| 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=$LINENO' ERR
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| 78 |
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| 79 | if test -f /nope; then echo file exists; fi
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| 80 |
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| 81 | ## STDOUT:
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| 82 | ## END
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| 83 |
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| 84 | #### trap ERR does not run in errexit situations
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| 85 |
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| 86 | trap 'echo line=$LINENO' ERR
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| 87 |
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| 88 | if false; then
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| 89 | echo if
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| 90 | fi
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| 91 |
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| 92 | while false; do
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| 93 | echo while
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| 94 | done
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| 95 |
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| 96 | until false; do
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| 97 | echo until
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| 98 | break
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| 99 | done
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| 100 |
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| 101 | false || false || false
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| 102 |
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| 103 | false && false && false
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| 104 |
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| 105 | false; false; false
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| 106 |
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| 107 | echo ok
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| 108 |
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| 109 | ## STDOUT:
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| 110 | until
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| 111 | line=16
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| 112 | line=20
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| 113 | line=20
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| 114 | line=20
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| 115 | ok
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| 116 | ## END
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| 117 |
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| 118 | #### trap ERR pipeline (also errexit)
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| 119 |
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| 120 | # mksh and bash have different line numbers in this case
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| 121 | #trap 'echo line=$LINENO' ERR
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| 122 | trap 'echo line=$LINENO' ERR
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| 123 |
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| 124 | # it's run for the last 'false'
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| 125 | false | false | false
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| 126 |
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| 127 | { echo pipeline; false; } | false | false
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| 128 |
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| 129 | # it's never run here
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| 130 | ! true
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| 131 | ! false
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| 132 |
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| 133 | ## STDOUT:
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| 134 | line=3
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| 135 | line=5
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| 136 | ## END
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| 137 |
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| 138 | ## BUG mksh/ash STDOUT:
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| 139 | line=1
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| 140 | line=1
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| 141 | ## END
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| 142 |
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| 143 | #### trap ERR subprogram - subshell, command sub, async
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| 144 |
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| 145 | trap 'echo line=$LINENO' ERR
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| 146 |
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| 147 | ( false; echo subshell )
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| 148 |
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| 149 | x=$( false; echo command sub )
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| 150 |
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| 151 | false & wait
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| 152 |
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| 153 | { false; echo async; } & wait
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| 154 |
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| 155 | false
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| 156 | echo ok
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| 157 |
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| 158 | ## STDOUT:
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| 159 | subshell
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| 160 | async
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| 161 | line=11
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| 162 | ok
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| 163 | ## END
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| 164 |
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| 165 | #### trap ERR not active in shell functions in (bash behavior)
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| 166 |
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| 167 | trap 'echo line=$LINENO' ERR
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| 168 |
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| 169 | f() {
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| 170 | false
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| 171 | true
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| 172 | }
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| 173 |
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| 174 | f
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| 175 |
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| 176 | ## STDOUT:
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| 177 | ## END
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| 178 |
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| 179 | ## N-I mksh STDOUT:
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| 180 | line=4
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| 181 | ## END
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| 182 |
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| 183 | #### trap ERR shell function - with errtrace
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| 184 |
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| 185 | trap 'echo line=$LINENO' ERR
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| 186 |
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| 187 | passing() {
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| 188 | false # line 4
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| 189 | true
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| 190 | }
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| 191 |
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| 192 | failing() {
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| 193 | true
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| 194 | false
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| 195 | }
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| 196 |
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| 197 | passing
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| 198 | failing
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| 199 |
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| 200 | set -o errtrace
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| 201 |
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| 202 | echo 'now with errtrace'
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| 203 | passing
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| 204 | failing
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| 205 |
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| 206 | echo ok
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| 207 |
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| 208 | ## STDOUT:
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| 209 | line=14
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| 210 | now with errtrace
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| 211 | line=4
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| 212 | line=10
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| 213 | line=20
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| 214 | ok
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| 215 | ## END
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| 216 |
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| 217 | ## BUG mksh status: 1
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| 218 | ## BUG mksh STDOUT:
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| 219 | line=4
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| 220 | line=10
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| 221 | ## END
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| 222 |
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| 223 |
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| 224 | #### trap ERR with YSH proc
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| 225 |
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| 226 | case $SH in bash|mksh|ash) exit ;; esac
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| 227 |
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| 228 | # seems the same
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| 229 |
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| 230 | shopt -s ysh:upgrade
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| 231 |
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| 232 | proc abc { echo abc }
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| 233 | if test -f /nope { echo file exists }
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| 234 | trap abc ERR
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| 235 | if test -f /nope { echo file exists }
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| 236 |
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| 237 | ## STDOUT:
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| 238 | abc
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| 239 | ## END
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| 240 |
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| 241 | ## N-I bash/mksh/ash STDOUT:
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| 242 | ## END
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| 243 |
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| 244 | #### trap ERR
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| 245 | err() {
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| 246 | echo "err [$@] $?"
