All Questions
1,623
questions
3
votes
2
answers
100
views
Equivalent for pipe() in bash or other shell
In libc, there is an ability to create an (anonymous) pipe:
https://man7.org/linux/man-pages/man2/pipe.2.html
I am aware of mkfifo in bash and similar shells, and I am aware of the | which allows ...
- 2,184
1
vote
1
answer
67
views
How to get available data in a pipe in linux
In Linux, after writing some data in a pipe (yet not read), when using fstat on read/write side of a pipe, the st_size field is zero. Is it possible to get the size of data available in a pipe?
Sample ...
- 129
0
votes
1
answer
56
views
Linux got stuck using pipe() and dup2()
I am simulating the linux shell pipe operator, and I got stuck. The below is the minimal reproducable example of what I tried.
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h&...
- 2,200
-3
votes
1
answer
51
views
How could I untar a file and then tar using pipe? [closed]
I have a tar file original.tar, and I need to untar it and then re-tar it for some reason. I do not want to untar it to disk and then tar from disk. I hope I can untar the file into stdout, and then ...
- 1,065
1
vote
1
answer
62
views
Piping input into running Python script
Maybe this is the wrong approach, so feel free to redirect.
I am trying to asynchronously pipe input into a python script. The idea is that I have a background Python script do some long initial setup ...
- 69
0
votes
0
answers
67
views
How can I create multiple children using one parent with 2D array for UNIX using pipes and fork only?
I'm trying to write code that creates N processes 1, 2, 3, 4, ..., N for
UNIX (using fork()), where N is given by the user. The
processes can be created in any order.
Each process must print ...
1
vote
1
answer
28
views
python on Linux: os.pipe() with cumulative byte counter?
Is it possible to get a cumulative count of bytes written to an os.pipe()? I tried os.fdopen(...).tell() but got IOError: [Errno 29] Illegal seek. Is there some other way to wrap the fd to get a ...
- 4,284
1
vote
1
answer
79
views
Pipe an output into echo as an variable for calculation
My goal is to divide 2 text files, each containing a single integer,
but limiting the answer to 2 decimal places.
I managed to do it with paste total.txt count.txt | awk '{printf "%.2f\n", $...
- 157
0
votes
1
answer
44
views
Remote to server and run tmux in detached mode with pipe
I am trying to remote to server with ssh and run a tmux on the remote server with a command in detached mode. The command I want to run in tmux needs a pipe character.
I have tried escaping the | ...
- 819
0
votes
1
answer
77
views
How to replace the occurrences of pipe (|) without replacing the pipe used as a delimiter
On Linux server, I have pipe-delimited files that have pipe (|) characters in some string columns. The files are pipe-delimited but the delimiter pipe is always in double quotes while pipes in the ...
- 3
2
votes
1
answer
96
views
(Bad file descriptor error) Pipe between a execl() C and a Python in Python program
I tried to exchange a string between Python and C programs using a pipe(), but I got nothing.
After that I tried to exchange a string between two C programs using a pipe() and everything was fine.
...
- 21
0
votes
1
answer
78
views
Broken pipe while timestamping and appending to log file
I am running a python program like this
nohup python3 -u /home/myuser/foo.py | ts '[%Y-%m-%d %H:%M:%.S]' &>> /var/log/mylogs/foo.log &
The program processes input and prints output. It ...
- 306
0
votes
0
answers
33
views
How does python work with outside pipe and sys.stdin [duplicate]
In a Linux sandbox, I tried to run a python3 script from network by piping python3. And the script also reads data from sys.stdin.
It was a little bit like :
echo 'import sys ; print(f"python ...
- 80
3
votes
2
answers
212
views
How to use “grep -f file-with-patterns” in a pipe where “file-with-patterns” changes frequently?
I am trying to do dynamic logging of dropped firewall events whereby I can dynamically specify what events not to log.
I use:
logread -f | grep -v -f file-with-patterns >> logfile
in a script ...
- 33
1
vote
0
answers
47
views
Named Pipes in Linux with Python read/write miss some lines of text
I am learning how to use named pipes to pass data between processes. To test it out, I wrote two Python scripts, which I called pipewriter.py and pipereader.py, and a named pipe called my_pipe (using ...
- 2,708