Questions tagged [shell]
The shell is Unix's command-line interface. You can type commands in a shell interactively, or write scripts to automate tasks. Use this tag for questions applying to /bin/sh and most compatible shells (ash, bash, ksh, zsh, …). For shell scripts with errors, please check them in http://shellcheck.net before posting here.
11,989
questions
2
votes
3
answers
239
views
Two ssh output as awk input
I have two remote servers that I am trying to ssh and cat some files.. I want to input the output of the ssh to a awk command.
This is what I have got
ssh username@host1 “cat /tmp/test/*” ssh ...
- 43
0
votes
1
answer
29
views
Find file in directories of PATH env which match partially
Idea is to match a filename in any of directories mentioned in PATH environment. Usually, we do this by running "which <executable_filename>".
This works fine, when the file your are ...
- 3
1
vote
0
answers
17
views
Is there a way to change text size on a console screen, specifically XAMPP shell console?
I simply just want to be able to display the text at a smaller size as it currently is too large and messes with the display of the output (at least on my laptop screen which isn't all too big, but ...
0
votes
1
answer
30
views
how to source tmux session_id into tmux
I have this:
export session_uuid="$(uuidgen)"
remove_session() {
tmux kill-session -t "$session_uuid"
}
export -f remove_session
trap remove_session TERM INT SIGINT SIGTERM
...
- 9,718
0
votes
1
answer
65
views
Upload a file with SSH and then give back the control to the user
I'm trying to create a script that, when you connect on a remote server with SSH, the script checks things and deploy your personals scripts before giving you back the stdin, all in one SSH connection ...
- 3
1
vote
1
answer
33
views
How to disable "long descriptions" of commands in ZSH
I have a program named fhome that provides shell completion for Zsh:
$ fhome <tab>
config -- Manage system configuration
event -- Manage events
help h -- Shows a list of commands or ...
- 135
0
votes
0
answers
29
views
why does ZSH pass # and arguments following to process? [duplicate]
I did some experimenting and:
alex.mills@alex wss % node /Users/alex.mills/codes/vibeirl/wss/scripts/arg-test.js -v a # 3
[
'/Users/alex.mills/.nodenv/versions/14.17.0/bin/node',
'/Users/alex....
- 9,718
2
votes
2
answers
169
views
How to run all scripts of the form `sh my_dir/subdir*/qsub.sh`
I have several directories of the form:
my_dir/subdir*/qsub.sh
I want to execute all of the qsub.sh in each of these subdirectories, but when I tried to do
sh my_dir/subdir*/qsub.sh
it seems to only ...
- 131
1
vote
0
answers
38
views
Sudoers env_keep wildcard expression with exceptions
When running sudo, I'm trying to retain all environment variables related to the Borg backup program, with 2 exceptions.
Using env_keep in my sudoers config (with env_reset enabled), here is what I ...
-1
votes
2
answers
89
views
How can I get a file list, recursively?
I would like to have output with the following format:
/media/username/New/Audio/ｔｉｍｅ ｍａｃｈｉｎｅ by Ariya Hedie.mp3
/media/username/New/Audio/You areever alone by Dj Quads.flac
/media/username/New/Audio/...
- 101
1
vote
1
answer
146
views
How to run the command "sudo sh /path/to/script.sh" by double clicking?
I have a question from this thread How to run a bash script by double clicking by entering the path in sudoers?. Since it was explained to me that it is unsafe to grant sudo privileges to the script....
- 15
4
votes
1
answer
206
views
Is there a away to override a shell's non-interactive state?
A big company, jealous guardian of their highly customized Unix flavor, is restricting code-signing to interactive shells. We, however, would like our gitlab-runner to sign software products as part ...
- 43
0
votes
1
answer
61
views
multiple commands in linux shell
I have just come across an article describing process of installing containerD runtime and I'm a little dubious about the command mentioned, maybe a typo but I want to get clarity on it. The command ...
- 103
-1
votes
0
answers
21
views
How to deal with unresponsive shell on the server?
I am working on a binary exploitation challenge. I was able to interact with the server successfully by responding with a correct response. Looks like I gain a shell (normal user), and I am supposed ...
- 1
-1
votes
2
answers
73
views
How does the `tr` command work?
I was playing around with tr and got some unexpected results. What is happening in these situations? I don't understand what is happening under the hood, or perhaps I'm not using this command ...
- 141
0
votes
0
answers
33
views
Strange incongruent output for both nc and fifo
I have this exact code:
#!/bin/bash
gtimeout(){
if type -f gtimeout &> /dev/null; then
command gtimeout "$@"
else
timeout "$@"
fi
}
export -f gtimeout;
...
