glib/gspawn-win32-helper.c

   1 /* gspawn-win32-helper.c - Helper program for process launching on Win32.
   2  *
   3  *  Copyright 2000 Red Hat, Inc.
   4  *  Copyright 2000 Tor Lillqvist
   5  *
   6  * GLib is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public License as
   8  * published by the Free Software Foundation; either version 2 of the
   9  * License, or (at your option) any later version.
  10  *
  11  * GLib is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with GLib; see the file COPYING.LIB.  If not, write
  18  * to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19  * Boston, MA 02111-1307, USA.
  20  */
  21
  22 #include "config.h"
  23
  24 #undef G_LOG_DOMAIN
  25 #include "glib.h"
  26 #define GSPAWN_HELPER
  27 #include "gspawn-win32.c"       /* For shared definitions */
  28
  29
  30 static GString *debugstring;
  31
  32 static void
  33 write_err_and_exit (gint fd,
  34                     gint msg)
  35 {
  36   gint en = errno;
  37
  38   if (debug)
  39     {
  40       debugstring = g_string_new (NULL);
  41       g_string_append (debugstring,
  42                        g_strdup_printf ("writing error code %d and errno %d",
  43                                         msg, en));
  44       MessageBox (NULL, debugstring->str, "gspawn-win32-helper", 0);
  45     }
  46
  47   write (fd, &msg, sizeof(msg));
  48   write (fd, &en, sizeof(en));
  49
  50   _exit (1);
  51 }
  52
  53 #ifdef __GNUC__
  54 #  ifndef _stdcall
  55 #    define _stdcall  __attribute__((stdcall))
  56 #  endif
  57 #endif
  58
  59 /* We build gspawn-win32-helper.exe as a Windows GUI application
  60  * to avoid any temporarily flashing console windows in case
  61  * the gspawn function is invoked by a GUI program. Thus, no main()
  62  * but a WinMain(). We do, however, still use argc and argv tucked
  63  * away in the global __argc and __argv by the C runtime startup code.
  64  */
  65
  66 int _stdcall
  67 WinMain (struct HINSTANCE__ *hInstance,
  68          struct HINSTANCE__ *hPrevInstance,
  69          char               *lpszCmdLine,
  70          int                 nCmdShow)
  71 {
  72   int child_err_report_fd;
  73   int i;
  74   int fd;
  75   int mode;
  76   int handle;
  77   int no_error = CHILD_NO_ERROR;
  78   int zero = 0;
  79   gint file_and_argv_zero = 0;
  80   gchar **new_argv;
  81
  82   SETUP_DEBUG();
  83
  84   if (debug)
  85     {
  86       debugstring = g_string_new (NULL);
  87
  88       g_string_append (debugstring,
  89                        g_strdup_printf ("g-spawn-win32-helper: "
  90                                         "argc = %d, argv: ",
  91                                         __argc));
  92       for (i = 0; i < __argc; i++)
  93         {
  94           if (i > 0)
  95             g_string_append (debugstring, " ");
  96           g_string_append (debugstring, __argv[i]);
  97         }
  98
  99       MessageBox (NULL, debugstring->str, "gspawn-win32-helper", 0);
 100     }
 101
 102   g_assert (__argc >= ARG_COUNT);
 103
 104   /* argv[ARG_CHILD_ERR_REPORT] is the file descriptor onto which
 105    * write error messages.
 106    */
 107   child_err_report_fd = atoi (__argv[ARG_CHILD_ERR_REPORT]);
 108
 109   /* Hack to implement G_SPAWN_FILE_AND_ARGV_ZERO */
 110   if (__argv[ARG_CHILD_ERR_REPORT][strlen (__argv[ARG_CHILD_ERR_REPORT]) - 1] == '#')
 111     file_and_argv_zero = 1;
 112
 113   /* argv[ARG_STDIN..ARG_STDERR] are the file descriptors that should
 114    * be dup2'd to stdin, stdout and stderr, '-' if the corresponding
 115    * std* should be let alone, and 'z' if it should be connected to
 116    * the bit bucket NUL:.
