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+// file : butl/process.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2015 Code Synthesis Ltd
+// license : MIT; see accompanying LICENSE file
+
+#include <butl/process>
+
+#ifndef _WIN32
+# include <unistd.h> // execvp, fork, dup2, pipe, {STDIN,STDERR}_FILENO
+# include <sys/wait.h> // waitpid
+#else
+# ifndef WIN32_LEAN_AND_MEAN
+# define WIN32_LEAN_AND_MEAN
+# endif
+# include <windows.h> // CreatePipe, CreateProcess
+# include <io.h> // _open_osfhandle
+# include <fcntl.h> // _O_TEXT
+#endif
+
+using namespace std;
+
+namespace butl
+{
+#ifndef _WIN32
+
+ process::
+ process (char const* args[], bool in, bool err, bool out)
+ {
+ int out_fd[2];
+ int in_efd[2];
+ int in_ofd[2];
+
+ if ((in && pipe (out_fd) == -1) ||
+ (err && pipe (in_efd) == -1) ||
+ (out && pipe (in_ofd) == -1))
+ throw process_error (errno, false);
+
+ id = fork ();
+
+ if (id == -1)
+ throw process_error (errno, false);
+
+ if (id == 0)
+ {
+ // Child. If requested, close the write end of the pipe and duplicate
+ // the read end to stdin. Then close the original read end descriptor.
+ //
+ if (in)
+ {
+ if (close (out_fd[1]) == -1 ||
+ dup2 (out_fd[0], STDIN_FILENO) == -1 ||
+ close (out_fd[0]) == -1)
+ throw process_error (errno, true);
+ }
+
+ // Do the same for the stderr if requested.
+ //
+ if (err)
+ {
+ if (close (in_efd[0]) == -1 ||
+ dup2 (in_efd[1], STDERR_FILENO) == -1 ||
+ close (in_efd[1]) == -1)
+ throw process_error (errno, true);
+ }
+
+ // Do the same for the stdout if requested.
+ //
+ if (out)
+ {
+ if (close (in_ofd[0]) == -1 ||
+ dup2 (in_ofd[1], STDOUT_FILENO) == -1 ||
+ close (in_ofd[1]) == -1)
+ throw process_error (errno, true);
+ }
+
+ if (execvp (args[0], const_cast<char**> (&args[0])) == -1)
+ throw process_error (errno, true);
+ }
+ else
+ {
+ // Parent. Close the other ends of the pipes.
+ //
+ if ((in && close (out_fd[0]) == -1) ||
+ (err && close (in_efd[1]) == -1) ||
+ (out && close (in_ofd[1]) == -1))
+ throw process_error (errno, false);
+ }
+
+ this->out_fd = in ? out_fd[1] : 0;
+ this->in_efd = err ? in_efd[0] : 0;
+ this->in_ofd = out ? in_ofd[0] : 0;
+ }
+
+ bool process::
+ wait ()
+ {
+ int status;
+ int r (waitpid (id, &status, 0));
+ id = 0; // We have tried.
+
+ if (r == -1)
+ throw process_error (errno, false);
+
+ return WIFEXITED (status) && WEXITSTATUS (status) == 0;
+ }
+
+#else // _WIN32
+
+ static void
+ print_error (char const* name)
+ {
+ LPTSTR msg;
+ DWORD e (GetLastError());
+
+ if (!FormatMessage(
+ FORMAT_MESSAGE_ALLOCATE_BUFFER |
+ FORMAT_MESSAGE_FROM_SYSTEM |
+ FORMAT_MESSAGE_IGNORE_INSERTS,
+ 0,
+ e,
+ MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
+ (LPTSTR) &msg,
+ 0,
+ 0))
+ {
+ cerr << name << ": error: unknown error code " << e << endl;
+ return;
+ }
+
+ cerr << name << ": error: " << msg << endl;
+ LocalFree (msg);
+ }
+
+ static process_info
+ start_process (char const* args[], char const* name, bool err, bool out)
+ {
+ HANDLE out_h[2];
+ HANDLE in_eh[2];
+ HANDLE in_oh[2];
+ SECURITY_ATTRIBUTES sa;
+
+ sa.nLength = sizeof (SECURITY_ATTRIBUTES);
+ sa.bInheritHandle = true;
+ sa.lpSecurityDescriptor = 0;
+
+ if (!CreatePipe (&out_h[0], &out_h[1], &sa, 0) ||
+ !SetHandleInformation (out_h[1], HANDLE_FLAG_INHERIT, 0))
+ {
+ print_error (name);
+ throw process_failure ();
+ }
+
+ if (err)
+ {
+ if (!CreatePipe (&in_eh[0], &in_eh[1], &sa, 0) ||
+ !SetHandleInformation (in_eh[0], HANDLE_FLAG_INHERIT, 0))
+ {
+ print_error (name);
+ throw process_failure ();
+ }
+ }
+
+ if (out)
+ {
+ if (!CreatePipe (&in_oh[0], &in_oh[1], &sa, 0) ||
+ !SetHandleInformation (in_oh[0], HANDLE_FLAG_INHERIT, 0))
+ {
+ print_error (name);
+ throw process_failure ();
+ }
+ }
+
+ // Create the process.
