fish-shell/doc_src/psub.txt

\section psub psub - perform process substitution

\subsection psub-synopsis Synopsis
\fish{synopsis}
COMMAND1 (COMMAND2 | psub [-f])
\endfish

\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. `psub` 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.

\subsection psub-example Example

\fish
diff (sort a.txt | psub) (sort b.txt | psub)
# shows the difference between the sorted versions of files `a.txt` and `b.txt`.
\endfish
Fix casing and other minor issues in documentation darcs-hash:20061031152316-ac50b-e68db9853d6e9461a0c054f1ea290704ccfc0a31.gz 2006-10-31 15:23:16 +00:00			`\section psub psub - perform process substitution`
Documentation and completion updates darcs-hash:20051021123945-ac50b-3d3b5004fdf8424190cae84c7b27b2088c87c080.gz 2005-10-21 12:39:45 +00:00
			`\subsection psub-synopsis Synopsis`
Simplify styling 2014-08-01 12:25:41 +00:00			`\fish{synopsis}`
Tutorial auto colouring, Man page and Make fixes Completely fixes #1557 and the underlying Doxygen changes that caused it. Should make fish docs simpler and more robust, more consistent and generally prettier. todo: - trap unmarked text as arguments in context - test & fix sed portability - see in particular. (so far tested on BSD (Mac) and GNU sed). - test Makefile changes - last round of aesthetic changes and getting that ascii fish in there… 2014-08-08 02:44:37 +00:00			`COMMAND1 (COMMAND2 \| psub [-f])`
Documentation update Rework for Doxygen >1.8. Moved large parts of the documentation to a simplified format, making use of Markdown enhancements and fixing bad long options. 2014-08-01 02:37:32 +00:00			`\endfish`
Documentation and completion updates darcs-hash:20051021123945-ac50b-3d3b5004fdf8424190cae84c7b27b2088c87c080.gz 2005-10-21 12:39:45 +00:00
			`\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`
Documentation update Rework for Doxygen >1.8. Moved large parts of the documentation to a simplified format, making use of Markdown enhancements and fixing bad long options. 2014-08-01 02:37:32 +00:00			program. `psub` combined with a
Documentation and completion updates darcs-hash:20051021123945-ac50b-3d3b5004fdf8424190cae84c7b27b2088c87c080.gz 2005-10-21 12:39:45 +00:00			`regular command substitution provides the same functionality.`

Documentation update Rework for Doxygen >1.8. Moved large parts of the documentation to a simplified format, making use of Markdown enhancements and fixing bad long options. 2014-08-01 02:37:32 +00:00			If the `-f` or `--file` switch is given to `psub`, `psub` will use a
Document -f option for psub, add tab completions darcs-hash:20070115181924-ac50b-6ac48aec8937e9dd172858dfa7eaaac1aca14775.gz 2007-01-15 18:19:24 +00:00			`regular file instead of a named pipe to communicate with the calling`
Documentation update Rework for Doxygen >1.8. Moved large parts of the documentation to a simplified format, making use of Markdown enhancements and fixing bad long options. 2014-08-01 02:37:32 +00:00			process. This will cause `psub` to be significantly slower when large
Document -f option for psub, add tab completions darcs-hash:20070115181924-ac50b-6ac48aec8937e9dd172858dfa7eaaac1aca14775.gz 2007-01-15 18:19:24 +00:00			`amounts of data are involved, but has the advantage that the reading`
			`process can seek in the stream.`

Documentation and completion updates darcs-hash:20051021123945-ac50b-3d3b5004fdf8424190cae84c7b27b2088c87c080.gz 2005-10-21 12:39:45 +00:00			`\subsection psub-example Example`

Tutorial auto colouring, Man page and Make fixes Completely fixes #1557 and the underlying Doxygen changes that caused it. Should make fish docs simpler and more robust, more consistent and generally prettier. todo: - trap unmarked text as arguments in context - test & fix sed portability - see in particular. (so far tested on BSD (Mac) and GNU sed). - test Makefile changes - last round of aesthetic changes and getting that ascii fish in there… 2014-08-08 02:44:37 +00:00			`\fish`
			`diff (sort a.txt \| psub) (sort b.txt \| psub)`
			# shows the difference between the sorted versions of files `a.txt` and `b.txt`.
			`\endfish`