2 Concurrent shell support for the Midnight Commander
4 Copyright (C) 1994-2016
5 Free Software Foundation, Inc.
8 Alexander Kriegisch <Alexander@Kriegisch.name>
9 Aliaksey Kandratsenka <alk@tut.by>
10 Andreas Mohr <and@gmx.li>
11 Andrew Borodin <aborodin@vmail.ru>
12 Andrew Borodin <borodin@borodin.zarya>
13 Andrew V. Samoilov <sav@bcs.zp.ua>
14 Chris Owen <chris@candu.co.uk>
15 Claes Nästén <me@pekdon.net>
16 Egmont Koblinger <egmont@gmail.com>
17 Enrico Weigelt, metux IT service <weigelt@metux.de>
18 Igor Urazov <z0rc3r@gmail.com>
19 Ilia Maslakov <il.smind@gmail.com>
20 Leonard den Ottolander <leonard@den.ottolander.nl>
21 Miguel de Icaza <miguel@novell.com>
22 Mikhail S. Pobolovets <styx.mp@gmail.com>
23 Norbert Warmuth <nwarmuth@privat.circular.de>
24 Patrick Winnertz <winnie@debian.org>
25 Pavel Machek <pavel@suse.cz>
26 Pavel Roskin <proski@gnu.org>
27 Pavel Tsekov <ptsekov@gmx.net>
28 Roland Illig <roland.illig@gmx.de>
29 Sergei Trofimovich <slyfox@inbox.ru>
30 Slava Zanko <slavazanko@gmail.com>, 2013,2015.
31 Timur Bakeyev <mc@bat.ru>
32 Vit Rosin <vit_r@list.ru>
34 This file is part of the Midnight Commander.
36 The Midnight Commander is free software: you can redistribute it
37 and/or modify it under the terms of the GNU General Public License as
38 published by the Free Software Foundation, either version 3 of the License,
39 or (at your option) any later version.
41 The Midnight Commander is distributed in the hope that it will be useful,
42 but WITHOUT ANY WARRANTY; without even the implied warranty of
43 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
44 GNU General Public License for more details.
46 You should have received a copy of the GNU General Public License
47 along with this program. If not, see <http://www.gnu.org/licenses/>.
51 * \brief Source: concurrent shell support
66 #include <sys/types.h>
68 #ifdef HAVE_SYS_IOCTL_H
69 #include <sys/ioctl.h>
74 #include <stropts.h> /* For I_PUSH */
75 #endif /* HAVE_STROPTS_H */
77 #include "lib/global.h"
79 #include "lib/unixcompat.h"
80 #include "lib/tty/tty.h" /* LINES */
81 #include "lib/tty/key.h" /* XCTRL */
82 #include "lib/vfs/vfs.h"
83 #include "lib/strutil.h"
84 #include "lib/mcconfig.h"
86 #include "lib/widget.h"
91 /*** global variables ****************************************************************************/
93 /* State of the subshell:
94 * INACTIVE: the default state; awaiting a command
95 * ACTIVE: remain in the shell until the user hits 'subshell_switch_key'
96 * RUNNING_COMMAND: return to MC when the current command finishes */
97 enum subshell_state_enum subshell_state
;
99 /* Holds the latest prompt captured from the subshell */
100 GString
*subshell_prompt
= NULL
;
102 /* Subshell: if set, then the prompt was not saved on CONSOLE_SAVE */
103 /* We need to paint it after CONSOLE_RESTORE, see: load_prompt */
104 gboolean update_subshell_prompt
= FALSE
;
106 /*** file scope macro definitions ****************************************************************/
109 #define WEXITSTATUS(stat_val) ((unsigned)(stat_val) >> 8)
113 #define WIFEXITED(stat_val) (((stat_val) & 255) == 0)
116 /* Initial length of the buffer for the subshell's prompt */
117 #define INITIAL_PROMPT_SIZE 10
119 /* Used by the child process to indicate failure to start the subshell */
120 #define FORK_FAILURE 69 /* Arbitrary */
122 /* Length of the buffer for all I/O with the subshell */
123 #define PTY_BUFFER_SIZE BUF_SMALL /* Arbitrary; but keep it >= 80 */
125 /*** file scope type declarations ****************************************************************/
134 /*** file scope variables ************************************************************************/
136 /* tcsh closes all non-standard file descriptors, so we have to use a pipe */
137 static char tcsh_fifo
[128];
139 static int subshell_pty_slave
= -1;
141 /* The key for switching back to MC from the subshell */
143 static const char subshell_switch_key
= XCTRL ('o') & 255;
146 /* For reading/writing on the subshell's pty */
147 static char pty_buffer
[PTY_BUFFER_SIZE
