root/src/main.c

/*   */

DEFINITIONS

1. check_codeset
2. OS_Setup
3. sigchld_handler_no_subshell
4. init_sigchld
5. check_sid
6. main

   1 /*
   2    Main program for the Midnight Commander
   3 
   4    Copyright (C) 1994-2020
   5    Free Software Foundation, Inc.
   6 
   7    Written by:
   8    Miguel de Icaza, 1994, 1995, 1996, 1997
   9    Janne Kukonlehto, 1994, 1995
  10    Norbert Warmuth, 1997
  11 
  12    This file is part of the Midnight Commander.
  13 
  14    The Midnight Commander is free software: you can redistribute it
  15    and/or modify it under the terms of the GNU General Public License as
  16    published by the Free Software Foundation, either version 3 of the License,
  17    or (at your option) any later version.
  18 
  19    The Midnight Commander is distributed in the hope that it will be useful,
  20    but WITHOUT ANY WARRANTY; without even the implied warranty of
  21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22    GNU General Public License for more details.
  23 
  24    You should have received a copy of the GNU General Public License
  25    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  26  */
  27 
  28 /** \file main.c
  29  *  \brief Source: this is a main module
  30  */
  31 
  32 #include <config.h>
  33 
  34 #include <ctype.h>
  35 #include <errno.h>
  36 #include <locale.h>
  37 #include <pwd.h>                /* for username in xterm title */
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #include <sys/types.h>
  42 #include <sys/wait.h>
  43 #include <signal.h>
  44 #include <unistd.h>             /* getsid() */
  45 
  46 #include "lib/global.h"
  47 
  48 #include "lib/event.h"
  49 #include "lib/tty/tty.h"
  50 #include "lib/tty/key.h"        /* For init_key() */
  51 #include "lib/tty/mouse.h"      /* init_mouse() */
  52 #include "lib/skin.h"
  53 #include "lib/filehighlight.h"
  54 #include "lib/fileloc.h"
  55 #include "lib/strutil.h"
  56 #include "lib/util.h"
  57 #include "lib/vfs/vfs.h"        /* vfs_init(), vfs_shut() */
  58 
  59 #include "filemanager/filemanager.h"
  60 #include "filemanager/treestore.h"      /* tree_store_save */
  61 #include "filemanager/layout.h"
  62 #include "filemanager/ext.h"    /* flush_extension_file() */
  63 #include "filemanager/command.h"        /* cmdline */
  64 #include "filemanager/panel.h"  /* panalized_panel */
  65 
  66 #include "vfs/plugins_init.h"
  67 
  68 #include "events_init.h"
  69 #include "args.h"
  70 #ifdef ENABLE_SUBSHELL
  71 #include "subshell/subshell.h"
  72 #endif
  73 #include "setup.h"              /* load_setup() */
  74 
  75 #ifdef HAVE_CHARSET
  76 #include "lib/charsets.h"
  77 #include "selcodepage.h"
  78 #endif /* HAVE_CHARSET */
  79 
  80 #include "consaver/cons.saver.h"        /* cons_saver_pid */
  81 
  82 /*** global variables ****************************************************************************/
  83 
  84 /*** file scope macro definitions ****************************************************************/
  85 
  86 /*** file scope type declarations ****************************************************************/
  87 
  88 /*** file scope variables ************************************************************************/
  89 
  90 /*** file scope functions ************************************************************************/
  91 /* --------------------------------------------------------------------------------------------- */
  92 
  93 static void
  94 check_codeset (void)
     /*   */
  95 {
  96     const char *current_system_codepage = NULL;
  97 
  98     current_system_codepage = str_detect_termencoding ();
  99 
 100 #ifdef HAVE_CHARSET
 101     {
 102         const char *_display_codepage;
 103 
 104         _display_codepage = get_codepage_id (mc_global.display_codepage);
 105 
 106         if (strcmp (_display_codepage, current_system_codepage) != 0)
 107         {
