r_bash – Telegram
How to fix unbound variables?

I've been using the following noscript for several years without issues.

https://github.com/Cody-Learner/aurch/blob/main/aurch

When I try to implement set -euo pipefail in the noscript, specifically the set -u exits with line 23: 2: unbound variable.

Trying to see how many unbound variables there are, I comment out line 23, and it fails on line 45 now. Comment out line 45 and 46, it still exits with line 45: package: unbound variable

1) I don't understand why set -u won't ignore line 45/46 being commented out.
2) I have no idea how to fix these unbound variables, because they work, without them the noscript would be broken, and they're obviously being set or the noscript would fail to work properly.

What am I not getting with "unbound variables" and possibly provide an alternate method to noscript a problematic lines for an example?

https://redd.it/1bh6fwj
@r_bash
How to play a beep when the emby server process die using a bash noscript.

Hello to everyone.

I'm trying to keep up one Emby server on my ARM Chromebook arm 32 bit aka SNOW where I have installed Devuan 5.

The real problem is that it is up only for some time and then it closes.

To fix this problem,I've added this line :

​

7:2345:respawn:/opt/emby-server/bin/emby-server

to /etc/inittab.

Furthermore,for the sake of my curiosity I would like to hear a beep when the emby server process dies. I tried some noscripts written in bash found on Internet,but none of them worked.

​

​

https://redd.it/1bheafr
@r_bash
Pass arguments to other noscript

In bash noscript ./noscript there is such line

su - usr -c "VAR1=text VAR2=text command --options"

I want if I call like ./noscript --outside-option outside-value then inside noscript will be called like

su - usr -c "VAR1=text VAR2=text command --options --outside-option outside-value"

So in noscript I changed line to

su - usr -c "VAR1=text VAR2=text command --options $@"

But that isn't working. command shows error like it is detecting --outside-option without outside-value.

It is recommended to always surround $@ with quotes like "$@". Is that the cause for error? I can't see how to escape it properly inside quotes in the noscript.

https://redd.it/1bhdx6b
@r_bash
Command not Found in Script Only

Hi,

I recently starting learning bash. I thought to create a bash noscript to automate installing and configuring ollama.

#!/usr/bin/bash
curl -fsSL https://ollama.com/install.sh | sh // This is for installing ollama
ollama run llama2
touch Modelfile
// rest of file


Once it reach line 3, it says command not found: ollama and the noscript fails from that point. What could be the problem?

https://redd.it/1bhr4yi
@r_bash
Securely Store API Key & Use Crontab

Hi, I have a bash noscript which requires an API key for SendGrid to send an email. I am planning on calling this noscript every 6hrs so adding to crontab.

What are the best practices for storing the API key? Obviously not in the noscript itself but I have read that environment variables is also not great and the fact that I want to call via crontab.

Thoughts? Thanks.

https://redd.it/1bhs5zh
@r_bash
i am running rsync in a while loop and it isn't releasing when finished.

Everything runs as it should, but at the end of the program rsync isn't signalling that it is finished and the "Working" stays in an infinite loop until I shut it down. What am I missing? I should be simple enough, print out the stuff while the program runs, when finished, stop.

​

RUN_RSYNC() {
tput sc ; tput civis ; tput ed ; size=5 ;
host=$1 ; dest=$2 ;
declare exitcode ;
printf '\t%s\r\t' "One moment. Checking destination drive..." ;
while [[ $( rsync "${RSYNC_FLAGS[*]}" -- "${host}/" "${dest}" | sed "s/^/$(date +%m-%d-%Y_%H%M)\t>>\t" |& tee -a "${RSYNC_LOG}" ) != 0 ]] ; do
unset i ;
tput el ;
printf '\r\tWorking' ;
for (( i=1 ; i<="${size}" ; i++ )) ; do
printf '%s' "." ;
sleep 0.5 ; done ;
printf '\r\tWorking' ;
for (( i=1 ; i<="${size}" ; i++ )) ; do
printf '%s' " " ;
sleep 0.5 ; done ;
printf '\r' ;
done ;
exitcode=$? ;
return "${exitcode}" ;
tput cnorm ; tput rc ;
} ;

Edit: I have tried not using != 0, and using just the process itself, and there is the same issue

https://redd.it/1bhuqn4
@r_bash
what are favorite commands in bash?

so i searched "what are favorite commands in bash?" in reddit and i was surprised to find that this question doesn't seem to have ever been asked in r/bash

so i wanted to take this opportunity, what are your favorite commands in the bash shell and why?

doesn't matter why you like them, or what their purpose is, just what are your flat out favorite commands and why?

thank you

https://redd.it/1biemu1
@r_bash
Anyone know of a pure-bash hack to read 1 byte *before* a file denoscriptor's current byte offset?