- 9,718
0
votes
1
answer
42
views
How to execute a subshell directly
I have this:
timeout 25 bash -c '
for i in {1..9}; do
if read line < "$my_fifo"; then
if test "$line" != "0"; then
exit 0;
...
- 9,718
-1
votes
0
answers
49
views
script to exit 0 when stdin match is made
I need to wait for a server to actually start listening before initiating a new process, something like this:
mkfifo my_fifo
(
timeout 15 docker logs -f rabbitmq | on_first_match 'ready for ...
- 9,718
6
votes
3
answers
2k
views
How to referencing $@ without pass it in bash function?
I wants to know how can I reference the $@ from another function or another script
file without pass it just like what getopts do. Thank you very much!
# previous question :
How bash getopts get to ...
- 193
2
votes
1
answer
265
views
How bash getopts knows what arguments the call has
If getopts is a bash function, by my understanding, you need to pass $@ - the whole arguments to getopts to let the function know what kind of arguments you have in order to proceed, right?
It seems ...
- 193
0
votes
0
answers
50
views
How to run a process in the background using a bash script? [duplicate]
When I run the command in the terminal: sudo badvpn-tun2socks --tundev tun0 --netif-ipaddr 10.0.0.2 --netif-netmask 255.255.255.0 --socks-server-addr 127.0.0.1:8080 I get a terminal with packet data ...
- 15
5
votes
0
answers
119
views
Is there a command to run an executable?
bashenables to run bash scripts with bash somescript, python python scripts with python3 somescript. Alternatively, with the right shebang, I can run directly the previous scripts with ./somescript.
...
- 203
1
vote
1
answer
50
views
How to convert all newlines to "\n" in POSIX sh strings
I have a string that contains newline characters. I want to escape all newlines in that string by replacing all newline characters with a string of two characters: "\n". How can I do this in ...
- 2,770
0
votes
0
answers
23
views
why the nohup background process did not started
I am using this script to startup my application:
#!/usr/bin/env bash
set -u
set -e
set -x
nohup pdm run python3.10 /root/visa/main_api.py > /root/visa/starup.log &
tail -f /root/visa/starup....
- 589
4
votes
3
answers
223
views
How to sort the list of positional parameters in POSIX sh
Is there a way to sort the list of positional parameters in POSIX sh? Each positional parameter could contain arbitrary characters (e.g. spaces, newlines, tabs, etc.). The sort algorithm should be ...
- 2,770
2
votes
3
answers
742
views
ARGV[] not accepting the argument
I have a shell script that I am trying to pass a date argument to ARGV[1] but the script is giving a blank output
Here is the command:
#!/bin/bash
dt=$(date -d "yesterday" '+%m%d%Y')
cat /...
- 43
0
votes
1
answer
33
views
Set PATH for /bin/sh in Debian:11 image
Background
I am building an image based on Debian:11. I am trying to set the PATH for the /bin/sh with a dynamic value determined at image build-time. (The "at image build time" is important....
- 103
1
vote
1
answer
80
views
How to decode base64-encoded inline attachments in email files saved from Thunderbird or Gmail?
Although base64 [--decode] works well when encoding and decoding files locally, I can't decode a base64-encoded inline attachment in an eml file saved from Thunderbird or Gmail.
I observed that base64-...
- 475
-1
votes
1
answer
69
views
sh split value into variables
This works on the command line, but not in a script.
read -r local_temperature system_mode preset running_state current_heating_setpoi
nt <<< $(thermostat)
Syntax error: redirection ...
0
votes
2
answers
68
views
Add a process to an already executing process? Like && or so
This question inspired me to another related question. Imagine that you start
% nohup a.sh &
and then want b.sh to execute when a.sh is finished (E.g., b.sh will process the output from a.sh. ...
- 1,853
-1
votes
0
answers
19
views
Consistent Ansible Playbook Fails on Specific Servers with RPM Digest Mismatch [duplicate]
I'm facing an issue with an Ansible playbook named checkmk_playbook.yml, which installs check_mk on our servers. It executes without issues on servers [servernameaprhel003], [servernameaprhel002], and ...
- 11
-2
votes
0
answers
38
views
ERROR! conflicting action statements: command, ignore errors [duplicate]
I am experiencing a persistent issue with an Ansible playbook that is intended to forcefully install the check_mk_agent on a number of Red Hat Enterprise Linux servers. The playbook works as expected ...
- 11
0
votes
1
answer
81
views
A && B || C vs if then else fi [duplicate]
Stéphane commented that
A && B || C cannot be used in place of proper if then else fi
Can someone explain what's the difference?
