psub

psub(1)                              fish                              psub(1)



NAME
       psub - perform process substitution

   Synopsis
       COMMAND1 ( COMMAND2 | psub [-F | --fifo] [-f | --file] [-s SUFFIX])

   Description
       Some shells (e.g., ksh, bash) 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. psub combined with a regular command substitution provides the
       same functionality.

       The following options are available:

       · -f or --file will cause psub to 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.
         This is the default.

       · -F or --fifo will cause psub to use a named pipe rather than a file.
         You should only use this if the command produces no more than 8 KiB
         of output. The limit on the amount of data a FIFO can buffer varies
         with the OS but is typically 8 KiB, 16 KiB or 64 KiB. If you use this
         option and the command on the left of the psub pipeline produces more
         output a deadlock is likely to occur.

       · -s or --suffix will append SUFFIX to the filename.

   Example
       diff (sort a.txt | psub) (sort b.txt | psub)
         shows the difference between the sorted versions of files a.txt and b.txt.

       source-highlight -f esc (cpp main.c | psub -f -s .c)
         highlights main.c after preprocessing as a C source.

Version 3.0.2                   Tue Mar 26 2019                        psub(1)