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Updated SC1138 (markdown)
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SC1138.md
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SC1138.md
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## Shells are space sensitive. Use `< <(cmd)`, not `<< (cmd)`.
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## Remove spaces between (( in arithmetic for loop.
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### Problematic code:
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```sh
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while read -r line
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do
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echo "You said: $line"
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done <<(cmd)
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for( (i=0; i<10; i++) ); do echo $i; done
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```
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### Correct code:
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```sh
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while read -r line
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do
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echo "You said: $line"
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done < <(cmd)
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for((i=0; i<10; i++)); do echo $i; done
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```
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### Rationale:
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When redirecting `<` from a process substitution `<(cmd)`, make sure there is a space between the two `<` characters as shown in the example.
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With a space `cmd1 < <(cmd2)`, is correctly interpreted as "run cmd1, reading stdin from cmd2, without forking for a pipeline".
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Without a space, `<<` is incorrectly considered a here document, and `(cmd2)` is an invalid delimiter token.
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ShellCheck finds arithmetic for ((;;)) expressions where (( or )) are intervening with spaces
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### Exceptions:
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