Tarefas em Bash

Eu sou um "recém-convertido" ao sistema operacional Linux e a primeira coisa que me veio em mente foi trabalhar com as configurações do sistema e a automatização de tarefas. O estímulo para ir um pouco mais a fundo nas linhas de programação em Shell Bash foi a grande popularidade entre os programadores mais experientes do ambiente Unix e a reputação de estabilidade e portabilidade entre programas que possui este sistema.

Descobri em curtíssimo espaço de tempo recursos bastante úteis para automatizar desde tarefas simples até alguns processos mais complicados como os arquivos de configuração do sistema.

Para aqueles que trabalham em servidores, há comandos simples que podem ser executados através de noscripts para manipular arquivos de 'logs' de usuários e gerenciamento de arquivos diversos. Pois é exatamente isso: no Linux, tudo é baseado em arquivos.

A programação baseada no sistema de arquivos no Linux permite que possamos realizar o mesmo procedimento que fazemos com arquivos em lotes do sistema operacional Windows porém com ferramentas de longe mais sofisticadas. Eu coloquei em prática quando tomei a decisão de trabalhar vários arquivos de uma só vez e sem precisar de fazer a mesma coisa com todos os arquivos de meu computador. Uma dessas ferramentas de programação é o comando 'for' que pode iterar uma lista de arquivos e executar um ou mais comandos. Aliás, muitas diretivas de programação são parecidas com a linguagem C/C++ como os comandos 'printf', "for(( 'início', 'enquanto, 'incremento'))"' ...embora não sejam muito usados, eles são de fácil assimilação para os que já possuem experiência em linguagem C/C++. Talvez seja esse o motivo pelo qual minha curva de aprendizado em Bash tenha tido um alto coeficiente de aproveitamento no espaço curto de tempo. Abaixo, coloco o exemplo de alguns comandos de rotina executados em minhas pastas pessoais Automatizando tarefas no Bash \~ exemplo prático \~

https://redd.it/1104tg3
@r_bash

Test -f and -e give the same results when testing a symlink

I created a symlink in the same folder as a noscript. This noscript does 1 thing: Test if the symlink points to an existing file.

#!/usr/bin/env bash

cd "$(dirname "$0")" || { echo "cd $(dirname "$0") failed!"; exit 1; }

echo "Checking if files exist"
if [ -f "test.config" ]; then # check if file exists
echo "-f test.config exists"
else
echo "-f test.config missing"
fi

echo "Checking if files symlinks point to exist"
if [ -e "test.config" ]; then # check if file symlink points to exists
echo "-e test.config exists"
else
echo "-e test.config missing"
fi

If the symlink points to a file named test.config both -f and -e return true.

If the symlink points to a missing file both -f and -e return false.

What is the point of -e if -f works exactly the same?

https://redd.it/111x8g2
@r_bash

Get output from your bash noscript directly in Vim, with colors too.

Hello.

This is a snippet that I use for getting output from noscripts directly in a newly created window. You can close the output window by hitting q, and rerun the noscript by hitting <leader> r

It works for me. The AnsiEsc sequences too, which I downloaded from https://www.vim.org/noscripts/noscript.php?noscript_id=302

Ahh, and the noscript was originally made by the guy that made "Learn Vim noscripting the hard way" Steve Losh. And, you should save it in your ~/.vim/plugin directory, as Shell.vim for instance, so it gets sourced into Vim at startup.

This is posted here, because it may if not increase your productivity when writing shell noscripts, but maybe a tad more comfortable. If you ever want to save the contents of the output buffer, then you can :set buftype="" on the command line before you save, having the output buffer active as you do of course.

