1 /* 2 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /* @test 25 * @bug 4763384 26 * @summary Ensure that piped input always works with exec'd processes 27 */ 28 29 import java.io.*; 30 31 32 /** 33 * This class demonstrates a regression in java1.4.1 in the handling of the 34 * Process OutputStream (exec'd process stdin). The subprocess completes 100% 35 * of the time in 1.4, but about only about 50% of the time under 1.4.1. Issue 36 * exists for client JVM, Linux Redhat 6.2 not sure about other variants of 37 * Linux or other OSes, or server JVM. 38 */ 39 40 public class ExecWithInput { 41 42 private static final int N = 200; 43 44 static int go(int i) throws Exception { 45 /* 46 * Execute /bin/cat supplying two lines of input. cat should 47 * read the input lines and copy them to stdout. On completion, 48 * p.waitFor should return and the exit status is printed and this 49 * program exits. Under 1.4.1, cat sometimes gets stuck on a pipe 50 * read and never terminates. 51 */ 52 Process p = Runtime.getRuntime().exec(UnixCommands.cat()); 53 54 String input = i + ": line 1\n" + i + ": line 2\n"; 55 StringBufferInputStream in = new StringBufferInputStream(input); 56 // create threads to handle I/O streams 57 IO ioIn = new IO("stdin", in, p.getOutputStream()); 58 IO ioOut = new IO("stdout", p.getInputStream(), System.out); 59 IO ioErr = new IO("stderr", p.getErrorStream(), System.err); 60 61 // wait for process to exit 62 return p.waitFor(); 63 } 64 65 public static void main(String[] args) throws Exception { 66 if (! System.getProperty("os.name").startsWith("Linux")) { 67 System.err.println("Only for Linux"); 68 return; 69 } 70 for (int i = 0; i < N; i++) 71 go(i); 72 } 73 74 /** 75 * Handle IO. Thread is started in constructor. 76 */ 77 static class IO extends Thread { 78 79 private InputStream in; 80 private OutputStream out; 81 82 IO(String name, InputStream in, OutputStream out) 83 { 84 this.in = in; 85 this.out = out; 86 setName(name); 87 start(); 88 } 89 90 public void run() { 91 try { 92 byte[] buf = new byte[8192]; 93 int n; 94 while ((n = in.read(buf)) != -1) { 95 out.write(buf, 0, n); 96 out.flush(); 97 } 98 /* 99 while ((c = in.read()) != -1) { 100 out.write(c); 101 if (c == '\n') 102 out.flush(); 103 } 104 out.flush(); 105 */ 106 } catch (IOException e) { 107 e.printStackTrace(); 108 } finally { 109 if (!System.out.equals(out) && !System.err.equals(out)) { 110 // Note: in order to get an exec'd java process to 111 // see EOF on input, it is necessary to close stdin 112 if (out != null) { 113 try { out.close(); } catch (Exception e) { 114 e.printStackTrace(); 115 } 116 } 117 } 118 } 119 } 120 } 121 122 }