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/timer.h"
  53 #include "lib/skin.h"
  54 #include "lib/filehighlight.h"
  55 #include "lib/fileloc.h"
  56 #include "lib/strutil.h"
  57 #include "lib/util.h"
  58 #include "lib/vfs/vfs.h"        /* vfs_init(), vfs_shut() */
  59 
  60 #include "filemanager/midnight.h"       /* current_panel */
  61 #include "filemanager/treestore.h"      /* tree_store_save */
  62 #include "filemanager/layout.h"
  63 #include "filemanager/ext.h"    /* flush_extension_file() */
  64 #include "filemanager/command.h"        /* cmdline */
  65 #include "filemanager/panel.h"  /* panalized_panel */
  66 
  67 #include "vfs/plugins_init.h"
  68 
  69 #include "events_init.h"
  70 #include "args.h"
  71 #ifdef ENABLE_SUBSHELL
  72 #include "subshell/subshell.h"
  73 #endif
  74 #include "setup.h"              /* load_setup() */
  75 
  76 #ifdef HAVE_CHARSET
  77 #include "lib/charsets.h"
  78 #include "selcodepage.h"
  79 #endif /* HAVE_CHARSET */
  80 
  81 #include "consaver/cons.saver.h"        /* cons_saver_pid */
  82 
  83 /*** global variables ****************************************************************************/
  84 
  85 /*** file scope macro definitions ****************************************************************/
  86 
  87 /*** file scope type declarations ****************************************************************/
  88 
  89 /*** file scope variables ************************************************************************/
  90 
  91 /*** file scope functions ************************************************************************/
  92 /* --------------------------------------------------------------------------------------------- */
  93 
  94 static void
  95 check_codeset (void)
     /*   */
  96 {
  97     const char *current_system_codepage = NULL;
  98 
  99     current_system_codepage = str_detect_termencoding ();
 100 
 101 #ifdef HAVE_CHARSET
 102     {
 103         const char *_display_codepage;
 104 
 105         _display_codepage = get_codepage_id (mc_global.display_codepage);
 106 
 107         if (strcmp (_display_codepage, current_system_codepage) != 0)
 108         {
 109             mc_global.display_codepage = get_codepage_index (current_system_codepage);
 110             if (mc_global.display_codepage == -1)
 111                 mc_global.display_codepage = 0;
 112 
 113             mc_config_set_string (mc_global.main_config, CONFIG_MISC_SECTION, "display_codepage",
 114                                   cp_display);
 115         }
 116     }
 117 #endif
 118 
 119     mc_global.utf8_display = str_isutf8 (current_system_codepage);
 120 }
 121 
 122 /* --------------------------------------------------------------------------------------------- */
 123 /** POSIX version.  The only version we support.  */
 124 
 125 static void
 126 OS_Setup (void)
     /*   */
 127 {
 128     const char *datadir_env;
 129 
 130     mc_shell_init ();
 131 
 132     /* This is the directory, where MC was installed, on Unix this is DATADIR */
 133     /* and can be overriden by the MC_DATADIR environment variable */
 134     datadir_env = g_getenv ("MC_DATADIR");
 135     if (datadir_env != NULL)
 136         mc_global.sysconfig_dir = g_strdup (datadir_env);
 137     else
 138         mc_global.sysconfig_dir = g_strdup (SYSCONFDIR);
 139 
 140     mc_global.share_data_dir = g_strdup (DATADIR);
 141 }
 142 
 143 /* --------------------------------------------------------------------------------------------- */
 144 
 145 static void
 146 sigchld_handler_no_subshell (int sig)