" Shell ------------------------------------------------------------------- {{{
" From Steven Losh's vim.rc
function! s:ExecuteInShell(command) " {{{
if &filetype == "sh"
let command = join(map(split(a:command), 'expand(v:val)'))
let winnr = bufwinnr('^' . command . '$')
echom winnr
silent! execute winnr < 0 ? 'botright vnew ' . fnameescape(command) : 'vert vnew'
setlocal buftype=nowrite bufhidden=wipe nobuflisted noswapfile nowrap nonumber
echo 'Execute ' . command . '...'
silent! execute 'silent %!'. command
silent! redraw
silent! execute 'au BufUnload <buffer> execute bufwinnr(' . bufnr('#') . ') . ''wincmd w'''
silent! execute 'nnoremap <silent> <buffer> <LocalLeader>r :call <SID>ExecuteInShell(''' . command . ''')<CR>:AnsiEsc<CR>'
silent! execute 'nnoremap <silent> <buffer> q :q<CR>'
silent! execute 'AnsiEsc'
echo 'Shell command ' . command . ' executed.'
endif
endfunction " }}}
command! -complete=shellcmd -nargs=+ Shell call s:ExecuteInShell(<q-args>)
nnoremap <leader>! :Shell

Here is a mapping I have in my .vimrc to execute the current buffer, which should be a shell noscript when I do, by hitting Function key 5

nnoremap <F5> :Shell %:p<cr>

Enjoy!

https://redd.it/1126owg
@r_bash

Move all files from same group to its newly created corresponding folder

Hello,

I have many files like this:

File1-BLABLA.mkv
File2-BLABLA.mkv
File3-Toto.mkv
File4-Toto.mkv

BLABLA and Toto being the groups who made these files.

I want all these files grouped in newly created corresponding folders like this:

BLABLA/File1-BLABLA.mkv
BLABLA/File2-BLABLA.mkv
Toto/File3-Toto.mkv
Toto/File4-Toto.mkv

Basically all files made by a certain group moved to a folder dedicated to that group.

But without having to specify the pattern because I have thousands of files with different groups.

So I want to avoid typing for all the different groups mv *-GROUP.mkv GROUP/

Is this possible?

Sorry for my bad english.

https://redd.it/1129p6f
@r_bash

Trying to iterate through folders until a file is found

So i have a collection of folders that have files at different depths, and I'm trying to iterate through them in such a way that I can recursive perform some operations in the folder that contains said files. I'm able to do this with for dir in */ or find if they are all at the same depth, but I can't seem to figure out how to do it when the files are arbitrarily deep (well, maximum of 5 or so levels). My filesystem looks a bit like this:

/rock/artist1/songs.mp3
/rock/artist2/album/songs.mp3
/pop/artist1/songs.mp3
/pop/artist2/album/disc1/songs.mp3
/pop/artist2/album/disc2/songs.mp3

And so on.
So basically I want to iterate through an entire directory with sub directories and identify all directory paths that contain *.mp3 files, and not ones that don't contain any. Then I'll execute, for instance, normalize "$dir/*.mp3"

This seems like something that should be relatively easy, but I can't seem to figure it out. My files do have white spaces in the names, so a solution that takes that into account is ideal. Though I suppose I just go through and replacing all " " with "_" if I really need to.

Thanks for your consideration.

https://redd.it/112ls1v
@r_bash

tar error "Exiting with failure status due to previous errors"

When I use 1st tar -cvfz output filename directory to backup I get a bunch of file paths/names that scroll quickly by, then it stops and says 10mg tar: Exiting with failure status due to previous errors. I googled this error message and people said not to use verbose so you can see more info about the error. So I ran tar -cfz [output filename] [directory to backup] and got

tar: ./flash64/raro-docker.tar.gz: Cannot stat: No such file or directory
tar: Exiting with failure status due to previous errors

I know the "c" in "-cfz" means "create file" so I was puzzled by this but I went ahead and touched the file then reran the command. Good news: the command ran all the way through with no error messages. Bad news: the output file is a zero byte file.

I've tried backing up sub-subdirectories of the docker container (e.g. ~/docker/containers/caddy) but I get the same error. Can anyone tell me what’s going wrong and how I can fix it?

https://redd.it/112x71r
@r_bash

Store the output of command in a variable to then perform calculation on it?

