package votorola.g; // Copyright 2009-2010, Michael Allan.  Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Votorola Software"), to deal in the Votorola Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicence, and/or sell copies of the Votorola Software, and to permit persons to whom the Votorola Software is furnished to do so, subject to the following conditions: The preceding copyright notice and this permission notice shall be included in all copies or substantial portions of the Votorola Software. THE VOTOROLA SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE VOTOROLA SOFTWARE OR THE USE OR OTHER DEALINGS IN THE VOTOROLA SOFTWARE.

import java.io.*;
import java.nio.charset.*;
import votorola.g.lang.*;
import votorola.g.logging.*;


/** Utilities for the Bourne-Again Shell.
  */
public @ThreadSafe final class BASH
{

    private BASH() {}



    /** Looks up the home directory of a user, via BASH tilde expansion.
      */
    public static String homeDirectory( final String loginName ) throws IOException
    {
        final ProcessBuilder pB = new ProcessBuilder( "/bin/bash", "-c", "echo -n ~" + loginName ); // note, this is BASH's own echo command
        LoggerX.i(BASH.class).config( "calling out to OS: " + pB.command() );
        final Process p = pB.start();
        final String homeDirectory = ProcessX.appendTo( new StringBuilder(), p,
          Charset.defaultCharset() ).toString();
        final int exitValue = ProcessX.waitForWithoutInterrupt( p );
        if( exitValue != 0 ) throw new IOException( "exit value of " + exitValue + " from process: " + pB.command() );

        return homeDirectory;
    }



}