murex Shell Docs

Command Reference: <> (murex named pipe)

Reads from a murex named pipe

Description

Sometimes you will need to start a command line with a murex named pipe, eg

» <namedpipe> -> match: foobar

See the documentation on pipe for more details about murex named pipes.

Usage

Read from pipe

<namedpipe> -> <stdout>

Write to pipe

<stdin> -> <namedpipe>

Examples

The follow two examples function the same

» pipe: example
» bg { <example> -> match: 2 }
» a: <example> [1..3]
2
» !pipe: example

Detail

What are murex named pipes?

In POSIX, there is a concept of STDIN, STDOUT and STDERR, these are FIFO files while are "piped" from one executable to another. ie STDOUT for application 'A' would be the same file as STDIN for application 'B' when A is piped to B: A | B. murex adds a another layer around this to enable support for passing data types and builtins which are agnostic to the data serialization format traversing the pipeline. While this does add overhead the advantage is this new wrapper can be used as a primitive for channelling any data from one point to another.

murex named pipes are where these pipes are created in a global store, decoupled from any executing functions, named and can then be used to pass data along asynchronously.

For example

pipe: example

bg {
    <example> -> match: Hello
}

out: "foobar"        -> <example>
out: "Hello, world!" -> <example>
out: "foobar"        -> <example>

!pipe: example

This returns Hello, world! because out is writing to the example named pipe and match is also reading from it in the background (bg).

Named pipes can also be inlined into the command parameters with <> tags

pipe: example

bg {
    <example> -> match: Hello
}

out: <example> "foobar"
out: <example> "Hello, world!"
out: <example> "foobar"

!pipe: example

Please note this is also how test works.

murex named pipes can also represent network sockets, files on a disk or any other read and/or write endpoint. Custom builtins can also be written in Golang to support different abstractions so your murex code can work with those read or write endpoints transparently.

To see the different supported types run

runtime --pipes

Namespacing and used in modules and packages

Pipes created via pipe are created in the global namespace. This allows pipes to be used across different functions easily however it does pose a risk with name clashes where murex named pipes are used heavily. Thus is it recommended that pipes created in modules should be prefixed with the name of its package.

Synonyms

See Also

This site is rebuilt weekly, the content is automatically generated from murex's source code. Last built on Mon Aug 3 06:12:53 UTC 2020 against commit 2557f7c2557f7cc7535c452c21d89164bd38ed8996f02fd. Downloadable murex binaries are also built weekly. Current version is 0.52.2000 BETA which has been verified against tests.