The following is a command with ffmpeg/ffprobe to get the bitrate of a video file. The problem is that the result is in bits, instead of kilobits.

`ffprobe -v quiet -select_streams v:0 -show_entries stream=bit_rate -of default=noprint_wrappers=1 inputvideo.mp4`

Output:
`bit_rate=19858777`

I tried to the following:
`br=$(ffprobe -v quiet -select_streams v:0 -show_entries stream=bit_rate -of default=noprint_wrappers=1 inputvideo.mp4)`

Extract value after 'bit_rate=', the following failed to extract/display the value 198...
`echo {($br)#*=}`

Main goal is divide the integer by 1000 to get the kbps.

https://redd.it/1136i4z
@r_bash

Just for fun: cowsay and dad jokes

I am forever amused by *cowsay*, which can be installed with your favorite package manager (e.g. apt install cowsay). I combined it with a REST call to a dad joke API:

$ cat which dadjoke
foo=$(curl -s -H "Accept: text/plain" https://icanhazdadjoke.com/)
/usr/games/cowsay $foo

And produces output thusly:

$ dadjoke

/ Did you hear about the new restaurant \
| on the moon? The food is great, but |
\ there’s just no atmosphere. /
---------------------------------------
\ ^^
\ (oo)\
()\ )\/\
||----w |
|| ||

https://redd.it/113arse
@r_bash

(I don't really know how to name this post but) how to execute more commands after entering a process?

Ok so I have a noscript where I want to play a song using mpv and then do something else after but after I play the song using mpv, I am stuck inside of the mpv process and everything after the mpv command doesn't run. So when I run the command I get stuck here and nothing after mpv runs.





https://preview.redd.it/oibpb02jagia1.png?width=266&format=png&auto=webp&v=enabled&s=6f69d74da345b4d86133e018654ba165b6c09dda

The noscript looks something like this

mpv path/to/song
cd folder/
.....

https://redd.it/113e55o
@r_bash

How to 'refresh' connection between two consecutive WGET commands

I use WGET to download a first file, then read the second line of this file (which is a URL) and WGET that again.

Both of these point to different URLs of same website. The first WGET works, but the second one fails and tells me that it failed with error as below

Reusing existing connection to website.com:443.
HTTP request sent, awaiting response... 404 Not Found
ERROR 404: Not Found.

But if I happen to run that exact command independently in a separate noscript it works. I think that it's because it's doing the Reusing existing connection to website. so how do I avoid this?

https://redd.it/113k4aw
@r_bash

Write a bash noscript which runs other bash noscripts one after the other?

In python and other languages I can write two noscripts, and then reference them in a main() function and run them one after the other.

is there an equivalent in bash?

Is it like below?

#!/bin/bash

# Run noscript1.sh
./noscript1.sh

# Run noscript2.sh
./noscript2.sh

&#x200B;

https://redd.it/113k546
@r_bash

Killport - A Simple Script to Kill Processes on a Port

Have you ever encountered the issue of not being able to start a process because the port is already in use? Killport is a simple noscript that allows you to quickly kill any process running on a specified port.

Using Killport is easy. Simply provide the port number as a command-line argument and the noscript will automatically find and kill any process running on that port. The noscript works on both macOS and Linux, and it is easy to install.

&#x200B;

killport

Give it a try and let me know what you think.

give a ✨ star, if you liked it. Github

https://redd.it/113jses
@r_bash

Question How would I rewrite this command using no pipe?

Hey, today I wanted to create a tcp shell. But I don't want to write the pipe (|) symbol. Is there a way to restructure this command without breaking its functionality?

nc $IP $PORT < myfifo | /bin/bash -i > myfifo 2>&

https://redd.it/113t90p
@r_bash

How can I run commands in parallel and write the output of each command to different linux terminals, one linux terminal for each command running in parallel.

I want to run commands in parallel with a bash noscript. I know adding the ampersand allows to run a command in background and continue with the noscript without waiting for the launched process to finish. I think the processess launched in background with ampersand do not output a log on a terminal though.

