Best practices for noscripting in the command line?

Say I entering something simple

for i in {1..5}; do
> echo $i
> done

When I press the up arrow, it will show this for i in {1..5}; do echo $i; done. Not too difficult to read.

Now if we have a more complicated example with embedded for loops, cases, etc, I wouldn't be able to understand the code that is a singleline. Code with indents and linebreaks are much easier to debug, so if you had to enter long and complicated code into the commandline and had to modify it again by pressing the up arrow, how would you understand it? Is it possible to have the indents and the newlines it was originally entered with when we press the up arrow? I know we should enter our noscripts through Vim but sometimes for onetime things, I enter directly onto the command line.

https://redd.it/17492ek
@r_bash

Flacky "here documents"

"here documents" are really good and it saves you from having to repeat a lot of echo or printf statements. They are also very simple, nothing complicated about them.

On Ubuntu bash they are a hit and miss if they work. Often the the runtime interpreter gets confused. Problems don't seem to be related to contents, even with plain text the sometimes may not work

I've been using them like this for a long time on in Korn, in Bash they should be the same. Any ideas why?

cat << msgend
This message was written on $(date) about when I $(touch this).
But its not as bad as last Tuesday.
msgend

&#x200B;

&#x200B;

&#x200B;

&#x200B;

https://redd.it/174b9ka
@r_bash

play - TUI playground for your favorite programs, such as grep, sed and awk
https://redd.it/174rsd6
@r_bash

Help Moving files in a directory (SCRIPT)

Hey y'all, im trying to learn Bash noscripting and figured i'd start with something that will be useful to me.

Objective: Allow users (me) to be able to select which source + destination to move files from and to. The goal is to be able to run the noscript and move everything in my downloads folder to wherever i may want it. But i also want to be able to do this with any directory.

&#x200B;

#!/bin/bash
echo Can you show me where the source directory is?
read source

echo $source is the source directory. What is the Destination directory?
read dest

cd $(echo $source)
ls
pwd

mv -v $dest


If i replace $dest with the file path instead of using the variable created by "read" then it works flawlessly. I tried to add $HOME as a prefix to $data but that wasn't working.

&#x200B;

mv -v ~/Documents

Any tips would be greatly appreciated as i am new to noscripting and fairly new to linux. TIA

https://redd.it/174zmfv
@r_bash

Does going through the entire noscript just to find the help function slow down noscript?

My noscript looks like this

Help function
All the other functions

My reasoning is that if the user just wants to use the -h flag then the noscript shouldn't pass through all the main functions which aren't going to be used. But having the help function at the beginning looks ugly in my noscript so I want to move it down. But then the noscript (I think) would have to read through all the main functions which aren't going to be used which would slow down the noscript.

&#x200B;

https://redd.it/1753fda
@r_bash

ssh user maker

Guys, I’ve created a bash noscript for creating ssh users on server with expire date,and speed limit, would be happy if you check it out and tell me your feedbacks, feel free to commit to it and if it have any problems please let me know.

Btw README file was generated by ChatGPT.

https://github.com/momalekiii/sshmaker

https://redd.it/175gqvy
@r_bash

[Help] tput setab colors stretch to terminal width on term scroll. (noscript in comments)
https://redd.it/175m914
@r_bash

Building options from array. What am I doing wrong?

I am trying to find a range of files, but I want to be able to keep the extensions in an array. I try to echo the final find command and it echos correctly, but if I try run it, I just get a null result. Copy and pasting the echoed command returns a result.


#!/bin/bash

extarray=( "3gp" "mp4" "mkv" "m4a" "webm" "mpg" "mpeg" "avi" "vob" "asf" "wmf" )

for ((n=0; n<${#extarray@}; n++))
do
if [ $n == "0" ]
then
optiname="-iname \".${extarray[$n]}\""
else
temp=$optiname
optiname="$temp -o -iname \".${extarray$n}\""
fi
done

echo "find . -type f \( $optiname \) | sort"

find . -type f \( "$optiname" \)

&#x200B;

https://redd.it/1760ifx
@r_bash

Struggles of a noscripting noob

I decided to use a Windows subsystem for Linux, install Debian and play around with bash noscripting.

I have to say it has been somewhat frustrating. As a first attempt at something somewhat useful I decided to make a command function to start a new noscript.

I learned that functions don't even need a type declaration. you don't need to put the word function in the code for it to become a function.

I learned there is no one proper syntax for an if structure. There are multiple acceptable sysntaxes, but sometimes a space or lack of a space in the wrong place is fatal, while whether you use parens or square brackets might not matter.

Here is what I ended up sticking in the end of my .bashrc file:

function mbs { # command to make a new noscript

FILE=$1

echo $FILE

if [ $# -gt 0 \]

then

echo "%! /bin/bash" > $FILE

chmod u+x $FILE

echo "# $FILE" >> $FILE

nano $FILE

&#x200B;

else echo "You need to supply a filename."

