| 1 | ## oils_failures_allowed: 2
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| 2 | ## compare_shells: bash mksh ash
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| 3 |
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| 4 | # Notes on bash semantics:
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| 5 | #
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| 6 | # https://www.gnu.org/software/bash/manual/bash.html
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| 7 | #
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| 8 | # The trap builtin (see Bourne Shell Builtins) allows an ERR pseudo-signal
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| 9 | # specification, similar to EXIT and DEBUG. Commands specified with an ERR trap
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| 10 | # are executed after a simple command fails, with a few exceptions. The ERR
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| 11 | # trap is not inherited by shell functions unless the -o errtrace option to the
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| 12 | # set builtin is enabled.
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| 13 |
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| 14 |
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| 15 | #### trap can use original $LINENO
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| 16 |
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| 17 | trap 'echo line=$LINENO' ERR
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| 18 |
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| 19 | false
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| 20 | false
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| 21 | echo ok
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| 22 |
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| 23 | ## STDOUT:
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| 24 | line=3
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| 25 | line=4
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| 26 | ok
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| 27 | ## END
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| 28 |
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| 29 | #### trap ERR and set -o errexit
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| 30 |
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| 31 | trap 'echo line=$LINENO' ERR
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| 32 |
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| 33 | false
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| 34 | echo a
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| 35 |
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| 36 | set -o errexit
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| 37 |
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| 38 | echo b
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| 39 | false # trap executed, and executation also halts
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| 40 | echo c # doesn't get here
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| 41 |
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| 42 | ## status: 1
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| 43 | ## STDOUT:
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| 44 | line=3
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| 45 | a
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| 46 | b
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| 47 | line=9
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| 48 | ## END
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| 49 |
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| 50 | #### trap ERR and errexit disabled context
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| 51 |
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| 52 | trap 'echo line=$LINENO' ERR
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| 53 |
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| 54 | false
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| 55 | echo a
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| 56 |
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| 57 | set -o errexit
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| 58 |
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| 59 | echo b
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| 60 | if false; then
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| 61 | echo xx
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| 62 | fi
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| 63 | echo c # doesn't get here
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| 64 |
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| 65 | ## STDOUT:
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| 66 | line=3
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| 67 | a
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| 68 | b
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| 69 | c
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| 70 | ## END
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| 71 |
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| 72 | #### trap ERR and if statement
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| 73 |
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| 74 | if test -f /nope; then echo file exists; fi
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| 75 |
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| 76 | trap 'echo err' ERR
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| 77 | #trap 'echo line=$LINENO' ERR
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| 78 |
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| 79 | if test -f /nope; then echo file exists; fi
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| 80 |
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| 81 | ## STDOUT:
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| 82 | ## END
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| 83 |
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| 84 |
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| 85 | #### trap ERR and || conditional
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| 86 |
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| 87 | trap 'echo line=$LINENO' ERR
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| 88 |
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| 89 | false || false || false
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| 90 | echo ok
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| 91 |
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| 92 | false && false
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| 93 | echo ok
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| 94 |
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| 95 | ## STDOUT:
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| 96 | line=3
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| 97 | ok
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| 98 | ok
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| 99 | ## END
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| 100 |
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| 101 | #### trap ERR and pipeline
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| 102 |
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| 103 | # mksh and bash have different line numbers in this case
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| 104 | #trap 'echo line=$LINENO' ERR
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| 105 | trap 'echo line=$LINENO' ERR
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| 106 |
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| 107 | # it's run for the last 'false'
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| 108 | false | false | false
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| 109 |
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| 110 | { echo pipeline; false; } | false | false
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| 111 |
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| 112 | # it's never run here
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| 113 | ! true
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| 114 | ! false
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| 115 |
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| 116 | ## STDOUT:
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| 117 | line=3
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| 118 | line=5
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| 119 | ## END
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| 120 |
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| 121 | ## BUG mksh/ash STDOUT:
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| 122 | line=1
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| 123 | line=1
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| 124 | ## END
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| 125 |
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| 126 |
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| 127 | #### trap ERR pipelines without simple commands
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| 128 |
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| 129 | trap 'echo assign' ERR
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| 130 | a=$(false) | a=$(false) | a=$(false)
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| 131 |
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| 132 | trap 'echo dparen' ERR
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| 133 | (( 0 )) | (( 0 )) | (( 0 ))
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| 134 |
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| 135 | trap 'echo dbracket' ERR
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| 136 | [[ a = b ]] | [[ a = b ]] | [[ a = b ]]
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| 137 |
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| 138 | # bash anomaly - it gets printed twice?
