I used #!/bin/bash to say happy birthday to my mate...

Hi everyone...

My name is Ze'ev and I am a proper noscript bunny. If I can't noscript it I don't want to do it. Obviously that means BASH and I have a very very close relationship. I use it for everything.

So, it's my mate's birthday today, and he has recently become very interested in BASH, when I showed him how 38 lines can solve a problem they were having at work, that they had been spending weeks on using C#. He was blown away, and now wants to learn BASH.

So I figured, what would be the coolest way to say happy birthday then? Using BASH of course...

I whipped up a small noscript for him this morning, wrote my message out in a text file, then used OBS to record it. BEST BIRTHDAY WISH EVER!!!

#!/bin/bash
declare a=""
while read string
do
for ((i=0; i<=${#string}; i++))
do
a=$( shuf -i 1-5 -n 1 )
mpg123 -q $a.mp3
printf '%s' "${string:$i:1}"
sleep 0.$(( (RANDOM % 5) + 1 ))
done
sleep 0.8
mpg123 -q 0.mp3
echo ""
done < typeit.txt

&#x200B;

https://reddit.com/link/w0anz5/video/ibfdxsz1rvb91/player

https://youtube.com/watch?v=Z3npE5Orqs0&feature=share

https://redd.it/w0anz5
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> Input Redirect. Can someone help me understand it?

I originally posted this in r/linuxquestions. Realized this may be the better place for it.

I am trying to get very familiar with bash and the only thing that stumps me, on the topic on redirection, is < input redirection. I'm not understanding how it works really or how to utilize it. I have looked at tutorial after tutorial and its still not clicking.

Can someone give examples of how they typically use it? Perhaps, good examples to really showcase its uses and potential.

\> output redirection is easy, makes sense. but for some reason the input part really throws me off.

https://redd.it/w0pa88
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my first ever bash noscript is completed only took 4 hours because im stupid
https://redd.it/w1klky
@r_bash

If I know that my noscript is a bash noscript, is there any reason to use ./noscript.sh instead of bash noscript.sh?

Just realised I still have this very basic question.

./noscript.sh runs into several permission problems with execution & requires I put a shebang in the noscript.

bash noscript.sh doesn't need permissions & doesn't need me to put a shebang.

Is there any reason I should still use ./noscript.sh? Thanks!

https://redd.it/w2kpu7
@r_bash

Centering dynamic text

The below code will sort and format a multi-line string into 2 to 4 columns depending on the size of the screen top left justify leaving a lot of space to the right and bottom.

Is it possible to center it both vertically and horizontally using just built-in linux commands?

clear; echo "$all_denoscriptions" | sort -u | column

https://redd.it/w2yad9
@r_bash

Do You Prefer Backticks () or Parentheses ($()) For Command Substitution

The following two lines of code do the exact same thing:

var=`head -1 file`
var=$(head -1 file)

Which version do you prefer?
I think that backticks look nicer and cleaner but most people use parentheses.
I know that you need to escape nested backticks, so what about using parantheses in that case but backticks otherwise?
Also, there is an insignificant functional difference:

`# user` echo "`echo \"test\" `"
test
`# user` echo "$(echo \"test\" )"
"test"

https://redd.it/w3jqlz
@r_bash

Trying to pipe output of one program into grep but I can't get it right

xflux outputs this:

> Welcome to xflux (f.lux for X)
This will only work if you're running X on console. Found 1 screen.
Your location (lat, long) is -180.0, 35.0. Your night-time color temperature is 3400.
It's night time. Your screen is changing now.
Going to background: 'kill 30031' to turn off

The only important part is the kill process-ID. I want to copy it to an executable file so I can stop the program easily. Just using > for redirection makes it a stream file which cannot be executed even after using chmod +x. Sadly xflux doesn't just have a flag to stop the program built in.

Here's what I tried running:

> xflux -g 35.0 | grep -e "^kill \d+$" > StopFlux

^ means beginning ofa string, \d means a digit, + means one or more of the preceeding, and $ means end of string if I did it right

https://redd.it/w47l61
@r_bash

grep -P vs grep -E vs grep -G

Hello guys!

I did read this post:

https://superuser.com/questions/269803/which-regular-expression-standard-is-used-in-grep

about grep and regex, but I got a noob question, what is the best choice for a general purpose? I remember oftentimes, I had to use \\( \\) \\{ \\} etc... because basic grep does not support meta chars (If I'm not wrong) I started to use grep -P {pattern} and is very comfortable, is that okay? In your experience, what is the best choice?

https://redd.it/w5ige9
@r_bash

Manipulating images & PDFs using CLI commands
https://kau.sh/blog/terminal-cli-image-pdf-conversion/

https://redd.it/w5mafo
@r_bash

Store jquery value as variable in Bash noscript?

