| 1 | ## oils_failures_allowed: 0
|
| 2 | ## compare_shells: bash dash mksh zsh ash yash
|
| 3 |
|
| 4 | #### true is not special; prefix assignments don't persist, it can be redefined
|
| 5 | foo=bar true
|
| 6 | echo foo=$foo
|
| 7 |
|
| 8 | true() {
|
| 9 | echo true func
|
| 10 | }
|
| 11 | foo=bar true
|
| 12 | echo foo=$foo
|
| 13 |
|
| 14 | ## STDOUT:
|
| 15 | foo=
|
| 16 | true func
|
| 17 | foo=
|
| 18 | ## END
|
| 19 |
|
| 20 | ## BUG mksh STDOUT:
|
| 21 | foo=
|
| 22 | true func
|
| 23 | foo=bar
|
| 24 | ## END
|
| 25 |
|
| 26 | # POSIX rule about special builtins pointed at:
|
| 27 | #
|
| 28 | # https://www.reddit.com/r/oilshell/comments/5ykpi3/oildev_is_alive/
|
| 29 |
|
| 30 | #### Prefix assignments persist after special builtins, like : (set -o posix)
|
| 31 | case $SH in
|
| 32 | bash) set -o posix ;;
|
| 33 | esac
|
| 34 |
|
| 35 | foo=bar :
|
| 36 | echo foo=$foo
|
| 37 |
|
| 38 | # Not true when you use 'builtin'
|
| 39 | z=Z builtin :
|
| 40 | echo z=$Z
|
| 41 |
|
| 42 | ## STDOUT:
|
| 43 | foo=bar
|
| 44 | z=
|
| 45 | ## END
|
| 46 |
|
| 47 | ## BUG zsh STDOUT:
|
| 48 | foo=
|
| 49 | z=
|
| 50 | ## END
|
| 51 |
|
| 52 | #### Prefix assignments persist after readonly, but NOT exported (set -o posix)
|
| 53 |
|
| 54 | # Bash only implements it behind the posix option
|
| 55 | case $SH in
|
| 56 | bash) set -o posix ;;
|
| 57 | esac
|
| 58 | foo=bar readonly spam=eggs
|
| 59 | echo foo=$foo
|
| 60 | echo spam=$spam
|
| 61 |
|
| 62 | # should NOT be exported
|
| 63 | printenv.py foo
|
| 64 | printenv.py spam
|
| 65 |
|
| 66 | ## STDOUT:
|
| 67 | foo=bar
|
| 68 | spam=eggs
|
| 69 | None
|
| 70 | None
|
| 71 | ## END
|
| 72 |
|
| 73 | ## BUG bash/yash STDOUT:
|
| 74 | foo=bar
|
| 75 | spam=eggs
|
| 76 | bar
|
| 77 | None
|
| 78 | ## END
|
| 79 |
|
| 80 | #### Prefix binding for exec is a special case (versus e.g. readonly)
|
| 81 |
|
| 82 | pre1=pre1 readonly x=x
|
| 83 | pre2=pre2 exec sh -c 'echo pre1=$pre1 x=$x pre2=$pre2'
|
| 84 |
|
| 85 | ## STDOUT:
|
| 86 | pre1= x= pre2=pre2
|
| 87 | ## END
|
| 88 | ## BUG yash STDOUT:
|
| 89 | pre1=pre1 x= pre2=pre2
|
| 90 | ## END
|
| 91 |
|
| 92 | #### exec without args is a special case of the special case in some shells
|
| 93 |
|
| 94 | FOO=bar exec >& 2
|
| 95 | echo FOO=$FOO
|
| 96 | #declare -p | grep FOO
|
| 97 |
|
| 98 | ## STDERR:
|
| 99 | FOO=
|
| 100 | ## END
|
| 101 |
|
| 102 | ## OK dash/mksh/ash/yash STDERR:
|
| 103 | FOO=bar
|
| 104 | ## END
|
| 105 |
|
| 106 | #### Which shells allow special builtins to be redefined?
|
| 107 | eval() {
|
| 108 | echo 'eval func' "$@"
|
| 109 | }
|
| 110 | eval 'echo hi'
|
| 111 |
|
| 112 | # we allow redefinition, but the definition is NOT used!
|
| 113 | ## status: 0
|
| 114 | ## STDOUT:
|
| 115 | hi
|
| 116 | ## END
|
| 117 |
|
| 118 | # we PREVENT redefinition
|
| 119 | ## OK dash/ash status: 2
|
| 120 | ## OK dash/ash STDOUT:
|
| 121 | ## END
|
| 122 |
|
| 123 | # should not allow redefinition
|
| 124 | ## BUG bash/zsh status: 0
|
| 125 | ## BUG bash/zsh STDOUT:
|
| 126 | eval func echo hi
|
| 127 | ## END
|
| 128 |
|
| 129 |
|
| 130 | #### Special builtins can't be redefined as shell functions (set -o posix)
|
| 131 | case $SH in
|
| 132 | bash) set -o posix ;;
|
| 133 | esac
|
| 134 |
|
| 135 | eval 'echo hi'
|
| 136 |
|
| 137 | eval() {
|
| 138 | echo 'sh func' "$@"
|
| 139 | }
|
| 140 |
|
| 141 | eval 'echo hi'
|
| 142 |
|
| 143 | ## status: 0
|
| 144 | ## STDOUT:
|
| 145 | hi
|
| 146 | hi
|
| 147 | ## END
|
| 148 |
|
| 149 | ## OK bash/dash/ash status: 2
|
| 150 | ## OK bash/dash/ash STDOUT:
|
| 151 | hi
|
| 152 | ## END
|
| 153 |
|
| 154 | ## BUG zsh status: 0
|
| 155 | ## BUG zsh STDOUT:
|
| 156 | hi
|
| 157 | sh func echo hi
|
| 158 | ## END
|
| 159 |
|
| 160 | #### Non-special builtins CAN be redefined as functions
|
| 161 | test -n "$BASH_VERSION" && set -o posix
|
| 162 | true() {
|
| 163 | echo 'true func'
|
| 164 | }
|
| 165 | true hi
|
| 166 | echo status=$?
