how to parallelize a for loop in batches?

On a Proxmox PVE host, I'd like to do scheduled live migrations. My "oneliner" already works, but I've got 2 NICs in adaptive-alb, so I can do 2 migrations at the same time, I presume nearly doubling the speed.

This oneliner will "serialize" the migrations of all VMs it finds on a host (except VM with VMID 120).

Question: how do I change the oneliner below so it does 2 parallel migrations, if those finish, continue with the next two VMs. Ideally, if one finishes, it could immediately start another migration, but it's OK if I can do 100, 101, wait, then 102, 103 wait, then 104 and 105, ... until all VMs are done.

time for vmid in $(qm list | awk '$3=="running" && $1!="120" { print $1 }'); do qm migrate $vmid pve3 --online --migration_network 10.100.80.0/24 --bwlimit 400000; done



https://redd.it/1km88ka
@r_bash

I'm thinking to start to work as a freelancer with shelll scrippting. Realistically, is there a market for that out there?

Just adding to the noscript: I'm thinking about doing this from home on sites like Upwork, Fiverr, **Freelancer.com**, Toptal, and PeoplePerHour. Working in an organization isn't an option at the moment.

I have some portfolio to show, but let's say the noscript's purposes are kind of shallow to show in this context, I'd guess. They're noscripts to help my day-to-day flow. The code itself is fine, most are pure-bash and performance-sensitive noscripts, but their purpose.. Anyway, if you guys say that's an issue, I can find projects to engage in. It's a good way to learn anyway, which is never enough. Thankfully, I have no rush to start working. I've been solely on Linux for around 10 years, and improving or switching my portfolio is not a huge deal.

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

[Update] Added Security for dotfold (Previously No Security)
https://redd.it/1kmqmbc
@r_bash

Advance a pattern of numbers incrementally

Hi, I am trying to advance a pattern of numbers incrementally.



The pattern is: 4 1 2 3 8 5 6 7



Continuing the pattern the digits should produce: 4,1,2,3,8,5,6,7,12,9,10,11,16,13,14,15... onwards etc.



What I am trying to archive is to print a book on A4 paper, 2 pages each side so that's 4 pages per sheet when folded and then bind it myself. I have a program that can rearrange pages in a PDF but I have to feed it the correct sequence and I am not able to do this via the printer settings for various reasons hence setting up the PDF page order first. I know I can increment a simple sequence in using something like:



for i in \seq -s, 1 1 100; do echo $i; done

But obviously I am missing the the important arithmetic bits in between to repeat the pattern



Start with: 4

take the 1st input and: -3

take that last input +1

take that last input +1

take that last input +5 etc etc



I am not sure how to do this.



Thanks!

https://redd.it/1kn6ozs
@r_bash

help with noscript to verify rom, output variable, and flash

I tried to write a bash noscript that verifies a rom file using sha256sum.
The output should go into a variable
If the variable contains data exit
Else, flash the rom.
i cant seem to get the output variable to work correctly

I'm still learning bash noscript, so if anyone has any ideas on how to make it work, or improve it?
Thank you

\#!/bin/bash

output=`$(cat *.sha256) *.rom | sha256sum --check --status`
\#output=`ls`

if ! test -z "$output"
then
echo $output
exit
fi

echo "sha256sum correct"
echo
read -p "Are you sure you want to flash? [y/n\]" -n 1 -r
echo

if [[ $REPLY =\~ \^[Yy\]$ \]\]
then
echo
\#flashrom -w *.rom -p internal:boardmismatch=force
echo
echo "finished"
fi

https://redd.it/1kphj67
@r_bash

Stop auto execute after exit ^x^e

Hi, \
As noscript, how do I stop Bash from auto executing command after I'm done editing using ^x^e?

https://redd.it/1kph7k1
@r_bash

Version managers ARE SLOW

It really is too much. You add one nvm here, another rbenv there and top it of with some zoxide. I had to wait about one second just for my shell to start up! That really is suckless-less.

