Questions tagged [mkfifo]
The mkfifo tag has no usage guidance.
16
questions
0
votes
0answers
13 views
Streaming to FIFO-Q: how to copy into two streams, and operate on the new streams?
This question is about pipes, and I have created a small problem to illustrate my issue. Suppose I have a file:
// foo.csv
a,b,c
d,e,f
In script bar.sh, I do the following:
A=`mktmp -u`
B=`mktmp -...
0
votes
1answer
31 views
Why don't named pipes respect the order at which readers were attached?
I have this test script:
#!/usr/bin/env bash
fif="foooz"; rm "$fif" ; mkfifo "$fif"
( cat "$fif" | cat && echo "1") &
sleep 0.1
( cat "$fif" | cat && echo "2") &
sleep 0....
2
votes
1answer
279 views
How to write something to named pipe even if there are no readers
I have this little test script:
rm fooo | cat
mkfifo fooo
echo 'bar' > fooo # blocks here
echo 'done'
I am guessing that because there is nobody reading from the named pipe, that the write call ...
2
votes
1answer
428 views
How to check for presence of named pipe on the file system [duplicate]
I tried using the -f flag to test if a named pipe is present
if [[ ! -f "$fifo" ]]; then
echo 'There should be a fifo.lock file in the dir.' > /dev/stderr
return 0;
fi
this check does not ...
0
votes
1answer
43 views
Run program when/instead of writing to FIFO? [closed]
I have a program that writes data every second to a FIFO. Now I want to alter some of this data and write it to another FIFO.
What would be the best approach? Can I somehow pipe this directly to my ...
6
votes
1answer
724 views
Why doesn't mkfifo with a mode of 1755 grant read permissions and sticky bit to the user?
I'm creating a server and client situation where i want to create a pipe so they can communicate.
I created the pipe in the server code with
mkfifo("fifo",1755);:
1 for only user that created and ...
1
vote
1answer
130 views
mkfifo to copy / move files
Is it possible to use mkfifo (named pipes) in Linux to copy files?
For example: I am extracting files from tar archive and I want them to be moved immediately to another location.
1
vote
2answers
52 views
Two named PIPEs (PIPE_in/PIPE_out) connected with `tail -f` | String sent to PIPE_in doesn't reach PIPE_out
1.Create named PIPEs, pipe_in and pipe_out by running:
$ mkfifo pipe_in
$ mkfifo pipe_out
2.Connect pipe_in to pipe_out:
TERM0: $ tail -f pipe_in > pipe_out
3.Send string hello world! to ...
2
votes
1answer
297 views
How to redirect stdin using mkfifo? [closed]
I searched on askubuntu, stackoverflow and I found this:
$ mkfifo fif.pipe
$ bash script.sh < fif.pipe
$ echo 'say HELLO' > fif.pipe (say command do something in the script)
But after $ bash ...
1
vote
0answers
31 views
Where should I place named pipe files on RHEL7?
I done some quicky web searches to find out how to make a named pipe. It looks very straight forward I just need to execute as root: mkfifo filename, but what the best practice on where on the ...
2
votes
1answer
363 views
How to create a bidirectional pipe in bash?
I have a program which reads from and writes to file descriptor 3. I want to let it write to fd 3, and be able to write to the other end of the pipe interactively which the program should read over ...
0
votes
1answer
387 views
Process substitution vs FIFO (created by `makefifo`)
As far as I know, process substitution in bash and FIFO (created by mkfifo) are both named pipes. They both seem viable solutions for communication between processes. I was wondering how to decide ...
0
votes
1answer
54 views
When does a command in a process substitution or FIFO start and finish running?
When does a command in a process substitution in bash start and finish running?
E.g.
when does command1 in command2 >(command1) start and finish running respectively?
when does command3 in ...
1
vote
1answer
2k views
What is the purpose of using a FIFO vs a temporary file or a pipe?
From APUE
FIFOs can be used to duplicate an output stream in a series of shell
commands. This prevents writing the data to an intermediate disk
file (similar to using pipes to avoid intermediate ...
4
votes
1answer
2k views
How does this command work? mkfifo /tmp/f; cat /tmp/f | /bin/sh -i 2>&1 | nc -l 1234 > /tmp/f
Today I was reading the nc man page and stumbled on this command. I know that:
mkfifo /tmp/f is creating a named pipe at /tmp/f.
cat /tmp/f is printing whatever is written to that named pipe
and the ...
2
votes
1answer
902 views
pipe data into process that's already started
Say I start a node.js process like so:
node script.js &
is there a way to pipe data into that process after it has started?
normally, we do this:
cat <file> | node script.js
but the ...