] = "\0";
149 /* To pass CWD info from the subshell to MC */
150 static int subshell_pipe
[2];
152 /* The subshell's process ID */
153 static pid_t subshell_pid
= 1;
155 /* One extra char for final '\n' */
156 static char subshell_cwd
[MC_MAXPATHLEN
+ 1];
158 /* Flag to indicate whether the subshell is ready for next command */
159 static int subshell_ready
;
161 /* The following two flags can be changed by the SIGCHLD handler. This is */
162 /* OK, because the 'int' type is updated atomically on all known machines */
163 static volatile int subshell_alive
, subshell_stopped
;
165 /* We store the terminal's initial mode here so that we can configure
166 the pty similarly, and also so we can restore the real terminal to
167 sanity if we have to exit abruptly */
168 static struct termios shell_mode
;
170 /* This is a transparent mode for the terminal where MC is running on */
171 /* It is used when the shell is active, so that the control signals */
172 /* are delivered to the shell pty */
173 static struct termios raw_mode
;
175 /* --------------------------------------------------------------------------------------------- */
176 /*** file scope functions ************************************************************************/
177 /* --------------------------------------------------------------------------------------------- */
179 * Write all data, even if the write() call is interrupted.
183 write_all (int fd
, const void *buf
, size_t count
)
191 ret
= write (fd
, (const unsigned char *) buf
+ written
, count
);
196 if (mc_global
.tty
.winch_flag
!= 0)
197 tty_change_screen_size ();
202 return written
> 0 ? written
: ret
;
210 /* --------------------------------------------------------------------------------------------- */
212 * Prepare child process to running the shell and run it.
214 * Modifies the global variables (in the child process only):
221 init_subshell_child (const char *pty_name
)
223 char *init_file
= NULL
;
224 char *putenv_str
= NULL
;
228 setsid (); /* Get a fresh terminal session */
230 /* Make sure that it has become our controlling terminal */
232 /* Redundant on Linux and probably most systems, but just in case: */
235 ioctl (subshell_pty_slave
, TIOCSCTTY
, 0);
238 /* Configure its terminal modes and window size */
240 /* Set up the pty with the same termios flags as our own tty */
241 if (tcsetattr (subshell_pty_slave
, TCSANOW
, &shell_mode
))
243 fprintf (stderr
, "Cannot set pty terminal modes: %s\r\n", unix_error_string (errno
));
244 my_exit (FORK_FAILURE
);
247 /* Set the pty's size (80x25 by default on Linux) according to the */
248 /* size of the real terminal as calculated by ncurses, if possible */
249 tty_resize (subshell_pty_slave
);
251 /* Set up the subshell's environment and init file name */
253 /* It simplifies things to change to our home directory here, */
254 /* and the user's startup file may do a 'cd' command anyway */
258 ret
= chdir (mc_config_get_home_dir ()); /* FIXME? What about when we re-run the subshell? */
262 /* Set MC_SID to prevent running one mc from another */
266 char sid_str
[BUF_SMALL
];
268 g_snprintf (sid_str
, sizeof (sid_str
), "MC_SID=%ld", (long) mc_sid
);
269 putenv (g_strdup (sid_str
));
272 switch (mc_global
.shell
->type
)
275 /* Do we have a custom init file ~/.local/share/mc/bashrc? */
276 init_file
= mc_config_get_full_path ("bashrc");
278 /* Otherwise use ~/.bashrc */
279 if (!exist_file (init_file
))
282 init_file
= g_strdup (".bashrc");
285 /* Make MC's special commands not show up in bash's history and also suppress
286 * consecutive identical commands*/
287 putenv ((char *) "HISTCONTROL=ignoreboth");
289 /* Allow alternative readline settings for MC */
293 input_file
= mc_config_get_full_path ("inputrc");
294 if (exist_file (input_file
))
296 putenv_str
= g_strconcat ("INPUTRC=", input_file
, (char *) NULL
);
304 case SHELL_ASH_BUSYBOX
:
306 /* Do we have a custom init file ~/.local/share/mc/ashrc? */
307 init_file
= mc_config_get_full_path ("ashrc");
309 /* Otherwise use ~/.profile */
