read contents of a file into a variable with bash without invoking other commands?

Is there some internal bash way to do this?

x=$(cat /proc/uptime)

And i am not thinking about the line-by-line "while read l; do bla bla; done < file" (for various reasons).

https://redd.it/z3ue97
@r_bash

I've been working on this CLI tool to automate creation of noscript files, modification of file permissions, and input typical text. I spend a lot of time in the command line for work, but consider myself still learning noscripting. If you have any input I'd appreciate it!
https://redd.it/z4hi9r
@r_bash

Sorting by size with ls -S and reading each first line of .txt files

So i have this task to sort .txt files by size and then reading the first line of each of them and displaying them

i do know that i can sort by size with ls -S

also for the reading and displaying part

for i in *.txt; do head -n 1 $i; done

problem is that if i put ls -S | before this ... it doesnt work .. like i get the output but its not sorted by size

i do know that there is an awk command, tried with that either, but i cant use it as its for class and we just started with bash so we have to stick to the .. "basics"

https://redd.it/z4mvws
@r_bash

Having trouble with a bash user creation noscript for homework

The bash noscript pulls some stuff out of a csv file (firstname, lastname, dob, group)

I can get that stuff into an array, but when I try to massage the data in the array, it tries to run one of the variables as a command.
Can someone tell me what I'm doing wrong?




\#!/bin/bash

\#set -x

testdata="/home/diana/testdata.csv"

declare -a fnames

declare -a lnames

declare -a dob

declare -a course

while IFS="," read -r Student_Firstname Student_Lastname Student_BirthDate Course_Data trash;

do

fnames+=("$Student_Firstname")

lnames+=("$Student_Lastname")

dob+=("$Student_BirthDate")

done<$testdata

\## usernames[index\]= ${fnames[index\]::1}${lnames[index\]} | tr [:upper:\] [:lower:\]

for index in "${!fnames[@\]}";do

\#this next line tries to "run" the username.
usernames= "${fnames[index\]::1}${lnames[index\]} | tr [:upper:\] [:lower:\]"

\# echo ${fnames[index\]::1}${lnames[index\]} | tr [:upper:\] [:lower:\]

\# echo ${fnames[index\]::1}${lnames[index\]::1}${dob[index\]} | tr [:upper:\] [:lower:\]

\# echo $usernames

\#printf ${fnames[index\]}

done

https://redd.it/z4niaz
@r_bash

Cron job for shell noscript not running

https://stackoverflow.com/questions/74577211/cron-job-for-shell-noscript-not-running

Full/detailed q in stack overflow above.

tl;dr cannot get my cron job to successfully execute a shell noscript, nor can I seem to get it to format as intended, despite the noscript working when called manually and absolute paths used for everything.

https://redd.it/z4mj18
@r_bash

Help with creating a noscript for transcoding files located in subdirectories with FFMPEG

Hi. I'm trying to write a noscript that locates all video files (.mkv in this case) from subdirectories, transcodes them with FFMPEG to HEVC, and stores the output in another HDD, **preserving the directory tree**.

**Example:**

I want to transcode /videos/pets/cats.mkv to HEVC and store the output inside /hdd2/pets/cats\_hevc.mkv

This is the noscript that I currently have, but it doesn't preserve the directory structure nor search in subdirectories (I tried to use 'find' but I couldn't create new folders in the output location):

#! /bin/bash
for file in *.mkv;
do
ffmpeg -i "$file" -pix_fmt yuv420p10le -map 0:v -map 0:a -c:v libx265 -crf 21 -preset slow -c:a aac -b:a 128k "/path/to/output/directory/${file%.*}_hevc.mkv";
done
echo "Conversion complete!"

How can I do that? I've been trying for hours but couldn't find a way to make it work.

Thanks.

https://redd.it/z4qa0n
@r_bash

Master the command line, in one page
https://github.com/jlevy/the-art-of-command-line

https://redd.it/z4zcy5
@r_bash

Help with Bash homework, convert Uppercase to Lowercase in txt file

Hello, I have to write a line of simple Bash code to convert every Uppercase letter to lowercase in a .txt file.

Can anyone help?

https://redd.it/z5302q
@r_bash

no way to record PWD in the bash history i guess?

I want a better history, and did this


export HISTTIMEFORMAT="%F%H:%M:%S [$sshkeycomment] "

$ssh\key_comment is figured out in a profile.d noscript and simply contains the ssh key comment of the key of the person that logged in (via ssh...). Or contains "n/a".

I can see that the timestamps are now recorded as a #-comment in .bash_history.

Its just one thing missing, would be nice to see the current PWD where the comment was entered.
Adding $PWD to HISTTIMEFORMAT doesnt work because thats simply not recorded in the history.

