |
489 |
|
490 |
x=bar |
491 |
p |
492 |
echo p x=$x |
493 |
|
494 |
x=spam |
495 |
p2 |
496 |
echo p2 x=$x |
497 |
|
498 |
## STDOUT: |
499 |
f x= |
500 |
p x=bar |
501 |
p2 x= |
502 |
## END |
503 |
|
504 |
#### unset composes when you turn on dynamic scope |
505 |
shopt -s oil:all |
506 |
|
507 |
proc unset-two { |
508 |
shopt --set dynamic_scope { |
509 |
unset $1 |
510 |
unset $2 |
511 |
} |
512 |
} |
513 |
|
514 |
demo() { |
515 |
local x=X |
516 |
local y=Y |
517 |
|
518 |
echo "x=$x y=$y" |
519 |
|
520 |
unset-two x y |
521 |
|
522 |
shopt --unset nounset |
523 |
echo "x=$x y=$y" |
524 |
} |
525 |
|
526 |
demo |
527 |
## STDOUT: |
528 |
x=X y=Y |
529 |
x= y= |
530 |
## END |
531 |
|
532 |
#### Temp Bindings |
533 |
shopt --set parse_proc |
534 |
|
535 |
myfunc() { |
536 |
echo myfunc FOO=$FOO |
537 |
} |
538 |
proc myproc() { |
539 |
echo myproc FOO=$FOO |
540 |
} |
541 |
|
542 |
FOO=bar myfunc |
543 |
FOO=bar myproc |
544 |
FOO=bar echo inline FOO=$FOO |
545 |
FOO=bar printenv.py FOO |
546 |
|
547 |
## STDOUT: |
548 |
myfunc FOO=bar |
549 |
myproc FOO= |
550 |
inline FOO= |
551 |
bar |
552 |
## END |
553 |
|
554 |
#### cd blocks don't introduce new scopes |
555 |
shopt --set oil:upgrade |
556 |
|
557 |
var x = 42 |
558 |
cd / { |
559 |
var y, z = 0, 1 |
560 |
echo $x $y $z |
561 |
setvar y = 43 |
562 |
} |
563 |
setvar z = 44 |
564 |
echo $x $y $z |
565 |
|
566 |
## STDOUT: |
567 |
42 0 1 |
568 |
42 43 44 |
569 |
## END |
570 |
|
571 |
#### IFS=: myproc exports when it doesn't need to |
572 |
shopt --set parse_proc |
573 |
shopt --set parse_brace |
574 |
|
575 |
s='xzx zxz' |
576 |
|
577 |
myfunc() { |
578 |
echo myfunc IFS="$IFS" |
579 |
argv.py $s |
580 |
} |
581 |
|
582 |
proc myproc() { |
583 |
echo myproc IFS="$IFS" |
584 |
argv.py $s |
585 |
} |
586 |
|
587 |
IFS=: $REPO_ROOT/spec/bin/printenv.py IFS |
588 |
|
589 |
# default value |
590 |
echo "$IFS" | od -A n -t x1 |
591 |
|
592 |
IFS=' z' |
593 |
echo IFS="$IFS" |
594 |
|
595 |
IFS=' x' myfunc |
596 |
|
597 |
# Problem: $IFS in procs only finds GLOBAL values. But when actually |
598 |
# splitting, $IFS is a 'shvar' which respects DYNAMIC scope. |
599 |
# - TODO: shvar_get('IFS') |
600 |
|
601 |
IFS=' x' myproc |
602 |
|
603 |
# Oil solution to the problem |
604 |
shvar IFS=' x' { |
605 |
myproc |
606 |
} |
607 |
|
608 |
## STDOUT: |
609 |
: |
610 |
20 09 0a 0a |
611 |
IFS= z |
612 |
myfunc IFS= x |
613 |
['', 'z', 'z', 'z'] |
614 |
myproc IFS= z |
615 |
['', 'z', 'z', 'z'] |
616 |
myproc IFS= x |
617 |
['', 'z', 'z', 'z'] |
618 |
## END |
619 |
|
620 |
#### shvar usage |
621 |
shopt --set oil:upgrade |
622 |
shopt --unset errexit |
623 |
|
624 |
# no block |
625 |
shvar |
626 |
echo status=$? |
627 |
|
628 |
shvar { # no arg |
629 |
true |
630 |
} |
631 |
echo status=$? |
632 |
|
633 |
shvar foo { # should be name=value |
