Fifo and Cat: Share a Session with Multiple Users

Introduction

This technique can be used to show a remote colleague or client what you're working on on the server.

It's just for visual sharing and not interactive like with screen (see this documentation).

Creating a fifo file

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mkfifo /tmp/sortieScript
ls -l /tmp/sortieScript
prw-r--r-- 1 yannick yannick 0 Jul 6 02:59 /tmp/sortieScript

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mkfifo - Create named pipes (FIFOs) with the given NAMEs.
A FIFO special file (a named pipe) is similar to a pipe, except that it is accessed as part of the file system.
[...] the FIFO special file has no contents on the file system

Reading the file by the remote user

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cat /tmp/sortieScript

Warning: as long as the file is not "catted", it cannot be used by the following command...

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When a process tries to write to a FIFO that is not opened for read on the other side, the process is sent a SIGPIPE signal.

Output script to this file

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script -f /tmp/sortieScript

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Script started, file is /tmp/sortieScript

From now on, everything that is typed is visible to the person "catting" the sortieScript file, including interactive sessions like vi...

Stop logging to the file with CTRL-D

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-f Flush output after each write. This is nice for telecooperation [...]

Amazing: the demo