Im trying to find a [better] solution to a very specific and unusual problem.

I have two processes using the same file. One is appending data to the end of this file

cat >>file &

The other is reading from the start of the file in chunks of `N` lines using

{ while true; do
...
mapfile [-t] -d $delim -n $N -u $fd A
...
done; } {fd}<file

Problem is that the reading process can occasionally "catch up" to the writing process while it is buffering data. When this happens it hits an EOF and returns, often in the middle of a line. The code this is in requires lines to be read as complete lines (not partial ones), making this a problem.

Unfortunately, `mapfile` (unlike `read`) does not change its exit status / return value depending on whether or not returned because you hit an EOF. As such, the only way ive thought of to detect this is to check if the last byte read was a `$delim` or not. Hense this question.

Any ideas? I have a working approach right now, but being able to, say, rewind the file denoscriptor 1 byte and then read 1 byte would be a considerably faster and more efficient solution. (this is going in my [forkrun](https://github.com/jkool702/forkrun/blob/main/forkrun.bash) utility, which I am always trying to make faster and more efficient).

Thanks in advance.

Side note: The ${fd} file denoscriptor cannot be closed between reads, as it is shared with other processes. ponly 1 process reads at a given time, but when 1 is done the next picks up where it left off, requiring the file denoscriptor to stay open. It could, perhaps, be locally overwritten for the current reading process though.

***

***

### CURRENT APPROACH

My current approach is typically to drop the `-t` from mapfile, then check if the last char of the last element in `A` is a `$delim`, and if not loop `read` until i hit one and append to the last element.

mapfile -d $delim -n $N -u $fd A
[[ "${A[-1]: -1}" == "$delim" ]] || {
until read -r -d $delim -u $fd; do
A[-1]+="$REPLY"
done
}
A=("${A%"$delim"}")

# note that `read` returns `false` if it hits an EOF (or times out) and `true` otherwise

I say "typically" because this doesnt work if the delimiter is a NULL, since bash drop's NULL's regardless if you use mapfile's `-t` flag. In this case I get the last byte read by figuring out the byte position using procfs, then using `dd` to skip to that byte position in the file and read 1 byte:

mapfile -t -d '' -n $N -u $fd A
read -r fd_pos </proc/self/fdinfo/$fd
fd_pos="${fd_pos%%$'\t'*}"
dd if=file bs=1 count=1 skip=$((fd_pos-1)) status=none | read -r -d '' || {
until read -r -d '' -u $fd; do
A[-1]+="$REPLY"
done
}

***

***

Id love to replace these both with something like

mapfile -t -d $delim -n $N -u $fd A
rewind_FD_1_byte $fd
read -r -n 1 -u $fd
[[ ${REPLY} ]] || {
until read -r -d $delim -u $fd; do
A[-1]+="$REPLY"
done
}

https://redd.it/1bilrb2
@r_bash
get return code of command in new process

hello

im currently writing (or rather improving) a noscript i wrote in bash. its basically an alarm timer, that automatically pauses media playback, so you can actually hear the notification sound. over the time i included more features, the latest being the option to launch a program, when the timer is finished.

i want the noscript to continue after launching the progam and display a notification if launching fails.

the way i solved it is this

( eval "$command" || info_window "command '${command}' could not be executed" ) &

but i am not content with this, since the or statement also runs in the new process. however i couldnt find a way to get this right. yesterday i tried to find a solution, but i wasnt really successful.

i thought something like this

eval "$command" &
wait $! || info_window "command '${command}' could not be executed"

could be the solution, but its not. wait does what it says, it waits until the program is finished. i wanna get the return code, not the exit code.

i would really like to find a clean solution, but the only other option i could think of is creating a tempfile

( eval "$command" || temp=$(mktemp) ) &
[[ -f "$temp" ]] && info_window "command '${command}' could not be executed"

this should work i think, i didnt actually try it yet. theres got to be a cleaner solution for this!

thanks in advance

https://redd.it/1biqz5b
@r_bash
How to kill a process identifying it with the maximum precision...

