1 ## compare_shells: bash-4.4
2
3 # Var refs are done with ${!a}
4 #
5 # local/declare -n is tested in spec/named-ref.test.sh.
6 #
7 # http://stackoverflow.com/questions/16461656/bash-how-to-pass-array-as-an-argument-to-a-function
8
9 #### var ref ${!a}
10 a=b
11 b=c
12 echo ref ${!a} ${a}
13 ## stdout: ref c b
14
15 #### ${!ref-default}
16 ref=x
17 echo x=${!ref-default}
18
19 x=''
20 echo x=${!ref-default}
21
22 x=foo
23 echo x=${!ref-default}
24
25 ## STDOUT:
26 x=default
27 x=
28 x=foo
29 ## END
30
31 #### ${!undef:-}
32 # bash gives empty string, but I feel like this could be an error
33 echo undef=${!undef-'default'}
34 echo undef=${!undef}
35
36 set -u
37 echo NOUNSET
38 echo undef=${!undef-'default'}
39 echo undef=${!undef}
40
41 ## status: 1
42 ## STDOUT:
43 undef=default
44 undef=
45 NOUNSET
46 undef=default
47 ## END
48
49 #### comparison to ${!array[@]} keys (similar SYNTAX)
50
51 declare -a a=(x y)
52 argv.py "${!a[@]}"
53 echo a_keys=$?
54
55 argv.py "${!a}" # missing [] is equivalent to ${!a[0]} ?
56 echo a_nobrackets=$?
57
58 echo ---
59 declare -A A=([A]=a [B]=b)
60
61 argv.py ${!A[@]}
62 echo A_keys=$?
63
64 argv.py "${!A}" # missing [] is equivalent to ${!A[0]} ?
65 echo A_nobrackets=$?
66
67 ## STDOUT:
68 ['0', '1']
69 a_keys=0
70 ['']
71 a_nobrackets=0
72 ---
73 ['A', 'B']
74 A_keys=0
75 ['']
76 A_nobrackets=0
77 ## END
78
79 #### ${!a[@]-'default'} is illegal
80
81 # bash disallows this when a is an array. We make it an error because [@]
82 # implies it's an array.
83
84 argv.py "${!a[@]-default}"
85 echo status=$?
86
87 a=(x y z)
88 argv.py "${!a[@]-default}"
89 echo status=$?
90 ## status: 1
91 ## STDOUT:
92 ## END
93 ## BUG bash status: 0
94 ## BUG bash STDOUT:
95 ['default']
96 status=0
97 status=1
98 ## END
99
100
101 #### var ref to $@ with @
102 set -- one two
103 ref='@'
104 echo ref=${!ref}
105 ## STDOUT:
106 ref=one two
107 ## END
108
109 #### var ref to $1 and $2 with 1 and 2
110 set -- one two
111 ref1='1'
112 echo ref1=${!ref1}
113 ref2='2'
114 echo ref2=${!ref2}
115
116 ## STDOUT:
117 ref1=one
118 ref2=two
119 ## END
120
121 #### var ref: 1, @, *
122 set -- x y
123 ref=1; argv.py "${!ref}"
124 ref=@; argv.py "${!ref}"
125 ref=*; argv.py "${!ref}" # maybe_decay_array bug?
126
127 ## STDOUT:
128 ['x']
129 ['x', 'y']
130 ['x y']
131 ## END
132
133 #### var ref to special var BASH_SOURCE
134 ref='LINENO'
135 echo lineno=${!ref}
136 ## STDOUT:
137 lineno=2
138 ## END
139
140 #### var ref to $? with '?'
141 myfunc() {
142 local ref=$1
143 echo ${!ref}
144 }
145 myfunc FUNCNAME
146 myfunc '?'
147 ## STDOUT:
148 myfunc
149 0
150 ## END
151
152
153 #### Var ref, then assignment with ${ := }
154 z=zz
155 zz=
156 echo ${!z:=foo}
157 echo ${!z:=bar}
158 ## STDOUT:
159 foo
160 foo
161 ## END
162
163 #### Var ref, then error with ${ ? }
164 w=ww
165 ww=
166 echo ${!w:?'my message'}
167 echo done
168 ## status: 1
169 ## STDOUT:
170 ## END
171
172 #### Indirect expansion, THEN suffix operators
173
174 check_eq() {
175 [ "$1" = "$2" ] || { echo "$1 vs $2"; }
176 }
177 check_expand() {
178 val=$(eval "echo \"$1\"")
179 [ "$val" = "$2" ] || { echo "$1 -> expected $2, got $val"; }
180 }
181 check_err() {
182 e="$1"
183 msg=$(eval "$e" 2>&1) && echo "bad success: $e"
184 if test -n "$2"; then
185 if [[ "$msg" != $2 ]]; then
186 echo "Expected error: $e"
187 echo "Got error : $msg"
188 fi
189 fi
190 }
191 # Nearly everything in manual section 3.5.3 "Shell Parameter Expansion"
192 # is allowed after a !-indirection.