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| 139 | trap 'echo subshell' ERR
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| 140 | (false) | (false) | (false) | (false)
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| 141 |
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| 142 | # same bug
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| 143 | trap 'echo subshell2' ERR
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| 144 | (false) | (false) | (false) | (false; false)
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| 145 |
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| 146 | trap 'echo group' ERR
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| 147 | { false; } | { false; } | { false; }
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| 148 |
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| 149 | echo ok
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| 150 |
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| 151 | ## STDOUT:
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| 152 | assign
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| 153 | dparen
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| 154 | dbracket
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| 155 | subshell
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| 156 | subshell2
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| 157 | group
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| 158 | ok
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| 159 | ## END
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| 160 |
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| 161 | ## BUG bash STDOUT:
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| 162 | assign
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| 163 | dparen
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| 164 | dbracket
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| 165 | subshell
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| 166 | subshell
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| 167 | subshell2
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| 168 | subshell2
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| 169 | group
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| 170 | ok
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| 171 | ## END
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| 172 |
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| 173 |
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| 174 | #### Pipeline group quirk
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| 175 |
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| 176 | # Oh this is because it's run for the PIPELINE, not for the last thing! Hmmm
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| 177 |
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| 178 | trap 'echo group2' ERR
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| 179 | { false; } | { false; } | { false; false; }
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| 180 |
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| 181 | echo ok
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| 182 |
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| 183 | ## STDOUT:
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| 184 | group2
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| 185 | ok
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| 186 | ## END
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| 187 |
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| 188 | #### trap ERR does not run in errexit situations
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| 189 |
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| 190 | trap 'echo line=$LINENO' ERR
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| 191 |
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| 192 | if false; then
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| 193 | echo if
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| 194 | fi
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| 195 |
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| 196 | while false; do
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| 197 | echo while
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| 198 | done
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| 199 |
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| 200 | until false; do
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| 201 | echo until
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| 202 | break
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| 203 | done
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| 204 |
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| 205 | false || false || false
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| 206 |
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| 207 | false && false && false
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| 208 |
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| 209 | false; false; false
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| 210 |
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| 211 | echo ok
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| 212 |
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| 213 | ## STDOUT:
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| 214 | until
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| 215 | line=16
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| 216 | line=20
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| 217 | line=20
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| 218 | line=20
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| 219 | ok
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| 220 | ## END
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| 221 |
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| 222 |
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| 223 | #### trap ERR doesn't run in subprograms - subshell, command sub, async
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| 224 |
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| 225 | trap 'echo line=$LINENO' ERR
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| 226 |
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| 227 | ( false; echo subshell )
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| 228 |
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| 229 | x=$( false; echo command sub )
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| 230 |
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| 231 | false & wait
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| 232 |
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| 233 | { false; echo async; } & wait
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| 234 |
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| 235 | false
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| 236 | echo ok
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| 237 |
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| 238 | ## STDOUT:
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| 239 | subshell
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| 240 | async
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| 241 | line=11
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| 242 | ok
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| 243 | ## END
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| 244 |
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| 245 | #### set -o errtrace: trap ERR runs in subprograms
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| 246 | case $SH in mksh) exit ;; esac
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| 247 |
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| 248 | set -o errtrace
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| 249 | trap 'echo line=$LINENO' ERR
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| 250 |
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| 251 | ( false; echo subshell )
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| 252 |
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| 253 | x=$( false; echo command sub )
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| 254 |
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| 255 | false
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| 256 | echo ok
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| 257 |
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| 258 | ## STDOUT:
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| 259 | line=6
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| 260 | subshell
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| 261 | line=10
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| 262 | ok
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| 263 | ## END
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| 264 |
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| 265 | # ash doesn't reject errtrace, but doesn't implement it
