\section psub psub - perform process substitution

\subsection psub-synopsis Synopsis
 <tt>COMMAND1 (COMMAND2|psub) </tt>

\subsection psub-description Description

Posix shells feature a syntax that is a mix between command
substitution and piping, called process substitution. It is used to
send the output of a command into the calling command, much like
command substitution, but with the difference that the output is not
sent through commandline arguments but through a named pipe, with the
filename of the named pipe sent as an argument to the calling
program. The psub shellscript function, which when combined with a
regular command substitution provides the same functionality.

\subsection psub-example Example

<tt>diff (sort a.txt|psub) (sort b.txt|psub)</tt> shows the difference
between the sorted versions of files a.txt and b.txt.