 108             mc_global.display_codepage = get_codepage_index (current_system_codepage);
 109             if (mc_global.display_codepage == -1)
 110                 mc_global.display_codepage = 0;
 111 
 112             mc_config_set_string (mc_global.main_config, CONFIG_MISC_SECTION, "display_codepage",
 113                                   cp_display);
 114         }
 115     }
 116 #endif
 117 
 118     mc_global.utf8_display = str_isutf8 (current_system_codepage);
 119 }
 120 
 121 /* --------------------------------------------------------------------------------------------- */
 122 /** POSIX version.  The only version we support.  */
 123 
 124 static void
 125 OS_Setup (void)
     /*   */
 126 {
 127     const char *datadir_env;
 128 
 129     mc_shell_init ();
 130 
 131     /* This is the directory, where MC was installed, on Unix this is DATADIR */
 132     /* and can be overriden by the MC_DATADIR environment variable */
 133     datadir_env = g_getenv ("MC_DATADIR");
 134     if (datadir_env != NULL)
 135         mc_global.sysconfig_dir = g_strdup (datadir_env);
 136     else
 137         mc_global.sysconfig_dir = g_strdup (SYSCONFDIR);
 138 
 139     mc_global.share_data_dir = g_strdup (DATADIR);
 140 }
 141 
 142 /* --------------------------------------------------------------------------------------------- */
 143 
 144 static void
 145 sigchld_handler_no_subshell (int sig)
     /*   */
 146 {
 147 #ifdef __linux__
 148     int pid, status;
 149 
 150     if (mc_global.tty.console_flag == '\0')
 151         return;
 152 
 153     /* COMMENT: if it were true that after the call to handle_console(..INIT)
 154        the value of mc_global.tty.console_flag never changed, we could simply not install
 155        this handler at all if (!mc_global.tty.console_flag && !mc_global.tty.use_subshell). */
 156 
 157     /* That comment is no longer true.  We need to wait() on a sigchld
 158        handler (that's at least what the tarfs code expects currently). */
 159 
 160     pid = waitpid (cons_saver_pid, &status, WUNTRACED | WNOHANG);
 161 
 162     if (pid == cons_saver_pid)
 163     {
 164         if (WIFSTOPPED (status))
 165         {
 166             /* Someone has stopped cons.saver - restart it */
 167             kill (pid, SIGCONT);
 168         }
 169         else
 170         {
 171             /* cons.saver has died - disable console saving */
 172             handle_console (CONSOLE_DONE);
 173             mc_global.tty.console_flag = '\0';
 174         }
 175     }
 176     /* If we got here, some other child exited; ignore it */
 177 #endif /* __linux__ */
 178 
 179     (void) sig;
 180 }
 181 
 182 /* --------------------------------------------------------------------------------------------- */
 183 
 184 static void
 185 init_sigchld (void)
     /*   */
 186 {
 187     struct sigaction sigchld_action;
 188 
 189     memset (&sigchld_action, 0, sizeof (sigchld_action));
 190     sigchld_action.sa_handler =
 191 #ifdef ENABLE_SUBSHELL
 192         mc_global.tty.use_subshell ? sigchld_handler :
 193 #endif /* ENABLE_SUBSHELL */
 194         sigchld_handler_no_subshell;
 195 
 196     sigemptyset (&sigchld_action.sa_mask);
 197 
 198 #ifdef SA_RESTART
 199     sigchld_action.sa_flags = SA_RESTART;
 200 #endif /* !SA_RESTART */
 201 
 202     if (sigaction (SIGCHLD, &sigchld_action, NULL) == -1)
 203     {
 204 #ifdef ENABLE_SUBSHELL
 205         /*
 206          * This may happen on QNX Neutrino 6, where SA_RESTART
 207          * is defined but not implemented.  Fallback to no subshell.
 208          */
 209         mc_global.tty.use_subshell = FALSE;
 210 #endif /* ENABLE_SUBSHELL */
 211     }
 212 }
 213 
 214 /* --------------------------------------------------------------------------------------------- */
 215 /**
 216  * Check MC_SID to prevent running one mc from another.
 217  *
 218  * @return TRUE if no parent mc in our session was found, FALSE otherwise.