|
| 167 | ## STDOUT:
|
| 168 | true func
|
| 169 | status=0
|
| 170 | ## END
|
| 171 |
|
| 172 | #### Shift is special and fails whole script
|
| 173 |
|
| 174 | # https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_14
|
| 175 | #
|
| 176 | # 2.8.1 - Consequences of shell errors
|
| 177 | #
|
| 178 | # Special built-ins should exit a non-interactive shell
|
| 179 | # bash and busybox dont't implement this even with set -o posix, so it seems risky
|
| 180 | # dash and mksh do it; so does AT&T ksh
|
| 181 |
|
| 182 | $SH -c '
|
| 183 | if test -n "$BASH_VERSION"; then
|
| 184 | set -o posix
|
| 185 | fi
|
| 186 | set -- a b
|
| 187 | shift 3
|
| 188 | echo status=$?
|
| 189 | '
|
| 190 | if test "$?" != 0; then
|
| 191 | echo 'non-zero status'
|
| 192 | fi
|
| 193 |
|
| 194 | ## STDOUT:
|
| 195 | non-zero status
|
| 196 | ## END
|
| 197 |
|
| 198 | ## N-I bash/zsh/ash/yash/osh status: 0
|
| 199 | ## N-I bash/zsh/ash/yash/osh STDOUT:
|
| 200 | status=1
|
| 201 | ## END
|
| 202 |
|
| 203 | #### set is special and fails whole script, even if using || true
|
| 204 | $SH -c '
|
| 205 | if test -n "$BASH_VERSION"; then
|
| 206 | set -o posix
|
| 207 | fi
|
| 208 |
|
| 209 | shopt -s invalid_ || true
|
| 210 | echo ok
|
| 211 | set -o invalid_ || true
|
| 212 | echo should not get here
|
| 213 | '
|
| 214 | if test "$?" != 0; then
|
| 215 | echo 'non-zero status'
|
| 216 | fi
|
| 217 |
|
| 218 | ## STDOUT:
|
| 219 | ok
|
| 220 | non-zero status
|
| 221 | ## END
|
| 222 |
|
| 223 | ## N-I bash/ash/yash/osh status: 0
|
| 224 | ## N-I bash/ash/yash/osh STDOUT:
|
| 225 | ok
|
| 226 | should not get here
|
| 227 | ## END
|
| 228 |
|
| 229 | #### bash 'type' gets confused - says 'function', but runs builtin
|
| 230 | case $SH in dash|mksh|zsh|ash|yash) exit ;; esac
|
| 231 |
|
| 232 | echo TRUE
|
| 233 | type -t true # builtin
|
| 234 | true() { echo true func; }
|
| 235 | type -t true # now a function
|
| 236 | echo ---
|
| 237 |
|
| 238 | echo EVAL
|
| 239 |
|
| 240 | type -t eval # builtin
|
| 241 | # define function before set -o posix
|
| 242 | eval() { echo "shell function: $1"; }
|
| 243 | # bash runs the FUNCTION, but OSH finds the special builtin
|
| 244 | # OSH doesn't need set -o posix
|
| 245 | eval 'echo before posix'
|
| 246 |
|
| 247 | if test -n "$BASH_VERSION"; then
|
| 248 | # this makes the eval definition invisible!
|
| 249 | set -o posix
|
| 250 | fi
|
| 251 |
|
| 252 | eval 'echo after posix' # this is the builtin eval
|
| 253 | # bash claims it's a function, but it's a builtin
|
| 254 | type -t eval
|
| 255 |
|
| 256 | # it finds the function and the special builtin
|
| 257 | #type -a eval
|
| 258 |
|
| 259 | ## BUG bash STDOUT:
|
| 260 | TRUE
|
| 261 | builtin
|
| 262 | function
|
| 263 | ---
|
| 264 | EVAL
|
| 265 | builtin
|
| 266 | shell function: echo before posix
|
| 267 | after posix
|
| 268 | function
|
| 269 | ## END
|
| 270 |
|
| 271 | ## STDOUT:
|
| 272 | TRUE
|
| 273 | builtin
|
| 274 | function
|
| 275 | ---
|
| 276 | EVAL
|
| 277 | builtin
|
| 278 | before posix
|
| 279 | after posix
|
| 280 | builtin
|
| 281 | ## END
|
| 282 |
|
| 283 | ## N-I dash/mksh/zsh/ash/yash STDOUT:
|
| 284 | ## END
|
| 285 |
|
| 286 | #### command, builtin - both can be redefined, not special (regression)
|
| 287 | case $SH in dash|ash|yash) exit ;; esac
|
| 288 |
|
| 289 | builtin echo b
|
| 290 | command echo c
|
| 291 |
|
| 292 | builtin() {
|
| 293 | echo builtin-redef "$@"
|
| 294 | }
|
| 295 |
|
| 296 | command() {
|
| 297 | echo command-redef "$@"
|
| 298 | }
|
| 299 |
|
| 300 | builtin echo b
|
| 301 | command echo c
|
| 302 |
|
| 303 | ## STDOUT:
|
| 304 | b
|
| 305 | c
|
| 306 | builtin-redef echo b
|
| 307 | command-redef echo c
|
| 308 | ## END
|
| 309 | ## N-I dash/ash/yash STDOUT:
|
| 310 | ## END
|