How can I write this if condition more efficiently?

if $a -eq 0 && $b -eq 0 && $c -eq 0 ; then

I want to do something like:

if $a && $b && $c -eq 0

i just don't know how to format it correctly

https://redd.it/x37adx
@r_bash

Any tip on optimizing this?

Hi!

I have a waybar module to track Spotify that runs every two seconds.
Since it runs so frequently I want it to be as performant as possible.

This is what I came so far:

#!/bin/sh

player="playerctl -p 'spotify'"
metadata="$player metadata"

playerstatus=$(eval $player status 2> /dev/null)

([ "$playerstatus" = "Playing" ] || "$player_status" = "Paused" ) && \
printf "$(eval $metadata artist) - $(eval $metadata noscript)"

It works, but I figured this is a nice opportunity to learn something new about shell-noscripts.
Does anybody have any tip or idea on how to improve this for runtime footprint?

Thanks in advance :D

EDIT: result thanks to @rustyflavor and @oh5nxo:

player=$(playerctl -p 'spotify' metadata -f "{{ artist }} - {{ noscript }}")

"$player" != "No players found" && printf "$player"

https://redd.it/x3ez5w
@r_bash

Are parentheses wrapped around the primary case statement variable required?

Parentheses:

case "$1" in
esac

Without parentheses:

case $1 in
esac

Would I have to worry about whitespace, and or weird ass symbols in the $1 variable? Or does the case statement simply not care? If parentheses are not required in any stretch of the imagination, then I will write all my dash noscript case statements without parentheses.

https://redd.it/x3vnes
@r_bash

How can I replace this grep command? I'm getting the Argument list too long error.

Hello, I'm very new to bash so this can probably be easily solved.

I'm writing a bash noscript that stores a list of files in a variable, and then I need to grep those files from a much larger list that contains the files from the first list. Don't know if that makes sense. Here's how I did it:

finalList=$(cat <(echo "$completeList") | grep "$partialList")

It works fine most of the time, however, in some cases the "$partialList" has a lot of files, and the "grep: Argument list too long" error pops up. Any workaround I can use? I read I could use the find command but I'm not really sure how to apply it here.

Thanks in advance!

https://redd.it/x42cnc
@r_bash

I've been trying to make a noscript to simplify my very common find command usage, but it's not working in three ways

First, I can't figure out how to use . in a variable. I want to use . so that output from find is like ./dir1/dir2/file, instead of /home/user/project/date/dir1/dir2/file. In line 7 below at the point SEARCH_DIR="$PWD" is what I need help with for using . please, as I've resorted to $PWD.

Second, the find command when executed from my bash noscript is not doing wildcard expansion on the *. I echo the command I'm running and copy and paste it into bash and it works as intended, but when run from my noscript file it says No such file or directory.

Third, it can't actually find the directory I pass to it. So if I do ff *test* -s /, it says No such file or directory.

Here is the noscript:

#!/bin/bash

# File Find

FILENAME="$1"
shift
SEARCHDIR="$PWD"
EXCLUDEDDIRS=

-z "$FILENAME" && echo "No filename pattern supplied."

while "$#" -gt 0 ; do
echo "$#"
case "$1" in
-x | --exclude ) EXCLUDEDDIRS="${EXCLUDEDDIRS} ! -path '${2}'"; shift 2 ;;
-s | --search-dir ) SEARCHDIR="$2"; shift 2 ;;
* ) shift ;;
esac
done

case "$SEARCHDIR" in
"WebModules") EXCLUDEDDIRS="${EXCLUDEDDIRS} ! -path '${PWD}/obj/'" ;;
) ;;
esac