 219  */
 220 
 221 static gboolean
 222 check_sid (void)
     /*   */
 223 {
 224     pid_t my_sid, old_sid;
 225     const char *sid_str;
 226 
 227     sid_str = getenv ("MC_SID");
 228     if (sid_str == NULL)
 229         return TRUE;
 230 
 231     old_sid = (pid_t) strtol (sid_str, NULL, 0);
 232     if (old_sid == 0)
 233         return TRUE;
 234 
 235     my_sid = getsid (0);
 236     if (my_sid == -1)
 237         return TRUE;
 238 
 239     /* The parent mc is in a different session, it's OK */
 240     return (old_sid != my_sid);
 241 }
 242 
 243 /* --------------------------------------------------------------------------------------------- */
 244 /*** public functions ****************************************************************************/
 245 /* --------------------------------------------------------------------------------------------- */
 246 
 247 int
 248 main (int argc, char *argv[])
     /*   */
 249 {
 250     GError *mcerror = NULL;
 251     int exit_code = EXIT_FAILURE;
 252 
 253     mc_global.run_from_parent_mc = !check_sid ();
 254 
 255     /* We had LC_CTYPE before, LC_ALL includs LC_TYPE as well */
 256 #ifdef HAVE_SETLOCALE
 257     (void) setlocale (LC_ALL, "");
 258 #endif
 259     (void) bindtextdomain (PACKAGE, LOCALEDIR);
 260     (void) textdomain (PACKAGE);
 261 
 262     /* do this before args parsing */
 263     str_init_strings (NULL);
 264 
 265     mc_setup_run_mode (argv);   /* are we mc? editor? viewer? etc... */
 266 
 267     if (!mc_args_parse (&argc, &argv, "mc", &mcerror))
 268     {
 269       startup_exit_falure:
 270         fprintf (stderr, _("Failed to run:\n%s\n"), mcerror->message);
 271         g_error_free (mcerror);
 272       startup_exit_ok:
 273         mc_shell_deinit ();
 274         str_uninit_strings ();
 275         return exit_code;
 276     }
 277 
 278     /* do this before mc_args_show_info () to view paths in the --datadir-info output */
 279     OS_Setup ();
 280 
 281     if (!g_path_is_absolute (mc_config_get_home_dir ()))
 282     {
 283         mc_propagate_error (&mcerror, 0, "%s: %s", _("Home directory path is not absolute"),
 284                             mc_config_get_home_dir ());
 285         mc_event_deinit (NULL);
 286         goto startup_exit_falure;
 287     }
 288 
 289     if (!mc_args_show_info ())
 290     {
 291         exit_code = EXIT_SUCCESS;
 292         goto startup_exit_ok;
 293     }
 294 
 295     if (!events_init (&mcerror))
 296         goto startup_exit_falure;
 297 
 298     mc_config_init_config_paths (&mcerror);
 299     if (mcerror != NULL)
 300     {
 301         mc_event_deinit (NULL);
 302         goto startup_exit_falure;
 303     }
 304 
 305     vfs_init ();
 306     vfs_plugins_init ();
 307 
 308     load_setup ();
 309 
 310     /* Must be done after load_setup because depends on mc_global.vfs.cd_symlinks */
 311     vfs_setup_work_dir ();
 312 
 313     /* Set up temporary directory after VFS initialization */
 314     mc_tmpdir ();
 315 
 316     /* do this after vfs initialization and vfs working directory setup
 317        due to mc_setctl() and mcedit_arg_vpath_new() calls in mc_setup_by_args() */
 318     if (!mc_setup_by_args (argc, argv, &mcerror))
 319     {
 320         vfs_shut ();
 321         done_setup ();
 322         g_free (saved_other_dir);
 323         mc_event_deinit (NULL);
 324         goto startup_exit_falure;
 325     }
 326 
 327     /* Resolve the other_dir panel option.
 328      * 1. Must be done after vfs_setup_work_dir().
 329      * 2. Must be done after mc_setup_by_args() because of mc_run_mode.