310 if (!exist_file (init_file
))
313 init_file
= g_strdup (".profile");
316 /* Put init file to ENV variable used by ash */
317 putenv_str
= g_strconcat ("ENV=", init_file
, (char *) NULL
);
319 /* Do not use "g_free (putenv_str)" here, otherwise ENV will be undefined! */
323 /* TODO: Find a way to pass initfile to TCSH, ZSH and FISH */
330 fprintf (stderr
, __FILE__
": unimplemented subshell type %u\r\n", mc_global
.shell
->type
);
331 my_exit (FORK_FAILURE
);
334 /* Attach all our standard file descriptors to the pty */
336 /* This is done just before the fork, because stderr must still */
337 /* be connected to the real tty during the above error messages; */
338 /* otherwise the user will never see them. */
340 dup2 (subshell_pty_slave
, STDIN_FILENO
);
341 dup2 (subshell_pty_slave
, STDOUT_FILENO
);
342 dup2 (subshell_pty_slave
, STDERR_FILENO
);
344 close (subshell_pipe
[READ
]);
345 close (subshell_pty_slave
); /* These may be FD_CLOEXEC, but just in case... */
346 /* Close master side of pty. This is important; apart from */
347 /* freeing up the descriptor for use in the subshell, it also */
348 /* means that when MC exits, the subshell will get a SIGHUP and */
349 /* exit too, because there will be no more descriptors pointing */
350 /* at the master side of the pty and so it will disappear. */
351 close (mc_global
.tty
.subshell_pty
);
353 /* Execute the subshell at last */
355 switch (mc_global
.shell
->type
)
358 execl (mc_global
.shell
->path
, "bash", "-rcfile", init_file
, (char *) NULL
);
362 /* Use -g to exclude cmds beginning with space from history
363 * and -Z to use the line editor on non-interactive term */
364 execl (mc_global
.shell
->path
, "zsh", "-Z", "-g", (char *) NULL
);
368 case SHELL_ASH_BUSYBOX
:
372 execl (mc_global
.shell
->path
, mc_global
.shell
->path
, (char *) NULL
);
379 /* If we get this far, everything failed miserably */
382 my_exit (FORK_FAILURE
);
386 /* --------------------------------------------------------------------------------------------- */
388 * Check MC_SID to prevent running one mc from another.
390 * 0 if no parent mc in our session was found,
391 * 1 if parent mc was found and the user wants to continue,
392 * 2 if parent mc was found and the user wants to quit mc.
398 pid_t my_sid
, old_sid
;
402 sid_str
= getenv ("MC_SID");
406 old_sid
= (pid_t
) strtol (sid_str
, NULL
, 0);
414 /* The parent mc is in a different session, it's OK */
415 if (old_sid
!= my_sid
)
418 r
= query_dialog (_("Warning"),
419 _("GNU Midnight Commander is already\n"
420 "running on this terminal.\n"
421 "Subshell support will be disabled."), D_ERROR
, 2, _("&OK"), _("&Quit"));
423 return (r
!= 0) ? 2 : 1;
426 /* --------------------------------------------------------------------------------------------- */
431 static gboolean initialized
= FALSE
;
433 /* MC calls tty_reset_shell_mode() in pre_exec() to set the real tty to its */
434 /* original settings. However, here we need to make this tty very raw, */
435 /* so that all keyboard signals, XON/XOFF, etc. will get through to the */
436 /* pty. So, instead of changing the code for execute(), pre_exec(), */
437 /* etc, we just set up the modes we need here, before each command. */
439 if (!initialized
) /* First time: initialise 'raw_mode' */
441 tcgetattr (STDOUT_FILENO
, &raw_mode
);
442 raw_mode
.c_lflag
&= ~ICANON
; /* Disable line-editing chars, etc. */
443 raw_mode
.c_lflag
&= ~ISIG
; /* Disable intr, quit & suspend chars */
444 raw_mode
.c_lflag
&= ~ECHO
; /* Disable input echoing */
445 raw_mode
.c_iflag
&= ~IXON
; /* Pass ^S/^Q to subshell undisturbed */
446 raw_mode
.c_iflag
&= ~ICRNL
; /* Don't translate CRs into LFs */
447 raw_mode
.c_oflag
&= ~OPOST
; /* Don't postprocess output */
448 raw_mode
.c_cc
[VTIME
] = 0; /* IE: wait forever, and return as */
449 raw_mode
.c_cc
[VMIN
] = 1; /* soon as a character is available */
454 /* --------------------------------------------------------------------------------------------- */
456 * Wait until the subshell dies or stops. If it stops, make it resume.
