| 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 |
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| 247 | case $SH in mksh) exit ;; esac
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| 248 |
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| 249 | set -o errtrace
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| 250 | trap 'echo line=$LINENO' ERR
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| 251 |
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| 252 | ( false; echo subshell )
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| 253 |
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| 254 | x=$( false; echo command sub )
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| 255 |
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| 256 | false & wait
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| 257 |
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| 258 | { false; echo async; } & wait
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| 259 |
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| 260 | false
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| 261 | echo ok
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| 262 |
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| 263 | ## STDOUT:
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| 264 | line=6
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| 265 | subshell
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| 266 | line=12
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| 267 | async
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| 268 | line=14
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| 269 | ok
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| 270 | ## END
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| 271 |
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| 272 | # ash doesn't reject errtrace, but doesn't implement it
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| 273 | ## BUG ash STDOUT:
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| 274 | subshell
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| 275 | async
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| 276 | line=14
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| 277 | ok
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| 278 | ## END
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| 279 |
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| 280 | ## N-I mksh STDOUT:
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| 281 | ## END
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| 282 |
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| 283 |
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| 284 | #### trap ERR not active in shell functions in (bash behavior)
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| 285 |
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| 286 | trap 'echo line=$LINENO' ERR
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| 287 |
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| 288 | f() {
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| 289 | false
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| 290 | true
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| 291 | }
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| 292 |
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| 293 | f
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| 294 |
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| 295 | ## STDOUT:
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| 296 | ## END
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| 297 |
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| 298 | ## N-I mksh STDOUT:
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| 299 | line=4
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| 300 | ## END
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| 301 |
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| 302 | #### set -o errtrace - trap ERR runs in shell functions
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| 303 |
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| 304 | trap 'echo line=$LINENO' ERR
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| 305 |
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| 306 | passing() {
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| 307 | false # line 4
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| 308 | true
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| 309 | }
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| 310 |
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| 311 | failing() {
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| 312 | true
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| 313 | false
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| 314 | }
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| 315 |
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| 316 | passing
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| 317 | failing
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| 318 |
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| 319 | set -o errtrace
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| 320 |
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| 321 | echo 'now with errtrace'
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| 322 | passing
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| 323 | failing
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| 324 |
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| 325 | echo ok
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| 326 |
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| 327 | ## STDOUT:
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| 328 | line=14
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| 329 | now with errtrace
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| 330 | line=4
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| 331 | line=10
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| 332 | line=20
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| 333 | ok
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| 334 | ## END
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| 335 |
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| 336 | ## BUG mksh status: 1
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| 337 | ## BUG mksh STDOUT:
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| 338 | line=4
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| 339 | line=10
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| 340 | ## END
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| 341 |
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| 342 | #### trap ERR with "atoms": assignment (( [[
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| 343 |
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| 344 | trap 'echo line=$LINENO' ERR
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| 345 |
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| 346 | x=$(false)
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| 347 |
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| 348 | [[ a == b ]]
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| 349 |
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| 350 | (( 0 ))
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| 351 | echo ok
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| 352 |
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| 353 | ## STDOUT:
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| 354 | line=3
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| 355 | line=5
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| 356 | line=7
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| 357 | ok
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| 358 | ## END
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| 359 |
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| 360 | ## BUG mksh STDOUT:
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| 361 | line=3
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| 362 | line=3
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| 363 | line=7
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| 364 | ok
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| 365 | ## END
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| 366 |
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| 367 |
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| 368 | #### trap ERR with for, case, { }
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| 369 |
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| 370 | trap 'echo line=$LINENO' ERR
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| 371 |
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| 372 | for y in 1 2; do
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| 373 | false
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| 374 | done
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| 375 |
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| 376 | case x in
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| 377 | x) false ;;
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| 378 | *) false ;;
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| 379 | esac
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| 380 |
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| 381 | { false; false; false; }
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| 382 | echo ok
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| 383 |
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| 384 | ## STDOUT:
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| 385 | line=4
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| 386 | line=4
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| 387 | line=8
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| 388 | line=12
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| 389 | line=12
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| 390 | line=12
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| 391 | ok
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| 392 | ## END
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| 393 |
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| 394 | #### trap ERR with redirect
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| 395 |
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| 396 | trap 'echo line=$LINENO' ERR
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| 397 |
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| 398 | false
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| 399 |
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| 400 | { false
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| 401 | true
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| 402 | } > /zz # error
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| 403 | echo ok
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| 404 |
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| 405 | ## STDOUT:
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| 406 | line=3
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| 407 | line=7
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| 408 | ok
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| 409 | ## END
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| 410 |
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| 411 | # doesn't update line for redirect
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| 412 |
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| 413 | ## BUG bash/mksh STDOUT:
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| 414 | line=3
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| 415 | line=3
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| 416 | ok
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| 417 | ## END
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| 418 |
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| 419 | ## BUG ash STDOUT:
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| 420 | line=3
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| 421 | ok
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| 422 | ## END
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| 423 |
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| 424 |
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| 425 | #### trap ERR with YSH proc
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| 426 |
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| 427 | case $SH in bash|mksh|ash) exit ;; esac
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| 428 |
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| 429 | # seems the same
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| 430 |
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| 431 | shopt -s ysh:upgrade
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| 432 |
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| 433 | proc handler {
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| 434 | echo err
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| 435 | }
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| 436 |
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| 437 | if test -f /nope { echo file exists }
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| 438 |
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| 439 | trap handler ERR
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| 440 |
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| 441 | if test -f /nope { echo file exists }
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| 442 |
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| 443 | false || true # not run for the first part here
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| 444 | false
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| 445 |
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| 446 | ## status: 1
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| 447 | ## STDOUT:
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| 448 | err
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| 449 | ## END
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| 450 |
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| 451 | ## N-I bash/mksh/ash status: 0
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| 452 | ## N-I bash/mksh/ash STDOUT:
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| 453 | ## END
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| 454 |
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| 455 | #### trap ERR
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| 456 | err() {
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| 457 | echo "err [$@] $?"
