Notifies me through dunst, when volume changes.
It would be nice, if someone could help me, because I don't know a lot about scripting.
I think this problem is not too difficult.
I want to use wireplumber to show me the volume level in percent through
"wpctl get-volume "@DEFAULT_AUDIO_SINK@".
And I want the message to get displayed though the notifier dunst.
https://redd.it/1bs6iec
@r_bash
Building Signal for RaspberryPi. Look over the start of this script?
Using THIS blog post as a start I put this together. This will build but some things are hard coded and Id like to "detect" more. Like pulling a "stable" branch for Signal or always installing the latest nvm. I'm also struggling to use sed correctly to edit the packages.json file to add the "AppImage" part.
Any help is welcome. Hope theres a few folks out there that want this.
​
​
#!/bin/bash
## This script based on Andrea Fortunas blog post here: https://andreafortuna.org/2019/03/27/how-to-build-signal-desktop-on-linux/
## NVH Homepage: https://github.com/nvm-sh/nvm
## Signal-Desktop releases: https://github.com/signalapp/Signal-Desktop/releases
sudo apt install build-essential -y
curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.39.7/install.sh | bash
git clone https://github.com/signalapp/Signal-Desktop.git --branch v7.4.0-beta.2 .local/share/Signal-Desktop ; exit
####EXIT TERMINAL HERE (i think to reset bash enviornment)
cd ~/.local/share/Signal-Desktop/
#sed -i 's/original/new/g' package.json
nvm use ; nvm install 20.9.0 ; npm install --global yarn ; yarn install --frozen-lockfile ; yarn generate ; yarn build-release
mkdir ~/.local/share/applications
cat > ~/.local/share/applications/signal-desktop.desktop <<EOF
Desktop Entry
Name=Signal
Exec=env LANGUAGE=tlh ~/.local/share/Signal-Desktop/release/linux-arm64-unpacked/signal-desktop --no-sandbox %U
Terminal=false
Type=Application
Icon=signal-desktop
StartupWMClass=Signal
Comment=Private messaging from your desktop
MimeType=x-scheme-handler/sgnl;x-scheme-handler/signalcaptcha;
Categories=Network;InstantMessaging;Chat;
EOF
##REMOVAL
#rm -R ~/.local/share/applications/signal-desktop.desktop ~/.local/share/Signal-Desktop ~/.nvm ##.config/Signal/
​
Thanx
https://redd.it/1bru7yk
@r_bash
I've implemented a few utilities to enumerate/disable/enable Linux input devices using Bash shell scripts
https://gitlab.com/brlin/linux-input-utils
https://redd.it/1bqkrca
@r_bash
command help
I want to use a simple one-liner something like this:
whois $domainname | grep "Expir" | xargs $domainname = example.com
Something I can quickly change (or make into an useful alias).
I'm on the hunt for a new domain name, and want to avoid the long wall of text that comes from each whois search.
Is this possible without making it complicated and using script files etc?
https://redd.it/1bq8wii
@r_bash
why does /bin/bash -c 'ssh user@host' work?
I expected keyboard input for ssh running in a child shell to break, and that I would have to do something fancy with wiring the child process input/output to the parent shell's tty, but to my surprise this worked without any fanciness required? Would someone be able to explain what is happening at a low level that enables this to work? Thank you!
https://redd.it/1bptn6k
@r_bash
Validating input and adding a prefix before executing ansible playbook
I am creating a bash script that runs an ansible playbook. So far I have
cd /path/to/playbook
python3 inventory_updater.py
# Check if there are no errors from executing python script.
[ $? -eq 0 ] # Is this an appropriate way to check with an if condition and exit code ?
read -p "Enter store numbers separated by commas (e.g., 22345,28750): " store_numbers
ansible-playbook update_specific_stores.yml -e "target_hostnames=$store_numbers"
. Prompt user if incorrect.
duplicate a telnet entry
I am trying to replicate something simple like this
telnet IP
#011000 (typed in manually)
I hit the enter key and the command executes
when I try to duplicate that
echo '#011000' | netcat -N IP
this does NOT work. I'm guessing because of the carriage return isn't being sent.
