System.getenv(name) needs the name of environment variable.
I am trying to call Runtime.exec(String[], String[], File), the secondary parameter need an array of environment variable, I am not sure whether subprocess will inherit environment variables from current process if I specified this parameter.
For example, if I pass new String[]{"NEWDIR=/home"} as secondary parameter and current java process has environment OLDDIR=/var, what is the return value of System.getenv("OLDDIR") in the subprocess?
updated:
Sorry, I have to use Java 1.4 and it seems that System.getenv() was introduced in 1.5?
System.getenv()will return aMap<String,String>with all of the environment variables.But you could just as easily switch to
ProcessBuilderwhich is a more convenient API to start new processes.With
ProcessBuilderyou can simply callenvironment()and get aMapthat contains existing environment variables and which you can manipulate how you want: i.e., if you add something to it, then that will be added to the new processes environment variables. If you remove something from it, it will not be present in the new process.