 117    */
 118   if (__argv[ARG_STDIN][0] == '-')
 119     ; /* Nothing */
 120   else if (__argv[ARG_STDIN][0] == 'z')
 121     {
 122       fd = open ("NUL:", O_RDONLY);
 123       if (fd != 0)
 124         {
 125           dup2 (fd, 0);
 126           close (fd);
 127         }
 128     }
 129   else
 130     {
 131       fd = atoi (__argv[ARG_STDIN]);
 132       if (fd != 0)
 133         {
 134           dup2 (fd, 0);
 135           close (fd);
 136         }
 137     }
 138
 139   if (__argv[ARG_STDOUT][0] == '-')
 140     ; /* Nothing */
 141   else if (__argv[ARG_STDOUT][0] == 'z')
 142     {
 143       fd = open ("NUL:", O_WRONLY);
 144       if (fd != 1)
 145         {
 146           dup2 (fd, 1);
 147           close (fd);
 148         }
 149     }
 150   else
 151     {
 152       fd = atoi (__argv[ARG_STDOUT]);
 153       if (fd != 1)
 154         {
 155           dup2 (fd, 1);
 156           close (fd);
 157         }
 158     }
 159
 160   if (__argv[ARG_STDERR][0] == '-')
 161     ; /* Nothing */
 162   else if (__argv[ARG_STDERR][0] == 'z')
 163     {
 164       fd = open ("NUL:", O_WRONLY);
 165       if (fd != 2)
 166         {
 167           dup2 (fd, 2);
 168           close (fd);
 169         }
 170     }
 171   else
 172     {
 173       fd = atoi (__argv[ARG_STDERR]);
 174       if (fd != 2)
 175         {
 176           dup2 (fd, 2);
 177           close (fd);
 178         }
 179     }
 180
 181   /* __argv[ARG_WORKING_DIRECTORY] is the directory in which to run the
 182    * process.  If "-", don't change directory.
 183    */
 184   if (__argv[ARG_WORKING_DIRECTORY][0] == '-' &&
 185       __argv[ARG_WORKING_DIRECTORY][1] == 0)
 186     ; /* Nothing */
 187   else if (chdir (__argv[ARG_WORKING_DIRECTORY]) < 0)
 188     write_err_and_exit (child_err_report_fd,
 189                         CHILD_CHDIR_FAILED);
 190
 191   /* __argv[ARG_CLOSE_DESCRIPTORS] is "y" if file descriptors from 3
 192    *  upwards should be closed
 193    */
 194
 195   if (__argv[ARG_CLOSE_DESCRIPTORS][0] == 'y')
 196     for (i = 3; i < 1000; i++)  /* FIXME real limit? */
 197       if (i != child_err_report_fd)
 198         close (i);
 199
 200   /* __argv[ARG_WAIT] is "w" to wait for the program to exit */
 201
 202   if (__argv[ARG_WAIT][0] == 'w')
 203     mode = P_WAIT;
 204   else
 205     mode = P_NOWAIT;
 206
 207   /* __argv[ARG_USE_PATH] is "y" to use PATH, otherwise not */
 208
 209   /* __argv[ARG_PROGRAM] is program file to run,
 210    * __argv[ARG_PROGRAM+1]... is its __argv.
 211    */
 212
 213   protect_argv (__argv, &new_argv);
 214
 215   /* For the program name passed to spawnv(), don't use the quoted
 216    * version. */
 217
 218   if (debug)
 219     {
 220       debugstring = g_string_new (NULL);
 221       g_string_append (debugstring,
 222                        g_strdup_printf ("calling %s %s mode=%s argv: ",
 223                                         (__argv[ARG_USE_PATH][0] == 'y' ?
 224                                          "spawnvp" : "spawnv"),
 225                                         __argv[ARG_PROGRAM],
 226                                         (mode == P_WAIT ?
 227                                          "P_WAIT" : "P_NOWAIT")));
 228       i = ARG_PROGRAM + 1 + file_and_argv_zero;
 229       while (new_argv[i])
 230         {
 231           g_string_append (debugstring, new_argv[i++]);
 232           if (new_argv[i])
 233             g_string_append (debugstring, " ");
 234         }
 235       MessageBox (NULL, debugstring->str, "gspawn-win32-helper", 0);
 236     }
 237
 238   if (new_argv[ARG_USE_PATH][0] == 'y')
 239     handle = spawnvp (mode, __argv[ARG_PROGRAM], new_argv + ARG_PROGRAM + file_and_argv_zero);
 240   else
 241     handle = spawnv (mode, __argv[ARG_PROGRAM], new_argv + ARG_PROGRAM + file_and_argv_zero);
 242
 243   if (debug)
 244     {
 245       debugstring = g_string_new (NULL);
 246       g_string_append (debugstring,
 247                        g_strdup_printf ("%s returned %#x",
 248                                         (__argv[ARG_USE_PATH][0] == 'y' ?
 249                                          "spawnvp" : "spawnv"),
 250                                         handle));
 251       MessageBox (NULL, debugstring->str, "gspawn-win32-helper", 0);
 252     }
 253
 254   if (handle < 0)
 255     write_err_and_exit (child_err_report_fd, CHILD_SPAWN_FAILED);
 256
 257   write (child_err_report_fd, &no_error, sizeof (no_error));
 258   if (mode == P_NOWAIT)
 259     write (child_err_report_fd, &handle, sizeof (handle));
 260   else
 261     write (child_err_report_fd, &zero, sizeof (zero));
 262   return 0;
 263 }
 264