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    <p>I ran into a similar problem in Linux, except it was "ps -ef | grep someprocess".<br> At least with "ls" you have a language-independent (albeit slower) Java replacement. Eg.:</p> <pre><code>File f = new File("C:\\"); String[] files = f.listFiles(new File("/home/tihamer")); for (String file : files) { if (file.matches(.*some.*)) { System.out.println(file); } } </code></pre> <p>With "ps", it's a bit harder, because Java doesn't seem to have an API for it.</p> <p>I've heard that Sigar might be able to help us: <a href="https://support.hyperic.com/display/SIGAR/Home" rel="noreferrer">https://support.hyperic.com/display/SIGAR/Home</a></p> <p>The simplest solution, however, (as pointed out by Kaj) is to execute the piped command as a string array. Here is the full code:</p> <pre><code>try { String line; String[] cmd = { "/bin/sh", "-c", "ps -ef | grep export" }; Process p = Runtime.getRuntime().exec(cmd); BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream())); while ((line = in.readLine()) != null) { System.out.println(line); } in.close(); } catch (Exception ex) { ex.printStackTrace(); } </code></pre> <p>As to why the String array works with pipe, while a single string does not... it's one of the mysteries of the universe (especially if you haven't read the source code). I suspect that it's because when exec is given a single string, it parses it first (in a way that we don't like). In contrast, when exec is given a string array, it simply passes it on to the operating system without parsing it.</p> <p>Actually, if we take time out of busy day and look at the source code (at <a href="http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/6-b14/java/lang/Runtime.java#Runtime.exec%28java.lang.String%2Cjava.lang.String[]%2Cjava.io.File%29" rel="noreferrer">http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/6-b14/java/lang/Runtime.java#Runtime.exec%28java.lang.String%2Cjava.lang.String[]%2Cjava.io.File%29</a>), we find that is exactly what is happening:</p> <pre><code>public Process [More ...] exec(String command, String[] envp, File dir) throws IOException { if (command.length() == 0) throw new IllegalArgumentException("Empty command"); StringTokenizer st = new StringTokenizer(command); String[] cmdarray = new String[st.countTokens()]; for (int i = 0; st.hasMoreTokens(); i++) cmdarray[i] = st.nextToken(); return exec(cmdarray, envp, dir); } </code></pre>
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    1. POHow to make pipes work with Runtime.exec()?
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    1. USJeff Bridgman
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