Can someone help me understand why I'm getting this 'invalid bytes error"?

I have a noscript:

#!/bin/bash

echo FLASK_SECRET_KEY=\""$(< /dev/random tr -dc _A-Z-a-z-0-9 | head -c${1:-25}; echo;)"\" > .env

if [ "$1" = "rebuild" ]
then
if [ "$2" = "all" ]
then
docker compose down
docker image rm app1
docker image rm app2
docker image rm app3
else
for image in "${@:2}"
do
docker compose down
docker image rm "$image"
done
fi
else
echo Invalid argument.
exit
fi

docker compose up -d

Everytime i run it, it runs perfectly but it always shows this error at the start:

head: invalid number of bytes: ‘rebuild’

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https://redd.it/14i9196
@r_bash

Set PS1 variable information as a bar.

I was curious if there was a way to move all the usual information from the prompt to a line at the top of the terminal.

I have seen some wonderful and amazing terminal prompts but I’m at the point where just having a status line with the information I need seems more appealing.

Thanks for the help.

https://redd.it/14hdd49
@r_bash

Remove combinatorial match from a two column file

I've been running into a brick wall with a particular issue - there's a two column tsv file roughly in format of:

A B
A C
A H
B A
B C
B E
C B
C H

And I'm trying to remove duplicates regardless of order - so the outcome would be:

A C
A H
B E
C H

Since 'A B' = 'B A', 'B C' = 'C B' and so forth. I've tried shuffling the orders with awk, but of course it didn't work. Any lead would be appreciated.

Thank you!

https://redd.it/14gsupf
@r_bash

Combine values from a list

I am trying to use jq to put a list on one array of values.

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my input is this a newline separated inputs

name1

name2

name3

namex

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I would like to have this output

names : [name1, name2, name3, namex\]

Thanks for any guidance on how to tackle this, I am new to jq

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https://redd.it/14fkb6x
@r_bash

How to rsync to directory underneath mountpoint?

I have a normal directory: \~/.mozilla/firefox

I then mount something to \~/.mozilla/firefox

How can I rsync data to the original \~/.mozilla/firefox directory found underneath the mountpoint?

I'm using a tmpfs to reduce disk writes from firefox but would like the option to rsync the data while the tmpfs is mounted.

No, I don't want to use profile-sync-daemon

https://redd.it/14xbr7r
@r_bash

How to substring a variable using another variable as length?

Hi, I have this piece of code:



length_seq=${#sequence}
fold_without_mfe=${#fold_result:0:$length_seq}

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Where length_seq is the length of a genomic sequence, for example, 30. The fold_without_mfe variable is a simulation result, but it has a few more characters than I need, so I want to take only the firt 30 of this variable to match my sequence. I tried this but it throws me a bad substitution error, how can I approach this problem?

https://redd.it/14xlrwr
@r_bash

How can I get just part of the line in my text file?

I am running this command, trying to gather some data

grep -e "PROJECT" $(sudo find /path/to/dir/ -iname config) > projects.txt

and get a lot of output like this:

/path/to/dir/config/config-server.address:PROJECT="xyz";

All i want is the information between : and ;

I have tried using awk, but this gives me the same as no awk

grep -e "PROJECT" $(sudo find /path/to/dir/ -iname config | awk '{print $1}') > projects.txt

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https://redd.it/14xriut
@r_bash

Bash grievances

At this moment I have a love/hate relationship with Bash. I write in it for years and I can say that I write it, with modesty, well.

I understand that Bash isn’t like modern programming language like Golang.

But from time to time when I want to refractor code or more structured setup I felt more and more that the language is in the way.

Trying to translate something like the composite design pattern to Bash was not possible because it is so simple as it can be. That it doesn’t have support like inheritance. Return a type from a function and not by declaring or print it. Passing a function as a argument to a function is not possible.

All the things that could make life/noscripting a little bit easier, it doesn’t have any support for it.

And Bash has made progress in the last ten years. Arrays is something that I frequently use. But the speed of developments is way too irritating slow. Just as the speed of the shell it’s self.

And yes. I acknowledge the existence Python and others. But as someone who comes to different companies where there is no knowledge of these modern languages (even in 2023), I have to do it with Bash.

https://redd.it/14xwui5
@r_bash

How can I find files from a list without the extension?

I'm working on a personal project. I have 2 folders:


/JPG
/RAW


Each folder should contain files with identical filenames but with different extensions (they will always be either .jpg or .rw2)


For example:

/JPG/image1.jpg
/JPG/image2.jpg
/RAW/image1.rw2
/RAW/image2.rw2


Now there are some instances where a file only exists in one folder, but not the other.


I have identified these files and placed them into a list within a .txt file using the below command:

comm -3 <(print -lr JPG/*(:t:r)) <(print -lr RAW/*(:t:r)) > differences.txt


When I cat this file, I can see all the files which only belong to one of the folders. For example:

cat differences.txt
image7
image36
image49

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My next goal is to move these files into a new folder. But I'm not sure how. As you can see, the extensions were removed/excluded when they were outputted to "difference.txt"

I was thinking maybe I should use the find command and input a list but that doesn't seem to be possible. I've tried a few noscripts I found on stack overflow but to no avail.

Please could somebody point me in the right direction?

https://redd.it/14y0v6i
@r_bash

Need help with a one-liner for renaming files.

I have folders of files that start with a year, but need the year on the end in parentheses.

main/folder1/1999 - file1.txt
main/folder2/2000 - file02.log

rename to:

main/folder1/file1 (1999).txt
main/folder2/file02 (2000).log

I don't know enough to knock this out quickly, anybody give me a hand?

