Boredom PS1 project

I decided I was going to learn a bit more about the `PS1` prompt. I started out with a nice easy prompt with `\w` on one line and the prompt with a custom user token `𝝅` rather than the stock `$` on the next.

I liked the setup a lot, so I used the same configuration on my home work station and the termux installation on my phone.

The setup worked great until I started running the wrong commands on the wrong system. For good reason, as the prompts were identical, I decided to see if I could setup my prompt to show a different prompt for an ssh connection.

I had a fun time getting that to actually work. I was making it more complicated than it needed to be, but wait there's more. Now when I connect to my ssh server it shows the IP address of the login before last rather than the current login. With a remote login it is kind of useless to see that you just logged in but it is useful to see if someone logged in before you... Just in case you know.

Once I got that working I decided to take it to a whole new level of ridiculous... Solely because why not. I wanted to see what it would take to show in my local terminal that there was an active connection. Next was to make the command search for an active connection on my SSH port, if one was active it ran one prompt and if no connection, another. it took some trial and error to get that running correctly. Once it was running, I found that it would only update when a new terminal session was opened or if I sourced .bashrc. Which in and of itself wasn't that bad but there had to be a way to get that info without sourcing or starting a new terminal session.

After a bit more trial and error and research on the topic i found the answer to getting that info to update after each command. The `PROMPT_COMMAND` setting was what did the trick. By wrapping the whole command into a function i was able to call it in the `PROMPT_COMMAND` which gets evaluated after every command runs.

Now not only will it show an active connection, it will show the last IP to login to that users account. It will also search through a predefined list of known IP addresses and if they match the IP address will be green to denote a known IP and display a custom string so you don't have to look at your own IP addresses. If it returns an unknown IP address it will turn red.

Then to add the finishing touches to this ridiculous project, a red/green light for inactive/active connections respectively, just because I could

I'd like to hear how you all would make it better/different. It was a fun project to learn about the prompt and make sure I used proper escaping. So here is my absolutely, totally, over the top, unnecessary PS1 prompt. Complete with functions and PROMPT\_COMMAND

​

# This will show if there is an active SSH connection after each command is executed.
# Shows second to last login of current user; best used with AllowUsers in sshd_config
psONE_ssh()
{
if [[ "$(last | sed -n '2p' | awk '{ print $3 }')" =~ ("XXX.XXX."*|"XXX.XXX.XXX.XXX"|"XXX.XXX.XXX.XXX"|"XXX.XXX.XXX.XXX") ]]; then
printf %b "\\[\\e[1;32m\\]KNOWN CONNECTION\n"
else
last | sed -n '2p' | awk '{ print $3 }'
fi
}

psONE_local() # Shows the last login from the current user; best used with AllowUsers in sshd_config
{
if [[ "$(lastlog | grep $(whoami) | awk '{ print $3 }')" =~ ("XXX.XXX."*|"XXX.XXX.XXX.XXX"|"XXX.XXX.XXX.XXX"|"XXX.XXX.XXX.XXX") ]]; then
printf %b "\\[\\e[1;32m\\]KNOWN CONNECTION\n"
else
lastlog | grep $(whoami) | awk '{ print $3 }'
fi
}

_prompt_command()
{
if [[ -n $SSH_CLIENT ]]; then
PS1="\\[\\e[1;31m\\]🟢 $(psONE_ssh)\\[\\e[0m\\]\\[\\e[1;33m\\]\n\w/\n\\[\\e[0m\\]\\[\\e[1;31m\\]𝝅 \\[\\e[0m\\]\\[\\e[1;32m\\] "
else
ss -tn src :8222 | grep ESTAB &> /dev/null
if [ $? -ne "1" ]; then
PS1="\\[\\e[1;31m\\]🟢 $(psONE_local)\\[\\e[1;33m\\]\n\w/\n\\[\\e[0m\\]\\[\\e[1;31m\\]𝝅\\[\\e[0m\\]\\[\\e[1;32m\\] "
else
PS1="\\[\\e[1;31m\\]🔴

$(psONE_local)\\[\\e[1;33m\\]\n\w/\n\\[\\e[0m\\]\\[\\e[1;31m\\]𝝅\\[\\e[0m\\]\\[\\e[1;32m\\] "
}
# This will show if there is an active SSH connection after each command is executed.


PROMPT_COMMAND="_prompt_command; history -n; history -w; history -c; history -r; $PROMPT_COMMAND"

I know this is total overkill but it was fun.

https://redd.it/10kyw1i
@r_bash

Bash noscript says file not found even though the filename is the noscript itself
https://redd.it/10lpwi9
@r_bash

The Ultimate Coding Pal (AI-Powered)

Hey fellas 👋

I wrote CodePal.ai \- A free AI-powered service that provides many coding tools for coders and non-coders to make their life easier. It can code, review code, simplify code, find bugs,, and many more cool features.

My mission is to make coding easier, more accessible and fun for coders and non-coders.