What am I missing to get this to work. I'm guessing the echo isn't sending an "enter" key at the end
I also tried
echo '#011000\r' | netcat -N IP
but that didn't work either.
What am I missing?
https://redd.it/1bokgip
@r_bash
grep \ sed \ awk random parameter from a line between special characters
I have a echo of "getend passwd <user>" with format:
randomUsername:<random>:<random>:<random>:randomFullname:<random>:<random>
How to get randomFullname parameter between fixed quantity of special characters like : ?
THX
https://redd.it/1bog8s4
@r_bash
Enhance ArchLinux with this Bash Wrapper for Reflector
Greetings, r/bash and /r/archlinux enthusiasts,
I'm sharing a Bash script designed to automate the updating of your Pacman mirrorlist, ensuring you're always fetching packages from the fastest, most reliable mirrors. This tool not only updates your mirrorlist but also offers the flexibility to create a systemd service for automatic updates at your preferred frequency.
Key Features:
Update your Pacman mirrorlist with mirrors best suited for your region.
Customize the number of mirrors to test, filter by country, protocol, and more.
Create a systemd service to automate updates on an hourly, daily, weekly, or monthly basis.
Includes options for dry runs, logging, and verbose output for detailed process insights.
The script requires root or sudo privileges and is designed with options to tailor its operation to your needs, such as setting the country or region code for mirror filtering, excluding specific mirrors, and adjusting the number of mirrors to test.
Usage: ./update_mirrorlist.sh [OPTIONS]
Options include:
-h, --help for displaying the help menu.
-c, --country <code> to set the country or region code.
--config <path> to use a specific configuration file.
And more, detailed within the script's help section.
Example Commands:
To set the service frequency to daily and test 100 mirrors: ./update_mirrorlist.sh -f daily -m 100
For a dry run using HTTP protocol and creating the systemd service: ./update_mirrorlist.sh -s -p http --dry-run
The script is thoroughly commented, making customization straightforward for those different levels of Bash knowledge. Feel free to adapt, improve, and share your enhancements.
Half of why I post these things is to get feedback on how my submission can be improved and/or just done plain better. You don't know what you don't know.
Cheers!
GitHub Script
Config File
https://redd.it/1bnoxqv
@r_bash
I need to have something to detect and unmount a Windows OS drive. I have some code that I wrote in order to detect it whether it's mounted or not. This works fine so far...
...can I get some help smoothing this code down to something that is just as reliable.
Here is the function. It may be a bit crude but so far it has worked without any hitches. Can I do the same in a better way? This is for a backup script that allows me to find a Windows OS drive whether mounted or not in order to exclude that partition from any backups that are initiated, and the only way I could think of to do that was to look for the "Microsoft reserved" flag that is attached on every drive where an OS is installed. I couldn't reliably look solely for "Microsoft basic data" or anything merely "ntfs" because of /media drives that are formatted as ntfs and don't have any associated OS. This is what I came up with to find the drive partition where the OS is installed. It has been good finding only one Windows OS installed, but I have yet to try it on more than one (one is enough).
