Need help understanding and altering a noscript

Hello folks,

I am looking for some help on what this part of a noscript is doing but also alter it to spit out a different output.

p=system_profiler SPHardwareDataType | awk '/Serial/ {print $4}' | tr '[A-Z]' '[K-ZA-J]' | tr 0-9 4-90-3 | base64


This is a part of an Intune macOS noscript that creates a temp admin account and makes a password using the serial number of the device. The problem I am having is that newer macbooks don't contain numbers in their serial! This is conflicting with our password policy that requires a password have atleast 2 numbers and 1 non-alphanumeric.

I understand everything up to the tr and base64. From what I've gathered online, the tr is translating the range of characters, uppercase A to Z and numbers 0 to 9 but I can't get my head around what they're translating to (K-ZA-J and 4-90-3). After this I'm assuming base64 converts the whole thing again to something else.

Any help and suggestions on how to create some numerics out of a character serial would be greatly appreciated.

https://redd.it/1hiiopc
@r_bash

Executing a noscript from another noscript programmatically (regardless of run location)

I'm trying to build a simple noscript that will stop my docker containers, drop a volume, then start my containers back up. To start my containers, I have a helper noscript in the root of my project, compose.sh. The noscript I'm creating is in a subfolder, noscripts.

Is there a way to essentially do "if subfolder, go up a folder, then run noscript"? If I run the noscript from the root, it'd need to search the current location for the compose noscript. If run from elsewhere, it'd need to go up a level from the noscript's location to find the compose noscript.

I know I can hard code the noscript, but that's inflexible, as if the noscript is moved to another machine, it'd need to be modified. I don't know if my thinking of how to write this noscript is wrong, and would appreciate any feedback.

https://redd.it/1hhbaz2
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Change terminal color programmatically?

Hello mates, I am using bash terminal. I can change my terminal color if an ssh session is opened. I wrote a function if "$SSH_CONNECTION" then the terminal color is changed. However, I want to do similar change for virtualenv, nothing happens. I print "$VIRTUAL_ENV" and it's null. What should I do?

https://redd.it/1hj8oof
@r_bash

Why variable is not updated in the function called in a while loop?

```
readonly BATTERY_CRITICAL_THRESHOLD=15
readonly REFRESH_INTERVAL=1

readonly BAT_PATH="/sys/class/power_supply/BAT0/capacity"

BATTERY_ALERT_STATE=0

get_battery_status() {
local battery_pct ac_state icon
battery_pct=$(<"$BAT_PATH")
ac_state=$(<"$AC_PATH")

if ((battery_pct <= BATTERY_CRITICAL_THRESHOLD)) && ((BATTERY_ALERT_STATE == 0)); then
BATTERY_ALERT_STATE=1
notify-send "Battery Critical" "Battery level is at $battery_pct%"
elif ((battery_pct > BATTERY_CRITICAL_THRESHOLD)) && ((BATTERY_ALERT_STATE == 1)); then
BATTERY_ALERT_STATE=0
fi
printf '%s%%' "$battery_pct"
}

# Main loop in main shell context
while true; do
get_battery_status
sleep "$REFRESH_INTERVAL"
done
```

Above is a bash noscript I write.

What I expect is it will change `BATTERY_ALERT_STATE` to 1 when battery level is lower than 15, and then send a notification. After `BATTERY_ALERT_STATE` is changed to 1, it won't be changed until the battery_pct is greater than `BATTERY_CRITICAL_THRESHOLD`.

But, in practice, it's not the case, it seems that `BATTERY_ALERT_STATE` has never been changed, and therefore the notification is continueously being sent.

I don't know why, I have debugged it for days, searched online and asked ai, no result.