 330      */
 331     if (mc_global.mc_run_mode == MC_RUN_FULL)
 332     {
 333         char *buffer;
 334         vfs_path_t *vpath;
 335 
 336         buffer = mc_config_get_string (mc_global.panels_config, "Dirs", "other_dir", ".");
 337         vpath = vfs_path_from_str (buffer);
 338         if (vfs_file_is_local (vpath))
 339             saved_other_dir = buffer;
 340         else
 341             g_free (buffer);
 342         vfs_path_free (vpath);
 343     }
 344 
 345     /* check terminal type
 346      * $TERM must be set and not empty
 347      * mc_global.tty.xterm_flag is used in init_key() and tty_init()
 348      * Do this after mc_args_handle() where mc_args__force_xterm is set up.
 349      */
 350     mc_global.tty.xterm_flag = tty_check_term (mc_args__force_xterm);
 351 
 352     /* NOTE: This has to be called before tty_init or whatever routine
 353        calls any define_sequence */
 354     init_key ();
 355 
 356     /* Must be done before installing the SIGCHLD handler [[FIXME]] */
 357     handle_console (CONSOLE_INIT);
 358 
 359 #ifdef ENABLE_SUBSHELL
 360     /* Disallow subshell when invoked as standalone viewer or editor from running mc */
 361     if (mc_global.mc_run_mode != MC_RUN_FULL && mc_global.run_from_parent_mc)
 362         mc_global.tty.use_subshell = FALSE;
 363 
 364     if (mc_global.tty.use_subshell)
 365         subshell_get_console_attributes ();
 366 #endif /* ENABLE_SUBSHELL */
 367 
 368     /* Install the SIGCHLD handler; must be done before init_subshell() */
 369     init_sigchld ();
 370 
 371     /* We need this, since ncurses endwin () doesn't restore the signals */
 372     save_stop_handler ();
 373 
 374     /* Must be done before init_subshell, to set up the terminal size: */
 375     /* FIXME: Should be removed and LINES and COLS computed on subshell */
 376     tty_init (!mc_args__nomouse, mc_global.tty.xterm_flag);
 377 
 378     /* start check mc_global.display_codepage and mc_global.source_codepage */
 379     check_codeset ();
 380 
 381     /* Removing this from the X code let's us type C-c */
 382     load_key_defs ();
 383 
 384     load_keymap_defs (!mc_args__nokeymap);
 385 
 386 #ifdef USE_INTERNAL_EDIT
 387     macros_list = g_array_new (TRUE, FALSE, sizeof (macros_t));
 388 #endif /* USE_INTERNAL_EDIT */
 389 
 390     tty_init_colors (mc_global.tty.disable_colors, mc_args__force_colors);
 391 
 392     mc_skin_init (NULL, &mcerror);
 393     dlg_set_default_colors ();
 394     input_set_default_colors ();
 395     if (mc_global.mc_run_mode == MC_RUN_FULL)
 396         command_set_default_colors ();
 397 
 398     mc_error_message (&mcerror, NULL);
 399 
 400 #ifdef ENABLE_SUBSHELL
 401     /* Done here to ensure that the subshell doesn't  */
 402     /* inherit the file descriptors opened below, etc */
 403     if (mc_global.tty.use_subshell && mc_global.run_from_parent_mc)
 404     {
 405         int r;
 406 
 407         r = query_dialog (_("Warning"),
 408                           _("GNU Midnight Commander\nis already running on this terminal.\n"
 409                             "Subshell support will be disabled."),
 410                           D_ERROR, 2, _("&OK"), _("&Quit"));
 411         if (r == 0)
 412         {
 413             /* parent mc was found and the user wants to continue */
 414             ;
 415         }
 416         else
 417         {
 418             /* parent mc was found and the user wants to quit mc */
 419             mc_global.midnight_shutdown = TRUE;
 420         }
 421 
 422         mc_global.tty.use_subshell = FALSE;
 423     }
 424 
 425     if (mc_global.tty.use_subshell)
 426         init_subshell ();
 427 #endif /* ENABLE_SUBSHELL */
 428 
 429     if (!mc_global.midnight_shutdown)
 430     {
 431         /* Also done after init_subshell, to save any shell init file messages */
 432         if (mc_global.tty.console_flag != '\0')