COMMAND="find ${SEARCHDIR} ${EXCLUDEDDIRS} -name ${FILENAME} -print"
echo "$COMMAND"
"$COMMAND"

https://redd.it/x45d70
@r_bash

can someone what did I overlook

what is the purpose of the noscript: unlocking the dataset using the curl command

the code that works:

curl "`https://$host/api/v2.0/pool/dataset/unlock`" -k -X POST -H "accept: */*" -H "Content-Type: application/json" -H "Authorization: Bearer 1-$API_TOKEN" -d '{"id": "the_dataset_hardcoded","unlock_options": {"key_file": false,"recursive": false,"toggle_attachments": true,"datasets": [{"name" : "the_dataset_hardcoded" , "passphrase" : "the_password_hardcoded"}]}}'

now this one works flawlessly, but the moment i try to replace the "the_dataset_hardcoded" and/or the "the_password_hardcoded" as an environmental variable the noscript stops working

my next try is to create the part as a string that i can echo out for debugging so i create:

curl_builder3="'{\"id\": \"$pool\",\"unlock_options\": {\"key_file\": false,\"recursive\": false,\"toggle_attachments\": true,\"datasets\": [{\"name\" : \"$pool\" , \"passphrase\" : \"$pass\"}]}}'"

and run it like this:

curl "`https://$host/api/v2.0/pool/dataset/unlock`" -k -X POST -H "accept: */*" -H "Content-Type: application/json" -H "Authorization: Bearer 1-$API_TOKEN" -d $curl_builder3

but what i get for this is:

curl: (3) unmatched brace in URL position 1:

{"key_file":

^

bash: line 3: Server: command not found

&#x200B;

but when I echo the created env variable i get the correct string that if i copy and run in terminal it does what is supposed to do

&#x200B;

now what did I miss

&#x200B;

&#x200B;

edit:

the curl command is now fixed and it looks like this:

curl "`https://$host/api/v2.0/pool/dataset/unlock`" -k -X POST -H "accept: */*" -H "Content-Type: application/json" -H "Authorization: Bearer 1-$API_TOKEN" -d "{\"id\": \"$pool\",\"unlock_options\": {\"key_file\": false,\"recursive\": false,\"toggle_attachments\": true,\"datasets\": [{\"name\" : \"$pool\" , \"passphrase\" : \"$pass\"}]}}"

&#x200B;

https://redd.it/x5v910
@r_bash

I am once again asking for your noscripting support

How are you doing bash ninjas?

I learned a lot about noscripting in my last post here, and I want to see if there is some other hidden improvement that can be done on a little noscript I created, and hopefully learn something new on the way.

I use wireplumber to control volume, the command I use to increase volume is

wpctl set-volume @DEFAULTAUDIOSINK@ 1%+

but as a downside, this command allows to increase volume well over 100%, which I don't like.
I figured I could check the volume with this command

sicro@sicro ~ $ wpctl get-volume @DEFAULTAUDIOSINK@
Volume: 1.00

so if I were to pipe the output to awk I could: remove the Volume: part, compare the numbers, and pass the corresponding argument to the original command like this

wpctl set-volume @DEFAULTAUDIOSINK@ $(wpctl get-volume @DEFAULTAUDIOSINK@ | awk '{ print ($2 >= 1) ? "100%" : "1%+"}')

Now, this needs two calls to wpctl and awk to do the math.
Does anybody can come up with a better version that can reduce the processes spawned?

Thank you for your time :D

https://redd.it/x7ab4y
@r_bash

How do you create empty collection if $col.json is empty?

ls -1 *.json | sed 's/.json$//' | while read col;
do
mongoimport --host $host --port $port -d $db --collection $col --file $col.json
echo $cmd
done

I have this bash noscript, but the issue is that it doesn't create an empty collection if the file is empty. How do you remedy this situation?

https://redd.it/x7ig30
@r_bash

Using expect to give inputs to bash noscript

Suppose I have a noscript which takes two inputs

`

\#!/bin/bash

echo "enter username: "

read $UNAME

echo "enter port: "

read $PORT

echo $UNAME

echo $PORT

`

I want to use a expect noscript to give input directly for PORT, but allow user to enter username manually and then print both username and port.

https://redd.it/x91ujm
@r_bash

Trigger another noscript when a bin file executed?

Without modifying the executable.. is it possible to add a hook or some type of event on my system (bashrc?) that allows me to trigger a side-effect/another shell noscript when a bin executable has finished being executed

https://redd.it/xatgw3
@r_bash

I Just Want To Show Off Some Scripts I've Been Using

So a couple years ago I finally sat down and decided to get better at bash noscripting. I had a number of things I wanted to automate and was often needing "oddball" utilities no one else had done/I could find.

