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