193 #
194 # Not allowed: any further prefix syntax.
195 x=xx; xx=aaabcc
196 xd=x
197 check_err '${!!xd}'
198 check_err '${!!x*}'
199 a=(asdf x)
200 check_err '${!!a[*]}'
201 check_err '${!#x}'
202 check_err '${!#a[@]}'
203 # And an array reference binds tighter in the syntax, so goes first;
204 # there's no way to spell "indirection, then array reference".
205 check_expand '${!a[1]}' xx
206 b=(aoeu a)
207 check_expand '${!b[1]}' asdf # i.e. like !(b[1]), not (!b)[1]
208 #
209 # Allowed: apparently everything else.
210 y=yy; yy=
211 check_expand '${!y:-foo}' foo
212 check_expand '${!x:-foo}' aaabcc
213
214 check_expand '${!x:?oops}' aaabcc
215
216 check_expand '${!y:+foo}' ''
217 check_expand '${!x:+foo}' foo
218
219 check_expand '${!x:2}' abcc
220 check_expand '${!x:2:2}' ab
221
222 check_expand '${!x#*a}' aabcc
223 check_expand '${!x%%c*}' aaab
224 check_expand '${!x/a*b/d}' dcc
225
226 # ^ operator not fully implemented in OSH
227 #check_expand '${!x^a}' Aaabcc
228
229 p=pp; pp='\$ '
230 check_expand '${!p@P}' '$ '
231 echo ok
232 ## stdout: ok
233
234 #### var ref OF array var -- silent a[0] decay
235 declare -a a=(ale bean)
236 echo first=${!a}
237
238 ale=zzz
239 echo first=${!a}
240
241 ## status: 0
242 ## STDOUT:
243 first=
244 first=zzz
245 ## END
246
247 #### array ref
248
249 declare -a array=(ale bean)
250 ref='array[0]'
251 echo ${!ref}
252 ## status: 0
253 ## STDOUT:
254 ale
255 ## END
256
257 #### array ref with strict_array
258 shopt -s strict_array
259
260 declare -a array=(ale bean)
261 ref='array'
262 echo ${!ref}
263 ## status: 1
264 ## stdout-json: ""
265 ## N-I bash status: 0
266 ## N-I bash STDOUT:
267 ale
268 ## END
269
270 #### var ref TO array var
271 shopt -s compat_array
272
273 declare -a array=(ale bean)
274
275 ref='array' # when compat_array is on, this is like array[0]
276 ref_AT='array[@]'
277
278 echo ${!ref}
279 echo ${!ref_AT}
280
281 ## STDOUT:
282 ale
283 ale bean
284 ## END
285
286 #### var ref TO array var, with subscripts
287 f() {
288 argv.py "${!1}"
289 }
290 f 'nonexistent[0]'
291 array=(x y z)
292 f 'array[0]'
293 f 'array[1+1]'
294 f 'array[@]'
295 f 'array[*]'
296 # Also associative arrays.
297 ## STDOUT:
298 ['']
299 ['x']
300 ['z']
301 ['x', 'y', 'z']
302 ['x y z']
303 ## END
304
305 #### var ref TO assoc array a[key]
306 shopt -s compat_array
307
308 declare -A assoc=([ale]=bean [corn]=dip)
309 ref=assoc
310 #ref_AT='assoc[@]'
311
312 # UNQUOTED doesn't work with Oil's parser
313 #ref_SUB='assoc[ale]'
314 ref_SUB='assoc["ale"]'
315
316 ref_SUB_QUOTED='assoc["al"e]'
317
318 ref_SUB_BAD='assoc["bad"]'
319
320 echo ref=${!ref} # compat_array: assoc is equivalent to assoc[0]
321 #echo ref_AT=${!ref_AT}
322 echo ref_SUB=${!ref_SUB}
323 echo ref_SUB_QUOTED=${!ref_SUB_QUOTED}
324 echo ref_SUB_BAD=${!ref_SUB_BAD}
325
326 ## STDOUT:
327 ref=
328 ref_SUB=bean
329 ref_SUB_QUOTED=bean
330 ref_SUB_BAD=
331 ## END
332
333 #### var ref TO array with arbitrary subscripts
334 shopt -s eval_unsafe_arith compat_array
335
336 f() {
337 local val=$(echo "${!1}")
338 if test "$val" = y; then
339 echo "works: $1"
340 fi
341 }
342 # Warmup: nice plain array reference
343 a=(x y)
344 f 'a[1]'
345 #
346 # Not allowed:
347 # no brace expansion
348 f 'a[{1,0}]' # operand expected
349 # no process substitution (but see command substitution below!)
