001package 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.
002
003import java.io.*;
004import java.nio.charset.*;
005import votorola.g.lang.*;
006import votorola.g.logging.*;
007
008
009/** Utilities for the Bourne-Again Shell.
010  */
011public @ThreadSafe final class BASH
012{
013
014    private BASH() {}
015
016
017
018    /** Looks up the home directory of a user, via BASH tilde expansion.
019      */
020    public static String homeDirectory( final String loginName ) throws IOException
021    {
022        final ProcessBuilder pB = new ProcessBuilder( "/bin/bash", "-c", "echo -n ~" + loginName ); // note, this is BASH's own echo command
023        LoggerX.i(BASH.class).config( "calling out to OS: " + pB.command() );
024        final Process p = pB.start();
025        final String homeDirectory = ProcessX.appendTo( new StringBuilder(), p,
026          Charset.defaultCharset() ).toString();
027        final int exitValue = ProcessX.waitForWithoutInterrupt( p );
028        if( exitValue != 0 ) throw new IOException( "exit value of " + exitValue + " from process: " + pB.command() );
029
030        return homeDirectory;
031    }
032
033
034
035}