Improve ExternalTask::run_and_capture_output

Redirect input from /dev/null and allow stderr to be captured as well.

diff --git a/source/externaltask.cpp b/source/externaltask.cpp
index 257d1318fb22a42d31a5e2ed04e95424cb0a80ae..e4dfdc2ef9566122042d6ad430595acb1488f6b0 100644 (file)
--- a/source/externaltask.cpp
+++ b/source/externaltask.cpp
@@ -16,6 +16,7 @@ ExternalTask::ExternalTask(const Arguments &a, const FS::Path &wd):
        work_dir(wd),
        process(0),
        exit_code(-1),
+       stdin_action(PASSTHROUGH),
        stdout_action(PASSTHROUGH),
        stderr_action(PASSTHROUGH),
        capture_pipe(0)
@@ -45,7 +46,7 @@ string ExternalTask::get_command() const
                }
        }
 
-       if(!stdin_file.empty())
+       if(stdin_action==REDIRECT)
        {
                cmd += " <";
                cmd += stdin_file.str();
@@ -70,9 +71,11 @@ void ExternalTask::start()
 
        process = new Process;
 
-       if(stdout_action==IGNORE || stderr_action==IGNORE)
+       if(stdin_action==IGNORE || stdout_action==IGNORE || stderr_action==IGNORE)
        {
-               devnull = new IO::File("/dev/null", IO::M_WRITE);
+               devnull = new IO::File("/dev/null", IO::M_RDWR);
+               if(stdin_action==IGNORE)
+                       process->redirect_cin(*devnull);
                if(stdout_action==IGNORE)
                        process->redirect_cout(*devnull);
                if(stderr_action==IGNORE)
@@ -94,7 +97,7 @@ void ExternalTask::start()
                        process->redirect_cerr(*capture_pipe);
        }
 
-       if(!stdin_file.empty())
+       if(stdin_action==REDIRECT)
        {
                infile = new IO::File((work_dir/stdin_file).str());
                process->redirect_cin(*infile);
@@ -156,6 +159,7 @@ Task::Status ExternalTask::do_wait(bool block)
 
 void ExternalTask::set_stdin(const FS::Path &f)
 {
+       stdin_action = REDIRECT;
        stdin_file = f;
 }
 
@@ -179,11 +183,12 @@ void ExternalTask::set_stderr(StreamAction a)
        stderr_action = a;
 }
 
-string ExternalTask::run_and_capture_output(const Arguments &argv, const FS::Path &wd)
+string ExternalTask::run_and_capture_output(const Arguments &argv, const FS::Path &wd, bool capture_stderr)
 {
        ExternalTask task(argv, wd);
+       task.stdin_action = IGNORE;
        task.set_stdout(CAPTURE);
-       task.set_stderr(IGNORE);
+       task.set_stderr(capture_stderr ? CAPTURE : IGNORE);
        task.start();
        if(task.wait()!=SUCCESS)
                throw runtime_error(format("%s failed", argv.front()));

diff --git a/source/externaltask.h b/source/externaltask.h
index 00465f3af4f3ba501952f1a7bf29ce149d04865a..26a6acabe569356e630e109289ed8cb8e80e0546 100644 (file)
--- a/source/externaltask.h
+++ b/source/externaltask.h
@@ -31,6 +31,7 @@ private:
        Msp::FS::Path work_dir;
        Msp::Process *process;
        int exit_code;
+       StreamAction stdin_action;
        Msp::FS::Path stdin_file;
        StreamAction stdout_action;
        Msp::FS::Path stdout_file;
@@ -70,9 +71,9 @@ public:
        still running, but it will always return all output. */
        const std::string &get_output() const { return output; }
 
-       /** Executes a command and captures its output.  Stderr is ignored, but if
-       the command exits with a nonzero status, an exception is thrown. */
-       static std::string run_and_capture_output(const Arguments &, const Msp::FS::Path & = Msp::FS::Path());
+       /** Executes a command and captures its output.  If the command exits with
+       a nonzero status, an exception is thrown. */
+       static std::string run_and_capture_output(const Arguments &, const Msp::FS::Path & = Msp::FS::Path(), bool = false);
 };
 
 #endif