| 1 | ## oils_failures_allowed: 4
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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 does not run in errexit situations
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| 128 |
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| 129 | trap 'echo line=$LINENO' ERR
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| 130 |
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| 131 | if false; then
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| 132 | echo if
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| 133 | fi
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| 134 |
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| 135 | while false; do
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| 136 | echo while
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| 137 | done
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| 138 |
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| 139 | until false; do
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| 140 | echo until
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| 141 | break
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| 142 | done
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| 143 |
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| 144 | false || false || false
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| 145 |
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| 146 | false && false && false
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| 147 |
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| 148 | false; false; false
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| 149 |
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| 150 | echo ok
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| 151 |
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| 152 | ## STDOUT:
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| 153 | until
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| 154 | line=16
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| 155 | line=20
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| 156 | line=20
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| 157 | line=20
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| 158 | ok
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| 159 | ## END
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| 160 |
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| 161 |
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| 162 | #### trap ERR subprogram - subshell, command sub, async
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| 163 |
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| 164 | trap 'echo line=$LINENO' ERR
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| 165 |
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| 166 | ( false; echo subshell )
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| 167 |
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| 168 | x=$( false; echo command sub )
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| 169 |
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| 170 | false & wait
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| 171 |
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| 172 | { false; echo async; } & wait
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| 173 |
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| 174 | false
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| 175 | echo ok
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| 176 |
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| 177 | ## STDOUT:
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| 178 | subshell
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| 179 | async
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| 180 | line=11
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| 181 | ok
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| 182 | ## END
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| 183 |
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| 184 | #### trap ERR not active in shell functions in (bash behavior)
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| 185 |
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| 186 | trap 'echo line=$LINENO' ERR
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| 187 |
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| 188 | f() {
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| 189 | false
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| 190 | true
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| 191 | }
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| 192 |
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| 193 | f
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| 194 |
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| 195 | ## STDOUT:
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| 196 | ## END
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| 197 |
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| 198 | ## N-I mksh STDOUT:
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| 199 | line=4
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| 200 | ## END
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| 201 |
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| 202 | #### trap ERR shell function - with errtrace
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| 203 |
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| 204 | trap 'echo line=$LINENO' ERR
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| 205 |
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| 206 | passing() {
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| 207 | false # line 4
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| 208 | true
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| 209 | }
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| 210 |
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| 211 | failing() {
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| 212 | true
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| 213 | false
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| 214 | }
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| 215 |
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| 216 | passing
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| 217 | failing
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| 218 |
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| 219 | set -o errtrace
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| 220 |
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| 221 | echo 'now with errtrace'
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| 222 | passing
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| 223 | failing
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| 224 |
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| 225 | echo ok
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| 226 |
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| 227 | ## STDOUT:
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| 228 | line=14
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| 229 | now with errtrace
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| 230 | line=4
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| 231 | line=10
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| 232 | line=20
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| 233 | ok
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| 234 | ## END
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| 235 |
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| 236 | ## BUG mksh status: 1
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| 237 | ## BUG mksh STDOUT:
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| 238 | line=4
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| 239 | line=10
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| 240 | ## END
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| 241 |
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| 242 | #### trap ERR with assignment, for, case, { }
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| 243 |
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| 244 | trap 'echo line=$LINENO' ERR
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| 245 |
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| 246 | x=$(false)
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| 247 |
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| 248 | for y in 1 2; do
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| 249 | false
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| 250 | done
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| 251 |
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| 252 | case x in
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| 253 | x) false ;;
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| 254 | *) false ;;
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| 255 | esac
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| 256 |
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| 257 | { false; false; }
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| 258 | echo ok
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| 259 |
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| 260 | ## STDOUT:
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| 261 | line=3
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| 262 | line=6
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| 263 | line=6
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| 264 | line=10
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| 265 | line=14
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| 266 | line=14
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| 267 | ok
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| 268 | ## END
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| 269 |
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| 270 | #### trap ERR with redirect
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| 271 |
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| 272 | trap 'echo line=$LINENO' ERR
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| 273 |
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| 274 | false
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| 275 |
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| 276 | { false
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| 277 | true
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| 278 | } > /zz # error
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| 279 | echo ok
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| 280 |
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| 281 | ## STDOUT:
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| 282 | line=3
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| 283 | line=7
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| 284 | ok
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| 285 | ## END
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| 286 |
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| 287 | # doesn't update line for redirect
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| 288 |
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| 289 | ## BUG bash/mksh STDOUT:
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| 290 | line=3
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| 291 | line=3
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| 292 | ok
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| 293 | ## END
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| 294 |
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| 295 | ## BUG ash STDOUT:
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| 296 | line=3
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| 297 | ok
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| 298 | ## END
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| 299 |
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| 300 |
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| 301 | #### trap ERR with YSH proc
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| 302 |
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| 303 | case $SH in bash|mksh|ash) exit ;; esac
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| 304 |
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| 305 | # seems the same
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| 306 |
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| 307 | shopt -s ysh:upgrade
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| 308 |
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| 309 | proc handler {
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| 310 | echo err
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| 311 | }
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| 312 |
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| 313 | if test -f /nope { echo file exists }
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| 314 |
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| 315 | trap handler ERR
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| 316 |
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| 317 | if test -f /nope { echo file exists }
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| 318 |
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| 319 | false || true # not run for the first part here
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| 320 | false
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| 321 |
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| 322 | ## status: 1
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| 323 | ## STDOUT:
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| 324 | err
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| 325 | ## END
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| 326 |
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| 327 | ## N-I bash/mksh/ash status: 0
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| 328 | ## N-I bash/mksh/ash STDOUT:
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| 329 | ## END
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| 330 |
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| 331 | #### trap ERR
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| 332 | err() {
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| 333 | echo "err [$@] $?"