[Edit:\] I can't do anything about the formatting. As soon as I enter the change the browser left justifies everything, removing all my white spaces.unmount=true FIND_WIN_PARTITION(){ unset FIND_WIN_OS FIND_WIN_REC WIN_OS_DRIVE ; local FIND_WIN_OS FIND_WIN_REC WIN_OS_DRIVE ; FIND_WIN_REC=$(sudo fdisk -l | grep "Microsoft reserved" | awk '{print $1}') ; # Find the reserved drive flag. FIND_WIN_OS="${FIND_WIN_REC:5:3}" ; # removes ("/dev/") echoing the next 3 characters (sd?, nvm, dis...) if eval sudo fdisk -l | grep "${FIND_WIN_OS}" | grep "Microsoft basic data" | awk '{print $1}' ; then
# Now we can find the Windows OS drive
WIN_OS_DRIVE="$(sudo fdisk -l | grep "${FIND_WIN_OS}" | grep "Microsoft basic data" | grep -v "/media" | awk '{print $1}')" &>/dev/null ;
# unmount, true or false
if [[ "${unmount}" == true ]] ; then
if df | grep "$WIN_OS_DRIVE" &>/dev/null ;then sudo umount -f "$WIN_OS_DRIVE" ;fi ;
fi ;
if [[ -n "${FIND_WIN_OS}" ]] ; then { echo "${FIND_WIN_OS}" ; return 0 ; } ; fi ; else [[ -z ${FIND_WIN_REC} ]] && return 1 ;fi ; }
https://redd.it/1bn484p
@r_bash
performance between xargs and arrays in bash? External programs
In general, how do the performance between xargs and arrays in bash compare? I don't write scripts professionally but for personal scripts, I tend to prefer posix when possible for being ubiquitous (even though this will probably never benefit me for home use) and whatever marginal performances there are.
But it seems arrays are mainly the deciding factor for switching to bash and I was wondering:
How performance compares between xargs in posix script to get array-like features vs. bash's native array support (obviously you can use xargs in bash too but that's irrelevant). Are there other reasons to use one over the other?
Somewhat related to above, is calling external program like xargs always slower than something that can be done natively in the shell? Why is this generally the case, doesn't it depend more on how it's implemented in the external program and in bash, such as the coding language it's implemented in and how well it's optimized?
Unless you handling with a ton of data (not usually the case for simple home scripts unless you're dealing with logs or databases I assume), are there any other reasons to not simply write a script in the simplest way possible to quickly understand what's going on? E.g. Except in the case of logs, databases, or lots of files in the filesystem, I'm guessing you will not shave more than a second or two off execution time if you liberally pipe commands involving e.g. grep, sed, cut, column vs. a single long awk command but unless you're regularly dealing with awk the former seems preferable. I was initially set on learning enough awk to replace all those commands with just awk but now I'm having second thoughts.
I'm also wondering if there's a modern alternative to awk that might be less archaic in syntax/usage (e.g. maybe even a general programming language with libraries to do what awk can). Or perhaps awk is still worth learning in 2024 because it can do things modern applications/languages can't do as well?
https://redd.it/1bmbvy5
@r_bash
Terminals are Colorful and Beautiful with Powerlevel10k
https://dly.to/eIIlIJUvevj
https://redd.it/1bl2zo4
@r_bash
ShellCheck Wrapper Script for Bash Scripting
Hello r/bash,
I've written a Bash script that enhances the use of ShellCheck for linting shell scripts. This is a utility aimed at those who need to ensure their scripts adhere to best practices and are free of common errors.
Key Features:
Recursive or single-directory checking.
Verbose mode for detailed analysis.
Ability to specify ShellCheck exclusions.
Option to output results to a file.
Automatic ShellCheck installation if not present.
Moving error-free scripts to a specified directory.
Summary report of ShellCheck results.
Color output for easier reading.
The script supports various configurations, allowing you to tailor the linting process to your needs, including the exclusion of specific checks and the organization of scripts based on their linting results.
It's a straightforward tool designed to integrate with existing workflows, offering practical options for those looking to improve the quality of their Bash scripts.
Feel free to try it and see if it fits your scripting routine.