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| 458 | }
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| 459 | trap 'err x y' ERR
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| 460 |
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| 461 | echo A
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| 462 |
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| 463 | false
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| 464 | echo B
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| 465 |
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| 466 | ( exit 42 )
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| 467 | echo C
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| 468 |
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| 469 | trap - ERR # disable trap
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| 470 |
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| 471 | false
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| 472 | echo D
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| 473 |
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| 474 | trap 'echo after errexit $?' ERR
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| 475 |
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| 476 | set -o errexit
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| 477 |
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| 478 | ( exit 99 )
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| 479 | echo E
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| 480 |
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| 481 | ## status: 99
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| 482 | ## STDOUT:
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| 483 | A
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| 484 | err [x y] 1
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| 485 | B
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| 486 | err [x y] 42
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| 487 | C
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| 488 | D
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| 489 | after errexit 99
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| 490 | ## END
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| 491 | ## N-I dash STDOUT:
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| 492 | A
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| 493 | B
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| 494 | C
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| 495 | D
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| 496 | ## END
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| 497 |
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| 498 | #### trap ERR and pipelines - PIPESTATUS difference
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| 499 | case $SH in ash) exit ;; esac
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| 500 |
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| 501 | err() {
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| 502 | echo "err [$@] status=$? [${PIPESTATUS[@]}]"
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| 503 | }
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| 504 | trap 'err' ERR
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| 505 |
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| 506 | echo A
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| 507 |
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| 508 | false
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| 509 |
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| 510 | # succeeds
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| 511 | echo B | grep B
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| 512 |
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| 513 | # fails
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| 514 | echo C | grep zzz
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| 515 |
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| 516 | echo D | grep zzz | cat
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| 517 |
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| 518 | set -o pipefail
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| 519 | echo E | grep zzz | cat
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| 520 |
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| 521 | trap - ERR # disable trap
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| 522 |
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| 523 | echo F | grep zz
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| 524 | echo ok
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| 525 |
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| 526 | ## STDOUT:
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| 527 | A
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| 528 | err [] status=1 [1]
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| 529 | B
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| 530 | err [] status=1 [0 1]
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| 531 | err [] status=1 [0 1 0]
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| 532 | ok
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| 533 | ## END
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| 534 |
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| 535 | # we don't set PIPESTATUS unless we get a pipeline
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| 536 |
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| 537 | ## OK osh STDOUT:
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| 538 | A
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| 539 | err [] status=1 []
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| 540 | B
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| 541 | err [] status=1 [0 1]
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| 542 | err [] status=1 [0 1 0]
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| 543 | ok
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| 544 | ## END
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| 545 |
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| 546 | ## N-I ash STDOUT:
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| 547 | ## END
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| 548 |
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| 549 | #### error in trap ERR (recursive)
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| 550 | case $SH in dash) exit ;; esac
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| 551 |
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| 552 | err() {
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| 553 | echo err status $?
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| 554 | false
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| 555 | ( exit 2 ) # not recursively triggered
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| 556 | echo err 2
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| 557 | }
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| 558 | trap 'err' ERR
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| 559 |
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| 560 | echo A
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| 561 | false
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| 562 | echo B
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| 563 |
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| 564 | # Try it with errexit
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| 565 | set -e
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| 566 | false
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| 567 | echo C
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| 568 |
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| 569 | ## status: 1
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| 570 | ## STDOUT:
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| 571 | A
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| 572 | err status 1
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| 573 | err 2
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| 574 | B
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| 575 | err status 1
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| 576 | ## END
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| 577 | ## N-I dash STDOUT:
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| 578 | ## END
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| 579 |
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