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| 334 | }
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| 335 | trap 'err x y' ERR
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| 336 |
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| 337 | echo A
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| 338 |
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| 339 | false
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| 340 | echo B
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| 341 |
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| 342 | ( exit 42 )
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| 343 | echo C
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| 344 |
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| 345 | trap - ERR # disable trap
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| 346 |
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| 347 | false
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| 348 | echo D
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| 349 |
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| 350 | trap 'echo after errexit $?' ERR
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| 351 |
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| 352 | set -o errexit
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| 353 |
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| 354 | ( exit 99 )
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| 355 | echo E
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| 356 |
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| 357 | ## status: 99
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| 358 | ## STDOUT:
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| 359 | A
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| 360 | err [x y] 1
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| 361 | B
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| 362 | err [x y] 42
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| 363 | C
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| 364 | D
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| 365 | after errexit 99
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| 366 | ## END
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| 367 | ## N-I dash STDOUT:
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| 368 | A
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| 369 | B
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| 370 | C
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| 371 | D
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| 372 | ## END
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| 373 |
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| 374 | #### trap ERR and pipelines (lastpipe and PIPESTATUS difference)
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| 375 | case $SH in ash) exit ;; esac
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| 376 |
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| 377 | err() {
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| 378 | echo "err [$@] status=$? [${PIPESTATUS[@]}]"
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| 379 | }
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| 380 | trap 'err' ERR
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| 381 |
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| 382 | echo A
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| 383 |
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| 384 | false
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| 385 |
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| 386 | # succeeds
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| 387 | echo B | grep B
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| 388 |
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| 389 | # fails
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| 390 | echo C | grep zzz
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| 391 |
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| 392 | echo D | grep zzz | cat
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| 393 |
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| 394 | set -o pipefail
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| 395 | echo E | grep zzz | cat
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| 396 |
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| 397 | trap - ERR # disable trap
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| 398 |
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| 399 | echo F | grep zz
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| 400 | echo ok
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| 401 |
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| 402 | ## STDOUT:
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| 403 | A
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| 404 | err [] status=1 [1]
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| 405 | B
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| 406 | err [] status=1 [0 1]
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| 407 | err [] status=1 [0 1 0]
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| 408 | ok
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| 409 | ## END
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| 410 |
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| 411 | # lastpipe semantics mean we get another call!
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| 412 | # also we don't set PIPESTATUS unless we get a pipeline
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| 413 |
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| 414 | ## OK osh STDOUT:
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| 415 | A
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| 416 | err [] status=1 []
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| 417 | B
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| 418 | err [] status=1 [0 0]
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| 419 | err [] status=1 [0 1]
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| 420 | err [] status=1 [0 1 0]
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| 421 | ok
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| 422 | ## END
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| 423 |
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| 424 | ## N-I ash STDOUT:
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| 425 | ## END
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| 426 |
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| 427 | #### error in trap ERR (recursive)
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| 428 | case $SH in dash) exit ;; esac
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| 429 |
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| 430 | err() {
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| 431 | echo err status $?
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| 432 | false
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| 433 | ( exit 2 ) # not recursively triggered
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| 434 | echo err 2
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| 435 | }
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| 436 | trap 'err' ERR
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| 437 |
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| 438 | echo A
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| 439 | false
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| 440 | echo B
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| 441 |
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| 442 | # Try it with errexit
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| 443 | set -e
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| 444 | false
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| 445 | echo C
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| 446 |
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| 447 | ## status: 1
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| 448 | ## STDOUT:
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| 449 | A
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| 450 | err status 1
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| 451 | err 2
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| 452 | B
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| 453 | err status 1
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| 454 | ## END
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| 455 | ## N-I dash STDOUT:
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| 456 | ## END
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| 457 |
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