457 * Possibly modifies the globals 'subshell_alive' and 'subshell_stopped'
463 sigset_t sigchld_mask
, old_mask
;
465 sigemptyset (&sigchld_mask
);
466 sigaddset (&sigchld_mask
, SIGCHLD
);
467 sigprocmask (SIG_BLOCK
, &sigchld_mask
, &old_mask
);
470 * SIGCHLD should not be blocked, but we unblock it just in case.
471 * This is known to be useful for cygwin 1.3.12 and older.
473 sigdelset (&old_mask
, SIGCHLD
);
475 /* Wait until the subshell has stopped */
476 while (subshell_alive
&& !subshell_stopped
)
477 sigsuspend (&old_mask
);
479 if (subshell_state
!= ACTIVE
)
481 /* Discard all remaining data from stdin to the subshell */
482 tcflush (subshell_pty_slave
, TCIFLUSH
);
485 subshell_stopped
= FALSE
;
486 kill (subshell_pid
, SIGCONT
);
488 sigprocmask (SIG_SETMASK
, &old_mask
, NULL
);
489 /* We can't do any better without modifying the shell(s) */
492 /* --------------------------------------------------------------------------------------------- */
493 /** Feed the subshell our keyboard input until it says it's finished */
496 feed_subshell (int how
, gboolean fail_on_error
)
498 fd_set read_set
; /* For 'select' */
499 int bytes
; /* For the return value from 'read' */
500 int i
; /* Loop counter */
502 struct timeval wtime
; /* Maximum time we wait for the subshell */
503 struct timeval
*wptr
;
505 /* we wait up to 10 seconds if fail_on_error, forever otherwise */
508 wptr
= fail_on_error
? &wtime
: NULL
;
517 /* Prepare the file-descriptor set and call 'select' */
520 FD_SET (mc_global
.tty
.subshell_pty
, &read_set
);
521 FD_SET (subshell_pipe
[READ
], &read_set
);
522 maxfdp
= MAX (mc_global
.tty
.subshell_pty
, subshell_pipe
[READ
]);
525 FD_SET (STDIN_FILENO
, &read_set
);
526 maxfdp
= MAX (maxfdp
, STDIN_FILENO
);
529 if (select (maxfdp
+ 1, &read_set
, NULL
, NULL
, wptr
) == -1)
531 /* Despite using SA_RESTART, we still have to check for this */
534 if (mc_global
.tty
.winch_flag
!= 0)
535 tty_change_screen_size ();
537 continue; /* try all over again */
539 tcsetattr (STDOUT_FILENO
, TCSANOW
, &shell_mode
);
540 fprintf (stderr
, "select (FD_SETSIZE, &read_set...): %s\r\n",
541 unix_error_string (errno
));
545 if (FD_ISSET (mc_global
.tty
.subshell_pty
, &read_set
))
546 /* Read from the subshell, write to stdout */
548 /* This loop improves performance by reducing context switches
549 by a factor of 20 or so... unfortunately, it also hangs MC
550 randomly, because of an apparent Linux bug. Investigate. */
551 /* for (i=0; i<5; ++i) * FIXME -- experimental */
553 bytes
= read (mc_global
.tty
.subshell_pty
, pty_buffer
, sizeof (pty_buffer
));
555 /* The subshell has died */
556 if (bytes
== -1 && errno
== EIO
&& !subshell_alive
)
561 tcsetattr (STDOUT_FILENO
, TCSANOW
, &shell_mode
);
562 fprintf (stderr
, "read (subshell_pty...): %s\r\n", unix_error_string (errno
));
567 write_all (STDOUT_FILENO
, pty_buffer
, bytes
);
570 else if (FD_ISSET (subshell_pipe
[READ
], &read_set
))
571 /* Read the subshell's CWD and capture its prompt */
573 bytes
