| 1 | #!/usr/bin/env bash |
| 2 | |
| 3 | #### case |
| 4 | foo=a; case $foo in [0-9]) echo number;; [a-z]) echo letter;; esac |
| 5 | ## stdout: letter |
| 6 | |
| 7 | #### case in subshell |
| 8 | # Hm this subhell has to know about the closing ) and stuff like that. |
| 9 | # case_clause is a compound_command, which is a command. And a subshell |
| 10 | # takes a compound_list, which is a list of terms, which has and_ors in them |
| 11 | # ... which eventually boils down to a command. |
| 12 | echo $(foo=a; case $foo in [0-9]) echo number;; [a-z]) echo letter;; esac) |
| 13 | ## stdout: letter |
| 14 | |
| 15 | #### Command sub word part |
| 16 | # "The token shall not be delimited by the end of the substitution." |
| 17 | foo=FOO; echo $(echo $foo)bar$(echo $foo) |
| 18 | ## stdout: FOObarFOO |
| 19 | |
| 20 | #### Backtick |
| 21 | foo=FOO; echo `echo $foo`bar`echo $foo` |
| 22 | ## stdout: FOObarFOO |
| 23 | |
| 24 | #### Backtick 2 |
| 25 | echo `echo -n l; echo -n s` |
| 26 | ## stdout: ls |
| 27 | |
| 28 | #### Nested backticks |
| 29 | # Inner `` are escaped! Not sure how to do triple.. Seems like an unlikely |
| 30 | # use case. Not sure if I even want to support this! |
| 31 | echo X > $TMP/000000-first |
| 32 | echo `\`echo -n l; echo -n s\` $TMP | grep 000000-first` |
| 33 | ## stdout: 000000-first |
| 34 | |
| 35 | #### Making command out of command sub should work |
| 36 | # Works in bash and dash! |
| 37 | $(echo ec)$(echo ho) split builtin |
| 38 | ## stdout: split builtin |
| 39 | |
| 40 | #### Making keyword out of command sub should NOT work |
| 41 | # This doesn't work in bash or dash! Hm builtins are different than keywords / |
| 42 | # reserved words I guess. |
| 43 | # dash fails, but gives code 0 |
| 44 | $(echo f)$(echo or) i in a b c; do echo $i; done |
| 45 | echo status=$? |
| 46 | ## stdout-json: "" |
| 47 | ## status: 2 |
| 48 | ## BUG dash stdout-json: "\nstatus=0\n" |
| 49 | ## BUG dash status: 0 |
| 50 | ## OK mksh status: 1 |
| 51 | |
| 52 | #### Command sub with here doc |
| 53 | echo $(<<EOF tac |
| 54 | one |
| 55 | two |
| 56 | EOF |
| 57 | ) |
| 58 | ## stdout: two one |
| 59 | |
| 60 | #### Here doc with pipeline |
| 61 | <<EOF tac | tr '\n' 'X' |
| 62 | one |
| 63 | two |
| 64 | EOF |
| 65 | ## stdout-json: "twoXoneX" |
| 66 | |
| 67 | #### Command Sub word split |
| 68 | argv.py $(echo 'hi there') "$(echo 'hi there')" |
| 69 | ## stdout: ['hi', 'there', 'hi there'] |
| 70 | |
| 71 | #### Command Sub trailing newline removed |
| 72 | s=$(python -c 'print "ab\ncd\n"') |
| 73 | argv.py "$s" |
| 74 | ## stdout: ['ab\ncd'] |
| 75 | |
| 76 | #### Command Sub trailing whitespace not removed |
| 77 | s=$(python -c 'print "ab\ncd\n "') |
| 78 | argv.py "$s" |
| 79 | ## stdout: ['ab\ncd\n '] |
| 80 | |
| 81 | #### Command Sub and exit code |
| 82 | # A command resets the exit code, but an assignment doesn't. |
| 83 | echo $(echo x; exit 33) |
| 84 | echo $? |
| 85 | x=$(echo x; exit 33) |
| 86 | echo $? |
| 87 | ## STDOUT: |
| 88 | x |
| 89 | 0 |
| 90 | 33 |
| 91 | ## END |
| 92 | |
| 93 | #### Command Sub in local sets exit code |
| 94 | # A command resets the exit code, but an assignment doesn't. |
| 95 | f() { |
| 96 | echo $(echo x; exit 33) |
| 97 | echo $? |
| 98 | local x=$(echo x; exit 33) |
| 99 | echo $? |
| 100 | } |
| 101 | f |
| 102 | ## STDOUT: |
| 103 | x |
| 104 | 0 |
| 105 | 0 |
| 106 | ## END |
| 107 | |
| 108 | #### Double Quotes in Command Sub in Double Quotes |
| 109 | # virtualenv's bin/activate uses this. |
| 110 | # This is weird! Double quotes within `` is different than double quotes |
| 111 | # within $()! All shells agree. |
| 112 | # I think this is related to the nested backticks case! |
| 113 | echo "x $(echo hi)" |
| 114 | echo "x $(echo "hi")" |
| 115 | echo "x $(echo \"hi\")" |
| 116 | echo "x `echo hi`" |
| 117 | echo "x `echo "hi"`" |
| 118 | echo "x `echo \"hi\"`" |
| 119 | ## STDOUT: |
| 120 | x hi |
