exectask.java

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    public void setFailIfExecutionFails(boolean flag) {
        failIfExecFails = flag;
        incompatibleWithSpawn = true;
    }

    /**
     * Set whether output should be appended to or overwrite an existing file.
     * Defaults to false.
     *
     * @param append if true append is desired.
     *
     * @since 1.30, Ant 1.5
     */
    public void setAppend(boolean append) {
        redirector.setAppend(append);
        incompatibleWithSpawn = true;
    }

    /**
     * Add a <code>RedirectorElement</code> to this task.
     *
     * @param redirectorElement   <code>RedirectorElement</code>.
     * @since Ant 1.6.2
     */
    public void addConfiguredRedirector(RedirectorElement redirectorElement) {
        if (this.redirectorElement != null) {
            throw new BuildException("cannot have > 1 nested <redirector>s");
        }
        this.redirectorElement = redirectorElement;
        incompatibleWithSpawn = true;
    }


    /**
     * Restrict this execution to a single OS Family
     * @param osFamily the family to restrict to.
     */
    public void setOsFamily(String osFamily) {
        this.osFamily = osFamily.toLowerCase(Locale.US);
    }


    /**
     * The method attempts to figure out where the executable is so that we can feed
     * the full path. We first try basedir, then the exec dir, and then
     * fallback to the straight executable name (i.e. on the path).
     *
     * @param exec the name of the executable.
     * @param mustSearchPath if true, the executable will be looked up in
     * the PATH environment and the absolute path is returned.
     *
     * @return the executable as a full path if it can be determined.
     *
     * @since Ant 1.6
     */
    protected String resolveExecutable(String exec, boolean mustSearchPath) {
        if (!resolveExecutable) {
            return exec;
        }
        // try to find the executable
        File executableFile = getProject().resolveFile(exec);
        if (executableFile.exists()) {
            return executableFile.getAbsolutePath();
        }
        // now try to resolve against the dir if given
        if (dir != null) {
            executableFile = FILE_UTILS.resolveFile(dir, exec);
            if (executableFile.exists()) {
                return executableFile.getAbsolutePath();
            }
        }
        // couldn't find it - must be on path
        if (mustSearchPath) {
            Path p = null;
            String[] environment = env.getVariables();
            if (environment != null) {
                for (int i = 0; i < environment.length; i++) {
                    if (isPath(environment[i])) {
                        p = new Path(getProject(), getPath(environment[i]));
                        break;
                    }
                }
            }
            if (p == null) {
                Vector envVars = Execute.getProcEnvironment();
                Enumeration e = envVars.elements();
                while (e.hasMoreElements()) {
                    String line = (String) e.nextElement();
                    if (isPath(line)) {
                        p = new Path(getProject(), getPath(line));
                        break;
                    }
                }
            }
            if (p != null) {
                String[] dirs = p.list();
                for (int i = 0; i < dirs.length; i++) {
                    executableFile
                        = FILE_UTILS.resolveFile(new File(dirs[i]), exec);
                    if (executableFile.exists()) {
                        return executableFile.getAbsolutePath();
                    }
                }
            }
        }
        // mustSearchPath is false, or no PATH or not found - keep our
        // fingers crossed.
        return exec;
    }

    /**
     * Do the work.
     *
     * @throws BuildException in a number of circumstances:
     * <ul>
     * <li>if failIfExecFails is set to true and the process cannot be started</li>
     * <li>the java13command launcher can send build exceptions</li>
     * <li>this list is not exhaustive or limitative</li>
     * </ul>
     */
    public void execute() throws BuildException {
        // Quick fail if this is not a valid OS for the command
        if (!isValidOs()) {
            return;
        }
        File savedDir = dir; // possibly altered in prepareExec
        cmdl.setExecutable(resolveExecutable(executable, searchPath));
        checkConfiguration();
        try {
            runExec(prepareExec());
        } finally {
            dir = savedDir;
        }
    }

    /**
     * Has the user set all necessary attributes?
     * @throws BuildException if there are missing required parameters.
     */
    protected void checkConfiguration() throws BuildException {
        if (cmdl.getExecutable() == null) {
            throw new BuildException("no executable specified", getLocation());
        }
        if (dir != null && !dir.exists()) {
            throw new BuildException("The directory " + dir + " does not exist");
        }
        if (dir != null && !dir.isDirectory()) {
            throw new BuildException(dir + " is not a directory");
        }
        if (spawn && incompatibleWithSpawn) {
            getProject().log("spawn does not allow attributes related to input, "
            + "output, error, result", Project.MSG_ERR);
            getProject().log("spawn also does not allow timeout", Project.MSG_ERR);
            getProject().log("finally, spawn is not compatible "
                + "with a nested I/O <redirector>", Project.MSG_ERR);
            throw new BuildException("You have used an attribute "
                + "or nested element which is not compatible with spawn");
        }
        setupRedirector();
    }

    /**
     * Set up properties on the redirector that we needed to store locally.
     */
    protected void setupRedirector() {
        redirector.setInput(input);
        redirector.setInputString(inputString);
        redirector.setOutput(output);
        redirector.setError(error);
    }