= read (subshell_pipe
[READ
], subshell_cwd
, sizeof (subshell_cwd
));
576 tcsetattr (STDOUT_FILENO
, TCSANOW
, &shell_mode
);
577 fprintf (stderr
, "read (subshell_pipe[READ]...): %s\r\n",
578 unix_error_string (errno
));
582 subshell_cwd
[bytes
- 1] = 0; /* Squash the final '\n' */
586 subshell_ready
= TRUE
;
587 if (subshell_state
== RUNNING_COMMAND
)
589 subshell_state
= INACTIVE
;
594 else if (FD_ISSET (STDIN_FILENO
, &read_set
))
595 /* Read from stdin, write to the subshell */
597 bytes
= read (STDIN_FILENO
, pty_buffer
, sizeof (pty_buffer
));
600 tcsetattr (STDOUT_FILENO
, TCSANOW
, &shell_mode
);
602 "read (STDIN_FILENO, pty_buffer...): %s\r\n", unix_error_string (errno
));
606 for (i
= 0; i
< bytes
; ++i
)
607 if (pty_buffer
[i
] == subshell_switch_key
)
609 write_all (mc_global
.tty
.subshell_pty
, pty_buffer
, i
);
611 subshell_state
= INACTIVE
;
615 write_all (mc_global
.tty
.subshell_pty
, pty_buffer
, bytes
);
617 if (pty_buffer
[bytes
- 1] == '\n' || pty_buffer
[bytes
- 1] == '\r')
618 subshell_ready
= FALSE
;
625 /* --------------------------------------------------------------------------------------------- */
626 /* pty opening functions */
630 /* System V version of pty_open_master */
633 pty_open_master (char *pty_name
)
638 #ifdef HAVE_POSIX_OPENPT
639 pty_master
= posix_openpt (O_RDWR
);
640 #elif defined HAVE_GETPT
641 /* getpt () is a GNU extension (glibc 2.1.x) */
642 pty_master
= getpt ();
644 strcpy (pty_name
, "/dev/ptc");
645 pty_master
= open (pty_name
, O_RDWR
);
647 strcpy (pty_name
, "/dev/ptmx");
648 pty_master
= open (pty_name
, O_RDWR
);
651 if (pty_master
== -1)
654 if (grantpt (pty_master
) == -1 /* Grant access to slave */
655 || unlockpt (pty_master
) == -1 /* Clear slave's lock flag */
656 || !(slave_name
= ptsname (pty_master
))) /* Get slave's name */
661 strcpy (pty_name
, slave_name
);
665 /* --------------------------------------------------------------------------------------------- */
666 /** System V version of pty_open_slave */
669 pty_open_slave (const char *pty_name
)
673 pty_slave
= open (pty_name
, O_RDWR
);
676 fprintf (stderr
, "open (%s, O_RDWR): %s\r\n", pty_name
, unix_error_string (errno
));
679 #if !defined(__osf__) && !defined(__linux__)
680 #if defined (I_FIND) && defined (I_PUSH)
681 if (ioctl (pty_slave
, I_FIND
, "ptem") == 0)
682 if (ioctl (pty_slave
, I_PUSH
, "ptem") == -1)
684 fprintf (stderr
, "ioctl (%d, I_PUSH, \"ptem\") failed: %s\r\n",
685 pty_slave
, unix_error_string (errno
));
690 if (ioctl (pty_slave
, I_FIND
, "ldterm") == 0)
691 if (ioctl (pty_slave
, I_PUSH
, "ldterm") == -1)
694 "ioctl (%d, I_PUSH, \"ldterm\") failed: %s\r\n",
695 pty_slave
, unix_error_string (errno
));
699 #if !defined(sgi) && !defined(__sgi)
700 if (ioctl (pty_slave
, I_FIND
, "ttcompat") == 0)
701 if (ioctl (pty_slave
, I_PUSH
, "ttcompat") == -1)
704 "ioctl (%d, I_PUSH, \"ttcompat\") failed: %s\r\n",
705 pty_slave
, unix_error_string (errno
));
709 #endif /* sgi || __sgi */
710 #endif /* I_FIND && I_PUSH */
