Is it possible to export a bash function so that it will automatically enable extglob?

I have a bash function that uses some extglob which, if used in a shell with extglob disabled, fails to parse and throws a syntax error.

In the file containing the function source code I include a

shopt -s extglob

before the function is defined so that when the file is sourced extglob is enabled before the function is defined. But, if you export the function you only get the function, not the stuff before it. And any new bash shells will try and source the exported functions on startup.

In practice, this means that if I export my function, any future invocations of `/usr/bin/bash` that dont include `-O extglob` will print an error message to screen. This happens regardless if the bash shell being started is actually calling the exported function. It still runs if that exported function isnt used (since the error is that it cant parse the function), but is annoying nonetheless.

One specific annoyance with this that I use hyperfine to benchmark this function. the way hyperfine bootstraps the shells it runs, you can either use `--shell=bash` and itll use exported functions but wont have extglob, or you can use `--shell='/usr/bin/bash -O extglob'` to get extglob but you lose access to exported functions. You can use the ladder and then source the file defining the function and then run a the function, but then it skews the benchmarking times since you are timing how long it takes to source the function as well as timing the function runtime itself.

***

At any rate, does anyone know a trick so that exported functions that use extglob will parse correctly in a bash shell that doesnt explcitly enable extglob by being spawned via `bash -O extglob [...]`???

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

Formatting and mounting a flash drive via the terminal, not the UI

I'm issuing the following commands to format a 512GB flash drive:

sudo fdisk -l # fetch device ID (/dev/sdc1)

sudo umount /dev/sdc1

sudo mkfs.exfat -n USB-256GB /dev/sdc1

The output from the last command indicates that the flash drive was successfully formatted. How can I mount that device w/o having to select the device in the file explorer? I'd like to accomplish this using only the terminal.

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

argc - Top-tier utility/framework for creating shell noscripts

https://github.com/sigoden/argc

I’m not the author. Whoever it is, they are a bloody legend!

Figured I would share it as it deserves way more love.

https://redd.it/1eqvgj4
@r_bash

How to learn shell noscripting?

I have basic / intermediate knowledge of command line and would like to learn how to use shell noscripting. Are there websites or resources that provide problems that I can try and solve? I am also interested in shell noscripts for HPC so I was wondering what area I should focus on here.

https://redd.it/1erft7a
@r_bash

tmpmail v1.1.5 now supports receiving attachments
https://redd.it/1erzodj
@r_bash

What does - and -- mean in bash?

I've come across noscripts that use - or -- for arguments and it's never really explained what they do. What's it called and what's the usage?

# example using -
curl -fsSL 'some_url/install.sh' | env ENV="${HOME}/.bashrc" bash -

# example using --
command -- arg1 arg2

https://redd.it/1erzyy6
@r_bash

Using read -p to prompt bold variable with ANSI escape codes?

Hi,\
As the noscript, I was wondering if it is possible to do it.\
I've tried 1

var=candy
bold=$(tput bold)
normal=$(tput sgr0)

read -p "IS ${bold}$var${normal} correct? " ans
# assuming answer yes
printf "Your answer is \033[1m%s\033[0m." "$ans"

The output is what I desired, candy and yes are bold.\
I've tried 2

var=candy

read -rep $'Is \033[1m$var\033[0m correct?' ans
printf "Your answer is \033[1m%s\033[0m." "$ans"

It output $var, not candy,\
\
I'd like something similar to second options, that way I can easily make a new line using '\n'. 3\
Is there any better solution? Or better using printf and read separately. Something like

printf "Is \033[1m%s\033[0m correct?" "$var"
read ans
printf "Your answer is \033[1m%s\033[0m." "$ans"

~~I mean read -p is not supported in every shell, maybe it's a good habit to not use -p.~~

https://redd.it/1es3gp5
@r_bash

Configuration in bash?

