| 1 | #
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| 2 | # Only bash and zsh seem to implement [[ foo =~ '' ]]
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| 3 | #
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| 4 | # ^(a b)$ is a regex that should match 'a b' in a group.
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| 5 | #
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| 6 | # Not sure what bash is doing here... I think I have to just be empirical.
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| 7 | # Might need "compat" switch for parsing the regex. It should be an opaque
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| 8 | # string like zsh, not sure why it isn't.
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| 9 | #
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| 10 | # I think this is just papering over bugs...
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| 11 | # https://www.gnu.org/software/bash/manual/bash.html#Conditional-Constructs
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| 12 | #
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| 13 | # Storing the regular expression in a shell variable is often a useful way to
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| 14 | # avoid problems with quoting characters that are special to the shell. It is
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| 15 | # sometimes difficult to specify a regular expression literally without using
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| 16 | # quotes, or to keep track of the quoting used by regular expressions while
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| 17 | # paying attention to the shell’s quote removal. Using a shell variable to
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| 18 | # store the pattern decreases these problems. For example, the following is
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| 19 | # equivalent to the above:
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| 20 | #
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| 21 | # pattern='[[:space:]]*(a)?b'
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| 22 | # [[ $line =~ $pattern ]]
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| 23 | #
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| 24 | # If you want to match a character that’s special to the regular expression
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| 25 | # grammar, it has to be quoted to remove its special meaning. This means that in
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| 26 | # the pattern ‘xxx.txt’, the ‘.’ matches any character in the string (its usual
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| 27 | # regular expression meaning), but in the pattern ‘"xxx.txt"’ it can only match a
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| 28 | # literal ‘.’. Shell programmers should take special care with backslashes, since
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| 29 | # backslashes are used both by the shell and regular expressions to remove the
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| 30 | # special meaning from the following character. The following two sets of
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| 31 | # commands are not equivalent:
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| 32 | #
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| 33 | # From bash code: ( | ) are treated special. Normally they must be quoted, but
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| 34 | # they can be UNQUOTED in BASH_REGEX state. In fact they can't be quoted!
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| 35 |
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| 36 | #### BASH_REMATCH
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| 37 | [[ foo123 =~ ([a-z]+)([0-9]+) ]]
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| 38 | echo status=$?
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| 39 | argv.py "${BASH_REMATCH[@]}"
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| 40 |
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| 41 | [[ failed =~ ([a-z]+)([0-9]+) ]]
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| 42 | echo status=$?
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| 43 | argv.py "${BASH_REMATCH[@]}" # not cleared!
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| 44 |
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| 45 | ## STDOUT:
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| 46 | status=0
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| 47 | ['foo123', 'foo', '123']
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| 48 | status=1
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| 49 | []
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| 50 | ## END
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| 51 | ## N-I zsh STDOUT:
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| 52 | status=0
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| 53 | ['']
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| 54 | status=1
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| 55 | ['']
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| 56 | ## END
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| 57 |
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| 58 | #### Match is unanchored at both ends
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| 59 | [[ 'bar' =~ a ]] && echo true
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| 60 | ## stdout: true
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| 61 |
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| 62 | #### Failed match
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| 63 | [[ 'bar' =~ X ]] && echo true
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| 64 | ## status: 1
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| 65 | ## stdout-json: ""
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| 66 |
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| 67 | #### Regex quoted with \ -- preferred in bash
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| 68 | [[ 'a b' =~ ^(a\ b)$ ]] && echo true
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| 69 | ## stdout: true
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| 70 |
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| 71 | #### Regex quoted with single quotes
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| 72 | # bash doesn't like the quotes
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| 73 | [[ 'a b' =~ '^(a b)$' ]] && echo true
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| 74 | ## stdout-json: ""
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| 75 | ## status: 1
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| 76 | ## OK zsh stdout: true
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| 77 | ## OK zsh status: 0
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| 78 |
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| 79 | #### Regex quoted with double quotes
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| 80 | # bash doesn't like the quotes
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| 81 | [[ 'a b' =~ "^(a b)$" ]] && echo true
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| 82 | ## stdout-json: ""
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| 83 | ## status: 1
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| 84 | ## OK zsh stdout: true
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| 85 | ## OK zsh status: 0
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| 86 |
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| 87 | #### Fix single quotes by storing in variable
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| 88 | pat='^(a b)$'
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| 89 | [[ 'a b' =~ $pat ]] && echo true
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| 90 | ## stdout: true
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| 91 |
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| 92 | #### Fix single quotes by storing in variable
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| 93 | pat="^(a b)$"
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| 94 | [[ 'a b' =~ $pat ]] && echo true
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| 95 | ## stdout: true
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| 96 |
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| 97 | #### Double quoting pat variable -- again bash doesn't like it.