711 #endif /* __osf__ || __linux__ */
713 fcntl (pty_slave
, F_SETFD
, FD_CLOEXEC
);
717 #else /* !HAVE_GRANTPT */
719 /* --------------------------------------------------------------------------------------------- */
720 /** BSD version of pty_open_master */
722 pty_open_master (char *pty_name
)
725 const char *ptr1
, *ptr2
;
727 strcpy (pty_name
, "/dev/ptyXX");
728 for (ptr1
= "pqrstuvwxyzPQRST"; *ptr1
; ++ptr1
)
731 for (ptr2
= "0123456789abcdef"; *ptr2
!= '\0'; ++ptr2
)
735 /* Try to open master */
736 pty_master
= open (pty_name
, O_RDWR
);
737 if (pty_master
== -1)
739 if (errno
== ENOENT
) /* Different from EIO */
740 return -1; /* Out of pty devices */
741 continue; /* Try next pty device */
743 pty_name
[5] = 't'; /* Change "pty" to "tty" */
744 if (access (pty_name
, 6) != 0)
753 return -1; /* Ran out of pty devices */
756 /* --------------------------------------------------------------------------------------------- */
757 /** BSD version of pty_open_slave */
760 pty_open_slave (const char *pty_name
)
763 struct group
*group_info
;
765 group_info
= getgrnam ("tty");
766 if (group_info
!= NULL
)
768 /* The following two calls will only succeed if we are root */
769 /* [Commented out while permissions problem is investigated] */
770 /* chown (pty_name, getuid (), group_info->gr_gid); FIXME */
771 /* chmod (pty_name, S_IRUSR | S_IWUSR | S_IWGRP); FIXME */
773 pty_slave
= open (pty_name
, O_RDWR
);
775 fprintf (stderr
, "open (pty_name, O_RDWR): %s\r\n", pty_name
);
776 fcntl (pty_slave
, F_SETFD
, FD_CLOEXEC
);
779 #endif /* !HAVE_GRANTPT */
782 /* --------------------------------------------------------------------------------------------- */
784 * Set up `precmd' or equivalent for reading the subshell's CWD.
786 * Attention! Never forget that these are *one-liners* even though the concatenated
787 * substrings contain line breaks and indentation for better understanding of the
788 * shell code. It is vital that each one-liner ends with a line feed character ("\n" ).
790 * @return initialized pre-command string
794 init_subshell_precmd (char *precmd
, size_t buff_size
)
796 switch (mc_global
.shell
->type
)
799 g_snprintf (precmd
, buff_size
,
800 " PROMPT_COMMAND=${PROMPT_COMMAND:+$PROMPT_COMMAND\n}'pwd>&%d;kill -STOP $$'\n"
801 "PS1='\\u@\\h:\\w\\$ '\n", subshell_pipe
[WRITE
]);
804 case SHELL_ASH_BUSYBOX
:
805 /* BusyBox ash needs a somewhat complicated precmd emulation via PS1, and it is vital
806 * that BB be built with active CONFIG_ASH_EXPAND_PRMT, but this is the default anyway.
808 * A: This leads to a stopped subshell (=frozen mc) if user calls "ash" command
809 * "PS1='$(pwd>&%d; kill -STOP $$)\\u@\\h:\\w\\$ '\n",
811 * B: This leads to "sh: precmd: not found" in sub-subshell if user calls "ash" command
812 * "precmd() { pwd>&%d; kill -STOP $$; }; "
813 * "PS1='$(precmd)\\u@\\h:\\w\\$ '\n",
815 * C: This works if user calls "ash" command because in sub-subshell
816 * PRECMD is unfedined, thus evaluated to empty string - no damage done.
