Two named PIPEs (PIPE_in/PIPE_out) connected with `tail -f` | String sent to PIPE_in doesn't reach PIPE_out
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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 pipe_in and expect it to arrive at pipe_out:
TERM1: $ tail -f pipe_out
TERM2: $ echo "hello world!" > pipe_in
I can only see the string arriving at pipe_out if I kill command in 2..
It seems to be a buffering issue so I decided to run all commands above with stdbuf -i0 -e0 -o0 <command> but it didn't work.
pipe fifo mkfifo
edited 2 days ago
Rui F Ribeiro
42k1483142
asked Mar 11 at 16:27
fmagnofmagno
82
add a comment |
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 pipe_in and expect it to arrive at pipe_out:
TERM1: $ tail -f pipe_out
TERM2: $ echo "hello world!" > pipe_in
I can only see the string arriving at pipe_out if I kill command in 2..
It seems to be a buffering issue so I decided to run all commands above with stdbuf -i0 -e0 -o0 <command> but it didn't work.
pipe fifo mkfifo
edited 2 days ago
Rui F Ribeiro
42k1483142
asked Mar 11 at 16:27
fmagnofmagno
82
1
Good point, @Jeff Schaller. I have just deleted that question. I find this one, here, more fundamental. As soon as I solve this one I will likely be able to solve the other one too.
– fmagno
Mar 11 at 16:41
add a comment |
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 pipe_in and expect it to arrive at pipe_out:
TERM1: $ tail -f pipe_out
TERM2: $ echo "hello world!" > pipe_in
I can only see the string arriving at pipe_out if I kill command in 2..
It seems to be a buffering issue so I decided to run all commands above with stdbuf -i0 -e0 -o0 <command> but it didn't work.
pipe fifo mkfifo
edited 2 days ago
Rui F Ribeiro
42k1483142
asked Mar 11 at 16:27
fmagnofmagno
82
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 pipe_in and expect it to arrive at pipe_out:
TERM1: $ tail -f pipe_out
TERM2: $ echo "hello world!" > pipe_in
I can only see the string arriving at pipe_out if I kill command in 2..
It seems to be a buffering issue so I decided to run all commands above with stdbuf -i0 -e0 -o0 <command> but it didn't work.
pipe fifo mkfifo
pipe fifo mkfifo
edited 2 days ago
Rui F Ribeiro
42k1483142
asked Mar 11 at 16:27
fmagnofmagno
82
edited 2 days ago
Rui F Ribeiro
42k1483142
asked Mar 11 at 16:27
fmagnofmagno
82
edited 2 days ago
Rui F Ribeiro
42k1483142
edited 2 days ago
Rui F Ribeiro
42k1483142
edited 2 days ago
Rui F Ribeiro
42k1483142
42k1483142
asked Mar 11 at 16:27
fmagnofmagno
82
asked Mar 11 at 16:27
fmagnofmagno
82
asked Mar 11 at 16:27
fmagnofmagno
82
82
1
Good point, @Jeff Schaller. I have just deleted that question. I find this one, here, more fundamental. As soon as I solve this one I will likely be able to solve the other one too.
– fmagno
Mar 11 at 16:41
add a comment |
1
Good point, @Jeff Schaller. I have just deleted that question. I find this one, here, more fundamental. As soon as I solve this one I will likely be able to solve the other one too.
– fmagno
Mar 11 at 16:41
1
1
Good point, @Jeff Schaller. I have just deleted that question. I find this one, here, more fundamental. As soon as I solve this one I will likely be able to solve the other one too.
– fmagno
Mar 11 at 16:41
Good point, @Jeff Schaller. I have just deleted that question. I find this one, here, more fundamental. As soon as I solve this one I will likely be able to solve the other one too.
– fmagno
Mar 11 at 16:41
add a comment |
2 Answers
2
active
oldest
votes
tail only outputs the last n lines of a file/stream. While you are still generating lines, it can not know which are the last n.
Have you tried something like cat?
answered Mar 11 at 17:03
ctrl-alt-delorctrl-alt-delor
12.4k52662
It is interesting though that the tail from one pipe to the other works as expected :)
– gmagno
Mar 11 at 18:43
add a comment |
Please refer to @ctrl-alt-delor's answer for the reason why it doesn't work. But you can still achieve the same purpose with cat:
answered Mar 11 at 18:24
gmagnogmagno
1013
It is very interesting that it works on your setup. On my setup it doesn't. I am running this on OSX, btw - not sure if it should make any difference, though... Altough, if I replace bothtailcommands bycatit all works fine.
– fmagno
Mar 12 at 10:34
exactly, that is also puzzling me...
– gmagno
Mar 12 at 11:37
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
tail only outputs the last n lines of a file/stream. While you are still generating lines, it can not know which are the last n.
