當 AWS Auto Scaling 群組執行啟動腳本時,我在 ec2 Linux 實例中遇到了雙括號和雙美元符號的基本問題。
下面是錯誤:
-bash: syntax error near unexpected token `('
下面是程式碼
#!/bin/bash
total_ram=`free -g | awk 'FNR > 1 && FNR < 3 {print $2}'`
# if it's an odd value add one
if [ $$((total_ram%2)) -ne 0 ]; then total_ram=$$((total_ram+1)) ; fi
# divide by two
# half_ram=$((total_ram / 2))
sed "s,Xms.*,Xms$$((half_ram+0))g,g" -i /Users/rrapolu/ProjectDocs/shell/jvm.options
sed "s,Xmx.*,Xmx$$((half_ram+0))g,g" -i /Users/rrapolu/ProjectDocs/shell/jvm.options