     /*   */
 147 {
 148 #ifdef __linux__
 149     int pid, status;
 150 
 151     if (mc_global.tty.console_flag == '\0')
 152         return;
 153 
 154     /* COMMENT: if it were true that after the call to handle_console(..INIT)
 155        the value of mc_global.tty.console_flag never changed, we could simply not install
 156        this handler at all if (!mc_global.tty.console_flag && !mc_global.tty.use_subshell). */
 157 
 158     /* That comment is no longer true.  We need to wait() on a sigchld
 159        handler (that's at least what the tarfs code expects currently). */
 160 
 161     pid = waitpid (cons_saver_pid, &status, WUNTRACED | WNOHANG);
 162 
 163     if (pid == cons_saver_pid)
 164     {
 165         if (WIFSTOPPED (status))
 166         {
 167             /* Someone has stopped cons.saver - restart it */
 168             kill (pid, SIGCONT);
 169         }
 170         else
 171         {
 172             /* cons.saver has died - disable console saving */
 173             handle_console (CONSOLE_DONE);
 174             mc_global.tty.console_flag = '\0';
 175         }
 176     }
 177     /* If we got here, some other child exited; ignore it */
 178 #endif /* __linux__ */
 179 
 180     (void) sig;
 181 }
 182 
 183 /* --------------------------------------------------------------------------------------------- */
 184 
 185 static void
 186 init_sigchld (void)
     /*   */
 187 {
 188     struct sigaction sigchld_action;
 189 
 190     memset (&sigchld_action, 0, sizeof (sigchld_action));
 191     sigchld_action.sa_handler =
 192 #ifdef ENABLE_SUBSHELL
 193         mc_global.tty.use_subshell ? sigchld_handler :
 194 #endif /* ENABLE_SUBSHELL */
 195         sigchld_handler_no_subshell;
 196 
 197     sigemptyset (&sigchld_action.sa_mask);
 198 
 199 #ifdef SA_RESTART
 200     sigchld_action.sa_flags = SA_RESTART;
 201 #endif /* !SA_RESTART */
 202 
 203     if (sigaction (SIGCHLD, &sigchld_action, NULL) == -1)
 204     {
 205 #ifdef ENABLE_SUBSHELL
 206         /*
 207          * This may happen on QNX Neutrino 6, where SA_RESTART
 208          * is defined but not implemented.  Fallback to no subshell.
 209          */
 210         mc_global.tty.use_subshell = FALSE;
 211 #endif /* ENABLE_SUBSHELL */
 212     }
 213 }
 214 
 215 /* --------------------------------------------------------------------------------------------- */
 216 /**
 217  * Check MC_SID to prevent running one mc from another.
 218  *
 219  * @return TRUE if no parent mc in our session was found, FALSE otherwise.
 220  */
 221 
 222 static gboolean
 223 check_sid (void)
     /*   */
 224 {
 225     pid_t my_sid, old_sid;
 226     const char *sid_str;
 227 
 228     sid_str = getenv ("MC_SID");
 229     if (sid_str == NULL)
 230         return TRUE;
 231 
 232     old_sid = (pid_t) strtol (sid_str, NULL, 0);
 233     if (old_sid == 0)
 234         return TRUE;
 235 
 236     my_sid = getsid (0);
 237     if (my_sid == -1)
 238         return TRUE;
 239 
 240     /* The parent mc is in a different session, it's OK */
 241     return (old_sid != my_sid);
 242 }
 243 
 244 /* --------------------------------------------------------------------------------------------- */
 245 /*** public functions ****************************************************************************/
 246 /* --------------------------------------------------------------------------------------------- */
 247 
 248 int
 249 main (int argc, char *argv[])
     /*   */
 250 {
 251     GError *mcerror = NULL;
 252     gboolean config_migrated = FALSE;
