compose

Compose action can be used to compose any existing file or new on default mailcap edit tool

$ compose [filename]

$ run-mailcap --action=compose [filename]

compose [command1] [command2] ... [commandN]

[command1]
    The first command in the chain.

[command2]
    The second command in the chain. Its input comes from the output of command1.

[commandN]
    The Nth command in the chain. Its input comes from the output of command N-1.

The `compose` command is not a standard Linux utility and is not typically found on most distributions. It's conceptually similar to function composition in programming, where the output of one function serves as the input for the next.

Without a standard implementation, its exact behavior depends entirely on the custom script or alias defined as `compose`. Usually, such a custom command aims to improve readability and modularity when chaining several commands together. The typical use case will be to shorten or make it easier to read a pipeline command where the output of a set of commands is used as input for the other.

Because it is a user defined command, the exact functionality is completely up to the script definition or alias.

The `compose` command is not a standard Linux command. Its behavior depends entirely on how it is defined (e.g., via an alias or a shell script). The absence or incorrect definition of the `compose` command may lead to errors or unexpected results.

Assuming 'compose' is an alias for: `xargs -I {} sh -c '{}'`.

Then `compose ls -l | grep myfile` might be equivalent to `ls -l | xargs -I {} sh -c 'grep myfile {}'`.
However, this will pass the entire output of ls -l as a single argument. A proper implementation would likely handle each line separately. The real behavior will depend entirely on the implementation. Use `alias compose` or `type compose` to find the actual definition.

pipe(7), xargs(1), parallel(1)