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32 lines
809 B
Plaintext
32 lines
809 B
Plaintext
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====== Grouping commands in a subshell ======
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===== Synopsis =====
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<code>
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( <LIST> )
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</code>
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===== Description =====
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The [[syntax:basicgrammar#lists|list]] ''<LIST>'' is executed in a separate shell - a subprocess. No changes to the environment (variables etc...) are reflected in the "main shell".
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===== Examples =====
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Execute a command in a different directory.
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<code bash>
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echo "$PWD"
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( cd /usr; echo "$PWD" )
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echo "$PWD" # Still in the original directory.
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</code>
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===== Portability considerations =====
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* The subshell compound command is specified by POSIX.
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* Avoid ambiguous syntax.
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<code bash>
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(((1+1))) # Equivalent to: (( (1+1) ))
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</code>
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===== See also =====
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* [[syntax:ccmd:grouping_plain | grouping commands]]
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* [[http://mywiki.wooledge.org/SubShell | Subshells on Greycat's wiki]]
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