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| 266 | ## BUG ash STDOUT:
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| 267 | subshell
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| 268 | line=10
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| 269 | ok
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| 270 | ## END
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| 271 |
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| 272 | ## N-I mksh STDOUT:
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| 273 | ## END
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| 274 |
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| 275 | #### trap ERR doesn't run with &
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| 276 |
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| 277 | trap 'echo line=$LINENO' ERR
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| 278 |
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| 279 | false & wait
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| 280 |
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| 281 | { false; echo async; } & wait
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| 282 |
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| 283 | ## STDOUT:
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| 284 | async
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| 285 | ## END
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| 286 |
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| 287 |
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| 288 | #### set -o errtrace: trap ERR with &
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| 289 | case $SH in mksh) exit ;; esac
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| 290 |
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| 291 | set -o errtrace
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| 292 | trap 'echo line=$LINENO' ERR
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| 293 |
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| 294 | false & wait
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| 295 |
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| 296 | { false; echo async; } & wait
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| 297 |
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| 298 | ## STDOUT:
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| 299 | line=8
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| 300 | async
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| 301 | ## END
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| 302 |
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| 303 | ## BUG ash STDOUT:
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| 304 | async
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| 305 | ## END
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| 306 |
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| 307 | ## N-I mksh STDOUT:
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| 308 | ## END
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| 309 |
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| 310 |
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| 311 |
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| 312 | #### trap ERR not active in shell functions in (bash behavior)
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| 313 |
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| 314 | trap 'echo line=$LINENO' ERR
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| 315 |
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| 316 | f() {
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| 317 | false
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| 318 | true
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| 319 | }
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| 320 |
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| 321 | f
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| 322 |
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| 323 | ## STDOUT:
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| 324 | ## END
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| 325 |
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| 326 | ## N-I mksh STDOUT:
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| 327 | line=4
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| 328 | ## END
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| 329 |
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| 330 | #### set -o errtrace - trap ERR runs in shell functions
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| 331 |
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| 332 | trap 'echo err' ERR
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| 333 |
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| 334 | passing() {
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| 335 | false # line 4
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| 336 | true
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| 337 | }
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| 338 |
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| 339 | failing() {
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| 340 | true
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| 341 | false
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| 342 | }
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| 343 |
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| 344 | passing
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| 345 | failing
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| 346 |
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| 347 | set -o errtrace
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| 348 |
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| 349 | echo 'now with errtrace'
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| 350 | passing
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| 351 | failing
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| 352 |
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| 353 | echo ok
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| 354 |
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| 355 | ## STDOUT:
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| 356 | err
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| 357 | now with errtrace
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| 358 | err
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| 359 | err
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| 360 | err
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| 361 | ok
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| 362 | ## END
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| 363 |
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| 364 | ## BUG mksh status: 1
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| 365 | ## BUG mksh STDOUT:
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| 366 | err
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| 367 | err
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| 368 | ## END
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| 369 |
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| 370 | #### set -o errtrace - trap ERR runs in shell functions (LINENO)
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| 371 |
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| 372 | trap 'echo line=$LINENO' ERR
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| 373 |
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| 374 | passing() {
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| 375 | false # line 4
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| 376 | true
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| 377 | }
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| 378 |
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| 379 | failing() {
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| 380 | true
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| 381 | false
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| 382 | }
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| 383 |
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| 384 | passing
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| 385 | failing
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| 386 |
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| 387 | set -o errtrace
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| 388 |
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| 389 | echo 'now with errtrace'
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| 390 | passing
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| 391 | failing
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| 392 |
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| 393 | echo ok
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| 394 |
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| 395 | ## STDOUT:
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| 396 | line=14
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| 397 | now with errtrace
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| 398 | line=4
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| 399 | line=10
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| 400 | line=20
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| 401 | ok
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| 402 | ## END
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| 403 |
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| 404 | ## BUG mksh status: 1
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| 405 | ## BUG mksh STDOUT:
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| 406 | line=4
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| 407 | line=10
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| 408 | ## END
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| 409 |
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| 410 | #### trap ERR with "atoms": assignment (( [[
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| 411 |
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| 412 | trap 'echo line=$LINENO' ERR
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| 413 |
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| 414 | x=$(false)
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| 415 |
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| 416 | [[ a == b ]]
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| 417 |
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| 418 | (( 0 ))
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| 419 | echo ok
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| 420 |
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| 421 | ## STDOUT:
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| 422 | line=3
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| 423 | line=5
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| 424 | line=7
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| 425 | ok
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| 426 | ## END
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| 427 |
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| 428 | ## BUG mksh STDOUT:
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| 429 | line=3
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| 430 | line=3
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| 431 | line=7
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| 432 | ok
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| 433 | ## END
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| 434 |
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| 435 |
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| 436 | #### trap ERR with for, case, { }
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| 437 |
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| 438 | trap 'echo line=$LINENO' ERR
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| 439 |
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| 440 | for y in 1 2; do
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| 441 | false
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| 442 | done
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| 443 |
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| 444 | case x in
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| 445 | x) false ;;
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| 446 | *) false ;;
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| 447 | esac
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| 448 |
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| 449 | { false; false; false; }
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| 450 | echo ok
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| 451 |
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| 452 | ## STDOUT:
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| 453 | line=4
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| 454 | line=4
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| 455 | line=8
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| 456 | line=12
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| 457 | line=12
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| 458 | line=12
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| 459 | ok
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| 460 | ## END
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| 461 |
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| 462 | #### trap ERR with redirect
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| 463 |
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| 464 | trap 'echo line=$LINENO' ERR
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| 465 |
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| 466 | false
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| 467 |
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| 468 | { false
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| 469 | true
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| 470 | } > /zz # error
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| 471 | echo ok
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| 472 |
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| 473 | ## STDOUT:
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| 474 | line=3
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| 475 | line=7
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| 476 | ok
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| 477 | ## END
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| 478 |
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| 479 | # doesn't update line for redirect
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| 480 |
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| 481 | ## BUG bash/mksh STDOUT:
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| 482 | line=3
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| 483 | line=3
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| 484 | ok
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| 485 | ## END
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| 486 |
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| 487 | ## BUG ash STDOUT:
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| 488 | line=3
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| 489 | ok
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| 490 | ## END
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| 491 |
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| 492 |
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| 493 | #### trap ERR with YSH proc
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| 494 |
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| 495 | case $SH in bash|mksh|ash) exit ;; esac
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| 496 |
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| 497 | # seems the same
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| 498 |
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| 499 | shopt -s ysh:upgrade
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| 500 |
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| 501 | proc handler {
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| 502 | echo err
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| 503 | }
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| 504 |
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| 505 | if test -f /nope { echo file exists }
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| 506 |
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| 507 | trap handler ERR
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| 508 |
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| 509 | if test -f /nope { echo file exists }
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| 510 |
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| 511 | false || true # not run for the first part here
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| 512 | false
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| 513 |
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| 514 | ## status: 1
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| 515 | ## STDOUT:
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| 516 | err
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| 517 | ## END
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| 518 |
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| 519 | ## N-I bash/mksh/ash status: 0
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| 520 | ## N-I bash/mksh/ash STDOUT:
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| 521 | ## END
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| 522 |
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| 523 | #### trap ERR
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| 524 | err() {
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| 525 | echo "err [$@] $?"