So I currently am attempting to create a bash noscript which stores the value of a jquery item and outputs it to a variable. What I am a bit confused about is how to do this. I am currently doing the following:


#!/bin/bash

#Initial Curl Request

GETREQUEST=$(curl --request GET \
--- url https://...... \
--- header '.......... \
--- header '.......... \

#Get value of json response

echo $GETREQUEST | jq -r '.initial.value'

#Store Value as new variable
Value=$(jq -r '.initial.value')

echo $Value



Now the issue I believe here is when I echo $Value I get nothing because I believe that the new variable is not actually storing anything, am I trying to get this value incorrectly using the jquery?


Whereas with the echo of $GET_REQUEST I actually get the variable because it picks it out of the json response. Is there a way to maybe get that value and then store it as a variable then?


Let me know if any clarification is needed!

https://redd.it/w7l4xi
@r_bash

libby: a simple CLI tool to quickly download books from libgen (Library Genesis)

libby scrapes Library Genesis with curl and pup and gives you a list of downloads with fzf. I made this because I felt the alternatives were too slow. Feel free to add issues/feature requests/PRs!

The tool is available on the AUR as libby-git.

Demo

GitHub

Source

https://redd.it/w6rxrk
@r_bash

A shell (bash) puzzle. Don't cheat - try yourself before viewing my answers.
https://dmd.3e.org/a-shell-puzzle/

https://redd.it/w83k8u
@r_bash

Why Does No One Use Inline Comments

In C, there are two ways of writing comments:

// Regular comment
/* Inline comment */

I always preferred the second type of comment because it allows you to make inline comments.
I know a lot of programmers who agree with this.
bash also has two ways of writing comments:

# Regular comment
`# Inline comment`

But I have never seen anyone ever use this.
I wonder why.
Is it not portable to every other shell?
I like to use it because it has a beginning and an end.
Are there any downsides to bash's inline comments?

https://redd.it/w8dy8d
@r_bash

Script with arguments with spaces in it.

Hello people...I have a situation that is driving me crazy and I can't solve it. I have a noscript with a function that takes 4 arguments (paths and names of a file) from a text file (I could do it with 3, but I got used to all 4).

It works great when there is no space in the file/folder name, but the moment the space appears, I think what it does is take the next word as a newline and unset everything.

This is the part of the noscript:

#!/bin/bash

driveplex="Plex:Plex/Peliculas"
drivertorrent="rtorrent:rtorrent"
localdostb=$"/home/user/2tb"

func () {
hora=$(date +'%T')
localmoviepath=$(cut -d '/' -f1-7 <<< "${1/\/data\/Plex/$localdostb\/archivos}")
plexmoviepath=$(cut -d '/' -f1-3 <<< "${1/\/data\/Plex\/Peliculas/$driveplex}")
filename=$2
localsourcepath="${3/\/data/$localdostb}"
rtorrentsourcepath="${3/\/data\/transmission/$drivertorrent}"
rtorrentsourcefolder="${4/\/data\/transmission/$drivertorrent}"
localsourcefolder="${4/\/data/$localdostb}"
archivo="$localsourcefolder/$filename"

echo -e "localmoviepath: $localmoviepath
filename: $filename
localsourcepath: $localsourcepath
rtorrentsourcepath: $rtorrentsourcepath
rtorrentsourcefolder: $rtorrentsourcefolder
plexmoviepath: $plexmoviepath" >> /home/user/log.log
}


func "${1}" "${2}" "${3}" "${4}"

This is the input example:

/data/Plex/Peliculas/Divergent.(2014)/Divergent 2014 1080p BluRay DTS-HDMA 7.1 x264-RUXi.mkv
Divergent 2014 1080p BluRay DTS-HDMA 7.1 x264-RUXi.mkv
/data/transmission/radarr/Divergent 2014 1080p BluRay DTS-HDMA 7.1 x264-RUXi.mkv
/data/transmission/radarr

This is how i pass the file:

noscriptname $(<textfile)

This is what it returns:

localmoviepath: /home/user/2tb/archivos/Peliculas/Divergent.(2014)
filename: 2014
localsourcepath: 1080p
rtorrentsourcepath: 1080p
rtorrentsourcefolder: BluRay
plexmoviepath: Plex:Plex/Peliculas/Divergent.(2014)

This is what it returns if there are no spaces:

localmoviepath: /home/user/2tb/archivos/Peliculas/Divergent.(2014)
filename: Divergent.2014.1080p.BluRay.DTS-HDMA.7.1.x264-RUXi.mkv
localsourcepath: /home/user/2tb/transmission/radarr/Divergent.2014.1080p.BluRay.DTS-HDMA.7.1.x264-RUXi.mkv
rtorrentsourcepath: rtorrent:rtorrent/radarr/Divergent.2014.1080p.BluRay.DTS-HDMA.7.1.x264-RUXi.mkv
rtorrentsourcefolder: rtorrent:rtorrent/radarr
plexmoviepath: Plex:Plex/Peliculas/Divergent.(2014)

I've tried enclosing variables in quotes, in curly braces, tried escaping spaces with backslashes, even tried passing quoted arguments from the file directly, but still get the same behavior.

If you could give me a guide, I would really appreciate it.

Thanks!

https://redd.it/wapmlk
@r_bash

Better completion for bash?