&#x200B;

fi

}

The first improvement IMO would be to make sure it does not overwrite an existing file, but at least this is doing what I asked it to.

The reason for this post is just to express some surprise that the syntax of this language is important in some ways and not important in others. :D

https://redd.it/1769ezz
@r_bash

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https://discord.gg/unixverse

https://redd.it/176aqrh
@r_bash

Help with creating a bash code to compare two different files

Hello, everyone!

I'm currently encountering some challenges while working on a bash noscript in the Linux terminal to perform the following tasks:

1. Compare the values in the third column of two different files line by line.

2. If the values are different, save in a third output file the identifier from the second column of the input files, along with the corresponding values from both File 1 and File 2, similar to the "desired first output" example provided.

3. Additionally, create a fourth output file to tally the occurrences of each unique qualitative difference, taking into account the order (for example: 9690 0 ≠ 0 9690) while disregarding the identifier. This is illustrated in the "desired last output" example.

Any assistance or guidance in achieving this is greatly appreciated!

FILE 1

U E100033877L1C016R01601996031 0 140 0:106

U E100033877L1C023R03303214633 0 140 0:106

C E100033877L1C022R01901579971 27996 140 27996:1 0:7 27996:23 0:75

C E100033877L1C023R02603225407 27996 140 0:32 27996:23 0:7 27996:1 0:3 27996:4 0:36

C E100033877L1C020R02602000209 0 140 0:106

C E100033877L1C023R03303214633 27996 140 27996:3 0:4 27996:5 0:94

C E100033877L1C023R03101740491 9690 140 9690:13 0:8 9690:7 0:13 9690:9 0:56

C E100033877L1C006R00200498634 9690 140 9690:71 0:35

C E100033877L1C009R03603066069 27996 140 0:50 27996:2 0:1 27996:10 0:6 27996:11 0:26

C E100033877L1C005R03300436825 27996 140 27996:3 0:6 27996:3 0:3 27996:5 0:86

FILE2

U E100033877L1C016R01601996031 0 140 0:106

U E100033877L1C023R03303214633 0 140 0:106

C E100033877L1C022R01901579971 27996 140 27996:1 0:7 27996:23 0:75

C E100033877L1C023R02603225407 27996 140 0:32 27996:23 0:7 27996:1 0:3 27996:4 0:36

C E100033877L1C020R02602000209 27996 140 0:19 27996:4 0:3 27996:1 0:7 27996:23 0:49

C E100033877L1C023R03303214633 27996 140 27996:3 0:4 27996:5 0:94

U E100033877L1C023R03101740491 0 140 0:106

U E100033877L1C006R00200498634 0 140 4840:106

C E100033877L1C009R03603066069 4840 140 0:50 27996:2 0:1 27996:10 0:6 27996:11 0:26

C E100033877L1C005R03300436825 27996 140 27996:3 0:6 27996:3 0:3 27996:5 0:86

DESIRED FIRST OUTPUT

E100033877L1C020R02602000209 0 27996

E100033877L1C023R03101740491 9690 0

E100033877L1C006R00200498634 9690 0

E100033877L1C009R03603066069 27996 4840

DISIRED LAST OUTPUT

2 9690 0

1 0 27996

1 27996 4840

https://redd.it/176pcqr
@r_bash

Best way setting arguments to noscript that is not able to read from the environment

Hello. I am working with a noscript that is not able to read variables from the environment and that I am not able to modify.

printenv
# a=123 b=234 c=345

# Script expects the variable content in arguments
./noscript para=123 parb=234 parc=345

What is the best way to handle a situation like this?

https://redd.it/176utr4
@r_bash

Help... I got confused by the bash statement(while, if...)

Hello everyone, I have used bash since last year and was amazed by its powerful features, but I only treated it as a prompt that makes doing things faster then......

Until this month I started to learn bash noscripting and started to get confused by some of its logic... for example the noscript below, I still did not get it...

https://preview.redd.it/pv61mddgpytb1.png?width=947&format=png&auto=webp&s=6e807609771071c9d52af5178f0262d6a7a8d113

(1) If originally the battery was greater than 30, when battery was becoming lower than 30 , it did not quit the loop and did not showing the message either.

(2) If it was lower than 30 when I ran this program, it will show up the warning message and quit the loop.

&#x200B;

I've searched for some information on the internet saying that "if [ \]" and "if " different, but I'm still not clear about the concept...

I will be appreciate if someone can explain it to me...thanks

https://redd.it/176xs3b
@r_bash

How can I arrange this messy output in neater columns?
https://redd.it/17730bf
@r_bash

Job command help, not showing up
https://redd.it/1777589
@r_bash

Cant create a nested shells in bash beyond the Child shell using coproc command and process list

Suppose I run this command: coproc nested { sleep 10; } it executes sleep command within a childshell as expected. The process tree look like this when I run ps T --forest command.