Hello.

I'm trying to create a menu to be able to connect to the gateways offered by the VPN provider that I use,in realtime,because this feature is not present for the FreeBSD users. I've almost finished the noscript. It works,but it needs only a little bit more refining. This is the structure that I use to select the gateways :

select opt in "${options[@]}"
do
case $opt in
"1. Cairo")
/usr/local/sbin/openvpn --cd /usr/local/etc/
openvpn --daemon openvpn --config /home/marietto/Desktop/
Files/Gateways/openvpn.conf
echo "Tryng to connect..." && sleep 3
VPN_IP="$(curl api.ipify.org)"
echo $PUBLIC_IP
echo $VPN_IP
if [ "${PUBLIC_IP}" = "${VPN_IP}" ]; then
echo "This gateway didn't work. Try another
one."
ps ax | grep openvpn
ps ax | grep openvpn | awk '{ print $1; }' |
xargs kill -9
else
echo "Now you are connected to Cairo."
fi
;;

This is what happens when I run it :

==> ./start-vpn

kill: 6281: No such process

% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 13 100 13 0 0 50 0 --:--:-- --:--:-- --:--:-- 50

1) 1. Cairo

Please enter your choice: 1

Tryng to connect...

This gateway didn't work. Try another one.

6287 - Ss 0:00,00 /usr/local/sbin/openvpn --cd /usr/local/etc/openvpn --daemon openvpn --config /

6291 1 R+ 0:00,00 grep openvpn (ggrep)

kill: 6293: No such process

I want to suppress this error : ---> kill: 6293: No such process

I think that it happens because this command :

ps ax | grep openvpn | awk '{ print $1; }' | xargs kill -9

should be modified because it kills the two processes above (6287 and 6291) but it should kill only the first one. Can someone help me ?

https://redd.it/1bix3a5
@r_bash
Favorite PS1 in .bashrc?

I read this post asking for people's favorite bash commands, and it got me thinking about what people like to use for their PS1. And the last time it was asked was 9 years ago (here), so there surely have to be newer ones people have created, right?

PS2 suggestions are obviously welcome as well.

https://redd.it/1bj3mm0
@r_bash
Help with automation noscript!

Hello guys! I am trying to make an automated installer for my tool, I have only 2 problems.

&#x200B;

function configurervm() {
create
cwuser

gpg --keyserver hkp://keyserver.ubuntu.com --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 7D2BAF1CF37B13E2069D6956105BD0E739499BDB
gpg2 --keyserver hkp://keyserver.ubuntu.com --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 7D2BAF1CF37B13E2069D6956105BD0E739499BDB
curl -sSL
https://get.rvm.io | bash -s stable

export rvm
path="$HOME/.rvm"
source /etc/profile.d/rvm.sh

adduser folder rvm
}

function setupfolder() {
local secret=$(head /dev/urandom | tr -dc A-Za-z0-9 | head -c 63 ; echo '')
local RAILS
ENV=production
getpgpass

sudo -i -u folder << EOF
rvm --version
rvm autolibs disable
rvm install "ruby-3.2.2"
rvm use 3.2.2 --default

git clone
https://gitlab.com/xxxx/xxxx.git folder
echo "GitLab login successful."
cd folder
git folder "
$BRANCH"
bundle
yarn

cp .env.example .env
sed -i -e "/SECRET
KEYBASE/ s/=.*/=$secret/" .env
sed -i -e '/REDIS
URL/ s/=./=redis:\/\/localhost:6379/' .env
sed -i -e '/POSTGRES_HOST/ s/=.
/=localhost/' .env
sed -i -e '/POSTGRESUSERNAME/ s/=.*/=folder/' .env
sed -i -e "/POSTGRES
PASSWORD/ s/=./=$pg_pass/" .env
sed -i -e '/RAILS_ENV/ s/=.
/=$RAILSENV/' .env
echo -en "\nINSTALLATION
ENV=linuxnoscript" >> ".env"

rake assets:precompile RAILS
ENV=production NODEOPTIONS=--openssl-legacy-provider
EOF
}


this step source /etc/profile.d/rvm.shThe other problem I have, something exactly similar happens to me... which is here:

&
#x200B;

function install
dependencies() {
apt update && apt upgrade -y
apt list --upgradable -a
apt --fix-broken install
apt install -y curl gnupg gnupg1 gnupg2
curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add -
echo "deb https://dl.yarnpkg.com/debian/ stable main" | tee /etc/apt/sources.list.d/yarn.list
curl -fsSL https://packages.redis.io/gpg | sudo gpg --dearmor -o /usr/share/keyrings/redis-archive-keyring.gpg
echo "deb signed-by=/usr/share/keyrings/redis-archive-keyring.gpg https://packages.redis.io/deb $(lsbrelease -cs) main" | sudo tee /etc/apt/sources.list.d/redis.list
mkdir -p /etc/apt/keyrings
curl -fsSL
https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key | sudo gpg --dearmor -o /etc/apt/keyrings/nodesource.gpg
NODE
MAJOR=20
echo "deb signed-by=/etc/apt/keyrings/nodesource.gpg https://deb.nodesource.com/node$NODEMAJOR.x nodistro main" | sudo tee /etc/apt/sources.list.d/nodesource.list

apt update

apt install -y \
git software-properties-common ca-certificates imagemagick libpq-dev \
libxml2-dev libxslt1-dev file g++ gcc autoconf build-essential \
libssl-dev libyaml-dev libreadline-dev gnupg2 \
postgresql-client redis-tools \
nodejs yarn patch ruby-dev zlib1g-dev liblzma-dev \
libgmp-dev libncurses5-dev libffi-dev libgdbm6 libgdbm-dev sudo \
libvips python3-pip
}




once it is finishing it throws spanpd firefox pkg error... but here again if I manually run the apt --fix-broken install and run the noscript again everything works perfectly... this apt --fix I already have -broken install in the noscript but it doesn't seem to run.



https://redd.it/1bj2s55
@r_bash
Planetary hours in Shell Script

Greetings to all,

I have developed a Shell Script named AstroICON, a straightforward noscript that displays the weekday in relation to the planet and the planetary hour. I am sharing this code as I am aware that there are individuals in this community who are engaged in astrology and utilize Linux. This noscript operates seamlessly on i3blocks and, I believe, should also function correctly on polybar.

To use it, the process is quite simple: grant execution permission with chmod +x AstroICON\_v1.2A.sh
. Then, set the variables for sunrise, sunset, and the following day's sunrise times in the 24-hour format. After these steps, you can run the noscript using ./AstroICON\_v1.2A.sh
. It is worth noting that the noscript accepts parameters from 1 to 8, and if no parameter is provided, it automatically determines the current day and planetary hour.

If anyone is interested in enhancing the noscript, please feel free to do so; just get in touch. Warm regards to everyone.

Below is the code:

#!/bin/bash

# Configuration section: Enables or disables functionality for each day of the week and for the planetary hours chart.
# Set to 1 to enable or 0 to disable the functionality for the respective day or feature.
#IMPORTANT (The day variables must not exceed line 15): this version of the program is automatic and uses sed to configure the variables according to the day of the week, it does not require manual configuration, only the sunrise, sunset and next sunrise times must be configured manually.
MONDAY_MOON_=0
TUESDAY_MARS_=0
WEDNESDAY_MERCURY_=0
THURSDAY_JUPITER_=0
FRIDAY_VENUS_=0
SATURDAY_SATURN_=0
SUNDAY_SUN_=0
PLANETARY_HOURS_CHART_=0

# The name defined by the FILE variable must be the same as the file name
FILE="AstroICON_v1.2A.sh"

# Variable to control the display of the current day's planet symbol.
DAY_OF_WEEK_=1

# Time configuration: Define sunrise and sunset times in 24-hour format.
HOUR_SUNRISE="06"
MINUTES_SUNRISE="11"
HOUR_SUNSET="18"
MINUTES_SUNSET="30"
HOUR_SUNRISE_OF_NEXT_DAY="06"
MINUTES_SUNRISE_OF_NEXT_DAY="11"