 253     char *config_migrate_msg = NULL;
 254     int exit_code = EXIT_FAILURE;
 255 
 256     mc_global.run_from_parent_mc = !check_sid ();
 257 
 258     mc_global.timer = mc_timer_new ();
 259 
 260     /* We had LC_CTYPE before, LC_ALL includs LC_TYPE as well */
 261 #ifdef HAVE_SETLOCALE
 262     (void) setlocale (LC_ALL, "");
 263 #endif
 264     (void) bindtextdomain (PACKAGE, LOCALEDIR);
 265     (void) textdomain (PACKAGE);
 266 
 267     /* do this before args parsing */
 268     str_init_strings (NULL);
 269 
 270     mc_setup_run_mode (argv);   /* are we mc? editor? viewer? etc... */
 271 
 272     if (!mc_args_parse (&argc, &argv, "mc", &mcerror))
 273     {
 274       startup_exit_falure:
 275         fprintf (stderr, _("Failed to run:\n%s\n"), mcerror->message);
 276         g_error_free (mcerror);
 277       startup_exit_ok:
 278         mc_shell_deinit ();
 279         str_uninit_strings ();
 280         mc_timer_destroy (mc_global.timer);
 281         return exit_code;
 282     }
 283 
 284     /* do this before mc_args_show_info () to view paths in the --datadir-info output */
 285     OS_Setup ();
 286 
 287     if (!g_path_is_absolute (mc_config_get_home_dir ()))
 288     {
 289         mc_propagate_error (&mcerror, 0, "%s: %s", _("Home directory path is not absolute"),
 290                             mc_config_get_home_dir ());
 291         mc_event_deinit (NULL);
 292         goto startup_exit_falure;
 293     }
 294 
 295     if (!mc_args_show_info ())
 296     {
 297         exit_code = EXIT_SUCCESS;
 298         goto startup_exit_ok;
 299     }
 300 
 301     if (!events_init (&mcerror))
 302         goto startup_exit_falure;
 303 
 304     mc_config_init_config_paths (&mcerror);
 305     config_migrated = mc_config_migrate_from_old_place (&mcerror, &config_migrate_msg);
 306     if (mcerror != NULL)
 307     {
 308         mc_event_deinit (NULL);
 309         goto startup_exit_falure;
 310     }
 311 
 312     vfs_init ();
 313     vfs_plugins_init ();
 314 
 315     load_setup ();
 316 
 317     /* Must be done after load_setup because depends on mc_global.vfs.cd_symlinks */
 318     vfs_setup_work_dir ();
 319 
 320     /* Set up temporary directory after VFS initialization */
 321     mc_tmpdir ();
 322 
 323     /* do this after vfs initialization and vfs working directory setup
 324        due to mc_setctl() and mcedit_arg_vpath_new() calls in mc_setup_by_args() */
 325     if (!mc_setup_by_args (argc, argv, &mcerror))
 326     {
 327         vfs_shut ();
 328         done_setup ();
 329         g_free (saved_other_dir);
 330         mc_event_deinit (NULL);
 331         goto startup_exit_falure;
 332     }
 333 
 334     /* Resolve the other_dir panel option.
 335      * 1. Must be done after vfs_setup_work_dir().
 336      * 2. Must be done after mc_setup_by_args() because of mc_run_mode.
 337      */
 338     if (mc_global.mc_run_mode == MC_RUN_FULL)
 339     {
 340         char *buffer;
 341         vfs_path_t *vpath;
 342 
 343         buffer = mc_config_get_string (mc_global.panels_config, "Dirs", "other_dir", ".");
 344         vpath = vfs_path_from_str (buffer);
 345         if (vfs_file_is_local (vpath))
 346             saved_other_dir = buffer;
 347         else
 348             g_free (buffer);
 349         vfs_path_free (vpath);
 350     }
 351 
 352     /* check terminal type
 353      * $TERM must be set and not empty
 354      * mc_global.tty.xterm_flag is used in init_key() and tty_init()
 355      * Do this after mc_args_handle() where mc_args__force_xterm is set up.