Well, I thought you could fix that problem by lazy-loading all those init noscripts. But when writing all that directly in bash, it quickly gets kind of bloated and not really easy to maintain. So, I've gotten to write a simple lazy-loader to do all that for you.

With lazysh (very creative name), you can list your init noscripts inside of your bashrc (or your shell's rc-file) with the lazy loader and it figures out which commands a single init command modifies by itself and caches the result such that your shell will start up blazingly fast next time!

You can view the project on Github. After installing, you simply add the following lines to your *rc-file and put in your init commands (replacing bash with zsh or fish, respectively):

source $(echo '

# Initializing zoxide
eval "$(zoxide init bash)"

# Initializing rbenv
eval "$(rbenv init - bash)"

# ... any other init command

' | lazysh bash)

https://redd.it/1kpmq9g
@r_bash

Check if gzipped file is valid (fast).

I have a tgz, and I want to be sure that the download was not cut.

I could run tar -tzf foo.tgz >/dev/null. But this takes 30 seconds.

For the current use case, t would be enough to somehow check the final bytes. Afaik gzipped files have a some special bytes at the end.

How would you do that?

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

Bash Shell Scripting and Automated Backups with Cron: Your Comprehensive Guide

I just published a comprehensive guide on Medium that walks through bash shell noscripting fundamentals and how to set up automated backups using cron jobs.
If you have any questions or suggestions for improvements, I'd love to hear your feedback!
PS: This is my first time writing an article
Link: https://medium.com/@sharmamanav34568/bash-shell-noscripting-and-automated-backups-with-cron-your-comprehensive-guide-3435a3409e16

https://redd.it/1kqihm6
@r_bash

is there any naming convention for functions in bash noscripting?

Hello friends, I'm a c programmer who every once in a while makes little bash noscripts to automatize process.

right now I'm making a noscript a bit more complex than usual and I'm using functions for the first time in quite a while. I think it's the first time I use them since I started learning c, so it does bother me a bit to find that the parenthesis are used to define the function and not to call it and that to call a function you just have to write the name.

I have the impression that when reading a code I might have a difficult time remembering that the line that only has "get_path" is a call to the get_path function since I'm used to using get_path() to call said function. So my question is, is there any kind of naming convention for functions in bash noscripting? maybe something like ft_get_path ?

https://redd.it/1kqnyw5
@r_bash

Minimal Bash noscript to convert media files using yt-dlp + ffmpeg

Hey folks!!, I just wrote my first Bash noscript and packaged it into a tool called `m2m`.

It's a simple command-line utility that uses yt-dlp and ffmpeg to download and convert videos.



GitHub repo: https://github.com/Saffron-sh/m2m



It's very minimal, but I’m open to feedback, improvements, and general bash advice. Cheers!



https://redd.it/1kpjxq4
@r_bash

Any tips for a new bash enthusiast_?

Never will I ever use vim for text editing again 🥴.

Nano is my favorite for now, until I become a "pro" in bash noscripting 😁.

I heard this is the place to be to get proper help with bash, anyone here have time to teach me a bit more about it please.

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

Simplest way to make your noscripts nicer (to use)?
https://redd.it/1kr89kx
@r_bash

Do you actually use getopts in your noscripts?

I always see getopts in discussions, but in real life most noscripts that I come across are just parsing $@ manually. Curious if anyone actually uses it regularly, or if it's more of a 'looks good in theory' kind of thing.

https://redd.it/1ksm8f2
@r_bash

Run non bash command from noscript

Hello,


Newbie here, who started bash noscripting. I am trying to call cowsay from a noscript I am working on. It's just a basic noscript which reads input from a user and spits it out with cowsay. However the fails at the cowsay line with error command not found. Cowsay has been added to path as I am able to call it from anywhere in the terminal without issues. How do I get it to run from the noscript?

Thanks.

https://redd.it/1kt0mq1
@r_bash

Help parsing a string in Bash

Hi,

I was hopign that i could get some help on how to parse a string in bash.

I woudl like to take an input string and parse it to two different variables. The first variable is TITLE and the second is TAGS.