Have you tried something like cat?
answered Mar 11 at 17:03
ctrl-alt-delorctrl-alt-delor
12.4k52662
It is interesting though that the tail from one pipe to the other works as expected :)
– gmagno
Mar 11 at 18:43
add a comment |
tail only outputs the last n lines of a file/stream. While you are still generating lines, it can not know which are the last n.
Have you tried something like cat?
answered Mar 11 at 17:03
ctrl-alt-delorctrl-alt-delor
12.4k52662
It is interesting though that the tail from one pipe to the other works as expected :)
– gmagno
Mar 11 at 18:43
add a comment |
tail only outputs the last n lines of a file/stream. While you are still generating lines, it can not know which are the last n.
Have you tried something like cat?
answered Mar 11 at 17:03
ctrl-alt-delorctrl-alt-delor
12.4k52662
tail only outputs the last n lines of a file/stream. While you are still generating lines, it can not know which are the last n.
Have you tried something like cat?
answered Mar 11 at 17:03
ctrl-alt-delorctrl-alt-delor
12.4k52662
answered Mar 11 at 17:03
ctrl-alt-delorctrl-alt-delor
12.4k52662
answered Mar 11 at 17:03
ctrl-alt-delorctrl-alt-delor
12.4k52662
answered Mar 11 at 17:03
ctrl-alt-delorctrl-alt-delor
12.4k52662
12.4k52662
It is interesting though that the tail from one pipe to the other works as expected :)
– gmagno
Mar 11 at 18:43
add a comment |
It is interesting though that the tail from one pipe to the other works as expected :)
– gmagno
Mar 11 at 18:43
It is interesting though that the tail from one pipe to the other works as expected :)
– gmagno
Mar 11 at 18:43
It is interesting though that the tail from one pipe to the other works as expected :)
– gmagno
Mar 11 at 18:43
add a comment |
Please refer to @ctrl-alt-delor's answer for the reason why it doesn't work. But you can still achieve the same purpose with cat:
answered Mar 11 at 18:24
gmagnogmagno
1013
It is very interesting that it works on your setup. On my setup it doesn't. I am running this on OSX, btw - not sure if it should make any difference, though... Altough, if I replace bothtailcommands bycatit all works fine.
– fmagno
Mar 12 at 10:34
exactly, that is also puzzling me...
– gmagno
Mar 12 at 11:37
add a comment |
Please refer to @ctrl-alt-delor's answer for the reason why it doesn't work. But you can still achieve the same purpose with cat:
answered Mar 11 at 18:24
gmagnogmagno
1013
It is very interesting that it works on your setup. On my setup it doesn't. I am running this on OSX, btw - not sure if it should make any difference, though... Altough, if I replace bothtailcommands bycatit all works fine.
– fmagno
Mar 12 at 10:34
exactly, that is also puzzling me...
– gmagno
Mar 12 at 11:37
add a comment |
Please refer to @ctrl-alt-delor's answer for the reason why it doesn't work. But you can still achieve the same purpose with cat:
answered Mar 11 at 18:24
gmagnogmagno
1013
Please refer to @ctrl-alt-delor's answer for the reason why it doesn't work. But you can still achieve the same purpose with cat:
answered Mar 11 at 18:24
gmagnogmagno
1013
edited Mar 11 at 18:33
answered Mar 11 at 18:24
gmagnogmagno
1013
answered Mar 11 at 18:24
gmagnogmagno
1013
answered Mar 11 at 18:24
gmagnogmagno
1013
1013
It is very interesting that it works on your setup. On my setup it doesn't. I am running this on OSX, btw - not sure if it should make any difference, though... Altough, if I replace bothtailcommands bycatit all works fine.
– fmagno
Mar 12 at 10:34
exactly, that is also puzzling me...
– gmagno
Mar 12 at 11:37
add a comment |
It is very interesting that it works on your setup. On my setup it doesn't. I am running this on OSX, btw - not sure if it should make any difference, though... Altough, if I replace bothtailcommands bycatit all works fine.
– fmagno
Mar 12 at 10:34
exactly, that is also puzzling me...
– gmagno
Mar 12 at 11:37
It is very interesting that it works on your setup. On my setup it doesn't. I am running this on OSX, btw - not sure if it should make any difference, though... Altough, if I replace both
tail commands by cat it all works fine.– fmagno
Mar 12 at 10:34
It is very interesting that it works on your setup. On my setup it doesn't. I am running this on OSX, btw - not sure if it should make any difference, though... Altough, if I replace both
tail commands by cat it all works fine.– fmagno
Mar 12 at 10:34
exactly, that is also puzzling me...
– gmagno
Mar 12 at 11:37
exactly, that is also puzzling me...
– gmagno
Mar 12 at 11:37
add a comment |
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1
Good point, @Jeff Schaller. I have just deleted that question. I find this one, here, more fundamental. As soon as I solve this one I will likely be able to solve the other one too.
– fmagno
Mar 11 at 16:41