 433             handle_console (CONSOLE_SAVE);
 434 
 435         if (mc_global.tty.alternate_plus_minus)
 436             application_keypad_mode ();
 437 
 438         /* Done after subshell initialization to allow select and paste text by mouse
 439            w/o Shift button in subshell in the native console */
 440         init_mouse ();
 441 
 442         /* Done after tty_enter_ca_mode (tty_init) because in VTE bracketed mode is
 443            separate for the normal and alternate screens */
 444         enable_bracketed_paste ();
 445 
 446         /* subshell_prompt is NULL here */
 447         mc_prompt = (geteuid () == 0) ? "# " : "$ ";
 448     }
 449 
 450     /* Program main loop */
 451     if (mc_global.midnight_shutdown)
 452         exit_code = EXIT_SUCCESS;
 453     else
 454         exit_code = do_nc ()? EXIT_SUCCESS : EXIT_FAILURE;
 455 
 456     disable_bracketed_paste ();
 457 
 458     disable_mouse ();
 459 
 460     /* Save the tree store */
 461     (void) tree_store_save ();
 462 
 463     free_keymap_defs ();
 464 
 465     /* Virtual File System shutdown */
 466     vfs_shut ();
 467 
 468     flush_extension_file ();    /* does only free memory */
 469 
 470     mc_skin_deinit ();
 471     tty_colors_done ();
 472 
 473     tty_shutdown ();
 474 
 475     done_setup ();
 476 
 477     if (mc_global.tty.console_flag != '\0' && (quit & SUBSHELL_EXIT) == 0)
 478         handle_console (CONSOLE_RESTORE);
 479     if (mc_global.tty.alternate_plus_minus)
 480         numeric_keypad_mode ();
 481 
 482     (void) signal (SIGCHLD, SIG_DFL);   /* Disable the SIGCHLD handler */
 483 
 484     if (mc_global.tty.console_flag != '\0')
 485         handle_console (CONSOLE_DONE);
 486 
 487     if (mc_global.mc_run_mode == MC_RUN_FULL && mc_args__last_wd_file != NULL
 488         && last_wd_string != NULL && !print_last_revert)
 489     {
 490         int last_wd_fd;
 491 
 492         last_wd_fd = open (mc_args__last_wd_file, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL,
 493                            S_IRUSR | S_IWUSR);
 494         if (last_wd_fd != -1)
 495         {
 496             ssize_t ret1;
 497             int ret2;
 498             ret1 = write (last_wd_fd, last_wd_string, strlen (last_wd_string));
 499             ret2 = close (last_wd_fd);
 500             (void) ret1;
 501             (void) ret2;
 502         }
 503     }
 504     g_free (last_wd_string);
 505 
 506     mc_shell_deinit ();
 507 
 508     done_key ();
 509 
 510 #ifdef USE_INTERNAL_EDIT
 511     if (macros_list != NULL)
 512     {
 513         guint i;
 514 
 515         for (i = 0; i < macros_list->len; i++)
 516         {
 517             macros_t *macros;
 518 
 519             macros = &g_array_index (macros_list, struct macros_t, i);
 520             if (macros != NULL && macros->macro != NULL)
 521                 (void) g_array_free (macros->macro, TRUE);
 522         }
 523         (void) g_array_free (macros_list, TRUE);
 524     }
 525 #endif /* USE_INTERNAL_EDIT */
 526 
 527     str_uninit_strings ();
 528 
 529     if (mc_global.mc_run_mode != MC_RUN_EDITOR)
 530         g_free (mc_run_param0);
 531     else
 532         g_list_free_full ((GList *) mc_run_param0, (GDestroyNotify) mcedit_arg_free);
 533 
 534     g_free (mc_run_param1);
 535     g_free (saved_other_dir);
 536 
 537     mc_config_deinit_config_paths ();
 538 
 539     (void) mc_event_deinit (&mcerror);
 540     if (mcerror != NULL)
 541     {
 542         fprintf (stderr, _("\nFailed while close:\n%s\n"), mcerror->message);
 543         g_error_free (mcerror);
 544         exit_code = EXIT_FAILURE;
 545     }
 546 
 547     (void) putchar ('\n');      /* Hack to make shell's prompt start at left of screen */
 548 
 549     return exit_code;
 550 }
 551 
 552 /* --------------------------------------------------------------------------------------------- */

/*   */