PID TTY STAT TIME COMMAND
40305 pts/0 Ss 0:00 bash
46922 pts/0 S 0:00 _ bash
46923 pts/0 S 0:00 | _ sleep 10
46924 pts/0 R+ 0:00 _ ps T --forest



Ok no problem, its exactly what I expected. But then, when i run the command like this: coproc nested { (sleep 10); }, the process tree looks the same when I run ps T --forest command.

PID TTY STAT TIME COMMAND
40305 pts/0 Ss 0:00 bash
47064 pts/0 S 0:00 _ bash
47065 pts/0 S 0:00 | _ sleep 10
47066 pts/0 R+ 0:00 _ ps T --forest

Note that, here, (sleep 10) is a process list and it automatically should create a subshell to run the command sleep 10.

So, what I was expecting was a process tree like this:

bash
_ bash
| _bash
| _ sleep 10
_ps T --forest

https://redd.it/177sgyg
@r_bash

setting a variable inside of a variable for loop

I pretty much have

x=0
myvar=$(for f in blah blah blah
do
printf stuff
x=$((x+1))
done
)

x is still equal to 0 at the end

If this is impossible then I need another way to count interations of this for loop

https://redd.it/1784yqa
@r_bash

Input two characters and proceed

>VALUE=`zenity --entry --text="1-60"`

I have to enter two characters and then press enter. Is there an easy way to automatically complete the dialog after entering two characters?

https://redd.it/178ga2j
@r_bash

TMUX plugin for MacOS for playing Spotify playlists🌱
https://github.com/danjeltahko/spotify-tmux

https://redd.it/178jplg
@r_bash

function using unupdated information

this noscript is very long so I'll show the main idea

I orginally have a "$file" in "$mydir"

Then my noscript does this

function1 () {
for f in "$mydir"/*
do
printf "$f"
done
}


function2 () {
mv "$file" /tmp
function1
}

But when function1 is called, "$f" is still being printed even though it is no longer there.

I am using set -x to debug. The noscript works as expected. The file is moved to /tmp and no longer in "$mydir". I am also monitoring the directory using "ls" in realtime and again, it works as expected. When function 2 is called myfile is already gone from the directory so it should not be appearing there. But it is.

https://redd.it/178klt5
@r_bash

Every 4 minutes, backup to git and if there are changes, increment commit version number and post to twitter.

crontab -e

> */4 * * * * /var/www/html/./updater.sh


updater.sh

#!/bin/bash

subsubversion=$(cat /var/www/html/.subsubversion);

cd /var/www/html;

git add *
git commit -m "v1.2.$subsubversion"

if ! [ "$(git push 2>&1)" = "Everything up-to-date" ]; then
((subsubversion++))
echo $subsubversion > /var/www/html/.subsubversion
./tweet.sh $subsubversion
fi

.subsubversion
> 0

tweet.sh

#!/bin/bash
source .twitterkeys
urlencode () {
[ -n "$1" ] \
&& echo -n "$1" | perl -p -e 's/([^A-Za-z0-9-._~])/sprintf("%%%02X", ord($1))/seg'
}

signature_method='HMAC-SHA1'
timestamp=$(date +%s)
nonce=$(md5sum <<< "$RANDOM-$(date +%s.%N)" | cut -d' ' -f 1)

url="https://api.twitter.com/2/tweets"
encodedURL=$(urlencode $url)
PARAM=$(urlencode "oauth_consumer_key=$consumer_key&oauth_nonce=$nonce&oauth_signature_method=$signature_method&oauth_timestamp=$timestamp&oauth_token=$token&oauth_version=1.0")
signature=$(echo -n 'POST&'$encodedURL'&'$PARAM|openssl dgst -sha1 -binary -hmac "$consumer_secret&$token_secret" |base64)
encoded_signature=$(urlencode $signature)

data="lockedon.life\nv.1.2."$1" is live!"
echo $data
curl -v -X POST \
$url \
-H "Authorization: OAuth oauth_consumer_key=\"$consumer_key\",oauth_token=\"$token\",oauth_signature_method=\"$signature_method\",oauth_timestamp=\"$timestamp\",oauth_nonce=\"$nonce\",oauth_version=\"1.0\",oauth_signature=\"$encoded_signature\"" \
-H 'Content-Type: application/json' \
-H 'cache-control: no-cache' \
-d '{ "text" : "'"$data"'" } '

.twitterkeys

consumer_key="oSCP6sG3cxxxxxxxxxxxxxxxx"
consumer_secret="IPLhdABBjmJkoB0Swl9QxaJQ6fUQAqZqe2xxxxxxxxxxxxxxx"
token="1467985006530162690-qQG1dKMIZab504xxxxxxxxxxxxxxxx"
token_secret="40QZ6wql6TzCuXdMmvd9e1tubXjXsxxxxxxxxxxxxxxxx"

https://redd.it/178w823
@r_bash