Linux bash脚本有时会退出while循环

Question

我有这个简单的脚本，记录比特币的汇率。我发现每隔几天脚本就会停止。为了保持这种状态，我在无限循环之后立即调用了脚本本身，但我想知道为什么它会退出。谢谢你的提示。

#!/bin/bash

# logfile
logfile=/var/log/bitcoin_log
# frequency of updates, in minutes
sleepmins=1
# url of the bitcoin exchange rates
url=https://blockchain.info/it/ticker
# timeout
timeout=120
# number of bitcoins
balance=1

let sleepsecs=$sleepmins*60

#infinite loop
while true
do
    eur=`curl -m $timeout -s $url | grep EUR |  awk '{print $11}'`
    eur=${eur::-1}
    eurwall=`echo $eur*$balance | bc`

    echo `date --rfc-3339=seconds`' '$eur' '$eurwall >> $logfile
    sleep $sleepsecs
done

# if the script breaks out of the infinite loop, write to the log and restart it
echo `date --rfc-3339=seconds`' '$0' pid '$$': exited the infinite loop' >> \
    $logfile

./btcwallet &