The properties of TITLE is that it will always appear before tags and can be made of multiple words. The properties of the TAGS is that they may

For example the most complext input string that I can imagine would be somethign like the following

This is the noscript of the input string +These +are +the +tags

The above input string needs to be parsed into the following two variables

TITLE="This is the noscript of the input string"
TAGS="These are the tags"

Can anyone help?

Thanks

https://redd.it/1kt449m
@r_bash

need for speed

hello everyone,

let me start by saying that I'm not a coder

I wrote the following fetch noscript with scroll effect just for fun:

>https://codeberg.org/ldm/scr0ll



I also published it on r/unixporn, but I received some comments complaining about the speed...

is this problem due to a badly written noscript? or is bash slow? can the noscript be further optimized?

https://redd.it/1ktghg0
@r_bash

Exit Code for CLI Applications

I've been doing a lot of devops and bash lately, and I'm dissatisfied with the lack of standards around exit codes. Yes, there are some sensible standards such as exit codes over 68 and 126 mapping to signal and OS related failures, but what about custom exit codes?

Obviously 0 is everything went well, but how do you handle cases where the noscript ran as predicted (without crashing) but a distinct/warning-like outcome took place, and an exit code should inform the user on the kind of error that came accross.

I say this because 1 is the catch-all "something went wrong", but at the same time that means your successful but noteworthy exit codes are separated from 0 since you set them to 2,3,4...

Is there some solution I'm missing? I'm starting to settle towards:

0 - success

1 - catchall error

2-67 - custom output state, successful execution but important enough that automated noscripts will want to know about it.

Take diff for example: 0 means inputs are the same, 1 if different, 2 if trouble. Well for most other programs, 1 means they shit the bed. So I'm a little confused.

https://redd.it/1kt9n4c
@r_bash

Command to var

Maybe I'm just overly tired.... and the fact that I can't seem to type the right search query so I'm getting nothing.

Suppose I have a stupid long command

git --work-tree=/path/to/work/tree --git-dir=/path/folder

and this command will basically replace the base git command in my noscript. I want to be able to assign that long command and be able to call it.

I'll try to provide an example.

MY_COMMAND=`git --work-tree=/path/to/work/tree --git-dir=/path/folder`

MY_COMMAND commit -m "new commit"
MY_COMMAND push

For some reason, I can't get it to work.

I also tried it as a function, but when I run it, all I get is the git --help menu

my_command() {
    git --work-tree=/path/to/work/tree --git-dir=/path/folder
}

my_command commit -m "new commit"

https://redd.it/1ktrn4g
@r_bash

Check out my custom utility noscripts library

I've made a modular repogh-tsilvs-bashlib of utility function noscripts for bash.

Some of it may be useful for:

- Active Podman users
- Frequent Bash users
- Users daily driving Fedora Silverblue
- Developers versioning their code with Git
- ADB users
- And many more!

Would appreciate your feeedback.

gh-tsilvs-bashlib: https://github.com/tsilvs/bashlib

https://redd.it/1ktv7b7
@r_bash

I need help to be able to capture when Caps Lock is on or off

A while back, I saw a video where they were trying to give Caps Lock more uses, and today it occurred to me that maybe I could open the rofi using `super + Caps_Lock`. I wrote the following quick bash noscript to test my idea, and if I run it from the terminal, it correctly notifies me when it's enabled and when it's not.

```bash
#!/bin/bash

function main() {

(
export DISPLAY=${DISPLAY:-:0}

state=$(xset q | grep "Caps Lock:" | awk '{print $4}')

if [[ "$state" == "on" ]]; then
notify-send "Caps Lock activated"
else
notify-send "Caps Lock deactivated"
fi
)

}

main $@

```

So I added the following rule to my sxhkd configuration to run it:

```bash
super + Caps_Lock
sh ~/Workspace/Playground/caps-lock.sh
```

But when I press super + Caps_Lock, it only takes me to the case where it's enabled, and no key combination takes me to the other case. Do you have any idea what it could be or how I can fix this?

https://redd.it/1kty42l
@r_bash