I have this piece of code in Python:

URLVARIANTS = {
'barstool': {
'baseurl': 'mcepl@shell.eng.rdu.redhat.com:publichtml/',
'targeturl': 'http://file.rdu.redhat.com/~mcepl/',
'shortenapi': 'https://url.corp.redhat.com/new?'
},
'wotan': {
'baseurl': 'wotan:Export/',
'targeturl': 'https://w3.suse.de/~mcepl/'
},
'tmp': {
'baseurl': 'fedorapeople.org:publichtml/tmp/',
'targeturl': 'https://mcepl.fedorapeople.org/tmp/',
# 'shortenapi': 'http://is.gd/create.php?format=simple&url='
'shortenapi': 'https://da.gd/s?url='
}
}

curconf = URLVARIANTSsite

# now I am using curconf['baseurl'] etc.

How to rewrite it in bash? Yes, I know about https://linuxsimply.com/bash-noscripting-tutorial/array/array-of-arrays/ but the whole is so incredibly finicky and crazy, that I haven’t managed to pull it off (could somebody rewrite this example in the pure sh/bash?). The only alternative I could come up with is to make URL_VARIANTS a string contain JSON object, and then to use jq to separate requested values, but that sounds as a potential PITA as well.

Any thoughts?

https://redd.it/1esg0b3
@r_bash

[error] guys i think i broke bash in a way never before seen
https://redd.it/1etq4eu
@r_bash

how do i alias cowsay?

hello, i would like to take the command "cowsay" and alias so every time i type in "endvideo" into the terminal the cowsay command pops up and spits out

"like comment share and subscribe!"

how would i do this?

thank you

https://redd.it/1etti1j
@r_bash

Limit developers from running a command in command line in a project

We have a fresh Cloudflare worker Typenoscript project in which we currently use wrangler deploy --production command to deploy to production worker.

We want to disable using that command locally and enable it only on the CI/CD pipeline (Github Actions). The problem is that Cloudflare doesn't offer any kind of permissions to do that, except fully limitting developers from accessing Cloudflare by deleting their accounts, and obviously we don't want to do that.

Is there a way of using a bash noscript to accomplish this? And have that noscript fully executable for any developer who would have it locally in the project (git commited to the repository)?

I am fairly new to bash, so I'm not even sure I asked the right question, but I'd say you get the jist.

Also we are open to any other ideas to accomplish this.

Thanks

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

Any tricks to not have to escape a quote?

I have a pretty lengthy cURL that looks something like this:

--data '{
"denoscription": "Foo",
"expression": "this is csdude\'s, it has \"this\", \"that\", and \"the other thing\""
}'

The real one is much longer; the longest is about 3800 characters, and there are 5 of them called in the bash noscript.

For the sake of easier coding and minimizing typos, is there a way to NOT have to escape all of the inner quotes?

I tried surrounding it with `, but that just threw an error :-/

https://redd.it/1eu9je9
@r_bash

More fun with jq, getting results into a usable array

I'm using this in a cURL to get the data from `result[]`:

foo=$(curl --request GET \
--silent \
--url https://example.com \
--header 'Content-Type: application/json' | jq -r '.result[]')



When I print $foo, this is what I have:

[key]
default

firewall_custom
zone
34
[
{
"id": "example",
"version": "6",
"action": "block",
"expression": "lorem",
"denoscription": "ipsum",
"last_updated": "2024-08-15T19:10:24.913784Z",
"ref": "example",
"enabled": true
},
{
"id": "example2",
"version": "7",
"action": "block",
"expression": "this",
"denoscription": "that",
"last_updated": "2024-08-15T19:10:24.913784Z",
"ref": "example2",
"enabled": true
}
]



What I need from this is to create a loop where, in a series of addtional cURLs, I can insert action, expression, and denoscription.

I'm imagining that I would push these to 3 separate arrays (action, expression, and denoscription), so that ${action\[0\]} would coincide with ${expression\[0\]} and ${denoscription\[0\]}, and so on.

Something along the lines of:

# assuming that I have somehow created the following arrays:
# action=("block" "block")
# expression=("lorem" "this")
# denoscription=("ipsum" "that")

for x in ${action[@]}; do
bar=$(curl --request GET \
--silent \
--url https://example.com \
--data '{
"action": ${action[$x]},
"expression": ${expression[$x]},
"denoscription": ${denoscription[$x]}
}' | jq '.success')

if [[ $bar == true ]]
then
printf "$x succeeded\n"

else
printf "$x failed\n"
fi

# reset bar
bar=''
done


The question is, how to create action, expression, and denoscription arrays from the results of $foo (that original cURL)?

https://redd.it/1euba4a
@r_bash

Tab-completion for a command name

I have two custom commands: play-music and play-video. I want to write a bash noscript that allows me to autocomplete these commands when I press TAB.