# CSV2CUE
Probably the most niche of problems. I had exported a very long audio project from a DAW that had embedded CUE points. It was 4 entire CDs in one project. I could split the entire thing out by CUE points. The problem is that the DAW I edited everything on did not follow proper Redbook timecode format of MM:SS:FF (minutes:seconds:frames) and instead used HH:MM:SS:FF. This made the editor I use for splitting completely crash. So I had to make the DAW output a CSV file of CUE points...then process them in to something my other editor liked.

#!/bin/bash
tail -n +2 Markers.csv | tac | awk '{print $3}' | sed -e "s/:/ /g" >> cue.tmp
t=1
cat cue.tmp | while read line;
do
p=($(echo $line))
if [ ${p[0]} -gt 0 ]; then
p[1]=$(echo "(${p[0]} * 60) + ${p[1]}" | bc)
fi
cue=($(echo "${p[1]}:${p[2]}:${p[3]}"))
printf "\nTRACK %02d AUDIO\n" $t >> output.cue
printf "INDEX 01 %s\n" $cue >> output.cue
t=$((t + 1))
done
rm cue.tmp

Now it's not a full cue sheet; but all my editor wanted was TRACK and INDEX fields.

# VPS Backup

I back all my critical VPS stuff up with a bash noscript:

#!/bin/bash
rsync -a /etc/nginx/ /var/www/backups/etc-nginx
rsync -a /etc/asterisk/ /var/www/backups/etc-asterisk
rsync -a /home/dewdude/.znc/ /var/www/backups/znc-conf
rsync -a /home/dewdude/qspbot/ /var/www/backups/qspbot
rsync -a /home/git/ /var/www/backups/home-git-gogs
rsync -arvz -e 'ssh -p [SECRETPORT]' /var/www [HOME PC]:/media/remote/vpsbackup

I used to do a full MYSQL dump as well; but I ditched wordrpess for (semi)static site generation.

# Jekyll Lazy-Compose

Speaking of static site generators; I'm using Jekyll. The way I got it configured I became stupid reliant on front-matter for making everything work. So I decided to hack together a noscript so I can write posts from bash without having to do anything but write, save, and commit to my git so githooks render it.

#!/bin/bash

# usage: ./compose.sh [category] [noscript]
# example: /compose.sh blog MY AWESOME POST TITLE NO YOU DON'T NEED TO ENCLOSE IT!
# run in the root of your site files/repository
# assumes categories are directories in root

# Variables and category argument
category=$1
pd=$(date +'%Y-%m-%d')
pt=$(date +'%T')
file=blog$$.md
# Ditch the category argument
shift 1
# Read everything else as noscript.
noscript=$@
t=${noscript,,}
t=${t// /-}
fd=$(date +'%Y/%^b/%d')
# Let's write the front matter to our temp file.
printf -- "---\nnoscript: $noscript\nlayout: post\ndate: $pd $pt\npermalink: /$category/$fd-$t.php\nexcerpt_separator: <!--more-->\n---\n\n" >> $file
# Write the post in whatever editor you want.
nano + $file

# Move the file to category/_posts replacing spaces with hyphen
mv $file $category/_posts/$pd-${t// /-}.md
# Display some output to verify it's done.
printf "\nPost $noscript created in $category: $category/_posts/$pd-$t.md\n\n"

This one was fun because I had no idea how to make it blindly accept multiple words as arguments. The only issue is if you don't escape characters that require it. This is probably my second most used noscript.

# Asterisk MusicOnHold

Did you know you can do musiconhold from a streaming source with Asterisk? It can call an application and suck input in from stdin. This is fine till you want to use OGG sources since ogg123 doesn't resample and mplayer doesn't support stdout. Good thing noscripts count as executables.

#!/bin/bash

PIPE="/tmp/asterisk-pipe.$$"
mknod $PIPE p
mplayer -playlist http://host:port/playlist.m3u -really-quiet -quiet -ao pcm:file=$PIPE -af resample=8000,pan=1:0.5:0.5,channels=1,format=mulaw 2>/dev/null | cat $PIPE 2>/dev/null
rm $PIPE

I have made ogg123 work with a direct pipe to sox; but holy cow the CPU usage.

