CODEWITHSUNDEEP
java
voxter
voxter

Reputation: 925

Java:Runtime.getRuntime().exec(cmd) error with some commands,but works with other command

This is my code:

public static void main(String[] args) throws Exception {
    String[] cmd = {"which", "hive"};

    Process proc = Runtime.getRuntime().exec(cmd);

    BufferedReader reader = new BufferedReader(
        new InputStreamReader( proc.getInputStream() ) );

    String line = "";
    while((line = reader.readLine()) != null) {
        System.out.print(line + "\n");
    }

    proc.waitFor();   
}

In my terminal:

which hive:/home/as/hive/bin/hive
which gcc:/usr/bin/gcc

But when I run this java code:

which hive:no result
which gcc:/usr/bin/gcc

I've added $HIVE_HOME into ~/.bashrc (I'm using Ubuntu 14.04 64 bit and Java 8), so what should I do now?

Upvotes: 1

Views: 382

Answers (2)

voxter
voxter

Reputation: 925

in my terminal:
as@ubuntu:~$ echo $PATH;
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/home/as/bin:/home/as/jdk1.8.0_25/bin:/home/as/hadoop/bin:/home/as/hadoop/sbin:/home/as/bin:/home/as/jdk1.8.0_25/bin:/home/as/sqoop-1.4.5.bin__hadoop-2.0.4-alpha/bin:/home/as/hbase/bin:/home/as/hive/bin
but in java:
System.out.println(System.getenv().get("PATH"));

Result:
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/home/as/bin:/home/as/jdk1.8.0_25/bin
so this is $PATH of my account with $PATH of root?
so how to fix it?

Upvotes: 0

Erwin Bolwidt
Erwin Bolwidt

Reputation: 31279

The command which looks in all the directories specified in the environment variable PATH. On Linux, the directories are separated by a colon (:) and on Windows by a semicolon (;).

You can check what PATH is being passed to which by doing a

System.out.println(System.getenv("PATH"));

And you can pass a different path to Runtime.exec:

String[] env = { "PATH=/home/as/hive/bin" };
Process proc = Runtime.getRuntime().exec(cmd, env);

If you do that, it which will find the hive command (but it will not longer find gcc unless you also add /usr/bin to the PATH, as in PATH=/home/as/hive/bin:/usr/bin)

Upvotes: 1

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