Example Usage:
./shellcheck.sh --color -s -d GitHub-Projects -m "$PWD/GitHub-Projects/completed"
./shellcheck.sh --recursive -v --output script-errors.txt
GitHub Script
https://redd.it/1bk5fu2
@r_bash
- %-11s | ♂ | ☿ | ♃ | ♀ | ♄ | ☉ | ☽ |\n" "11" "$hour_day_11"
printf "%-2s - %-11s | ☉ | ☽ | ♂ | ☿ | ♃ | ♀ | ♄ |\n" "12" "$hour_day_12"
printf "%-2s NIGHT---------M---T---W---T---F---S---S-|\n"
printf "%-2s - %-11s | ♀ | ♄ | ☉ | ☽ | ♂ | ☿ | ♃ |\n" "1" "$hour_night_1"
printf "%-2s - %-11s | ☿ | ♃ | ♀ | ♄ | ☉ | ☽ | ♂ |\n" "2" "$hour_night_2"
printf "%-2s - %-11s | ☽ | ♂ | ☿ | ♃ | ♀ | ♄ | ☉ |\n" "3" "$hour_night_3"
printf "%-2s - %-11s | ♄ | ☉ | ☽ | ♂ | ☿ | ♃ | ♀ |\n" "4" "$hour_night_4"
printf "%-2s - %-11s | ♃ | ♀ | ♄ | ☉ | ☽ | ♂ | ☿ |\n" "5" "$hour_night_5"
printf "%-2s - %-11s | ♂ | ☿ | ♃ | ♀ | ♄ | ☉ | ☽ |\n" "6" "$hour_night_6"
printf "%-2s - %-11s | ☉ | ☽ | ♂ | ☿ | ♃ | ♀ | ♄ |\n" "7" "$hour_night_7"
printf "%-2s - %-11s | ♀ | ♄ | ☉ | ☽ | ♂ | ☿ | ♃ |\n" "8" "$hour_night_8"
printf "%-2s - %-11s | ☿ | ♃ | ♀ | ♄ | ☉ | ☽ | ♂ |\n" "9" "$hour_night_9"
printf "%-2s - %-11s | ☽ | ♂ | ☿ | ♃ | ♀ | ♄ | ☉ |\n" "10" "$hour_night_10"
printf "%-2s - %-11s | ♄ | ☉ | ☽ | ♂ | ☿ | ♃ | ♀ |\n" "11" "$hour_night_11"
printf "%-2s - %-11s | ♃ | ♀ | ♄ | ☉ | ☽ | ♂ | ☿ |\n" "12" "$hour_night_12"
}
# displays planetary hours using parameters
day_number="$1"
# Set variable for the specific day
case $day_number in
1) echo -n "$MOON" ; day_var="MONDAY_MOON_" ;;
2) echo -n "$MARS" ; day_var="TUESDAY_MARS_" ;;
3) echo -n "$MERCURY" ; day_var="WEDNESDAY_MERCURY_" ;;
4) echo -n "$JUPITER" ; day_var="THURSDAY_JUPITER_" ;;
5) echo -n "$VENUS" ; day_var="FRIDAY_VENUS_" ;;
6) echo -n "$SATURN" ; day_var="SATURDAY_SATURN_" ;;
7) echo -n "$SUN" ; day_var="SUNDAY_SUN_" ;;
8) day_var="PLANETARY_HOURS_CHART_" ;;
*)
# If day_number was set but is not valid
if [[ -n "$day_number" ]]; then
echo "Invalid day number. Please provide a number from 1 to 8."
exit 1
fi
esac
# Activate the selected day's variable
if [[ -n "$day_var" ]]; then
declare "$day_var=1"
fi
# Check each variable and call the corresponding function if enabled
if [ "${MONDAY_MOON_}" -eq 1 ]; then MONDAY_MOON; fi
if [ "${TUESDAY_MARS_}" -eq 1 ]; then TUESDAY_MARS; fi
if [ "${WEDNESDAY_MERCURY_}" -eq 1 ]; then WEDNESDAY_MERCURY; fi
if [ "${THURSDAY_JUPITER_}" -eq 1 ]; then THURSDAY_JUPITER; fi
if [ "${FRIDAY_VENUS_}" -eq 1 ]; then FRIDAY_VENUS; fi
if [ "${SATURDAY_SATURN_}" -eq 1 ]; then SATURDAY_SATURN; fi
if [ "${SUNDAY_SUN_}" -eq 1 ]; then SUNDAY_SUN; fi
if [ "${PLANETARY_HOURS_CHART_}" -eq 1 ]; then PLANETARY_HOURS_CHART; fi
https://redd.it/1bjpl4w
@r_bash
Printf -v var
Works
printf -v var “%s” “hi”
echo “$var”
Works
printf “%s” “hi” | tee somefile
cat somefile
Why this one doesnt work?
printf -v var “%s” “hi” | tee somefile
echo “$var” # var is empty
cat somefile # file is empty
https://redd.it/1brz5a9
@r_bash
So what is your bash coding environment?