I use this myself to perfect my code pretty often and I find it handy in many cases.

I've put many hours into this and would love to hear your feedback on it ❤️

Thank you!

https://redd.it/10ltuyv
@r_bash

Books or Websites to learn Bash noscripting

Hi I am newbie to Linux, I would like to learn Bash noscripting


Please suggest me some good resources.

https://redd.it/10ltudi
@r_bash

stail.sh - Short Tail

This is a fairly short (59 LOC) utility noscript that allows you to tail the output of a command, but while only showing the last -n (default 5) lines of output without scrolling the output buffer. It will trim lines to the terminal width (rather than wrap them) to avoid splitting terminal escape sequences. You can also optionally -p PREFIX each line of output. Finally, it (by default) removes blank/whitespaces lines, but they can be preserved with -w.

Video here.

https://reddit.com/link/10m102l/video/0y2nzxf22gea1/player

Code on GitHub Gist.

https://redd.it/10m102l
@r_bash

Read won't take any userinput except one

https://redd.it/10m4ave
@r_bash

Bash oneliner

What is your favourite bash oneliner?

https://redd.it/10m7pml
@r_bash

shell...???

What is the website I'm thinking of!!!??? We use it all the time for bash noscripting, and I can not figure it outt. I'm pretty sure it's shell something, but nothing so far sounds right. Can anyone help me or at least explain what this is doing, I get the general idea, but I'm curious how it helps make noscripts ready for reddit.

echo ; sed 's/^/ /' noscript.sh

https://redd.it/10mepie
@r_bash

Help with a scheduled (cron) bash noscript

Hi everyone, I’m new to this sub so I apologize in advance for any mistakes.

I created a noscript that checks if a python application is running and if not starts it. This is what it looks like:

#!/bin/bash
if pgrep -x "python3.10" > /dev/null
then
echo "Application is running."
else
source dev/bin/activate
cd dev
nohup python3.10 main.py > output.log 2>&1 &
echo "Application restarted."
fi`

This code works perfectly fine when I run it from the terminal, however, when I try to run it using cron I get the correct output but main.py doesn’t actually start.

I’m not sure what I’m doing wrong. Any help would be appreciated!

https://redd.it/10mjh9x
@r_bash

Interesting bash malware
https://www.trendmicro.com/en_gb/research/21/f/bash-ransomware-darkradiation-targets-red-hat--and-debian-based-linux-distributions.html

https://redd.it/10mmz8r
@r_bash

Bashkit V1

The first public release of BashkitV1 is now available with the URL

https://bashkit.wuage.io

and from the main branch of the Bashkit git repository

(https://github.com/Wuageorg/bashkit).

Bashkit is the Wuage’s shell noscripting framework. It is a collection of pure bash functions along with a lightweight noscripting model that, we believe, remediate some of the Bash quirks.

Out of the box, It supports advanced yet classical logging (including NDJSON), fail fast noscripting pattern (less to none `set -e` side effects), coloured outputs and more. It can easily be extended by adding modules to accommodate various use cases.

For more information on the features of Bashkit that are new to this type of shell noscripts, see the file `doc/manual.pdf’. There is also Unix-style man pages for every released function. The man pages are the definitive denoscriptions of the framework’s features.

The framework is released under APACHE LICENSE, VERSION 2.0.

The release tar file includes the formatted documentation (pdf).

Please use https://github.com/Wuageorg/bashkit/issues to report bugs with this version. It complements at least bash 5.x and can not be used without.

Happy noscripting!

The Wuage Team

Jan. 2023

https://redd.it/10moz5g
@r_bash

Echo commands IN variable

How would I place echo commands inside a variable? I am attempting to send an email with postfix under certain circumstances. For example:

OUTPUT=$(MP4Box -info $INPUTFILE 2>&1)
HTML="<pre style=\"white-space: pre-wrap; word-break: keep-all; background-color: whitesmoke;\"><code>${OUTPUT}</code></pre>"

if [[ $(MP4Box -info $INPUTFILE 2>&1) =~ "Incomplete" ]];
then
(
echo "From: from@email.com";
echo "To: send@email.com";
echo "Subject: Transfer Interrupted";
echo "Content-Type: text/html";
echo "MIME-Version: 1.0";
echo "";
echo -e "The mp4 transfer was interrupted and did not complete." \
"The output is as follows:\n\n" \
"${HTML}"
) | sendmail -t
elif [ $(MP4Box -info $INPUT_FILE 2>&1) =~ "Movie Info" ];
then
(
echo "From: from@email.com";
echo "To: send@email.com";
echo "Subject: Transfer complete.";
echo "Content-Type: text/html";
echo "MIME-Version: 1.0";
echo "";
echo -e "The mp4 transfer is complete." \
"The output is as follows:\n\n" \
"${HTML}"
) | sendmail -t
else
(
echo "From: from@email.com";
echo "To: send@email.com";
echo "Subject: Check on Transfer.";
echo "Content-Type: text/html";
echo "MIME-Version: 1.0";
echo "";
echo -e "Something could be wrong. Manually check the mp4." \
"The output is as follows:\n\n" \
"${HTML}"
) | sendmail -t
fi

