What should be noticed while using -n and -z Bash expression
[ -z $string ] is very easy to use. We use this expression to test whether the string is empty or undefined. But I did meet problem when use [ -n $string ]. It...
工程是介于科学与艺术之间的思维和实践方式
[ -z $string ] is very easy to use. We use this expression to test whether the string is empty or undefined. But I did meet problem when use [ -n $string ]. It...
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