waitUntil
26. 9. 2019‘Native’ ↓
While this naive code might look interesting it’s actually quite a cpu eater
#!/bin/bash
#set -x
# waitUntil
# This should run 'thecode' at approximate real-clock minute change.
update() {
# minutes from real clock without 0 padding
oldmin="$(date +%-M)"
newmin="$oldmin"
#echo "$newmin"
}
waitUntil() {
while (( oldmin == newmin ))
do
sleep 0.3
newmin="$(date +%-M)"
done
}
thecode() {
clear
date +%H%M | toilet -f 3x3
}
while true
do
thecode
update
waitUntil
done
‘Native’ better ↓
#!/bin/bash
waitUntil() {
sleep $((60 - $(date +%s) % 60))
}
thecode() {
date +%H%M | toilet -f 3x3
}
while true
do
thecode
waitUntil
done
https://unix.stackexchange.com/questions/194655/shell-sleep-until-next-full-minute
Datetools ↓
Similar, but using datetools
#!/bin/bash
#set -x
# waitUntil2, using https://github.com/caronc/datetools dateblock
# This should run 'thecode' at approximate real-clock minute change.
waitUntil() {
dateblock -n /1
}
thecode() {
date +%H%M | toilet -f 3x3
}
while true
do
thecode
waitUntil
done
Cron ↓
Using cron, lags about 1s
in crontab have
* * * * * touch /tmp/clock
script might look like
date +%H%M; while inotifywait -qq -e close_write /tmp/clock; do date +%H%M; done