 356      */
 357     mc_global.tty.xterm_flag = tty_check_term (mc_args__force_xterm);
 358 
 359     /* NOTE: This has to be called before tty_init or whatever routine
 360        calls any define_sequence */
 361     init_key ();
 362 
 363     /* Must be done before installing the SIGCHLD handler [[FIXME]] */
 364     handle_console (CONSOLE_INIT);
 365 
 366 #ifdef ENABLE_SUBSHELL
 367     /* Disallow subshell when invoked as standalone viewer or editor from running mc */
 368     if (mc_global.mc_run_mode != MC_RUN_FULL && mc_global.run_from_parent_mc)
 369         mc_global.tty.use_subshell = FALSE;
 370 
 371     if (mc_global.tty.use_subshell)
 372         subshell_get_console_attributes ();
 373 #endif /* ENABLE_SUBSHELL */
 374 
 375     /* Install the SIGCHLD handler; must be done before init_subshell() */
 376     init_sigchld ();
 377 
 378     /* We need this, since ncurses endwin () doesn't restore the signals */
 379     save_stop_handler ();
 380 
 381     /* Must be done before init_subshell, to set up the terminal size: */
 382     /* FIXME: Should be removed and LINES and COLS computed on subshell */
 383     tty_init (!mc_args__nomouse, mc_global.tty.xterm_flag);
 384 
 385     /* start check mc_global.display_codepage and mc_global.source_codepage */
 386     check_codeset ();
 387 
 388     /* Removing this from the X code let's us type C-c */
 389     load_key_defs ();
 390 
 391     load_keymap_defs (!mc_args__nokeymap);
 392 
 393 #ifdef USE_INTERNAL_EDIT
 394     macros_list = g_array_new (TRUE, FALSE, sizeof (macros_t));
 395 #endif /* USE_INTERNAL_EDIT */
 396 
 397     tty_init_colors (mc_global.tty.disable_colors, mc_args__force_colors);
 398 
 399     mc_skin_init (NULL, &mcerror);
 400     dlg_set_default_colors ();
 401     input_set_default_colors ();
 402     if (mc_global.mc_run_mode == MC_RUN_FULL)
 403         command_set_default_colors ();
 404 
 405     mc_error_message (&mcerror, NULL);
 406 
 407 #ifdef ENABLE_SUBSHELL
 408     /* Done here to ensure that the subshell doesn't  */
 409     /* inherit the file descriptors opened below, etc */
 410     if (mc_global.tty.use_subshell && mc_global.run_from_parent_mc)
 411     {
 412         int r;
 413 
 414         r = query_dialog (_("Warning"),
 415                           _("GNU Midnight Commander\nis already running on this terminal.\n"
 416                             "Subshell support will be disabled."),
 417                           D_ERROR, 2, _("&OK"), _("&Quit"));
 418         if (r == 0)
 419         {
 420             /* parent mc was found and the user wants to continue */
 421             ;
 422         }
 423         else
 424         {
 425             /* parent mc was found and the user wants to quit mc */
 426             mc_global.midnight_shutdown = TRUE;
 427         }
 428 
 429         mc_global.tty.use_subshell = FALSE;
 430     }
 431 
 432     if (mc_global.tty.use_subshell)
 433         init_subshell ();
 434 #endif /* ENABLE_SUBSHELL */
 435 
 436     if (!mc_global.midnight_shutdown)
 437     {
 438         /* Also done after init_subshell, to save any shell init file messages */
 439         if (mc_global.tty.console_flag != '\0')
 440             handle_console (CONSOLE_SAVE);
 441 
 442         if (mc_global.tty.alternate_plus_minus)
 443             application_keypad_mode ();
 444 
 445         /* Done after subshell initialization to allow select and paste text by mouse
 446            w/o Shift button in subshell in the native console */
 447         init_mouse ();
 448 
 449         /* Done after tty_enter_ca_mode (tty_init) because in VTE bracketed mode is
 450            separate for the normal and alternate screens */