Using zsh I like mostly the interactive auto-complete features: In zsh basically an interactive list of completions is shown, that can be navigated with the cursor keys or TAB, but first it completes to the longest beginning-of-a-completion, that matches the current input. This is basically a powerful combination of the default completion and bind 'TAB:menu-complete'.

&#x200B;

Path completion in zsh

Is it possible to obtain the same behavior for bash?

https://redd.it/wb37jw
@r_bash

Bash noscript to run a Python program in background

Hello,

I'm trying to write a bash wrapper noscript (in Linux) to run a python program in background, allowing the user to logout keeping the noscript running. I'm trying to do it with `nohup`. I'm also trying to support a proper `'` escape to support space in the arguments (see below).

My goal is that the bash noscript works like a bash command, passing to the python code all the command line arguments entered by the user.

Here is how I run the python code, without going to background:

$ python3 /noscripts/pyprog.py --arg1='argument 1','argument 2','argument 3' --arg2='argument 4','argument 5'

I did something like:

#!/bin/bash

NOHUP=$(which nohup)

ARGS=($*)

exec "${NOHUP} python3 /noscripts/pyprog.py ${ARGS[@]} &"

However, bash tells it cannot run that `exec` line. I'm clearly missing some point :-) I would very much appreciate any help.

Thanks!

https://redd.it/wdh3xk
@r_bash

Get the keyboard layout in bash

I started doing some noscripting, but I need to get the current keyboard layout. I use 3 keyboards: Russian, Portuguese and English (Colemak). I already have them mapped to alt space, but I can't seem to get the current layout. I am using DWM as my window manager. Void is my distro.

https://redd.it/wf4hty
@r_bash

Determine if the term/console supports UTF8?

I'm trying to automatically determine if a terminal supports UTF8 is order to pick the appropriate characters (i.e. using ASCII instead of UTF8).

The UTF8 increases readability, but on terms that don't support it it causes a mess and harms readability.

Right now I have a switch for picking utf8 or ascii, but I'd really like it to be automatic.

"Solutions" I've found that haven't helped:

- Check the locale command or the $LC_.... variables.
- This just shows environment variables and has nothing to do with terminal ability.
- Just use a different terminal
- The entire point is to have this work on different terminals / consoles.
- print something to the term and look at it.
- That's not automated.
- Testing echo supports utf8.
- Only testsecho and bash internals, not the terminal.

Hackishly works:

- Check $TERM
- If the $TERM is linux (local console) it uses ascii, else utf8.
- Does not explicitly list utf8 support.
- Does not take into account a variety of other terms than don't support utf8.

If there's a better way I'd love to know it. Otherwise it'll be just adding TERMs to ascii as I run across them.

Thanks,
Whale

https://redd.it/wfbf3w
@r_bash

What does this bit of code mean?

log () {
 echo -e "$(basename $0) [$$]: $*" >&2 || :
}

This part: >&2 || :

https://redd.it/wfky2q
@r_bash

Can someone translate this line of code from BASH to Windows CMD

I need this line of code to run on Windows CMD (or powershell), preferably one line if possible. If anyone can help me please

LC_ALL=C </dev/urandom tr -dc 'A-Za-z0-9!"#$%&()*+,-./:;<=>?@[\]^_`{|}~' | head -c 50 > secret.txt

https://redd.it/wg2xyp
@r_bash

How to unify parsing arguments --key=value -key=value -k=value -k value in bash

Hi guys, i'm developing an toolkit for linux engineers and have some issues with auto completions due all my parsing logic depend on one string argument parsing and should contain "=" after key, i want to unify it such way it parse value after -k with space delimeter(or without delimeter at all) and also $ARG1 should not declaring if there "-k some_value" in arguments is there some simple and common way to achieve that?

this is my current implementation which works only -one_string=argument

cat > /tmp/testnoscript.sh << 'EOL'
#!/bin/bash
#Filter arguments by regex for security reasons
CLDOPTS="$(expr "$(tr '\n' ' ' <<< "${@}")" : '\(A-Za-z0-9/ :.,@_=+^*-\+\)' 2>/dev/null | tr ' ' '\n')"

#Simple parsing arguments
for i in ${CLDOPTS}
do
case $i in
-k=|-key=|--key=) KEY="${i#=}" ;;
-f=|-foo=|--foo=) BAR="${i#=}" ;;
-j|-json|--json) JSON=1 ;;
-) ;;
) let ii++; declare ARG$ii=${i} ;;
esac
done

#Print variables
echo key: $KEY
echo foo: $BAR
echo json: $JSON
echo ARG1: $ARG1
EOL
chmod 755 /tmp/testnoscript.sh

how it works:

$ /tmp/testnoscript.sh -k=testkey -f=bar -j arg1
key: testkey
foo: bar
json: 1
ARG1: arg1

how i want it work

$ /tmp/testnoscript.sh -f=bar -k testkey -j arg1
key: testkey
foo: bar
json: 1
ARG1: arg1

any ideas how to refactor argument parsing but save the current use cases logic? Thank you!

https://redd.it/whvgpt
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