- 103
-2
votes
2
answers
110
views
defining variables inside function
After some reading somewhere on this interwebs, I found that it was best practice to to the following when using the output of a command as a variable:
FILE_CORE_NAME="$(/usr/bin/env basename $(/...
- 54
0
votes
1
answer
76
views
File backed, key value store implemented with posix utilities
I imagine this is a pretty common thing to do.
Which posix utility for reads, which for writes? What are the most common file formats to do this with?
Is inplace modification possible?
My first ...
- 103
-2
votes
1
answer
225
views
Identifying Linux distribution from screenshot
A friend is asking me to help him out with this old linux box that he has which i believe it like over 15 years old.
He only sent me this screenshot so I don't know much about it yet until i meet with ...
- 97
0
votes
1
answer
76
views
How to pass the standard input of a shell script to a background command
In a shell script, I am trying to start a background command that has the same stdin as that of the shell script.
#!/bin/sh
# ...
the-program &
However, the-program above will not have access to ...
- 2,770
-3
votes
1
answer
116
views
What happens if you put /dev/urandom into a shell script and run it?
I want to know what happens when you run the contents of /dev/urandom as a shell script. I know when you cat it into a terminal it will set off a bunch of random things in the terminal environment. ...
- 3
2
votes
2
answers
112
views
"set editing-mode vi" v/s "set -o vi" what is the difference?
On multiple forums I have come across adding set -o vi to my .bashrc file. Today I saw the option of adding set editing-mode vi to .inputrc.
I googled and both appear to do the same thing, are there ...
- 121
7
votes
5
answers
2k
views
For loop through servers with custom ports (for i in "user1@server1 -p 12345" "user2@server2 -p 54321" ...; do)
I'm trying to run a command on a series of servers via ssh. I have recently changed ssh ports to avoid Internet scanners, but it broke my script. Does anyone know "an easy way" to specify ...
- 309
9
votes
1
answer
931
views
GNU Coreutils `\time --version` and `/bin/true --version` work but `\true --version` does not?
$ \time --version
time (GNU Time) UNKNOWN
Copyright (C) 2018 Free Software Foundation, Inc.
...
$ /bin/true --version
true (GNU coreutils) 8.32
Copyright (C) 2020 Free Software Foundation, Inc.
...
$...
- 245
0
votes
0
answers
50
views
Is there a way to not exit a shell if jobs are stopped/suspended?
If one types exit and a job is stopped/suspended, the shell will print a warning message instead of exiting.
1: some_command &
[1] 4018347
2: exit
zsh: you have suspended jobs.
But if one types ...
- 166
1
vote
0
answers
53
views
SH script fails when something already exists [duplicate]
I have a problem with my SH script, I'm writing a SH script that automates the installation of OpenStack Keystone, and also uses a small configuration file, everything works fine but due to a syntax ...
1
vote
0
answers
21
views
How to enable sh emulation mode only when using zsh interactively
When using zsh interactively, I would like it to emulate the behavior of sh as much as possible. I have tried adding emulate sh to the end of ~/.zshrc, but since I am using zsh plugins that rely on ...
- 2,770
4
votes
3
answers
459
views
Safely save and restore environment variables
I have a script that parses a rudimentary .env file and exports its contents as environment variables, before taking further action:
set -eu
test -f .env && load_dotenv
exec ./foobar x y z &...
- 1,278
3
votes
1
answer
432
views
How to exclude swapfile from rsync backup?
I'm trying to write a simple script that would back up my system files. Here's what I wrote so far:
#!/usr/bin/sh
if [ $UID != 0 ]; then
echo "Please run me as root"
exit 1;
...
- 33
0
votes
1
answer
59
views
Is there any way to enable ansi colors in journalctl logs?
foo.py prints ansi colored output in my terminal
Now if I execute foo.pyin a systemd unit and journalctl --all -u foo.service --output cat -f all output is monochrome.
How can I journalctl systemd ...
- 399
0
votes
1
answer
561
views
Removing GitHub tools on termux?
I don't know if i can ask this question here or not. I have cloned some tools from GitHub on my termux. Then i ran the bash file "install.sh" that was a customized login with password tool. ...
-1
votes
1
answer
129
views
Handling user input of * with case in shell script
i am creating a simple calculator in bash. the user can enter operators "+", "-", "/", and "*".
however, when the user inputs * as an operator, it goes to the ...
0
votes
2
answers
61
views
Nesting quotes in shell
I want to execute a command which looks like
$ sh -c 'exec python -c "print('$1$2MyString')"'
with the desired result '$1$2MyString'.
However, when I execute the command, I get
Traceback (...
- 3