    /**
     * Is this the OS the user wanted?
     * @return boolean.
     * <ul>
     * <li>
     * <li><code>true</code> if the os and osfamily attributes are null.</li>
     * <li><code>true</code> if osfamily is set, and the os family and must match
     * that of the current OS, according to the logic of
     * {@link Os#isOs(String, String, String, String)}, and the result of the
     * <code>os</code> attribute must also evaluate true.
     * </li>
     * <li>
     * <code>true</code> if os is set, and the system.property os.name
     * is found in the os attribute,</li>
     * <li><code>false</code> otherwise.</li>
     * </ul>
     */
    protected boolean isValidOs() {
        //hand osfamily off to Os class, if set
        if (osFamily != null && !Os.isOs(osFamily, null, null, null)) {
            return false;
        }
        //the Exec OS check is different from Os.isOs(), which
        //probes for a specific OS. Instead it searches the os field
        //for the current os.name
        String myos = System.getProperty("os.name");
        log("Current OS is " + myos, Project.MSG_VERBOSE);
        if ((os != null) && (os.indexOf(myos) < 0)) {
            // this command will be executed only on the specified OS
            log("This OS, " + myos
                    + " was not found in the specified list of valid OSes: " + os,
                    Project.MSG_VERBOSE);
            return false;
        }
        return true;
    }

    /**
     * Set whether to launch new process with VM, otherwise use the OS's shell.
     * Default value is true.
     * @param vmLauncher true if we want to launch new process with VM,
     * false if we want to use the OS's shell.
     */
    public void setVMLauncher(boolean vmLauncher) {
        this.vmLauncher = vmLauncher;
    }

    /**
     * Create an Execute instance with the correct working directory set.
     *
     * @return an instance of the Execute class.
     *
     * @throws BuildException under unknown circumstances.
     */
    protected Execute prepareExec() throws BuildException {
        // default directory to the project's base directory
        if (dir == null) {
            dir = getProject().getBaseDir();
        }
        if (redirectorElement != null) {
            redirectorElement.configure(redirector);
        }
        Execute exe = new Execute(createHandler(), createWatchdog());
        exe.setAntRun(getProject());
        exe.setWorkingDirectory(dir);
        exe.setVMLauncher(vmLauncher);
        exe.setSpawn(spawn);
        String[] environment = env.getVariables();
        if (environment != null) {
            for (int i = 0; i < environment.length; i++) {
                log("Setting environment variable: " + environment[i],
                    Project.MSG_VERBOSE);
            }
        }
        exe.setNewenvironment(newEnvironment);
        exe.setEnvironment(environment);
        return exe;
    }

    /**
     * A Utility method for this classes and subclasses to run an
     * Execute instance (an external command).
     *
     * @param exe instance of the execute class.
     *
     * @throws IOException in case of problem to attach to the stdin/stdout/stderr
     * streams of the process.
     */
    protected final void runExecute(Execute exe) throws IOException {
        int returnCode = -1; // assume the worst

        if (!spawn) {
            returnCode = exe.execute();

            //test for and handle a forced process death
            if (exe.killedProcess()) {
                String msg = "Timeout: killed the sub-process";
                if (failOnError) {
                    throw new BuildException(msg);
                } else {
                    log(msg, Project.MSG_WARN);
                }
            }
            maybeSetResultPropertyValue(returnCode);
            redirector.complete();
            if (Execute.isFailure(returnCode)) {
                if (failOnError) {
                    throw new BuildException(getTaskType() + " returned: "
                        + returnCode, getLocation());
                } else {
                    log("Result: " + returnCode, Project.MSG_ERR);
                }
            }
        } else {
            exe.spawn();
        }
    }

    /**
     * Run the command using the given Execute instance. This may be
     * overridden by subclasses.
     *
     * @param exe instance of Execute to run.
     *
     * @throws BuildException if the new process could not be started
     * only if failIfExecFails is set to true (the default).
     */
    protected void runExec(Execute exe) throws BuildException {
        // show the command
        log(cmdl.describeCommand(), Project.MSG_VERBOSE);

        exe.setCommandline(cmdl.getCommandline());
        try {
            runExecute(exe);
        } catch (IOException e) {
            if (failIfExecFails) {
                throw new BuildException("Execute failed: " + e.toString(), e,
                                         getLocation());
            } else {
                log("Execute failed: " + e.toString(), Project.MSG_ERR);
            }
        } finally {
            // close the output file if required
            logFlush();
        }
    }

    /**
     * Create the StreamHandler to use with our Execute instance.
     *
     * @return instance of ExecuteStreamHandler.
     *
     * @throws BuildException under unknown circumstances.
     */
    protected ExecuteStreamHandler createHandler() throws BuildException {
        return redirector.createHandler();
    }

    /**
     * Create the Watchdog to kill a runaway process.
     *
     * @return instance of ExecuteWatchdog.
     *
     * @throws BuildException under unknown circumstances.
     */
    protected ExecuteWatchdog createWatchdog() throws BuildException {
        return (timeout == null)
            ? null : new ExecuteWatchdog(timeout.longValue());
    }

    /**
     * Flush the output stream - if there is one.
     */
    protected void logFlush() {
    }

    private boolean isPath(String line) {
        return line.startsWith("PATH=")
            || line.startsWith("Path=");
    }

    private String getPath(String line) {
        return line.substring("PATH=".length());
    }
}