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| 98 | pat="^(a b)$"
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| 99 | [[ 'a b' =~ "$pat" ]] && echo true
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| 100 | ## stdout-json: ""
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| 101 | ## status: 1
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| 102 | ## OK zsh stdout: true
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| 103 | ## OK zsh status: 0
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| 104 |
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| 105 | #### Mixing quoted and unquoted parts
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| 106 | [[ 'a b' =~ 'a 'b ]] && echo true
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| 107 | [[ "a b" =~ "a "'b' ]] && echo true
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| 108 | ## STDOUT:
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| 109 | true
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| 110 | true
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| 111 | ## END
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| 112 |
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| 113 | #### Regex with == and not =~ is parse error, different lexer mode required
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| 114 | # They both give a syntax error. This is lame.
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| 115 | [[ '^(a b)$' == ^(a\ b)$ ]] && echo true
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| 116 | ## status: 2
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| 117 | ## OK zsh status: 1
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| 118 |
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| 119 | #### Omitting ( )
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| 120 | [[ '^a b$' == ^a\ b$ ]] && echo true
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| 121 | ## stdout: true
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| 122 |
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| 123 | #### Malformed regex
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| 124 | # Are they trying to PARSE the regex? Do they feed the buffer directly to
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| 125 | # regcomp()?
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| 126 | [[ 'a b' =~ ^)a\ b($ ]] && echo true
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| 127 | ## stdout-json: ""
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| 128 | ## status: 2
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| 129 | ## OK zsh status: 1
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| 130 |
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| 131 | #### Regex with char class containing space
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| 132 | # For some reason it doesn't work without parens?
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| 133 | [[ 'ba ba ' =~ ([a b]+) ]] && echo true
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| 134 | ## stdout: true
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| 135 |
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| 136 | #### Operators and space lose meaning inside ()
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| 137 | [[ '< >' =~ (< >) ]] && echo true
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| 138 | ## stdout: true
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| 139 | ## N-I zsh stdout-json: ""
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| 140 | ## N-I zsh status: 1
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| 141 |
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| 142 | #### Regex with |
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| 143 | [[ 'bar' =~ foo|bar ]] && echo true
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| 144 | ## stdout: true
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| 145 | ## N-I zsh stdout-json: ""
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| 146 | ## N-I zsh status: 1
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| 147 |
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| 148 | #### Regex to match literal brackets []
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| 149 |
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| 150 | # bash-completion relies on this, so we're making it match bash.
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| 151 | # zsh understandably differs.
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| 152 | [[ '[]' =~ \[\] ]] && echo true
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| 153 |
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| 154 | # Another way to write this.
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| 155 | pat='\[\]'
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| 156 | [[ '[]' =~ $pat ]] && echo true
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| 157 | ## STDOUT:
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| 158 | true
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| 159 | true
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| 160 | ## END
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| 161 | ## OK zsh STDOUT:
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| 162 | true
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| 163 | ## END
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| 164 |
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| 165 | #### Regex to match literals . ^ $ etc.
