libdeng2|CommandLine: Execute a process and wait

Optionally can retrieve standard output from the process.

doomsday/libdeng2/include/de/core/commandline.h

@@ -92,6 +92,11 @@ class DENG2_PUBLIC CommandLine
      */
     void append(String const &arg);
 
+    CommandLine &operator << (String const &arg) {
+        append(arg);
+        return *this;
+    }
+
     /**
      * Inserts a new argument to the list of arguments at index @a pos.
      *
@@ -212,6 +217,16 @@ class DENG2_PUBLIC CommandLine
      */
     bool execute() const;
 
+    /**
+     * Spawns a new process using the command line and blocks until it
+     * finishes running.
+     *
+     * @param output  Output produced by the started process.
+     *
+     * @return @c true if successful, otherwise @c false.
+     */
+    bool executeAndWait(String *output = 0) const;
+
 private:
     DENG2_PRIVATE(d)
 };

doomsday/libdeng2/src/core/commandline.cpp

@@ -442,3 +442,26 @@ bool CommandLine::execute() const
     LOG_DEBUG("Started detached process %i using \"%s\"") << pid << at(0);
     return true;
 }
+
+bool CommandLine::executeAndWait(String *output) const
+{
+    LOG_AS("CommandLine");
+
+    if(count() < 1) return false;
+
+    QStringList args;
+    for(int i = 1; i < count(); ++i) args << at(i);
+
+    LOG_DEBUG("Starting process \"%s\"") << at(0);
+
+    QProcess proc;
+    proc.start(at(0), args);
+    bool result = proc.waitForFinished();
+
+    if(output)
+    {
+        *output = String::fromUtf8(Block(proc.readAll()));
+    }
+
+    return result;
+}

doomsday/tests/test_commandline/main.cpp

@@ -0,0 +1,57 @@
+/*
+ * The Doomsday Engine Project
+ *
+ * Copyright (c) 2014 Jaakko Keränen <jaakko.keranen@iki.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <de/TextApp>
+#include <de/Log>
+
+#include <QDebug>
+
+using namespace de;
+
+int main(int argc, char **argv)
+{
+    try
+    {
+        TextApp app(argc, argv);
+        app.initSubsystems(App::DisablePlugins);
+
+        CommandLine cmd;
+#ifdef UNIX
+        cmd << "/bin/ls";
+        cmd << "-l";
+#endif
+
+        String output;
+        if(cmd.executeAndWait(&output))
+        {
+            LOG_MSG("Output from %s:\n") << cmd.at(0) << output;
+        }
+        else
+        {
+            LOG_WARNING("Failed to execute!");
+        }
+    }
+    catch(Error const &err)
+    {
+        qWarning() << err.asText();
+    }
+
+    qDebug() << "Exiting main()...";
+    return 0;        
+}

doomsday/tests/test_commandline/test_commandline.pro

@@ -0,0 +1,9 @@
+include(../config_test.pri)
+
+TEMPLATE = app
+TARGET = test_commandline
+
+SOURCES += main.cpp
+
+deployTest($$TARGET)
+

doomsday/tests/tests.pro

@@ -7,6 +7,7 @@ TEMPLATE = subdirs
 
 deng_tests: SUBDIRS += \
     test_archive \
+    test_commandline \
     test_bitfield \
     test_glsandbox \
     test_info \