+ //
+ path file (args[0]);
+
+ // Do PATH search.
+ //
+ if (file.directory ().empty ())
+ file = path_search (file);
+
+ if (file.empty ())
+ {
+ cerr << args[0] << ": error: file not found" << endl;
+ throw process_failure ();
+ }
+
+ // Serialize the arguments to string.
+ //
+ string cmd_line;
+
+ for (char const** p (args); *p != 0; ++p)
+ {
+ if (p != args)
+ cmd_line += ' ';
+
+ // On Windows we need to protect values with spaces using quotes.
+ // Since there could be actual quotes in the value, we need to
+ // escape them.
+ //
+ string a (*p);
+ bool quote (a.find (' ') != string::npos);
+
+ if (quote)
+ cmd_line += '"';
+
+ for (size_t i (0); i < a.size (); ++i)
+ {
+ if (a[i] == '"')
+ cmd_line += "\\\"";
+ else
+ cmd_line += a[i];
+ }
+
+ if (quote)
+ cmd_line += '"';
+ }
+
+ // Prepare other info.
+ //
+ STARTUPINFO si;
+ PROCESS_INFORMATION pi;
+
+ memset (&si, 0, sizeof (STARTUPINFO));
+ memset (&pi, 0, sizeof (PROCESS_INFORMATION));
+
+ si.cb = sizeof(STARTUPINFO);
+
+ if (err)
+ si.hStdError = in_eh[1];
+ else
+ si.hStdError = GetStdHandle (STD_ERROR_HANDLE);
+
+ if (out)
+ si.hStdOutput = in_oh[1];
+ else
+ si.hStdOutput = GetStdHandle (STD_OUTPUT_HANDLE);
+
+ si.hStdInput = out_h[0];
+ si.dwFlags |= STARTF_USESTDHANDLES;
+
+ if (!CreateProcess (
+ file.string ().c_str (),
+ const_cast<char*> (cmd_line.c_str ()),
+ 0, // Process security attributes.
+ 0, // Primary thread security attributes.
+ true, // Inherit handles.
+ 0, // Creation flags.
+ 0, // Use our environment.
+ 0, // Use our current directory.
+ &si,
+ &pi))
+ {
+ print_error (name);
+ throw process_failure ();
+ }
+
+ CloseHandle (pi.hThread);
+ CloseHandle (out_h[0]);
+
+ if (err)
+ CloseHandle (in_eh[1]);
+
+ if (out)
+ CloseHandle (in_oh[1]);
+
+ process_info r;
+ r.id = pi.hProcess;
+ r.out_fd = _open_osfhandle ((intptr_t) (out_h[1]), 0);
+
+ if (r.out_fd == -1)
+ {
+ cerr << name << ": error: unable to obtain C file handle" << endl;
+ throw process_failure ();
+ }
+
+ if (err)
+ {
+ // Pass _O_TEXT to get newline translation.
+ //
+ r.in_efd = _open_osfhandle ((intptr_t) (in_eh[0]), _O_TEXT);
+
+ if (r.in_efd == -1)
+ {
+ cerr << name << ": error: unable to obtain C file handle" << endl;
+ throw process_failure ();
+ }
+ }
+ else
+ r.in_efd = 0;
+
+ if (out)
+ {
+ // Pass _O_TEXT to get newline translation.
+ //
+ r.in_ofd = _open_osfhandle ((intptr_t) (in_oh[0]), _O_TEXT);
+
+ if (r.in_ofd == -1)
+ {
+ cerr << name << ": error: unable to obtain C file handle" << endl;
+ throw process_failure ();
+ }
+ }
+ else
+ r.in_ofd = 0;
+
+ return r;
+ }
+
+ static bool
+ wait_process (process_info pi, char const* name)
+ {
+ DWORD status;
+
+ if (WaitForSingleObject (pi.id, INFINITE) != WAIT_OBJECT_0 ||
+ !GetExitCodeProcess (pi.id, &status))
+ {
+ print_error (name);
+ throw process_failure ();
+ }
+
+ CloseHandle (pi.id);
+ return status == 0;
+ }
+
+#endif // _WIN32
+}