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| 166 | [[ 'x' =~ \. ]] || echo false
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| 167 | [[ '.' =~ \. ]] && echo true
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| 168 |
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| 169 | [[ 'xx' =~ \^\$ ]] || echo false
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| 170 | [[ '^$' =~ \^\$ ]] && echo true
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| 171 |
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| 172 | [[ 'xxx' =~ \+\*\? ]] || echo false
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| 173 | [[ '*+?' =~ \*\+\? ]] && echo true
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| 174 |
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| 175 | [[ 'xx' =~ \{\} ]] || echo false
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| 176 | [[ '{}' =~ \{\} ]] && echo true
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| 177 | ## STDOUT:
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| 178 | false
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| 179 | true
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| 180 | false
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| 181 | true
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| 182 | false
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| 183 | true
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| 184 | false
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| 185 | true
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| 186 | ## END
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| 187 | ## BUG zsh STDOUT:
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| 188 | true
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| 189 | false
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| 190 | false
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| 191 | false
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| 192 | ## END
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| 193 | ## BUG zsh status: 1
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| 194 |
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| 195 | #### Unquoted { is a regex parse error
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| 196 | [[ { =~ { ]] && echo true
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| 197 | echo status=$?
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| 198 | ## stdout-json: ""
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| 199 | ## status: 2
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| 200 | ## BUG bash stdout-json: "status=2\n"
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| 201 | ## BUG bash status: 0
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| 202 | ## BUG zsh stdout-json: "status=1\n"
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| 203 | ## BUG zsh status: 0
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| 204 |
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| 205 | #### Fatal error inside [[ =~ ]]
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| 206 |
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| 207 | # zsh and osh are stricter than bash. bash treats [[ like a command.
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| 208 |
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| 209 | [[ a =~ $(( 1 / 0 )) ]]
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| 210 | echo status=$?
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| 211 | ## stdout-json: ""
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| 212 | ## status: 1
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| 213 | ## BUG bash stdout: status=1
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| 214 | ## BUG bash status: 0
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| 215 |
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| 216 | #### Quoted { and +
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| 217 | [[ { =~ "{" ]] && echo 'yes {'
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| 218 | [[ + =~ "+" ]] && echo 'yes +'
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| 219 | [[ * =~ "*" ]] && echo 'yes *'
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| 220 | [[ ? =~ "?" ]] && echo 'yes ?'
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| 221 | [[ ^ =~ "^" ]] && echo 'yes ^'
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| 222 | [[ $ =~ "$" ]] && echo 'yes $'
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| 223 | [[ '(' =~ '(' ]] && echo 'yes ('
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| 224 | [[ ')' =~ ')' ]] && echo 'yes )'
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| 225 | [[ '|' =~ '|' ]] && echo 'yes |'
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| 226 | [[ '\' =~ '\' ]] && echo 'yes \'
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| 227 | echo ---
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| 228 |
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| 229 | [[ . =~ "." ]] && echo 'yes .'
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| 230 | [[ z =~ "." ]] || echo 'no .'
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| 231 | echo ---
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| 232 |
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| 233 | # This rule is weird but all shells agree. I would expect that the - gets
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| 234 | # escaped? It's an operator? but it behaves like a-z.
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| 235 | [[ a =~ ["a-z"] ]]; echo "a $?"
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| 236 | [[ - =~ ["a-z"] ]]; echo "- $?"
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| 237 | [[ b =~ ['a-z'] ]]; echo "b $?"
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| 238 | [[ z =~ ['a-z'] ]]; echo "z $?"
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| 239 |
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| 240 | echo status=$?
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| 241 | ## STDOUT:
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| 242 | yes {
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| 243 | yes +
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| 244 | yes *
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| 245 | yes ?
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| 246 | yes ^
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| 247 | yes $
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| 248 | yes (
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| 249 | yes )
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| 250 | yes |
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| 251 | yes \
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| 252 | ---
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| 253 | yes .
