wiki.bash-hackers.org/syntax/ccmd/user_select.markup

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====== User selections ======
===== Synopsis =====
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<code>
select <NAME>; do
<LIST>
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done
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</code>
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<code>
select <NAME> in <WORDS>; do
<LIST>
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done
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</code>
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<code>
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# alternative, historical and undocumented syntax
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select <NAME>
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{
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<LIST>
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}
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select <NAME> in <WORDS>
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{
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<LIST>
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}
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</code>
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===== Description =====
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This compound command provides a kind of menu. The user is prompted with a //numbered list// of the given words, and is asked to input the index number of the word. If a word was selected, the variable ''<NAME>'' is set to this word, and the [[syntax:basicgrammar#lists | list]] ''<LIST>'' is executed.
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If no ''in <WORDS>'' is given, then the positional parameters are taken as words (as if ''in &quot;$@&quot;'' was written).
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Regardless of the functionality, the //number// the user entered is saved in the variable ''REPLY''.
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Bash knows an alternative syntax for the ''select'' command, enclosing the loop body in ''{<nowiki>...</nowiki>}'' instead of ''do <nowiki>...</nowiki> done'':
<code>
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select x in 1 2 3
{
echo $x
}
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</code>
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This syntax is **not documented** and should not be used. I found the parser definitions for it in 1.x code, and in modern 4.x code. My guess is that it's there for compatiblity reasons. This syntax is not specified by POSIX(R).
===== Examples =====
===== Portability considerations =====
===== See also =====