# Hacky Auto-Update Page

I've been following this stuff with a particular provider's /16 block relentlessly attacking SIP

accounts. They seem to be doing nothing and the numbers have increased. We're almost to 5% of the /16 being blacklisted.

Anyway...this noscript just plops my iptables output between some pre-rendered HTML/PHP code; along with stuff to count the IPs and keep a list of prior counts.

I have filtered the full IP range and clues just to avoid breaking rules.

#!/bin/bash

date=$(date)
count=$(iptables -S | grep '###\.##\.[0-9]\{1,3\}\.[0-9]\{1,3\}' | wc -l)
count=$(($count - 1))
cp /root/head /root/tmp.tmp
printf "Last updated: $date - Last Count: $count\n<br><pre><code>\n" >> /root/tmp.tmp
iptables -S | grep '###\.##\.[0-9]\{1,3\}\.[0-9]\{1,3\}' >> /root/vypr.tmp
printf "$date : $count\n" >> /root/count
printf "<br>\n" >> /root/tmp.tmp
cat /root/count >> /root/tmp.tmp
printf "</code></pre><br>\n" >> /root/tmp.tmp
cat /root/vfoot >> /root/tmp.tmp
rm [path-to-www-root]/tmp.php
# the file is stored in a different directory because Jekyll wipes root every build
rm [path-to-www-stuff]/tmp.php
mv /root/tmp.tmp /var/www/tmp.php
chmod 777 /var/www/tmp.php
ln -s /var/www/tmp.php /var/www/pickmy/pbx/tmp.php

Since the blacklist only updates every 4 hours; the noscript only has to run every 4 hours. It does so 5 minutes after the blacklist updates.

That's all for now.

https://redd.it/xaxkn1
@r_bash

Syntax highlighting for command line tool options

Hello!

As in the noscript; I don't know where to ask, so I'm sorry if this is not the place to do so, but what syntax highlighting should I use for command line tool options? Basically to highlight the output of tool --help, or similar.

Thank you kindly for the help!

https://redd.it/xb3f23
@r_bash

Having issues with if-elif processing

I'm a little befuddled with a noscript I've been writing - and would appreciate some help!

This is one of those cases where each command seems to work fine on their own, but not so when put together into a noscript.

Here's a gist of what I'm trying to do:

&#x200B;

input=$1

singlefunc () {
command "$input"
}

multifunc () {
xargs < $input -n 1 singlefunc
}

if [[ "$input" == name1* || name2* ]];
then
singlefunc
elif [ -f "$input" ];
then
multifunc
else
echo "exiting"
exit
fi


&#x200B;

The idea here is - if the noscript is invoked with ./noscript.sh input, if will run if the input starts with name1 or name2, using single\func. If the input provided doesn't start with name1 or name2, and is a file containing a list of items, elif will run (reason for -f) using multi_fuc, which is just single_func running with xarg on the provided file.

The 'single_func' component runs on the command line fine on its own (command "input"), and the 'multi_func' component runs fine with a test file (xargs < testfile.txt -n 1 ./single_func.sh). But when I put them together as above and try to run them together, only the first 'if' part works correctly. When provided with a file or some nonsense line not containing name1 or name2, the noscript simply exits without returning anything.

For the curious, I'm running entrez direct commands within the single_func block.

What am I doing wrong?

https://redd.it/xb51hr
@r_bash

Should videos be allowed in r/bash?

Hi,

My recent post was removed by a mod because it was a video, however, I believe videos do provide value. It wasn't removed in r/zsh and people seemed to like it.

Looking at the history of the sub, I see many videos, one less than a month ago, but presumably these escaped the watch of this particular mod.

In fact, this post specifically requested YouYube channels: [youtube channels](https://www.reddit.com/r/bash/comments/szg3hr/youtube_channels/).