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| 247 | }
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| 248 | trap 'err x y' ERR
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| 249 |
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| 250 | echo A
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| 251 |
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| 252 | false
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| 253 | echo B
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| 254 |
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| 255 | ( exit 42 )
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| 256 | echo C
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| 257 |
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| 258 | trap - ERR # disable trap
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| 259 |
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| 260 | false
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| 261 | echo D
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| 262 |
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| 263 | trap 'echo after errexit $?' ERR
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| 264 |
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| 265 | set -o errexit
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| 266 |
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| 267 | ( exit 99 )
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| 268 | echo E
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| 269 |
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| 270 | ## status: 99
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| 271 | ## STDOUT:
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| 272 | A
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| 273 | err [x y] 1
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| 274 | B
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| 275 | err [x y] 42
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| 276 | C
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| 277 | D
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| 278 | after errexit 99
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| 279 | ## END
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| 280 | ## N-I dash STDOUT:
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| 281 | A
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| 282 | B
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| 283 | C
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| 284 | D
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| 285 | ## END
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| 286 |
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| 287 | #### trap ERR and pipelines (lastpipe and PIPESTATUS difference)
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| 288 | case $SH in ash) exit ;; esac
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| 289 |
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| 290 | err() {
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| 291 | echo "err [$@] status=$? [${PIPESTATUS[@]}]"
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| 292 | }
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| 293 | trap 'err' ERR
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| 294 |
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| 295 | echo A
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| 296 |
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| 297 | false
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| 298 |
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| 299 | # succeeds
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| 300 | echo B | grep B
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| 301 |
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| 302 | # fails
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| 303 | echo C | grep zzz
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| 304 |
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| 305 | echo D | grep zzz | cat
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| 306 |
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| 307 | set -o pipefail
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| 308 | echo E | grep zzz | cat
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| 309 |
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| 310 | trap - ERR # disable trap
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| 311 |
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| 312 | echo F | grep zz
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| 313 | echo ok
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| 314 |
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| 315 | ## STDOUT:
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| 316 | A
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| 317 | err [] status=1 [1]
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| 318 | B
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| 319 | err [] status=1 [0 1]
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| 320 | err [] status=1 [0 1 0]
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| 321 | ok
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| 322 | ## END
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| 323 |
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| 324 | # lastpipe semantics mean we get another call!
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| 325 | # also we don't set PIPESTATUS unless we get a pipeline
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| 326 |
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| 327 | ## OK osh STDOUT:
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| 328 | A
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| 329 | err [] status=1 []
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| 330 | B
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| 331 | err [] status=1 [0 0]
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| 332 | err [] status=1 [0 1]
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| 333 | err [] status=1 [0 1 0]
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| 334 | ok
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| 335 | ## END
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| 336 |
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| 337 | ## N-I ash STDOUT:
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| 338 | ## END
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| 339 |
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| 340 | #### error in trap ERR (recursive)
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| 341 | case $SH in dash) exit ;; esac
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| 342 |
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| 343 | err() {
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| 344 | echo err status $?
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| 345 | false
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| 346 | ( exit 2 ) # not recursively triggered
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| 347 | echo err 2
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| 348 | }
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| 349 | trap 'err' ERR
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| 350 |
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| 351 | echo A
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| 352 | false
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| 353 | echo B
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| 354 |
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| 355 | # Try it with errexit
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| 356 | set -e
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| 357 | false
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| 358 | echo C
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| 359 |
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| 360 | ## status: 1
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| 361 | ## STDOUT:
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| 362 | A
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| 363 | err status 1
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| 364 | err 2
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| 365 | B
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| 366 | err status 1
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| 367 | ## END
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| 368 | ## N-I dash STDOUT:
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| 369 | ## END
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| 370 |
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