 451         enable_bracketed_paste ();
 452 
 453         /* subshell_prompt is NULL here */
 454         mc_prompt = (geteuid () == 0) ? "# " : "$ ";
 455 
 456         if (config_migrated)
 457         {
 458             message (D_ERROR, _("Warning"), "%s", config_migrate_msg);
 459             g_free (config_migrate_msg);
 460         }
 461     }
 462 
 463     /* Program main loop */
 464     if (mc_global.midnight_shutdown)
 465         exit_code = EXIT_SUCCESS;
 466     else
 467         exit_code = do_nc ()? EXIT_SUCCESS : EXIT_FAILURE;
 468 
 469     disable_bracketed_paste ();
 470 
 471     disable_mouse ();
 472 
 473     /* Save the tree store */
 474     (void) tree_store_save ();
 475 
 476     free_keymap_defs ();
 477 
 478     /* Virtual File System shutdown */
 479     vfs_shut ();
 480 
 481     flush_extension_file ();    /* does only free memory */
 482 
 483     mc_skin_deinit ();
 484     tty_colors_done ();
 485 
 486     tty_shutdown ();
 487 
 488     done_setup ();
 489 
 490     if (mc_global.tty.console_flag != '\0' && (quit & SUBSHELL_EXIT) == 0)
 491         handle_console (CONSOLE_RESTORE);
 492     if (mc_global.tty.alternate_plus_minus)
 493         numeric_keypad_mode ();
 494 
 495     (void) signal (SIGCHLD, SIG_DFL);   /* Disable the SIGCHLD handler */
 496 
 497     if (mc_global.tty.console_flag != '\0')
 498         handle_console (CONSOLE_DONE);
 499 
 500     if (mc_global.mc_run_mode == MC_RUN_FULL && mc_args__last_wd_file != NULL
 501         && last_wd_string != NULL && !print_last_revert)
 502     {
 503         int last_wd_fd;
 504 
 505         last_wd_fd = open (mc_args__last_wd_file, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL,
 506                            S_IRUSR | S_IWUSR);
 507         if (last_wd_fd != -1)
 508         {
 509             ssize_t ret1;
 510             int ret2;
 511             ret1 = write (last_wd_fd, last_wd_string, strlen (last_wd_string));
 512             ret2 = close (last_wd_fd);
 513             (void) ret1;
 514             (void) ret2;
 515         }
 516     }
 517     g_free (last_wd_string);
 518 
 519     mc_shell_deinit ();
 520 
 521     done_key ();
 522 
 523 #ifdef USE_INTERNAL_EDIT
 524     if (macros_list != NULL)
 525     {
 526         guint i;
 527 
 528         for (i = 0; i < macros_list->len; i++)
 529         {
 530             macros_t *macros;
 531 
 532             macros = &g_array_index (macros_list, struct macros_t, i);
 533             if (macros != NULL && macros->macro != NULL)
 534                 (void) g_array_free (macros->macro, TRUE);
 535         }
 536         (void) g_array_free (macros_list, TRUE);
 537     }
 538 #endif /* USE_INTERNAL_EDIT */
 539 
 540     str_uninit_strings ();
 541 
 542     if (mc_global.mc_run_mode != MC_RUN_EDITOR)
 543         g_free (mc_run_param0);
 544     else
 545         g_list_free_full ((GList *) mc_run_param0, (GDestroyNotify) mcedit_arg_free);
 546 
 547     g_free (mc_run_param1);
 548     g_free (saved_other_dir);
 549 
 550     mc_config_deinit_config_paths ();
 551 
 552     (void) mc_event_deinit (&mcerror);
 553     if (mcerror != NULL)
 554     {
 555         fprintf (stderr, _("\nFailed while close:\n%s\n"), mcerror->message);
 556         g_error_free (mcerror);
 557         exit_code = EXIT_FAILURE;
 558     }
 559 
 560     mc_timer_destroy (mc_global.timer);
 561 
 562     (void) putchar ('\n');      /* Hack to make shell's prompt start at left of screen */
 563 
 564     return exit_code;
 565 }
 566 
 567 /* --------------------------------------------------------------------------------------------- */

/*   */