mirror of https://github.com/n-hys/bash.git
51 lines
1.3 KiB
Plaintext
51 lines
1.3 KiB
Plaintext
# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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#
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# nameref requires changes to unset
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bar=one
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typeset -n foo=bar
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# normal unset unsets only variable nameref references
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# need unset -n to unset nameref itself
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unset foo
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echo "expect <unset>"
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recho ${bar-unset}
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echo "expect <unset>"
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recho ${foo-unset}
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echo "expect <bar>"
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recho ${!foo}
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unset -n foo
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echo "expect <unset>"
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recho "${!foo-unset}"
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readonly bar=two
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typeset -n foo=bar
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unset foo # this should fail because bar is readonly
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echo "expect <two>"
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echo ${bar-unset}
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echo "expect <two>"
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echo ${foo-unset}
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# one question is what happens when you unset the underlying variable
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qux=three
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typeset -n ref
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ref=qux
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echo $ref
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unset qux
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echo ${ref-unset}
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qux=four
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echo ${ref-unset}
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