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| 254 | no .
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| 255 | ---
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| 256 | a 0
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| 257 | - 1
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| 258 | b 0
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| 259 | z 0
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| 260 | status=0
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| 261 | ## END
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| 262 | ## N-I zsh STDOUT:
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| 263 | yes ^
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| 264 | yes $
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| 265 | yes )
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| 266 | yes |
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| 267 | ---
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| 268 | yes .
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| 269 | ---
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| 270 | a 0
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| 271 | - 1
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| 272 | b 0
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| 273 | z 0
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| 274 | status=0
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| 275 | ## END
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| 276 |
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| 277 | #### Escaped {
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| 278 | # from bash-completion
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| 279 | [[ '$PA' =~ ^(\$\{?)([A-Za-z0-9_]*)$ ]] && argv.py "${BASH_REMATCH[@]}"
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| 280 | ## STDOUT:
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| 281 | ['$PA', '$', 'PA']
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| 282 | ## END
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| 283 | ## BUG zsh stdout-json: ""
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| 284 | ## BUG zsh status: 1
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| 285 |
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| 286 | #### Escaped { stored in variable first
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| 287 | # from bash-completion
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| 288 | pat='^(\$\{?)([A-Za-z0-9_]*)$'
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| 289 | [[ '$PA' =~ $pat ]] && argv.py "${BASH_REMATCH[@]}"
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| 290 | ## STDOUT:
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| 291 | ['$PA', '$', 'PA']
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| 292 | ## END
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| 293 | ## BUG zsh STDOUT:
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| 294 | ['']
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| 295 | ## END
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| 296 |
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| 297 | #### regex with ?
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| 298 | [[ 'c' =~ c? ]] && echo true
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| 299 | [[ '' =~ c? ]] && echo true
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| 300 | ## STDOUT:
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| 301 | true
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| 302 | true
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| 303 | ## END
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| 304 |
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| 305 | #### regex with unprintable characters
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| 306 | # can't have nul byte
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| 307 |
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| 308 | # This pattern has literal characters
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| 309 | pat=$'^[\x01\x02]+$'
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| 310 |
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| 311 | [[ $'\x01\x02\x01' =~ $pat ]]; echo status=$?
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| 312 | [[ $'a\x01' =~ $pat ]]; echo status=$?
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| 313 |
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| 314 | # NOTE: There doesn't appear to be any way to escape these!
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| 315 | pat2='^[\x01\x02]+$'
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| 316 |
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| 317 | ## STDOUT:
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| 318 | status=0
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| 319 | status=1
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| 320 | ## END
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| 321 |
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| 322 | #### pattern $f(x) -- regression
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| 323 | f=fff
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| 324 | [[ fffx =~ $f(x) ]]
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| 325 | echo status=$?
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| 326 | [[ ffx =~ $f(x) ]]
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| 327 | echo status=$?
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| 328 | ## STDOUT:
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| 329 | status=0
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| 330 | status=1
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| 331 | ## END
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| 332 |
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| 333 | #### pattern a=(1)
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| 334 | [[ a=x =~ a=(x) ]]
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| 335 | echo status=$?
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| 336 | [[ =x =~ a=(x) ]]
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| 337 | echo status=$?
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| 338 | ## STDOUT:
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| 339 | status=0
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| 340 | status=1
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| 341 | ## END
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| 342 | ## BUG zsh status: 1
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| 343 | ## BUG zsh STDOUT:
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| 344 | status=0
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| 345 | ## END
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| 346 |
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| 347 | #### pattern @f(x)
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| 348 | shopt -s parse_at
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| 349 | [[ @fx =~ @f(x) ]]
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| 350 | echo status=$?
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| 351 | [[ fx =~ @f(x) ]]
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| 352 | echo status=$?
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| 353 | ## STDOUT:
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| 354 | status=0
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| 355 | status=1
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| 356 | ## END
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