It's a quiet Saturday on the subreddit, so I was curious.
My setup is:
Neovim → conquer of completion (coc.nvim) → coc-sh Current version 1.2.2
I do want to learn lua to set up those nvim language server protocol to skip coc. Just not that good on learning new things.
I do not have any other bash related plugins. Ok, I use nerdtree to navigate sourced files, but I don't think that counts.
My PS4='•\[\e[1;33m\] ${BASH_SOURCE[0]##*/} ${LINENO}\[\e[m\] '
So I usually have the code in my right pane and the execution of the code with bash -x on the left, to see where I messed up.
Any workflow, cool plugins you might want to share?
https://redd.it/1brm1iy
@r_bash
Help with quotes and variables
Hi all, I am new to bash. I have a problem to which I haven't found a solution yet. I am starting to learn right now, so forgive me if my knowledge of bash isn't the best at all.
What I want to achieve is this output:
command $d
Where "command" is a command and $d is a variable. The variable d is based on another variable, called a.
It's something like this: d="/home/name/$a".
The problem is that variable a contains single quotes, like this: a='name of the file'
So, as you can guess the idea is to launch a command with the path of the file. However, the single quotes make it very difficult because when under the double quotes ("") are interpreted differently. How can I overcome this problem?
https://redd.it/1bqlxcj
@r_bash
Bash script help to launch docker container
I’m running Debian 12 and I have a Windows 11 docker container that I use with FreeRDP. I would like to have an “app” for lack of a better term that when clicked would start the windows container and start FreeRDP. I’ve written an easy little bash script that starts both the container and FreeRDP. I’m running into trouble checking to see if the windows container is already running. If it is, then just launch FreeRDP. If not, launch both.
I also need to have the script automatically stop the Windows container when I close out of FreeRDP.
Anyone have any ideas about the best way to do this?
https://redd.it/1bqbad2
@r_bash
TIL: not all line continuations are the same
An unquoted slash `\` can be used to continue some command onto the next line:
$ echo abc \
> def
abc def
Both `||` and `&&` act like that:
$ echo abc &&
> echo def
abc
def
$ ! echo 123 ||
> echo 345
123
345
But there is something more to the last two: you can put multiple newlines OR comments in-between:
$ echo abc &&
>
> # some
> # comment
>
> echo def
abc
def
Or in a more practical code:
[[ $repack_early3 == n ]] ||
# The symlink is no longer needed
rm "$initrd_main/lib/modules/$kernel/kernel"
https://redd.it/1bq0enr
@r_bash
What is the role of bash script in Machine Learning?
This is the requirement of a ML intern. Can anyone tell me what is the use cases of bash script in ML field?
Thanks in Advance
Qualifications
A bachelor’s, master's, or PhD (ongoing or complete) degree or equivalent from a top university, available to join for an in-office Summer Internship from May 2024.
Prior experience with training, building, and deploying models via Tensorflow/Pytorch (or similar) is mandatory.
Experience with CI/CD pipelines and MLOps for automating model deployments.
Skilled in using Linux, SQL, Git, and BASH scripting.
Strong knowledge of Python and hands-on.
https://redd.it/1bpnvp0
@r_bash
Help with variables
Hi all. I am not a programmer though I have some basics of coding from some years ago. I tried writing a script for my computer (Linux) mostly for fun.
I don't know much of bash, but since the script was overall easy, I only read the very basics.
The idea of the script is to launch some games with MelonDS or mgba.
The command for melonDS is "melonDS path/of/the game".
The script:
- lists the games
-asks for input for the name of the game and stores the name in a variable (a)
- if the last three letters are "nds" then executes the command "melonDS path/$a" (where a is the name of the game)
- haven't written the rest yet
The problem is that I don't understand what I might be doing wrong, because the final result is indeed "melonDS /path/of/the game" but melonDS just launches without the actual game. When I run the exact same command from terminal, it works.
