Could you help me decode this assignment:jvm_xmx=${jvm_xmx:-1024}Can't understand, what it does.
What does colon (':') in bash variable resolution syntax mean?
bash;shell script
man page for bash:${parameter:-word}          Use Default Values.  If parameter is unset or null, the expansion of          word is substituted.  Otherwise, the value of parameter is substituted.So if jvm_xmx is already set to something, it is left unchanged.If it is not already set to something, it is set to 1024.Example:$ echo $jvm_xmx$ jvm_xmx=${jvm_xmx:-1024}$ echo $jvm_xmx1024$ jvm_xmx=2048$ jvm_xmx=${jvm_xmx:-1024}$ echo $jvm_xmx2048$