Obviously doesn't need to be a one-liner, just seems like it should be pretty simple with the right knowledge.

https://redd.it/14yjick
@r_bash

Searching for multiple strings within a list

Hello - I have the following noscript



>\# Get list of images with specified tag for downloading
tags=$(aws ecr --region ${SOURCE_REGION} list-images --registry-id ${SOURCE_AWS_ACCOUNT_ID} --repository-name ${REPOSITORY_NAME} | jq -r 'map(.[\] | .imageTag) | join(" ")')
list=$(for tag in $tags; do
if [[ $tag == "release"* \]\]; then
echo "$tag"
fi
done)

is it possible to add more filters and add them to the $tag variable? So what if I had something like

> if [[ $tag == "release"* \]\] && [[ $tag == "testing"* \]\] ; then

basically, I'm trying to match and extract multiple strings from a list and then pass those filtered results further down the noscript. Help much appreciated!

https://redd.it/14yna3b
@r_bash

How does bash, and other shells, figure out the correct environment variables?

If I use the env command I see that bash and zsh both have figured out the correct TERM, HOME, LANG and XDG... variables. Where does the shell look to find the value of this variables?

https://redd.it/14zbo8z
@r_bash

C++ Build Error Handling

Hi, I wrote a .sh that catches an error if the make command fail, but it happens only when the make execution ends. So I just look at the return. I was wondering if it is possible to catch error during the compilation time. I hope to be clear

https://redd.it/14zpptp
@r_bash

su into account, from root, and get password prompt

Realize this is a weird situation, but far as I can tell, this is the only way out of the problem.

Alright, I have an extremely odd situation. I need to su to a user account but have it ask for the password, and I need to do it from root. lol.

So what I found was, I can be root, su to the user account (no password prompt), then I can su from the user into itself, and a password is prompted.

I tried something like

sudo -u account echo "password" | sudo -S -u account echo ""

but it didn't seem to work. it appears I can't just sudo, I have to actually su.

So I'm wondering if I can use expect, but it's not working either (likely my ignorance as to how expect works)

As root:

sudo -u account expect -c 'spawn su account;expect Password:;send "sekritPassword\\n";send "whoami\\n";send "exit\\n"'

Doesn't seem to do what I would _expect_. Har har.

Anyone think of a way to do this?

https://redd.it/14zsqp8
@r_bash

Bash Killring 101
https://piped.video/watch?v=Yat95AAV5k4

https://redd.it/1503j4b
@r_bash

Why printf over echo? (noob question)

I regularly come across comments in which it's recommended to rather use printf than echo in shell noscripts. I wonder why that is.
And in this regard: would it be worth the time and energy to replace all the echos in a working noscript with printf?
And last question: do people usually get annoyed when you use both, echo and printf in one noscripts (a published noscript that is)?

https://redd.it/1519wby
@r_bash

Bash Script To Retrieve Saved Wi-Fi Passwords On Rooted Android Devices
https://github.com/oxou/android-get-saved-wifi-passwords

https://redd.it/151b189
@r_bash

Kali Linux Can some one help me with these command? i am studying for isaca cybersecurity fundamentals and i can not find out how did the instructor find out "The nefarious file was being executed at server boot time and re-spawning if shutdown".

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https://preview.redd.it/woidolmv7kcb1.png?width=613&format=png&auto=webp&s=e58040e9c76b4964bed35d8e452caa15b20ce572

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https://preview.redd.it/7hverdnw7kcb1.png?width=1920&format=png&auto=webp&s=cf6acaa7457ee399b8036a2fe68be82096ed1825

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on the third page it says \\" The nefarious file was being executed at server boot time and respawning if shutdown\\". How did he come to that conclusion?

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https://preview.redd.it/5jhjpocy7kcb1.png?width=1236&format=png&auto=webp&s=53b58246ef4863a870d7b65a421f9790a0c12110

https://redd.it/15288qj
@r_bash

It's been a while... Anyone looking to add more crap to their bashrc?
https://gitlab.com/TheOuterLinux/Command-Line/-/blob/master/System/Terminals%20and%20Muxinators/bashrc/bashrc%20-%20Basic.txt

https://redd.it/152jwjm
@r_bash

Article: How to Create HTML, ODT, DOCX & PDFs Documents for FREE from the commandline
https://www.codeproject.com/Articles/5358126/How-to-Programmatically-Create-HTML-ODT-DOCX-PDFs

https://redd.it/152k6je
@r_bash

Pinging periodically using a noscript and crabtab

In the past week or so my home internet feels unstable. So I created the following little noscript to check it out:

'''bash
#!/bin/bash

# Change the destination log file path
log_file=~/Code/PingsLogger/pings.log

# Replace 'your_router_ip' with the IP address of your router or the server you want to ping
router_ip='8.8.8.8'

# Ping the router and record the result to the log file
ping_result=$(ping -c 1 $router_ip | grep 'bytes from' | cut -d '=' -f 4)
current_time=$(date +"%Y-%m-%d %H:%M:%S")

if [ -n "$ping_result" ]; then
echo "$current_time - Lag: $ping_result ms" >> $log_file
else
echo "$current_time - Request timed out" >> $log_file
fi
'''

Saved it to a file named [pings.sh](https://pings.sh) (called chmd and such), initiated a file name pings.log and I added to crontab the following line:
`* * * * * ~/Code/PingsLogger/pings.sh`

When I run the noscript manually it does the job and adds a new line to the log but when the crontab runs it it always adds only 'Request timed out' to the log file.


Can someone help me understand what am I doing wrong? :(


https://redd.it/152sx45
@r_bash