Sorry, if this is maybe a noob mistake, that's my real first script.
Update:code
Update 2: I noticed that the "d" variable part was wrong. Thanks for pointing out!
Now, I noticed that the name and path is not stored in the correct way. There are the '\' signs, so the final command comes out wrong.
picture
https://redd.it/1bpc37r
@r_bash
rsync-based mv--remove dirs in source as they get synced?
I'm implementing an rsync-based version of mv because destination is not reliable (not using --checksum though, rsync by default compares file sizes and modification times which I assume is good enough for media files)?
Any way, with --remove-source-files it only removes files, leaving behind empty directories under the source directory. I handle this manually by checking if there are files in source dir after the rsync operation and if not, rm -r it.
However, the rsync operation is potentially very long and I would like it to behave like mv where as a file gets moved, it gets deleted (vs. the existing behavior described above where empty remaining directories do not get deleted).
Is there a way to implement this without invoking an rsync on every sub directory of source directory (so that when each sub directory gets synced, rsync ends so clean up of files can begin for that sub directory)? I imagine that would significantly slow down performance of the overall sync. I guess rync would need to support some kind of hook otherwise (not that I would expect it to, it's not inline with unix philosophy of just doing one thing well).
https://redd.it/1boex01
@r_bash
crap
alias crap to cat so you can crap out files
https://redd.it/1bnrd5a
@r_bash
compgen -c
Hi,
I'm getting a bit confused with this command, I have a few machines that are configured in the same way, same bash version and distro, etc.
I've noticed that in one of those machines the output of `compgen -c` is sligthly different than on the rest, for example, commands that start with the letter k such as keepass* are grouped together, but on this machine it isn't.
Does anyone know what determines the output/ordering with this command? Does the number of installed programs affect it? I've checked things like the locale and it's all configured exactly the same.
Thanks.
https://redd.it/1bni2k2
@r_bash
Is it better to use if or [ for simple checks?
I'm not new to bash, but I don't know most things behind the scenes of bash script. So, if I'm doing something simple like checking if a variable has a value, is it better to use an if statement, or \[\[? Or does it even matter?
Example:
my_var="some value"
[[ "$my_var" ] && {
: Do something
}
if [ "$my_var" ]; then
: Do something
fi
​
https://redd.it/1bn3gu7
@r_bash
Docker log monitoring script help
I have a script that's monitoring the new log entries using:
docker logs -f -n 0 <container>
The problem is that when the container restarts, the script stops. I was able to get around it by putting it in a while loop that checks for the container name in docker ps:
docker ps | while read line; do if [ ${line} != *"<container>"* ]; then sleep 30; ...
I added the sleep to give the container the chance to spin up, and it works, but I'm sure there's probably an easier way. I'm completely new to bash, fairly new to linux, but with a little programming experience. Is there a way to keep the script alive even after the container stops without it erroring out?
https://redd.it/1bltzyc
@r_bash
BashPitfall local -g var is Pretty Useless
[Credit: This post was inspired by what seemed to be an odd comment in another thread.\]
Can you guess what this code prints?
z=42
a() {
local z
z=27
b
echo "a/z=$z"
}
b() {
local -g z
z=79
}
a
echo "main/z=$z"
If you guessed a/z is 27 and main/z is 79, because z in b() points to the global z, I'm afraid you've been misled by the bash docs:
$ ./test.sh
a/z=79
main/z=42
This code, however, prints a/z=27 and main/z=79:
z=42
a() {
local z
z=27
b
echo "a/z=$z"
}
b() {
local -g z=79
}
a
echo "main/z=$z"
And this one complains z: unbound variable:
set -u
a() {
local z
z=27
b
echo "a/z=$z"
}
b() {
local -g z
z=79
}
a
echo "main/z=$z"
But this one, that combines the declaration and assignment of global z, doesn't:
set -u
a() {
local z
z=27
b
echo "a/z=$z"
}
b() {
local -g z=79
}
a
echo "main/z=$z"
See, the description for declare (to which local is a rough twin) says this:
>The -g option forces variables to be created or modified at the global scope, even when declare is executed in a shell function. It is ignored in all other cases.