817 * Attention: BusyBox must be built with FEATURE_EDITING_FANCY_PROMPT to
818 * permit \u, \w, \h, \$ escape sequences. Unfortunately this cannot be guaranteed,
819 * especially on embedded systems where people try to save space, so let's use
820 * the dash version below. It should work on virtually all systems.
821 * "precmd() { pwd>&%d; kill -STOP $$; }; "
823 * "PS1='$(eval $PRECMD)\\u@\\h:\\w\\$ '\n",
826 /* Debian ash needs a precmd emulation via PS1, similar to BusyBox ash,
827 * but does not support escape sequences for user, host and cwd in prompt.
828 * Attention! Make sure that the buffer for precmd is big enough.
830 * We want to have a fancy dynamic prompt with user@host:cwd just like in the BusyBox
831 * examples above, but because replacing the home directory part of the path by "~" is
832 * complicated, it bloats the precmd to a size > BUF_SMALL (128).
834 * The following example is a little less fancy (home directory not replaced)
835 * and shows the basic workings of our prompt for easier understanding:
838 * "echo \"$USER@$(hostname -s):$PWD\"; "
843 * "PS1='$($PRECMD)$ '\n",
845 g_snprintf (precmd
, buff_size
,
847 "if [ ! \"${PWD##$HOME}\" ]; then "
850 "[ \"${PWD##$HOME/}\" = \"$PWD\" ] && MC_PWD=\"$PWD\" || MC_PWD=\"~/${PWD##$HOME/}\"; "
852 "echo \"$USER@$(hostname -s):$MC_PWD\"; "
855 "}; " "PRECMD=precmd; " "PS1='$($PRECMD)$ '\n", subshell_pipe
[WRITE
]);
859 g_snprintf (precmd
, buff_size
,
860 " _mc_precmd(){ pwd>&%d;kill -STOP $$ }; precmd_functions+=(_mc_precmd)\n"
861 "PS1='%%n@%%m:%%~%%# '\n", subshell_pipe
[WRITE
]);
865 g_snprintf (precmd
, buff_size
,
866 "set echo_style=both; "
867 "set prompt='%%n@%%m:%%~%%# '; "
868 "alias precmd 'echo $cwd:q >>%s; kill -STOP $$'\n", tcsh_fifo
);
872 /* We also want a fancy user@host:cwd prompt here, but fish makes it very easy to also
873 * use colours, which is what we will do. But first here is a simpler, uncoloured version:
874 * "function fish_prompt; "
875 * "echo (whoami)@(hostname -s):(pwd)\\$\\ ; "
876 * "echo \"$PWD\">&%d; "
877 * "kill -STOP %%self; "
880 * TODO: fish prompt is shown when panel is hidden (Ctrl-O), but not when it is visible.
881 * Find out how to fix this.
883 g_snprintf (precmd
, buff_size
,
884 "if not functions -q fish_prompt_mc;"
885 "functions -c fish_prompt fish_prompt_mc; end;"
886 "function fish_prompt;"
887 "echo (whoami)@(hostname -s):(set_color $fish_color_cwd)(pwd)(set_color normal)\\$\\ ; "
888 "echo \"$PWD\">&%d; fish_prompt_mc; kill -STOP %%self; end\n",
889 subshell_pipe
[WRITE
]);
897 /* --------------------------------------------------------------------------------------------- */
899 * Carefully quote directory name to allow entering any directory safely,
900 * no matter what weird characters it may contain in its name.
901 * NOTE: Treat directory name an untrusted data, don't allow it to cause
902 * executing any commands in the shell. Escape all control characters.
903 * Use following technique:
905 * printf(1) with format string containing a single conversion specifier,
906 * "b", and an argument which contains a copy of the string passed to
907 * subshell_name_quote() with all characters, except digits and letters,
908 * replaced by the backslash-escape sequence \0nnn, where "nnn" is the
909 * numeric value of the character converted to octal number.
