Process::set_stdin_fd

3 files changed, 47 insertions, 0 deletions

diff --git a/paludis/util/process.cc b/paludis/util/process.cc
index abcef4690..c2967dbb5 100644
--- a/paludis/util/process.cc
+++ b/paludis/util/process.cc
@@ -247,6 +247,7 @@ namespace paludis
         std::ostream * capture_output_to_fd_stream;
         int capture_output_to_fd_fd;
         std::string capture_output_to_fd_env_var;
+        int set_stdin_fd;
 
         std::map<std::string, std::string> setenvs;
         std::string chdir;
@@ -262,6 +263,7 @@ namespace paludis
             capture_stderr(0),
             capture_output_to_fd_stream(0),
             capture_output_to_fd_fd(-1),
+            set_stdin_fd(-1),
             setuid(getuid()),
             setgid(getgid()),
             echo_command_to(0)
@@ -348,6 +350,12 @@ Process::run()
                     ::setenv(_imp->capture_output_to_fd_env_var.c_str(), stringify(fd).c_str(), 1);
             }
 
+            if (-1 != _imp->set_stdin_fd)
+            {
+                if (-1 == ::dup2(_imp->set_stdin_fd, STDIN_FILENO))
+                    throw ProcessError("dup2() failed");
+            }
+
             for (auto m(_imp->setenvs.begin()), m_end(_imp->setenvs.end()) ;
                     m != m_end ; ++m)
                 ::setenv(m->first.c_str(), m->second.c_str(), 1);
@@ -421,6 +429,13 @@ Process::capture_output_to_fd(std::ostream & s, int fd_or_minus_one, const std::
 }
 
 Process &
+Process::set_stdin_fd(int f)
+{
+    _imp->set_stdin_fd = f;
+    return *this;
+}
+
+Process &
 Process::setenv(const std::string & a, const std::string & b)
 {
     _imp->setenvs.insert(std::make_pair(a, b)).first->second = b;
diff --git a/paludis/util/process.hh b/paludis/util/process.hh
index 3865911a5..8a3fe3f3d 100644
--- a/paludis/util/process.hh
+++ b/paludis/util/process.hh
@@ -78,6 +78,7 @@ namespace paludis
             Process & capture_stdout(std::ostream &);
             Process & capture_stderr(std::ostream &);
             Process & capture_output_to_fd(std::ostream &, int fd_or_minus_one, const std::string & env_var_with_fd);
+            Process & set_stdin_fd(int);
             Process & setenv(const std::string &, const std::string &);
             Process & chdir(const FSEntry &);
             Process & use_ptys();
diff --git a/paludis/util/process_TEST.cc b/paludis/util/process_TEST.cc
index fc57c197a..b0abb159b 100644
--- a/paludis/util/process_TEST.cc
+++ b/paludis/util/process_TEST.cc
@@ -19,6 +19,8 @@
 
 #include <paludis/util/process.hh>
 #include <paludis/util/fs_entry.hh>
+#include <paludis/util/pipe.hh>
+#include <paludis/util/safe_ofstream.hh>
 #include <test/test_framework.hh>
 #include <test/test_runner.hh>
 #include <sstream>
@@ -262,5 +264,34 @@ namespace test_cases
             TEST_CHECK_EQUAL(fd_stream.str(), "monkey\n");
         }
     } test_grab_fd_fixed;
+
+    struct StdinFDTest : TestCase
+    {
+        StdinFDTest() : TestCase("stdin fd") { }
+
+        void run()
+        {
+            std::unique_ptr<Pipe> input_pipe(new Pipe(true));
+
+            std::stringstream stdout_stream;
+            Process cat_process(ProcessCommand({"rev"}));
+            cat_process.capture_stdout(stdout_stream);
+            cat_process.set_stdin_fd(input_pipe->read_fd());
+
+            RunningProcessHandle handle(cat_process.run());
+
+            {
+                {
+                    SafeOFStream s(input_pipe->write_fd());
+                    s << "backwards" << std::endl;
+                }
+                TEST_CHECK(0 == ::close(input_pipe->write_fd()));
+                input_pipe->clear_write_fd();
+            }
+
+            TEST_CHECK_EQUAL(handle.wait(), 0);
+            TEST_CHECK_EQUAL(stdout_stream.str(), "sdrawkcab\n");
+        }
+    } test_stdin_fd;
 }