For example:

$ play<TAB>
play-music play-video

$ play-vi<TAB>
play-video

I’ve found a tutorial on creating a bash-completion noscript, but it only works for command arguments. How can I achieve this for the command names themselves?

https://redd.it/1eugy51
@r_bash

what is an "option" in bash? and how is it different the other arguments?

so i understand what an argument is, i understand that an option is a type of argument,

but what i don't understand is how an option is different then other types of arguments

can someone explain it to me?

thank you

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

GitHub - AnonAmosAdmn/OTTO-STACK-DEPLOYER
https://github.com/AnonAmosAdmn/OTTO-STACK-DEPLOYER

https://redd.it/1euwj08
@r_bash

Bashtutor - interactive bash tutorial


I wrote a minimal framework for creating CLI obstacle courses.
Currently there is one "module" which is for Bash itself.
While its a proof of concept, I attempted to make it entertaining and smoothen the edges as much as I could.
The main inspiration was vimtutor and how I would have liked something like this back when I was starting out.

https://github.com/agvxov/bashtutor

I'm hoping it will be useful to someone somewhere.

https://redd.it/1ev6ex5
@r_bash

I have written some helper noscripts to simplify on-demand GNU/Linux proxy configuration
https://gitlab.com/brlin/linux-proxy-configuration-helper

https://redd.it/1ev7j98
@r_bash

Interpolation and sed!

I hope this helps somebody, like it did for myself, last week.

I love this shit. And I am always happy to share/ read contructive critiscism.

I got tasked with a set of instructions, under immense pressure, the other day.

I needed to edit a 20k line file, and was told it needed batching into many, 100 line files, to avoid deadlocking our DB whilst running the finished article. In total, we were deleting millions of duplicate rows, with specific IDs. I also needed to add a comma, at the end of each newline (so far, no sweat). So I did for i in x*; do cat "$i" | tr \\n , >> $i.new;

I then batched that file, into many smaller ones, running split -l 100 FILE.txt. The newly created batched files then had naming conventions like, `xaa.new`, `xab.new` etc.

But, after I had done this, I discovered that I also needed to remove the very last comma in each file. This is so that the syntax is accepted by MySQL. So I did - for i in x*; do sed -e '$s/,$//' "$i" > "$i".new.

Then, here's the interpolation... courtesy of my wise and all-knowing colleague, who just happened to shoot me a message, making sure I was ok. I was stuck on how to run the MySQL statement, using the content in all my files. I was also very nervous, at this point. We ended up writing, for i in x*; do mysql databaseName -vvv -e "DELETE from table where table_id in ($(cat $i))" >> /home/userName/incidentNumber/output.sql after we had tested SELECT statements, echo'ing output (without any MySQL) and had it approved by all stakeholders.

I felt very accomplished, as I always do when I learn something new, and needed a little nudge to get over the line, in the end. But my goodness, it was such a rush! I hope someone finds this useful and/ or interesting. I know I did.

https://redd.it/1evju1s
@r_bash

mirror one GNU Screen session to another?

I'd like to create two screen sessions, then mirror the activity of one to another. So, if I create session_1 in one Terminal window, and create session_2 in another Terminal window, they'd look the exact same if I ran a certain program in session_1. It'd also be nice if detaching session_1 detached session_2 as well.

Is this possible using functionality built into screen, or would if be more complicated? I can't find anything about this online, so I'm guessing it's the latter.

https://redd.it/1evp3t5
@r_bash

Trap not taking effect in POSIX noscript

In this noscript I launch vim opening a temp file in the terminal window. If the terminal window is closed with vim running, the temp file should be deleted. Closing the terminal window should also kill vim process.

However, closing the terminal window doesn't remove the file and the vim process lingers when the terminal window is closed. If I remove the trap command, then the vim process will terminate as expected but the temp file will of course remain.

Any ideas? I have exec sh -c because for some reason without it, vim process lingers when its terminal window closes.

https://redd.it/1evoe9l
@r_bash