# Planet symbols: Assigns icons for each planet.
MOON="☽"
MARS="♂"
MERCURY="☿"
JUPITER="♃"
VENUS="♀"
SATURN="♄"
SUN="☉"

# always resets variables to 0
sed -i '1,15s/MONDAY_MOON_=1/MONDAY_MOON_=0/' "$FILE"
sed -i '1,15s/TUESDAY_MARS_=1/TUESDAY_MARS_=0/' "$FILE"
sed -i '1,15s/WEDNESDAY_MERCURY_=1/WEDNESDAY_MERCURY_=0/' "$FILE"
sed -i '1,15s/THURSDAY_JUPITER_=1/THURSDAY_JUPITER_=0/' "$FILE"
sed -i '1,15s/FRIDAY_VENUS_=1/FRIDAY_VENUS_=1/' "$FILE"
sed -i '1,15s/SATURDAY_SATURN_=1/SATURDAY_SATURN_=0/' "$FILE"
sed -i '1,15s/SUNDAY_SUN_=1/SUNDAY_SUN_=0/' "$FILE"

# Conditional reset: Checks if any command-line argument is passed and resets the configuration.
if [[ $# -gt 0 ]]; then
MONDAY_MOON_=0
TUESDAY_MARS_=0
WEDNESDAY_MERCURY_=0
THURSDAY_JUPITER_=0
FRIDAY_VENUS_=0
SATURDAY_SATURN_=0
SUNDAY_SUN_=0
PLANETARY_HOURS_CHART_=0
DAY_OF_WEEK_=0
fi

# Total minutes in a day
TOTAL_MINUTES_IN_DAY=1440

# Convert sunrise and sunset times to total minutes from midnight
MINUTES_SUNRISE_TOTAL=$((HOUR_SUNRISE * 60 + MINUTES_SUNRISE))
MINUTES_SUNSET_TOTAL=$((HOUR_SUNSET * 60 + MINUTES_SUNSET))

# Calculate total daylight minutes
DAYLIGHT_MINUTES=$((MINUTES_SUNSET_TOTAL - MINUTES_SUNRISE_TOTAL))
# Calculate daylight period per hour
DAYLIGHT_PERIOD=$((DAYLIGHT_MINUTES / 12))

# Calculate total night minutes
# Note: This calculation assumes that the sunrise of the next day is the end of the night period
MINUTES_SUNRISE_NEXT_DAY_TOTAL=$((HOUR_SUNRISE_OF_NEXT_DAY * 60 + MINUTES_SUNRISE_OF_NEXT_DAY))
NIGHT_MINUTES=$((TOTAL_MINUTES_IN_DAY - MINUTES_SUNSET_TOTAL + MINUTES_SUNRISE_NEXT_DAY_TOTAL))
# Calculate night period per hour
NIGHT_PERIOD=$((NIGHT_MINUTES /
12))

# Calculate hourly intervals for the day period
hour_day_1=$(date -d "$HOUR_SUNRISE:$MINUTES_SUNRISE today + 0 minutes" +'%H:%M')

for i in {2..12}; do
minutes_x=$(( "$DAYLIGHT_PERIOD" * ($i - 1) ))
hour_day=$(date -d "$HOUR_SUNRISE:$MINUTES_SUNRISE today + ${minutes_x} minutes" +'%H:%M')
eval "hour_day_$i='$hour_day'"
done

# Calculate hourly intervals for the night period
hour_night_1=$(date -d "$HOUR_SUNSET:$MINUTES_SUNSET today + 0 minutes" +'%H:%M')

for i in {2..12}; do
minutes_nx=$(( "$NIGHT_PERIOD" * ($i - 1) ))
hour_night=$(date -d "$HOUR_SUNSET:$MINUTES_SUNSET today + ${minutes_nx} minutes" +'%H:%M')
eval "hour_night_$i='$hour_night'"
done

# Assign calculated hours to variables start1 through start24
for i in {1..24}; do
if [ "$i" -le 12 ]; then
eval "start$i=\$hour_day_$i"
else
j=$((i - 12)) # Adjust index for night hours
eval "start$i=\$hour_night_$j"
fi
done

# Transition threshold: Determines when the day transitions to the next in terms of planetary influence.
TRANSITION_THRESHOLD="$HOUR_SUNRISE:$MINUTES_SUNRISE"

# Get current time
NOW_TIME=$(date +%H:%M)

# Calculate current day of the week (1 is Monday, 7 is Sunday)
CURRENT_WEEKDAY=$(date +%u)

# Adjust current day based on the time threshold
if [[ "$NOW_TIME" < "$TRANSITION_THRESHOLD" ]]; then
if [[ "$CURRENT_WEEKDAY" -eq 1 ]]; then
CURRENT_WEEKDAY=7
else
CURRENT_WEEKDAY=$((CURRENT_WEEKDAY - 1))
fi
fi

day_of_week="$CURRENT_WEEKDAY"