&#x200B;

Is there any way to launch several commands in parallel while the output/log of each command is written to a different terminal window? I would like to see the logs of each process launched in parallel after all of them finish their execution.

Thanks

https://redd.it/1140cr2
@r_bash

Turbocharge your terminal productivity with zsh-autosuggestions! (1mn)

https://www.youtube.com/watch?v=0r1mxuAzqS0

https://redd.it/1142z89
@r_bash

fun with sed/awk

i do have to say it is a bit frustrating that some binaries in freeBSD/macOS dont translate over to other *nixs..probably licensing, however..

&#x200B;

i have out input in a var that reads as below, new lines and spaces:-


this is string 1
this is string two
this is string threeee

&#x200B;

and so forth, i have been able to get them on to one line and get quotes on the end in the standard macOS bash scrpit, but for the love of god, i cant get it into the right format, i've tried awk, sed and tr.

&#x200B;

what i need:

"this is string 1" "this is string two" "this is string threee"

grateful for any ideas..

https://redd.it/114hh6p
@r_bash

Show Output for Two Simultaneous Uploads

I have a noscript that uploads a file, at the same time, to two different platforms. I want to be able to see the progress of both uploads, at the same time. Here is part of my noscript:

#When the transfer is complete, attempt upload the mp4:
if [[ ! -f $SAJSON ]];
then
echo -e "No json file found. Not uploading. Please manually upload."
elif [[ {$OUTPUT} = *"Movie Info"* ]]; then
cp $SRVPATH/Archive/$yyyy/$EMAILFILENAME.mp4 \
$SRVPATH/Archive/$yyyy/$SA-ID.mp4
{ echo -e "Uploading to SA...\n" & \
rclone move $SRVPATH/Archive/$yyyy/$SA-ID.mp4 \
sa-auto:sa-id-text -P -v & echo -e "Uploading to YouTube...\n" & \
youtubeuploader -filename $SRVPATH/Archive/$yyyy/$EMAILFILENAME.mp4 \
-secrets $SRVPATH/AppData/youtubeuploader/client_secrets.json \
-cache $SRVPATH/AppData/youtubeuploader/request.token \
-metaJSON $YTJSON; } 2>&1
echo -e "\nDone.\n"
echo -e "Removing ${SAJSON##*/} & ${YTJSON##*/}\n"
rm $SAJSON $YTJSON
echo "Done."
fi

As you can see, I attempted `{ echo & command1 & echo & command2; } 2>&1` but it produces:

Uploading to SA...

Uploading to YouTube...

Uploading file '/srv/dev-disk-by-uuid-49e4aa1a-279a-45ce-b23e-467c2b2a4162/Archive/2023/2023-02-19_14-45-23.mp4'

And the rest is just the transferring status of YouTube only (I think; maybe it's a mixture?). Once YouTube completes, then it shows the other platform upload, but it als shows a weird mixture of both (my comments in the code):

Uploading to SA...

Uploading to YouTube...

#This is is YouTube:
Uploading file '/srv/dev-disk-by-uuid-49e4aa1a-279a-45ce-b23e-467c2b2a4162/Archive/2023/2023-02-19_14-45-23.mp4'
#This is SA platform:
2023-02-17 14:10:07 INFO : 2172307128007.mp4: Copied (new)
2023-02-17 14:10:07 INFO : 2172307128007.mp4: Deleted
#I'm not sure what this is:
Transferred: 56.265 MiB / 56.265 MiB, 100%, 622.384 KiB/s, ETA 0s
Checks: 2 / 2, 100%
Deleted: 1 (files), 0 (dirs)
Renamed: 1
Transferred: 1 / 1, 100%
Elapsed time: 1m18.0s
2023/02/17 14:10:07 INFO :
Transferred: 56.265 MiB / 56.265 MiB, 100%, 622.384 KiB/s, ETA 0s
Checks: 2 / 2, 100%
Deleted: 1 (files), 0 (dirs)
Renamed: 1
Transferred: 1 / 1, 100%
Elapsed time: 1m18.0s