Can anyone told me why?

https://redd.it/1hjbl7t
@r_bash

XDG & ~/.bashrc

I created a file to be sourced by bashrc to organize directories and files after running xdg-ninja.
I'm just not sure it's fool proof. I was hoping that a more experienced user could comment.
This is a shortened version with only one example. (cargo)

\#! /usr/bin/env dash



\# shellcheck shell=dash

\# shellcheck enable=all



\#------------------------------------------------------------------------------|

\# xdg-ninja

\#------------------------------------------------------------------------------|

alias 'xdg-ninja'='xdg-ninja --skip-ok --skip-unsupported' ;



\#------------------------------------------------------------------------------|

\# XDG Base Directory specification:

\#------------------------------------------------------------------------------|

export XDG_CACHE_HOME="${HOME}/.cache" ;

export XDG_CONFIG_HOME="${HOME}/.config" ;

export XDG_DATA_HOME="${HOME}/.local/share" ;

export XDG_STATE_HOME="${HOME}/.local/state" ;



\#------------------------------------------------------------------------------|

\# xdgmv

\#------------------------------------------------------------------------------|

xdgmv () {

test "${#}" -ne '2' && return ; test -e "${1}" || return ;

if test -d "${2%/*}" ;

then

mv --backup='numbered' --force "${1}" "${2}" ;

else

mkdir -p "${2%/*}" &&

mv --backup='numbered' --force "${1}" "${2}" ;

fi ;

} ;



\#------------------------------------------------------------------------------|

\# [cargo\]: "${HOME}/.cargo"

\#------------------------------------------------------------------------------|

xdgmv "${HOME}/.cargo" "${XDG_DATA_HOME}/cargo" &&

export CARGO_HOME="${XDG_DATA_HOME}/cargo" ;



\#------------------------------------------------------------------------------|

\# unset function(s)

\#------------------------------------------------------------------------------|

unset xdgmv ;



\#------------------------------------------------------------------------------|



https://redd.it/1hjybbv
@r_bash

friends I am looking for this but if you know bash manager types similar to this, can you share it?

https://redd.it/1hk3jpb
@r_bash

Grep question about dashes

Im pulling my hair out with this and could use some help. Im trying to match some strings with grep that contain a hyphen, but there are similar strings that dont contain a hyphen. Here is an example.

echo "test-case another-value foo" | grep -Eom 1 "test-case"
test-case
echo "test-case another-value foo" | grep -Eom 1 "test"
test
I dont want grep to return test, I only want it to return test-case. I also need to be able to grep for foo if needed.

https://redd.it/1hk9edb
@r_bash

Array lengths - this works but the traditional method doesn't

Any ideas? The first one works, The second one doesn't in a noscript, doing a test from the command prompt all is good. Its a simple list of numbers all <100 , array length < 10

len="$(echo "${nlist[@]}" | wc -w)" # Good
len="${#nlist@}" # Bad

https://redd.it/1hkn7gw
@r_bash

Multiple coprocs?

I have a use case where I have to execute several processes. For the most part, the processes will communicate with each other via CAN, or rather a virualized vcan0.

But I also need to retain each process's stdin/out/err in the top-level management session, so I can see things each process is printing, and send commands to them outside of their normal command and control channel on vcan0.

Just reading up on the coproc command and thought it sounded perfect, but then I read what is essentially the last line in the entire bash man page:

There may be only one active coprocess at a time.

Huh? How's come? What's the best practice for juggling multiple simultaneously running programs with all I/O streams available in a way that's not going to drive me insane, if I can't use multiple coprocs?

https://redd.it/1hkven3
@r_bash

Bash is getting pretty

https://redd.it/1hkywwd
@r_bash

pure-bash-bible alternative?

Since pure-bash-bible Got archived, is there any viable alternative for it? I know bash but I don't remember every little thing like reversing an array.

I want to have bash cheatsheet.

https://redd.it/1hjvy3m
@r_bash

I give up bash.

There is a structured way to learn every stupid programming language but not bash. There are textbooks with exercises, leetcode like problem solving series. but not for bash. Maybe, it is because one is expected to copy paste stuffs while doing bash.