But you also have to take into account dynamic scoping, also documented in the man page:
>The shell uses dynamic scoping to control a variable's visibility within functions. With dynamic scoping, visible variables and their values are a result of the sequence of function calls that caused execution to reach the current function. The value of a variable that a function sees depends on its value within its caller, if any, whether that caller is the "global" scope or another shell function. This is also the value that a local variable declaration "shadows", and the value that is restored when the function returns.
Everyone who's used local to shadow a throwaway variable like i from another variable named i in its caller function knows this in their gut.
But what the docs don't say is that the only thing local -g var is good for is enabling functions to create/modify global variables with special declare attributes, like the -A (associative array) flag, and only if you assign a value at the same time:
set -u
a() {
local z
z=27
b
echo "a/z=$z"
}
b() {
local -gA z=(Hi=there Lo=blow)
}
a
declare -p h
yields, instead of z: unbound variable...
$ ./test.sh
a/z=27
declare -A z=(Lo="blow" Hi="there" )
but divorce the assignment from the declaration:
set -u
a() {
local z
z=27
b
echo "a/z=$z"
}
b() {
local -gA z
z=(Hi=there Lo=blow)
}
a
declare -p z
and you get this, because this b's z is actually a's z, which is clearly not an associative array:
$ ./test.sh
./test.sh: line 11: Hi: unbound variable
Confused? So was I, so I filed a bug report, which led to an interesting email chat with Chet Ramey and the other bash maintainers. The upshot:
1. NOTABUG, but we'll accept documentation suggestions to remove this confusion.
2. Yes, a local -g var declaration-without-assignment is Pretty Useless.
https://redd.it/1bk9iyb
@r_bash
Seeing error message if stopped by set -e
We use set -e so that the bash script stops if a non-zero exit code happens.
But this unfortunately this silently stops. You don't see an error message from bash.
I got the recommendation to add this:
trap 'echo "Warning: A command has failed. Exiting the script. Line was ($0:$LINENO): $(sed -n "${LINENO}p" "$0")"; exit 3' ERR
"$start12"
"$start13" "$start14" "$start15" "$start16" "$start17" "$start18"
"$start19" "$start20" "$start21" "$start22" "$start23" "$start24"
)
# Loop through each time slot and check the planetary hour
for ((i = 0; i < ${#starts[@]}; i++)); do
next_index=$(( (i + 1 ) % ${#starts[@]} ))
check_time "${starts[i]}" "${starts[next_index]}" "${day_planets[i]}"