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| 526 | }
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| 527 | trap 'err x y' ERR
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| 528 |
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| 529 | echo A
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| 530 |
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| 531 | false
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| 532 | echo B
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| 533 |
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| 534 | ( exit 42 )
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| 535 | echo C
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| 536 |
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| 537 | trap - ERR # disable trap
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| 538 |
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| 539 | false
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| 540 | echo D
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| 541 |
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| 542 | trap 'echo after errexit $?' ERR
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| 543 |
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| 544 | set -o errexit
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| 545 |
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| 546 | ( exit 99 )
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| 547 | echo E
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| 548 |
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| 549 | ## status: 99
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| 550 | ## STDOUT:
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| 551 | A
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| 552 | err [x y] 1
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| 553 | B
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| 554 | err [x y] 42
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| 555 | C
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| 556 | D
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| 557 | after errexit 99
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| 558 | ## END
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| 559 | ## N-I dash STDOUT:
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| 560 | A
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| 561 | B
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| 562 | C
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| 563 | D
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| 564 | ## END
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| 565 |
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| 566 | #### trap ERR and pipelines - PIPESTATUS difference
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| 567 | case $SH in ash) exit ;; esac
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| 568 |
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| 569 | err() {
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| 570 | echo "err [$@] status=$? [${PIPESTATUS[@]}]"
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| 571 | }
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| 572 | trap 'err' ERR
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| 573 |
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| 574 | echo A
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| 575 |
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| 576 | false
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| 577 |
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| 578 | # succeeds
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| 579 | echo B | grep B
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| 580 |
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| 581 | # fails
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| 582 | echo C | grep zzz
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| 583 |
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| 584 | echo D | grep zzz | cat
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| 585 |
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| 586 | set -o pipefail
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| 587 | echo E | grep zzz | cat
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| 588 |
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| 589 | trap - ERR # disable trap
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| 590 |
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| 591 | echo F | grep zz
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| 592 | echo ok
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| 593 |
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| 594 | ## STDOUT:
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| 595 | A
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| 596 | err [] status=1 [1]
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| 597 | B
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| 598 | err [] status=1 [0 1]
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| 599 | err [] status=1 [0 1 0]
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| 600 | ok
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| 601 | ## END
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| 602 |
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| 603 | # we don't set PIPESTATUS unless we get a pipeline
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| 604 |
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| 605 | ## OK osh STDOUT:
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| 606 | A
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| 607 | err [] status=1 []
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| 608 | B
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| 609 | err [] status=1 [0 1]
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| 610 | err [] status=1 [0 1 0]
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| 611 | ok
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| 612 | ## END
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| 613 |
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| 614 | ## N-I ash STDOUT:
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| 615 | ## END
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| 616 |
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| 617 | #### error in trap ERR (recursive)
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| 618 | case $SH in dash) exit ;; esac
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| 619 |
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| 620 | err() {
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| 621 | echo err status $?
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| 622 | false
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| 623 | ( exit 2 ) # not recursively triggered
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| 624 | echo err 2
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| 625 | }
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| 626 | trap 'err' ERR
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| 627 |
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| 628 | echo A
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| 629 | false
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| 630 | echo B
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| 631 |
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| 632 | # Try it with errexit
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| 633 | set -e
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| 634 | false
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| 635 | echo C
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| 636 |
|
| 637 | ## status: 1
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| 638 | ## STDOUT:
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| 639 | A
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| 640 | err status 1
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| 641 | err 2
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| 642 | B
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| 643 | err status 1
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| 644 | ## END
|
| 645 | ## N-I dash STDOUT:
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| 646 | ## END
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| 647 |
|