I would like to simplify this with variables. When I try, I get the postfix error No recipient addresses found in message header. For example:

OUTPUT=$(MP4Box -info $INPUTFILE 2>&1)
HTML="<pre style=\"white-space: pre-wrap; word-break: keep-all; background-color: whitesmoke;\"><code>${OUTPUT}</code></pre>"
EMAILHEADER=$(echo "From: from@email.com";
echo "To: send@email.com";
echo "Subject: ${SUBJECT}";
echo "Content-Type: text/html";
echo "MIME-Version: 1.0";
echo "";)

if [[ $(MP4Box -info $INPUTFILE 2>&1) =~ "Incomplete" ]];
then
(
$EMAILHEADER
echo -e "The mp4 transfer was interrupted and did not complete." \
"The output is as follows:\n\n" \
"${HTML}"
) | sendmail -t
elif [ $(MP4Box -info $INPUT_FILE 2>&1) =~ "Movie Info" ];
then
(
$EMAILHEADER
echo -e "The mp4 transfer is complete." \
"The output is as follows:\n\n" \
"${HTML}"
) | sendmail -t
else
(
$EMAILHEADER
echo -e "Something could be wrong. Manually check the mp4." \
"The output is as follows:\n\n" \
"${HTML}"
) | sendmail -t
fi

I know I still have to define $SUBJECT and will get to that, but I at least want to get the basics of this working first.

I have one additional question... how can I break up the HTML= line (within the noscript)? It's long and I want to make it two lines to make the noscript more readable. So instead of:

HTML="<pre style=\"white-space: pre-wrap; word-break: keep-all; background-color: whitesmoke;\"><code>${OUTPUT}</code></pre>"

I want something like:

HTML="<pre style=\"white-space: pre-wrap; word-break: keep-all;" \
"background-color: whitesmoke;\"><code>${OUTPUT}</code></pre>"

But this fails for me (doesn't print out in the email).

https://redd.it/10mwah8
@r_bash

cannot run a noscript in /app directory

Trying to run a bash noscript. when i save it in my home, it can run just fine but when I move the noscript to a /app location, the noscript does not run. All permissions are ok but when i run the noscript, it does not run and also does not return an error. I also noticed that the color code I have in the noscript in my home is not appearing in when i have a noscript in the /app location. please help if you have any idea what the issue is here.

https://redd.it/10mvsvh
@r_bash

text editor in bash!

https://github.com/Agb43/text-editor.git

&#x200B;

I decided to write a terminal based text editor in bash for fun. Considering that i've never taken a coding class in my life, i'm pretty proud of it, even if inserting whitespace via blank echos is incredibly bad im sure.

https://redd.it/10n6u6m
@r_bash

Changing placeholder denoscription via sed

Hi! As an input for sed program I have smth like this: {bool some flag denoscription} (it's a part of an input string to be more precise) where:

- bool is a placeholder type
- some flag denoscription is it's denoscription

How do I replace all such placeholders to this {{some_flag_denoscription}}? I don't know how to replace spaces between 3 denoscription words with underscores. What sed technique should I use? I wanna transform some flag denoscription in a such way not to broke the whole placeholder. Another difficulty is that this placeholder can appear in any place in a command invocation example like some_executable --dark {bool whether to enable dark more} --colorize {bool whether to colorize files}. I need to know how to do this to fix my noscript.

https://redd.it/10nblyy
@r_bash

Beginner having trouble using variables as literal strings

Hello,

I'm new to Bash, and I've been hammering my way through issues with the help of ChatGPT, but it's running me in circles on this one.

I'm using Curl to make a request to Pushover's API. Many of the options that I call Curl with are exactly the same, so I thought that I'd put them in a variable to make things easier. I know that In an actual request, I would have to include more options, but I wanted to trim this example down.



po_token="ExampleToken"
po_user="ExampleUserKey"
curl_ops='-s -o "/dev/null" --connect-timeout "5" --retry "6" --retry-delay "600" -F "token=$po_token" -F "user=$po_user" "https://api.pushover.net/1/messages.json"'
curl $curl_ops



It seems that everything in my "curl_ops" variable is being passed as a single argument instead of a literal string, and I'm certain it has to do with my usage of quotes, but I have no idea how to fix it. The only noscripting language that I'm familiar with is AutoIt, and Bash seems to handle this kind of thing very differently. I was hoping someone here may have some suggestions.

Thanks

https://redd.it/10nbdv5
@r_bash

how to supress this

hi

im using psexec example PSEXEC \\\\workstation64 x:\\runme.bat


noscripts runs fine how ever i want to supress the displaying of the exit code here is the output

at exited on srv1 with error code 0.

https://redd.it/10nl7yc
@r_bash