| 121 | x hi |
| 122 | x "hi" |
| 123 | x hi |
| 124 | x hi |
| 125 | x hi |
| 126 | ## END |
| 127 | |
| 128 | #### Escaped quote in [[ ]] |
| 129 | file=$TMP/command-sub-dbracket |
| 130 | #rm -f $file |
| 131 | echo "123 `[[ $(echo \\" > $file) ]]` 456"; |
| 132 | cat $file |
| 133 | ## STDOUT: |
| 134 | 123 456 |
| 135 | " |
| 136 | ## END |
| 137 | |
| 138 | #### Quoting $ within `` |
| 139 | echo 1 `echo $` |
| 140 | echo 2 `echo \$` |
| 141 | echo 3 `echo \\$` |
| 142 | echo 4 `echo \\\$` |
| 143 | echo 5 `echo \\\\$` |
| 144 | ## STDOUT: |
| 145 | 1 $ |
| 146 | 2 $ |
| 147 | 3 $ |
| 148 | 4 $ |
| 149 | 5 \$ |
| 150 | ## END |
| 151 | |
| 152 | #### Quoting $ within `` within double quotes |
| 153 | echo "1 `echo $`" |
| 154 | echo "2 `echo \$`" |
| 155 | echo "3 `echo \\$`" |
| 156 | echo "4 `echo \\\$`" |
| 157 | echo "5 `echo \\\\$`" |
| 158 | ## STDOUT: |
| 159 | 1 $ |
| 160 | 2 $ |
| 161 | 3 $ |
| 162 | 4 $ |
| 163 | 5 \$ |
| 164 | ## END |
| 165 | |
| 166 | #### Quoting \ within `` |
| 167 | # You need FOUR backslashes to make a literal \. |
| 168 | echo [1 `echo \ `] |
| 169 | echo [2 `echo \\ `] |
| 170 | echo [3 `echo \\\\ `] |
| 171 | ## STDOUT: |
| 172 | [1 ] |
| 173 | [2 ] |
| 174 | [3 \] |
| 175 | ## END |
| 176 | |
| 177 | #### Quoting \ within `` within double quotes |
| 178 | echo "[1 `echo \ `]" |
| 179 | echo "[2 `echo \\ `]" |
| 180 | echo "[3 `echo \\\\ `]" |
| 181 | ## STDOUT: |
| 182 | [1 ] |
| 183 | [2 ] |
| 184 | [3 \] |
| 185 | ## END |
| 186 | |
| 187 | #### Quoting ( within `` |
| 188 | echo 1 `echo \(` |
| 189 | echo 2 `echo \\(` |
| 190 | echo 3 `echo \\ \\(` |
| 191 | ## STDOUT: |
| 192 | 1 ( |
| 193 | 2 ( |
| 194 | 3 ( |
| 195 | ## END |
| 196 | |
| 197 | #### Quoting ( within `` within double quotes |
| 198 | echo "1 `echo \(`" |
| 199 | echo "2 `echo \\(`" |
| 200 | echo "3 `echo \\ \\(`" |
| 201 | ## STDOUT: |
| 202 | 1 ( |
| 203 | 2 ( |
| 204 | 3 ( |
| 205 | ## END |
| 206 | |
| 207 | #### Quoting non-special characters within `` |
| 208 | echo [1 `echo \z]` |
| 209 | echo [2 `echo \\z]` |
| 210 | echo [3 `echo \\\z]` |
| 211 | echo [4 `echo \\\\z]` |
| 212 | ## STDOUT: |
| 213 | [1 z] |
| 214 | [2 z] |
| 215 | [3 \z] |
| 216 | [4 \z] |
| 217 | ## END |
| 218 | |
| 219 | #### Quoting non-special characters within `` within double quotes |
| 220 | echo "[1 `echo \z`]" |
| 221 | echo "[2 `echo \\z`]" |
| 222 | echo "[3 `echo \\\z`]" |
| 223 | echo "[4 `echo \\\\z`]" |
| 224 | ## STDOUT: |
| 225 | [1 z] |
| 226 | [2 z] |
| 227 | [3 \z] |
| 228 | [4 \z] |
| 229 | ## END |
| 230 | |
| 231 | #### Quoting double quotes within backticks |
| 232 | echo \"foo\" # for comparison |
| 233 | echo `echo \"foo\"` |
| 234 | echo `echo \\"foo\\"` |
| 235 | ## STDOUT: |
| 236 | "foo" |
| 237 | "foo" |
| 238 | "foo" |
| 239 | ## END |
| 240 | |
| 241 | # Documented in doc/known-differences.md (and Morbig paper brought up the same |
| 242 | # issue) |
| 243 | ## OK osh STDOUT: |
| 244 | "foo" |
| 245 | foo |
| 246 | "foo" |
| 247 | ## END |
| 248 | |
| 249 | #### More levels of double quotes in backticks |
| 250 | # Shells don't agree here, some of them give you form feeds! |
| 251 | # There are two levels of processing I don't understand. |
| 252 | echo BUG |
| 253 | exit |
| 254 | echo `echo \\\"foo\\\"` |
| 255 | echo `echo \\\\"foo\\\\"` |
| 256 | echo `echo \\\\\"foo\\\\\"` |
| 257 | ## BUG bash/dash/mksh/osh STDOUT: |
| 258 | BUG |
| 259 | ## END |
| 260 | |
| 261 | #### Syntax errors with double quotes within backticks |
| 262 | |
| 263 | # bash does print syntax errors but somehow it exits 0 |
| 264 | |
| 265 | $SH -c 'echo `echo "`' |
| 266 | echo status=$? |
| 267 | $SH -c 'echo `echo \\\\"`' |
| 268 | echo status=$? |
| 269 | |
| 270 | ## STDOUT: |
| 271 | status=2 |
| 272 | status=2 |
| 273 | ## END |
| 274 | ## OK mksh STDOUT: |
| 275 | status=1 |
| 276 | status=1 |
| 277 | ## END |
| 278 | ## OK bash stdout-json: "\nstatus=0\n\nstatus=0\n" |