Might there be a trick to get it recorded anyway? :)
Cant see any way from the man page...

https://redd.it/z583sh
@r_bash

My PS1 variable breaks shell completely [Help fix it]
https://redd.it/z57hpm
@r_bash

How do I validate user inputs to numbers only?

https://redd.it/z5dco1
@r_bash

social nets from bash lynx

m.facebook.com worked for me in 2021. gmail stopped working early 2021 because of javanoscript, tho had used html mode a decade. a coupla years ago linkedin kept trying to catchpa me but despite scp failed. have seen bash noscripts for twitter and reddit but never worked. anyone care to give a general status report with urls?

https://redd.it/z5jr1y
@r_bash

Pulling information about processes from /proc/pid/stat

Hi, I need to display information about all running processes (pid, ppid) from /proc/pid/stat. Any tips how to get around this?

https://redd.it/z5yxu4
@r_bash

How to log bash commands in some simple way?

I would like to log bash commands to a log file. Seems easy enough, but i have searched and searched and not found a simple and sufficient method.

It seems like this should be possible by hooking in to some bash function/variable, but there is always something missing:/

I tried enhancing the history a bit here https://www.reddit.com/r/bash/comments/z583sh/no\_way\_to\_record\_pwd\_in\_the\_bash\_history\_i\_guess but that failed.
Sorry for that untested post by the way.

The utility "noscript" almost seems good enough, but for some reason there is no way to get a timestamp for each command!? (or is there?)
(i have seen solutions where the output of noscript is piped through for instance 'ts', but i would really like to avoid too many sub-processes and pipes and stuff, that will just cause problems later on).

I saw one solution where PROMPT_COMMAND was used together with "history | tail -n", but that wont work when commands take long to complete. The timestamp will be when the command finished...

Basically i would like to log like this

>2022-11-27 12:00 [user\] [env-var\] [cwd\] the command...

Where 'env-var' could be any variable from the environment.

Is there really no way to just get bash to execute some function that gets the input passed as arguments each time a command is executed?

Sorry for posting yet another of these questions. I have found many many questions kinda like this, but really strangely enough no simple and satisfactory solutions.

https://redd.it/z6119l
@r_bash

any help for a noob learning his first noscripts? im trying to make them funny and functional

This all just fun between friends, my friend Lucy is interested in learning Linux like me, and make the joke that she'll always be a root vegetable not a root user. I even had help making another noscript which randomly decides which random yet amusingly shaped root vegetable she is today. She loves it. I'm working on another, and obviously I thought i put it together well enough, but I'm obviously just more confident than I am skilled, but that's how we learn right by trying stuff. Anyway here's my code if someone could make it work id study from it for days re-writing different but similar ones to check if my new-found instincts are right. But if someone could just give me general hints that'd be good too, i want to learn anyway I can.

\#!/bin/bash

echo "Thanks to traversery media"

sleep 3

read -p "what is your name?" NAME

if [ "$NAME" \] == lucy or == Lucy

then read -p "are you a potato?"

if $INPUT1 echo "$ANSWER1"

else

if $INPUT2 read -p you another root vegetable?

if $INPUT1 then echo "$ANSWER1" if $INPUT2 echo "$ANSWER3"

INPUT1 yes

INPUT2 no

\#ANSWER2 read -p are you another root vegetable?

ANSWER1 "Your ok then, your names on the root list you may enter"

ANSWER3 "fatal logical error does not compute according to my database all known

lucys are root vegetables not root fatal error forcing shutdown"

else echo "$ANSWER1"

fi

https://redd.it/z64iuf
@r_bash

Scraping weather info

Hi, I’m trying to scrape some weather information using sed and grep from: https://api.met.no/weatherapi/locationforecast/2.0/classic\?lat\=60.795\&lon\=10.691

What I’m trying to do is:
1. extract the temperature forecast for the current hour, the next hour and the hour after that.
2. extract the next precipitation forecast.
3. the date and time when the meteorological data has been scraped.

Example of how I want the output to look (I want them “stacked”/under each other, but couldn’t format that):
3
0
-4
Cloudy
2022-11-24 10:03

What I know is that I probably should grep something, but not sure what and how

curl -s https://api.met.no/weatherapi/locationforecast/2.0/classic\?lat\=60.795\&lon\=10.691 | grep

I have found these commands that I think could be useful, but I don’t know how to use them in this case.

grep -Eo "0-9{2}:0-9{2}:0-9{2}"
date +"%Y-%m-%d"
date +"%Y-%m-%d %H:%M"

https://redd.it/z3f73f
@r_bash

Is there something like w3school but for bash? or any other shell?

I'm looking for an online resource for learning shell noscripting. I dont really find youtube lessons helpful so written material works better for me. Books could also work tbh but no video plz :D

https://redd.it/z68zbh
@r_bash

I'm currently taking a Google Cloud Course that includes Qwiklabs. I've been tasked with translating one of the labs into a linux bash noscript. I've done that but i'd like someone who knows what they're doing to take a look at it before i turn it in. I'd really appreciate it. Thanks in anticipation.

I'm currently a big noob trying to wrap my head around tech. please be nice

https://redd.it/z6ala6
@r_bash

What does this noscript do? I need to explain what this noscript does for a question on my classwork but my teacher isn't satisfied with my answer. Can anyone provide some insight into what exactly is happening with this noscript?
https://redd.it/z6c7x0
@r_bash