#This is the SA platform (using Dropbox):
2023/02/17 14:10:07 INFO : Dropbox root 'sa-id-text': Commiting uploads - please wait...
Progress: 9.57 Mbps, 58998558 / 58998558 (100.000%) ETA 0s
#This is YouTube again:
Upload successful! Video ID: asdfghjkl
Video added to playlist 'Playlist Title' (qwertyuio-)

https://redd.it/114tyym
@r_bash

Script to change system spelling language

Right now I'm using an AppleScript to do this, but the noscript is a bit long to execute, plus it shows some UI elements and I'd like for the process to be hidden.

Is there a defaults write command that would allow to toggle the system spelling language between US English and French?, or at least to switch from one to the other?

Thanks.

https://redd.it/114wjw1
@r_bash

posix Properly store positional arguments in string

I have the following noscript:

cmd="rg --ignore-case --files-with-matches {q} $@"

file=$(
FZFDEFAULTCOMMAND="rg --files $@" fzf \
--bind "ctrl-a:select-all" \
--bind "change:reload:$cmd" \
--disabled \
--preview "rg --ignore-case --pretty --context 2 {q} {}"
)

Here I store the positional arguments (paths for rg to search from) into the string variable $cmd, which is then passed as a literal string in --bind "change:reload:$cmd" \. However, shellcheck throws an error regarding assigning array to string that I don't understand if it's relevant.

To test, I made a directory with a space in its name and ensures it should containing a match, then past this as an argument to the noscript quoted. Sure enough, it doesn't show up so apparently the directory named "test me" is not interpreted as "test" "me" where the quotes are lost.

So is the issue here that "quotes" are lost since POSIX doesn't support arrays, making everything space delimited, which is problematic when you also have spaces in the arguments? How would I go about properly storing the positioning arguments with them quoted to account for spaces in the cmd string then? I'm pretty sure the suggested solution from shellcheck does not apply--the page doesn't mention any sort of quoting issue either.

Essentially, the line --bind "change:reload:$cmd" \ should be expanded to e.g.

--bind "change:reload:rg --ignore-case --files-with-matches {q} '/home/user/bin' '/home/user/test me'" \

when the noscript is passed the arguments: ~/bin "~/test me"

Much appreciated.

https://redd.it/1150jis
@r_bash

File with a variable of the date as part of the filename.

I am trying to use bash to create a backup of an existing file with a variable of the date as part of the filename.

    #!/bin/bash
    dateandtime= date +%F-%H-%M-%S
    sudo cp /etc/pacman.d/mirrorlist /etc/pacman.d/mirrorlist${dateandtime}.bak
    echo "Mirror file backup created: /etc/pacman.d/mirrorlist${dateandtime}.bak"
    sudo reflector --latest 20 --protocol https --sort rate --save /etc/pacman.d/mirrorlist
    echo "Mirror list update complete."

This is the output I get

    Mirror file backup created: /etc/pacman.d/mirrorlist.bak

When looking in the file directory with a file manager I can see that is the only file that exists and it just keeps getting overwritten. sorry if this is a silly issue but I'm new to bash and I looked for about an hour on various forums and how to guides but was not able to find the solution.

https://redd.it/1159gor
@r_bash

Need helping figuring out what's wrong with this noscript on MacOS

I'm currently trying to turn some bash noscript that's in the form of a '.command' file into an App/Quickaction that can be run, using Automator on MacOS.

This is the original noscript: \(pastbin link\)

This is as far as I've gotten: \(pastebin link\)

When running the noscript, the finder window appears to choose a folder, I get a GUI popup to input a password, but then I get this error:

The action “Run Shell Script” encountered an error: “-: -c: line 143: syntax error: unexpected end of file”

I'm not really sure how to end this noscript, googling is not helping in this specific case either.

Any help would be appreciated!

https://redd.it/115a407
@r_bash