done
echo
}
# Day-specific functions: Define functions for each day to check and output planetary hours.
MONDAY_MOON() {
check_planetary_hours "$MOON" "$SATURN" "$JUPITER" "$MARS" "$SUN" "$VENUS" "$MERCURY" \
"$MOON" "$SATURN" "$JUPITER" "$MARS" "$SUN" "$VENUS" "$MERCURY" \
"$MOON" "$SATURN" "$JUPITER" "$MARS" "$SUN" "$VENUS" "$MERCURY" \
"$MOON" "$SATURN" "$JUPITER"
}
TUESDAY_MARS() {
check_planetary_hours "$MARS" "$SUN" "$VENUS" "$MERCURY" "$MOON" "$SATURN" "$JUPITER" \
"$MARS" "$SUN" "$VENUS" "$MERCURY" "$MOON" "$SATURN" "$JUPITER" \
"$MARS" "$SUN" "$VENUS" "$MERCURY" "$MOON" "$SATURN" "$JUPITER" \
"$MARS" "$SUN" "$VENUS"
}
WEDNESDAY_MERCURY() {
check_planetary_hours "$MERCURY" "$MOON" "$SATURN" "$JUPITER" "$MARS" "$SUN" "$VENUS" \
"$MERCURY" "$MOON" "$SATURN" "$JUPITER" "$MARS" "$SUN" "$VENUS" \
"$MERCURY" "$MOON" "$SATURN" "$JUPITER" "$MARS" "$SUN" "$VENUS" \
"$MERCURY" "$MOON" "$SATURN"
}
THURSDAY_JUPITER() {
check_planetary_hours "$JUPITER" "$MARS" "$SUN" "$VENUS" "$MERCURY" "$MOON" "$SATURN" \
"$JUPITER" "$MARS" "$SUN" "$VENUS" "$MERCURY" "$MOON" "$SATURN" \
"$JUPITER" "$MARS" "$SUN" "$VENUS" "$MERCURY" "$MOON" "$SATURN" \
"$JUPITER" "$MARS" "$SUN"
}
FRIDAY_VENUS() {
check_planetary_hours "$VENUS" "$MERCURY" "$MOON" "$SATURN" "$JUPITER" "$MARS" "$SUN" \
"$VENUS" "$MERCURY" "$MOON" "$SATURN" "$JUPITER" "$MARS" "$SUN" \
"$VENUS" "$MERCURY" "$MOON" "$SATURN" "$JUPITER" "$MARS" "$SUN" \
"$VENUS" "$MERCURY" "$MOON"
}
SATURDAY_SATURN() {
check_planetary_hours "$SATURN" "$JUPITER" "$MARS" "$SUN" "$VENUS" "$MERCURY" "$MOON" \
"$SATURN" "$JUPITER" "$MARS" "$SUN" "$VENUS" "$MERCURY" "$MOON" \
"$SATURN" "$JUPITER" "$MARS" "$SUN" "$VENUS" "$MERCURY" "$MOON" \
"$SATURN" "$JUPITER" "$MARS"
}
SUNDAY_SUN() {
check_planetary_hours "$SUN" "$VENUS" "$MERCURY" "$MOON" "$SATURN" "$JUPITER" "$MARS" \
"$SUN" "$VENUS" "$MERCURY" "$MOON" "$SATURN" "$JUPITER" "$MARS" \
"$SUN" "$VENUS" "$MERCURY" "$MOON" "$SATURN" "$JUPITER" "$MARS" \
"$SUN" "$VENUS" "$MERCURY"
}
PLANETARY_HOURS_CHART(){
printf " DAY-----------M---T---W---T---F---S---S--\n"
printf "%-2s - %-11s | ☽ | ♂ | ☿ | ♃ | ♀ | ♄ | ☉ |\n" "1" "$hour_day_1"
printf "%-2s - %-11s | ♄ | ☉ | ☽ | ♂ | ☿ | ♃ | ♀ |\n" "2" "$hour_day_2"
printf "%-2s - %-11s | ♃ | ♀ | ♄ | ☉ | ☽ | ♂ | ☿ |\n" "3" "$hour_day_3"
printf "%-2s - %-11s | ♂ | ☿ | ♃ | ♀ | ♄ | ☉ | ☽ |\n" "4" "$hour_day_4"
printf "%-2s - %-11s | ☉ | ☽ | ♂ | ☿ | ♃ | ♀ | ♄ |\n" "5" "$hour_day_5"
printf "%-2s - %-11s | ♀ | ♄ | ☉ | ☽ | ♂ | ☿ | ♃ |\n" "6" "$hour_day_6"
printf "%-2s - %-11s | ☿ | ♃ | ♀ | ♄ | ☉ | ☽ | ♂ |\n" "7" "$hour_day_7"
printf "%-2s - %-11s | ☽ | ♂ | ☿ | ♃ | ♀ | ♄ | ☉ |\n" "8" "$hour_day_8"
printf "%-2s - %-11s | ♄ | ☉ | ☽ | ♂ | ☿ | ♃ | ♀ |\n" "9" "$hour_day_9"
printf "%-2s - %-11s | ♃ | ♀ | ♄ | ☉ | ☽ | ♂ | ☿ |\n" "10" "$hour_day_10"
printf "%-2s