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Full Discussion: Issue with writing a pipe
Top Forums Shell Programming and Scripting Issue with writing a pipe Post 303045208 by sea on Friday 13th of March 2020 01:53:48 PM
Old 03-13-2020
Ok did some more research.

While this confirms my confusion (missing better words here..), I learned some new things allthough most of it was known.
Asdide the fact that 'echo' is both, for some reason I always thought that /bin/echo was the echo used when calling echo, and thus not realized the builtin existed - or that they are different 'code'.
How to distinguish between builtin and external util? (e.g. echo) - Unix & Linux Stack Exchange


This one here seems to confirm my most recent assumptions as since today:
shell - Which are the standard commands available in every Linux based distribution? - Unix & Linux Stack Exchange

That I most likley could rely on the bash builtin 'echo' for the use of SWARM.
But none of that sounded certain, so I then I followed a link of the 2nd post (46 up votes) about the standarized commands by PSIX and ended up here: echo

Now, when you go down to the 'Application Usage' section, you'll see this part:
Code:
It is not possible to use echo portably across all POSIX systems unless both -n (as the first argument) and escape sequences are omitted.

The printf utility can be used portably to emulate any of the traditional behaviors of the echo utility as follows (assuming that IFS has its standard value or is unset):

The historic System V echo and the requirements on XSI implementations in this volume of POSIX.1-2017 are equivalent to:

printf "%b\n" "$*"

The BSD echo is equivalent to:

if [ "X$1" = "X-n" ]
then
    shift
    printf "%s" "$*"
else
    printf "%s\n" "$*"
fi

New applications are encouraged to use printf instead of echo.

Now my final question, which of these 2 examples would you recomend?
I have to ask this, because I lack the practical experience of actual daily usage on different systems.

Anyway, I'm going to try this out now.
Lets see which works better as expected.

At least I know now that it wasnt a waste of time preparing $ECHO to use printf, what a relieve! Smilie
 

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FIFO(7) 						     Linux Programmer's Manual							   FIFO(7)

NAME
fifo - first-in first-out special file, named pipe DESCRIPTION
A FIFO special file (a named pipe) is similar to a pipe, except that it is accessed as part of the file system. It can be opened by multi- ple processes for reading or writing. When processes are exchanging data via the FIFO, the kernel passes all data internally without writ- ing it to the file system. Thus, the FIFO special file has no contents on the file system; the file system entry merely serves as a refer- ence point so that processes can access the pipe using a name in the file system. The kernel maintains exactly one pipe object for each FIFO special file that is opened by at least one process. The FIFO must be opened on both ends (reading and writing) before data can be passed. Normally, opening the FIFO blocks until the other end is opened also. A process can open a FIFO in nonblocking mode. In this case, opening for read only will succeed even if no-one has opened on the write side yet, opening for write only will fail with ENXIO (no such device or address) unless the other end has already been opened. Under Linux, opening a FIFO for read and write will succeed both in blocking and nonblocking mode. POSIX leaves this behavior undefined. This can be used to open a FIFO for writing while there are no readers available. A process that uses both ends of the connection in order to communicate with itself should be very careful to avoid deadlocks. NOTES
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. FIFO special files can be created by mkfifo(3), and are indicated by ls -l with the file type 'p'. SEE ALSO
mkfifo(1), open(2), pipe(2), sigaction(2), signal(2), socketpair(2), mkfifo(3), pipe(7) COLOPHON
This page is part of release 3.44 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. Linux 2008-12-03 FIFO(7)
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