Here's a quick list of past videos in this sub:

* [BASH programming video: user input, looping and text splitting with IFS/read](https://www.reddit.com/r/bash/comments/wq284v/bash_programming_video_user_input_looping_and/)
* [Writing bash noscript and not yet using shellcheck. I have just published a 5 minute intro video](https://www.reddit.com/r/bash/comments/r1s1up/writing_bash_noscript_and_not_yet_using_shellcheck/)
* [I made a video about how I applies all my bash, linux and terminal knowledge to finish a very important task in a real life situation under 30 min.](https://www.reddit.com/r/bash/comments/ldmyp8/i_made_a_video_about_how_i_applies_all_my_bash/)
* [In this video, you will learn how to pass arguments shell file and how to receive them inside the file. Also, will learn about asking user to certain input like username and password.](https://www.reddit.com/r/bash/comments/k42lva/in_this_video_you_will_learn_how_to_pass/)
* [In this video, you will learn how to write more complex bash commands using concepts like redirecting, pipelines, chaining and also how to write nested commands.](https://www.reddit.com/r/bash/comments/jxo56u/in_this_video_you_will_learn_how_to_write_more/)
* [Nice introduction video on regular expressions for anyone curious into learning more about regex. Thought some might appreciate it here:)](https://www.reddit.com/r/bash/comments/cjwu1c/nice_introduction_video_on_regular_expressions/)
* [Using one terminal command to create my own way to search from google sheet.](https://www.reddit.com/r/bash/comments/lh57ju/using_one_terminal_command_to_create_my_own_way/)
* [A simple bash program to Search and Play youtube videos with Terminal](https://www.reddit.com/r/bash/comments/lpb2y2/a_simple_bash_program_to_search_and_play_youtube/)
* [Bash noscript to do some common clipboard related operations quickly.](https://www.reddit.com/r/bash/comments/mb2pfw/bash_noscript_to_do_some_common_clipboard_related/)

These are just some of the ones posted straight up as a video, there's many more which are included in some text post.

What do you guys think? Do videos have a place in r/bash?

https://redd.it/xb6dji
@r_bash

GitHub - Wilfred/difftastic: a structural diff that understands syntax 🟥🟩
https://github.com/Wilfred/difftastic

https://redd.it/xa07ic
@r_bash

Backus-Naur form for bash/posix shell noscript

Does anyone have a the bash syntax described using backus-naur form?

https://redd.it/xa4bxi
@r_bash

Is there a bash noscript that allows you to generate a dump sql file on a postgres database?

Is there a bash noscript that allows you to generate a dump sql file on a postgres database?

I thought that every application had a way to generate dump sql files, but I don't think DBeaver allows you to do that. Is there a way to generate some dump file of a specific database, so I can compare it after running some migration noscript?

https://redd.it/xa94pt
@r_bash

Reliably get command denoscription offline, like tldr but offline

For historical reasons there are numerous ways to acquire command denoscription. During the time things got divergent and now we have several way to do it:

man, info, --help, -help, -h, -? ...continue the array.

But also, there are some commands that execute regardless of arguments passed to it. It is hard to explain to beginner how to do this, without him rolling his eyes on me. So, is there any initiative/project which resolve this?

https://redd.it/xa4n3o
@r_bash

dotfiles and root

Hi guys, I'm doing a noscript to install my dotfiles, the problem is when I want to link my files of 11X I execute my noscript with sudo but when I see my files are linked from the root directory like this /etc/X11/xorg.conf.d/20-intel.conf' -> '/root/dotfiles/X11/xorg.conf.d/20-intel.conf. I don't understand why it happened because when I run that command since the terminal that doesn't happen. How can I resolve it?

this is the line inside of my noscript: ln -sf $HOME/dotfiles/x11/ /etc/x11/

https://redd.it/x9snqf
@r_bash

Bash if condition not working

Hey there this is my first bash noscript and the problem is with the if statement, i ask when brightness is equal to 937 (which it 100% is, i echoed the brightness before the if statement) set it to 10. However when i execute the noscript it tells me the newbrightness = 9.
What am i doing wrong?

#!/bin/sh

path=/sys/class/backlight/intel_backlight
brightness=$(cat $path/brightness)

if [$brightness == 937]; then
newbrightness=10
else
newbrightness=$(($brightness/94))
fi

echo "BRIGHTNESS: $newbrightness"

Thanks in advance!

https://redd.it/x979s7
@r_bash