634 |
true |
635 |
} |
636 |
echo status=$? |
637 |
## STDOUT: |
638 |
status=2 |
639 |
status=2 |
640 |
status=2 |
641 |
## END |
642 |
|
643 |
#### shvar global |
644 |
shopt --set oil:upgrade |
645 |
shopt --unset nounset |
646 |
|
647 |
echo _ESCAPER=$_ESCAPER |
648 |
echo _DIALECT=$_DIALECT |
649 |
|
650 |
shvar _ESCAPER=html _DIALECT=ninja { |
651 |
echo block _ESCAPER=$_ESCAPER |
652 |
echo block _DIALECT=$_DIALECT |
653 |
} |
654 |
|
655 |
echo _ESCAPER=$_ESCAPER |
656 |
echo _DIALECT=$_DIALECT |
657 |
|
658 |
# Now set them |
659 |
_ESCAPER=foo |
660 |
_DIALECT=bar |
661 |
|
662 |
echo ___ |
663 |
|
664 |
echo _ESCAPER=$_ESCAPER |
665 |
echo _DIALECT=$_DIALECT |
666 |
|
667 |
shvar _ESCAPER=html _DIALECT=ninja { |
668 |
echo block _ESCAPER=$_ESCAPER |
669 |
echo block _DIALECT=$_DIALECT |
670 |
|
671 |
shvar _ESCAPER=nested { |
672 |
echo nested _ESCAPER=$_ESCAPER |
673 |
echo nested _DIALECT=$_DIALECT |
674 |
} |
675 |
} |
676 |
|
677 |
echo _ESCAPER=$_ESCAPER |
678 |
echo _DIALECT=$_DIALECT |
679 |
|
680 |
## STDOUT: |
681 |
_ESCAPER= |
682 |
_DIALECT= |
683 |
block _ESCAPER=html |
684 |
block _DIALECT=ninja |
685 |
_ESCAPER= |
686 |
_DIALECT= |
687 |
___ |
688 |
_ESCAPER=foo |
689 |
_DIALECT=bar |
690 |
block _ESCAPER=html |
691 |
block _DIALECT=ninja |
692 |
nested _ESCAPER=nested |
693 |
nested _DIALECT=ninja |
694 |
_ESCAPER=foo |
695 |
_DIALECT=bar |
696 |
## END |
697 |
|
698 |
#### shvar local |
699 |
shopt --set oil:upgrade # blocks |
700 |
shopt --unset simple_word_eval # test word splitting |
701 |
|
702 |
proc foo { |
703 |
shvar IFS=x MYTEMP=foo { |
704 |
echo IFS="$IFS" |
705 |
argv.py $s |
706 |
echo MYTEMP=${MYTEMP:-undef} |
707 |
} |
708 |
} |
709 |
var s = 'a b c' |
710 |
argv.py $s |
711 |
foo |
712 |
argv.py $s |
713 |
echo MYTEMP=${MYTEMP:-undef} |
714 |
## STDOUT: |
715 |
['a', 'b', 'c'] |
716 |
IFS=x |
717 |
['a b c'] |
718 |
MYTEMP=foo |
719 |
['a', 'b', 'c'] |
720 |
MYTEMP=undef |
721 |
## END |
722 |
|
723 |
#### shvar IFS |
724 |
shopt --set oil:upgrade |
725 |
|
726 |
proc myproc() { |
727 |
echo "$IFS" | od -A n -t x1 |
728 |
|
729 |
local mylocal=x |
730 |
shvar IFS=w { |
731 |
echo inside IFS="$IFS" |
732 |
echo mylocal="$mylocal" # I do NOT want a new scope! |
733 |
} |
734 |
echo "$IFS" | od -A n -t x1 |
735 |
} |
736 |
|
737 |
myproc |
738 |
## STDOUT: |
739 |
20 09 0a 0a |
740 |
inside IFS=w |
741 |
mylocal=x |
742 |
20 09 0a 0a |
743 |
## END |
744 |
|
745 |
#### shvar_get() |
746 |
shopt --set parse_proc |
747 |
|
748 |
s='xzx zxz' |
749 |
|
750 |
proc myproc { |
751 |
echo wrong IFS="$IFS" # NOT what's used |
752 |
echo shvar IFS=$[shvar_get('IFS')] # what IS used: dynamic scope |
753 |
argv.py $s |
754 |
} |
755 |
|
756 |
IFS=x |
757 |
IFS=z myproc |
758 |
## STDOUT: |
759 |
wrong IFS=x |
760 |
shvar IFS=z |
761 |
['x', 'x ', 'x'] |
762 |
## END |