bash: Process Substitution

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1 3.5.6 Process Substitution
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1 
1 Process substitution allows a process's input or output to be referred
1 to using a filename.  It takes the form of
1      <(LIST)
1 or
1      >(LIST)
1 The process LIST is run asynchronously, and its input or output appears
1 as a filename.  This filename is passed as an argument to the current
1 command as the result of the expansion.  If the '>(LIST)' form is used,
1 writing to the file will provide input for LIST.  If the '<(LIST)' form
1 is used, the file passed as an argument should be read to obtain the
1 output of LIST.  Note that no space may appear between the '<' or '>'
1 and the left parenthesis, otherwise the construct would be interpreted
1 as a redirection.  Process substitution is supported on systems that
1 support named pipes (FIFOs) or the '/dev/fd' method of naming open
1 files.
1 
1    When available, process substitution is performed simultaneously with
1 parameter and variable expansion, command substitution, and arithmetic
1 expansion.
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