psub(1) fish psub(1)
NAME
psub - perform process substitution
Synopsis
COMMAND1 (COMMAND2|psub [-f])
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.
If the -f or --file switch is given to psub, psub will use a regular
file instead of a named pipe to communicate with the calling process.
This will cause psub to be significantly slower when large amounts of
data are involved, but has the advantage that the reading process can
seek in the stream.
Example
diff (sort a.txt|psub) (sort b.txt|psub) shows the difference between
the sorted versions of files a.txt and b.txt.
Version 1.23.1 8 Mar 2009 psub(1)
fish 1.23.1 - Generated Sun Mar 8 14:14:41 CDT 2009