I've taken many many bash noscripting courses, but fk those courses. Courses teach you nothing. What you want is a structured problem solving approach.


I want to build something. I can;t do it without chatgpt. Learning to build with chatgpt is like learning to fly before learning to walk.

I ask in forums, but they are similar lke chatgpt in the sense that they provide you solution. And believe me, nobody who has got solutions to their programming problems from forums has ever learnt programming by asking. Ask a few more and people think you're a spammer.

I am learning java and bash noscripting/shell noscripting since a year. I can can see visible progress in java where I have outgrown myself before year. But bash, oh fck. I can't tell the syntax of array looping without chatgpt/google. I've to look up google for even the minor of the things.


This is because I have got nothing to practice. I don't want to be a prompt master that copies stuffs from chatgpt or google. Copying isn't bad, but when you haven't even build a muscle memory to declare an array there is when things go south.


Should I even tell what I am trying to build in bash?

Let me go ahead.

I've a csv file with 2 columns separated by a comma.



U-DLCI,6
C/R,1
EA,1
L-DLCI,4
FECN,1
BECN,1
DE,
EA,1

Like this, now I want to go through them one by one.

U-DLCI is 6, so I allocate 6 unit of distance for it. And print U-DLCI inside it center justified.

C/R is 1, so I slloate 1 unit of distance for it and print C/R inside it.


EA is 1 so I do ....

Now, the sum of past three numbers was 8.

So, I jump to a new line.


Then L-DLCI is 4 so I print it in a 4 units of distance at the center.

and so on....
Had I learnt file handling in java, this is a no-brainer in java. But bash, ffck whtat is this? How can a language be so deceptive?

https://redd.it/1hla31k
@r_bash

Guys, which platform would you recommend me to learn bash noscripting?



https://redd.it/1hlwlow
@r_bash

Convert JSON array to bash array

Hi guys,

I am a linux noob and am trying to write a noscript to extract info from a mkv file using mkvmerge but am not able to convert the target json noscript to a bash array. I have tried a number of solutions from stack overflow but with no success.

here are some of my attempts

dir="/mnt/Anime/Series/KonoSuba/Season 2/[Nep_Blanc] KonoSuba II 10 .mkv"
*********************************************************************************
ARRAY_SIZE=$(mkvmerge -J "$dir" | jq '.tracks | length')
count=0
arr=()

while [ $count -lt $ARRAY_SIZE ];
do
arr+=($(mkvmerge -J "$dir" | jq '.tracks'[$count]))
((count++))
done
*********************************************************************************
readarray -t test_array < <(mkvmerge -J "$dir" | jq '.tracks')
for element in "${test_array[@]}";
do
echo "$element"
done

*********************************************************************************
array=($(mkvmerge -J "$dir" | jq '.tracks' | sed -e 's/^\[/(/' -e 's/\]$/)/'))

but the echo prints out lines instead of the specific objects.

Though now it is helpling me with my python, originally the project was to help me learn bash noscripting. I would really like to have a bash implementation so any help overcoming this roadblock would be appreciated.

https://redd.it/1hm27y2
@r_bash

Tools to edit modified/createdAt infos about a file based on its name?

I have a bunch of files, and more or less their name can be categorized into these categories:

.trashed-1737661897-video20241213152336.mp4
.trashed-1737661969-IMG20241217205925.jpg
1675865719503..jpg
20190207063809.jpg
20200830202505.jpg
FBIMG1574447155845.jpg
IMG-20190622-WA0006.jpg
IMG20200724114950442.jpg
VID20240623230607.mp4
ReactNative-snapshot-image8923079110072067694.png
Screenshot20241212082715Chrome.jpg
originalbadf21d1-5c56-43a1-b19a-82f5d43de9beIMG20220707155608.jpg
video20240720102400.mp4

The problem is that their "created at" or "modified at" date are set to today. Do you know any tools that might help me change their dates based on their name?

https://redd.it/1hm2z2r
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