# Assign the corresponding planet symbol to the current day.
# Use sed to set the variable corresponding to the current day to 1 within the first 15 lines
case $day_of_week in
1) symbol="$MOON" ; sed -i '1,15s/MONDAY_MOON_=0/MONDAY_MOON_=1/' ;;
2) symbol="$MARS" ; sed -i '1,15s/TUESDAY_MARS_=0/TUESDAY_MARS_=1/' "$FILE" ;;
3) symbol="$MERCURY" ; sed -i '1,15s/WEDNESDAY_MERCURY_=0/WEDNESDAY_MERCURY_=1/' "$FILE" ;;
4) symbol="$JUPITER" ; sed -i '1,15s/THURSDAY_JUPITER_=0/THURSDAY_JUPITER_=1/' "$FILE" ;;
5) symbol="$VENUS" ; sed -i '1,15s/FRIDAY_VENUS_=0/FRIDAY_VENUS_=1/' "$FILE" ;;
6) symbol="$SATURN" ; sed -i '1,15s/SATURDAY_SATURN_=0/SATURDAY_SATURN_=1/' "$FILE" ;;
7) symbol="$SUN" ; sed -i '1,15s/SUNDAY_SUN_=0/SUNDAY_SUN_=1/' "$FILE" ;;
*) symbol="Unknown" ;;
esac

# Print the symbol if DAY_OF_WEEK_ is enabled
if [ "$DAY_OF_WEEK_" -eq 1 ]; then
echo -n "$symbol"
fi

# Get current time in HH:MM format
current_time=$(date +%H:%M)

# Function to check the current time against start and end times to determine the governing planet
check_time() {
# Converting hours to minutes since midnight for easier comparison
local start_minutes=$((10#${1:0:2} * 60 + 10#${1:3:2}))
local end_minutes=$((10#${2:0:2} * 60 + 10#${2:3:2}))
local current_minutes=$((10#${current_time:0:2} * 60 + 10#${current_time:3:2}))

# Handles the case of an interval that crosses midnight
if [[ "$end_minutes" -le "$start_minutes" ]]; then
# If the current time is before midnight and the interval ends after midnight
if [[ "$current_minutes" -gt "$start_minutes" || "$current_minutes" -lt "$end_minutes" ]]; then
echo -n "$3"
fi
else
# Normal interval, which doesn't cross midnight
if [[ "$current_minutes" -gt "$start_minutes" && "$current_minutes" -lt "$end_minutes" ]]; then
echo -n "$3"
fi
fi
}

# Define functions for each day to check planetary hours
check_planetary_hours() {
local day_planets=("$@") # Receives the planets for the specific day
local starts=(
"$start1" "$start2" "$start3" "$start4" "$start5" "$start6"
"$start7" "$start8" "$start9" "$start10" "$start11"
"$start12"
"$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
- %-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
Seeing error message if stopped by set -e

We use set -e so that the bash noscript 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 noscript. Line was ($0:$LINENO): $(sed -n "${LINENO}p" "$0")"; exit 3' ERR


This looks good, or do you have a better way, so that it is more obvious that the noscript was stopped because of a non-zero exit code?

https://redd.it/1bk0xrr
@r_bash
ShellCheck Wrapper Script for Bash Scripting

Hello r/bash,

I've written a Bash noscript that enhances the use of ShellCheck for linting shell noscripts. This is a utility aimed at those who need to ensure their noscripts 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 noscripts to a specified directory.
Summary report of ShellCheck results.
Color output for easier reading.

The noscript supports various configurations, allowing you to tailor the linting process to your needs, including the exclusion of specific checks and the organization of noscripts 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 noscripts.

Feel free to try it and see if it fits your noscripting routine.

Example Usage:

./shellcheck.sh --color -s -d GitHub-Projects -m "$PWD/GitHub-Projects/completed"
./shellcheck.sh --recursive -v --output noscript-errors.txt

GitHub Script

https://redd.it/1bk5fu2
@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 denoscription 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
Docker log monitoring noscript help

I have a noscript that's monitoring the new log entries using:

docker logs -f -n 0 <container>

The problem is that when the container restarts, the noscript 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 noscript alive even after the container stops without it erroring out?



https://redd.it/1bltzyc
@r_bash