350 f 'a[<(echo x)]' # operand expected
351 # TODO word splitting seems interesting
352 aa="1 0"
353 f 'a[$aa]' # 1 0: syntax error in expression (error token is "0")
354 # no filename globbing
355 f 'a[b*]' # operand expected
356 f 'a[1"]' # bad substitution
357 #
358 # Allowed: most everything else in section 3.5 "Shell Expansions".
359 # shell parameter expansion
360 b=1
361 f 'a[$b]'
362 f 'a[${c:-1}]'
363 # (... and presumably most of the other features there)
364 # command substitution, yikes!
365 f 'a[$(echo 1)]'
366 # arithmetic expansion
367 f 'a[$(( 3 - 2 ))]'
368
369 # All of these are undocumented and probably shouldn't exist,
370 # though it's always possible some will turn up in the wild and
371 # we'll end up implementing them.
372
373 ## STDOUT:
374 works: a[1]
375 works: a[$b]
376 works: a[${c:-1}]
377 works: a[$(echo 1)]
378 works: a[$(( 3 - 2 ))]
379 ## END
380
381 #### Bizarre tilde expansion in array index
382 a=(x y)
383 PWD=1
384 ref='a[~+]'
385 echo ${!ref}
386 ## status: 1
387 ## BUG bash status: 0
388 ## BUG bash STDOUT:
389 y
390 ## END
391
392 #### Indirect expansion TO fancy expansion features bash disallows
393
394 check_indir() {
395 result="${!1}"
396 desugared_result=$(eval 'echo "${'"$1"'}"')
397 [ "$2" = "$desugared_result" ] || { echo "$1 $desugared_result"; }
398 }
399 x=y
400 y=a
401 a=(x y)
402 declare -A aa
403 aa=([k]=r [l]=s)
404 # malformed array indexing
405 check_indir "a[0"
406 check_indir "aa[k"
407 # double indirection
408 check_indir "!x" a
409 check_indir "!a[0]" y
410 # apparently everything else in the manual under "Shell Parameter Expansion"
411 check_indir "x:-foo" y
412 check_indir "x:=foo" y
413 check_indir "x:?oops" y
414 check_indir "x:+yy" yy
415 check_indir "x:0" y
416 check_indir "x:0:1" y
417 check_indir "!a@" "a aa"
418 # (!a[@] is elsewhere)
419 check_indir "#x" 1
420 check_indir "x#y"
421 check_indir "x/y/foo" foo
422 check_indir "x@Q" "'y'"
423 echo done
424 ## status: 1
425 ## stdout-json: ""
426 ## OK bash status: 0
427 ## OK bash stdout: done
428
429 #### Bad var ref
430 a='bad var name'
431 echo ref ${!a}
432 echo status=$?
433
434 ## STDOUT:
435 status=1
436 ## END
437 ## OK osh stdout-json: ""
438 ## OK osh status: 1
439
440 #### Bad var ref 2
441 b='/' # really bad
442 echo ref ${!b}
443 echo status=$?
444 ## STDOUT:
445 status=1
446 ## END
447 ## OK osh stdout-json: ""
448 ## OK osh status: 1
449
450 #### ${!OPTIND} (used by bash completion
451 set -- a b c
452 echo ${!OPTIND}
453 f() {
454 local OPTIND=1
455 echo ${!OPTIND}
456 local OPTIND=2
457 echo ${!OPTIND}
458 }
459 f x y z
460 ## STDOUT:
461 a
462 x
463 y
464 ## END
465
466 #### var ref doesn't need cycle detection
467 x=y
468 y=x
469 echo cycle=${!x}
470
471 typeset -n a=b
472 typeset -n b=a
473 echo cycle=${a}
474 ## status: 1
475 ## STDOUT:
476 cycle=x
477 ## END
478 ## OK bash status: 0
479 ## OK bash STDOUT:
480 cycle=x
481 cycle=
482 ## END
483
484 #### Var Ref Code Injection $(tee PWNED)
485
486 typeset -a a
487 a=(42)
488
489 x='a[$(echo 0 | tee PWNED)]'
490
491 echo ${!x}
492
493 if test -f PWNED; then
494 echo PWNED
495 cat PWNED
496 else
497 echo NOPE
498 fi
499
500 ## status: 1
501 ## STDOUT:
502 ## END
503
504 ## BUG bash status: 0
505 ## BUG bash STDOUT:
506 42
507 PWNED
508 0
509 ## END