911 * cd "`printf "%b" 'ABC\0nnnDEF\0nnnXYZ'`"
916 subshell_name_quote (const char *s
)
920 const char *quote_cmd_start
, *quote_cmd_end
;
922 if (mc_global
.shell
->type
== SHELL_FISH
)
924 quote_cmd_start
= "(printf \"%b\" '";
925 quote_cmd_end
= "')";
927 /* TODO: When BusyBox printf is fixed, get rid of this "else if", see
928 http://lists.busybox.net/pipermail/busybox/2012-March/077460.html */
929 /* else if (subshell_type == ASH_BUSYBOX)
931 quote_cmd_start = "\"`echo -en '";
932 quote_cmd_end = "'`\"";
936 quote_cmd_start
= "\"`printf \"%b\" '";
937 quote_cmd_end
= "'`\"";
940 ret
= g_string_sized_new (64);
942 /* Prevent interpreting leading '-' as a switch for 'cd' */
944 g_string_append (ret
, "./");
946 /* Copy the beginning of the command to the buffer */
947 g_string_append (ret
, quote_cmd_start
);
950 * Print every character except digits and letters as a backslash-escape
951 * sequence of the form \0nnn, where "nnn" is the numeric value of the
952 * character converted to octal number.
954 for (su
= s
; su
[0] != '\0'; su
= n
)
956 n
= str_cget_next_char_safe (su
);
958 if (str_isalnum (su
))
959 g_string_append_len (ret
, su
, n
- su
);
964 for (c
= 0; c
< n
- su
; c
++)
965 g_string_append_printf (ret
, "\\0%03o", (unsigned char) su
[c
]);
969 g_string_append (ret
, quote_cmd_end
);
974 /* --------------------------------------------------------------------------------------------- */
975 /*** public functions ****************************************************************************/
976 /* --------------------------------------------------------------------------------------------- */
978 /* --------------------------------------------------------------------------------------------- */
980 * Fork the subshell, and set up many, many things.
982 * Possibly modifies the global variables:
983 * subshell_type, subshell_alive, subshell_stopped, subshell_pid
984 * mc_global.tty.use_subshell - Is set to FALSE if we can't run the subshell
985 * quit - Can be set to SUBSHELL_EXIT by the SIGCHLD handler
991 /* This must be remembered across calls to init_subshell() */
992 static char pty_name
[BUF_SMALL
];
993 /* Must be considerably longer than BUF_SMALL (128) to support fancy shell prompts */
994 char precmd
[BUF_MEDIUM
];
996 switch (check_sid ())
999 mc_global
.tty
.use_subshell
= FALSE
;
1002 mc_global
.tty
.use_subshell
= FALSE
;
1003 mc_global
.midnight_shutdown
= TRUE
;
1009 /* Take the current (hopefully pristine) tty mode and make */
1010 /* a raw mode based on it now, before we do anything else with it */
1013 if (mc_global
.tty
.subshell_pty
== 0)
1014 { /* First time through */
1015 if (mc_global
.shell
->type
== SHELL_NONE
)
1018 /* Open a pty for talking to the subshell */
1020 /* FIXME: We may need to open a fresh pty each time on SVR4 */
1022 mc_global
.tty
.subshell_pty
= pty_open_master (pty_name
);
1023 if (mc_global
.tty
.subshell_pty
== -1)
1025 fprintf (stderr
, "Cannot open master side of pty: %s\r\n", unix_error_string (errno
));
1026 mc_global
.tty
.use_subshell
= FALSE
;
1029 subshell_pty_slave
= pty_open_slave (pty_name
);
1030 if (subshell_pty_slave
== -1)
1032 fprintf (stderr
, "Cannot open slave side of pty %s: %s\r\n",
1033 pty_name
, unix_error_string (errno
));
1034 mc_global
.tty
.use_subshell
= FALSE
;
1038 /* Create a pipe for receiving the subshell's CWD */
1040 if (mc_global
.shell
->type
== SHELL_TCSH
)
1042 g_snprintf (tcsh_fifo
, sizeof (tcsh_fifo
), "%s/mc.pipe.%d",
1043 mc_tmpdir (), (int) getpid ());
1044 if (mkfifo (tcsh_fifo
, 0600) == -1)
1046 fprintf (stderr
, "mkfifo(%s) failed: %s\r\n", tcsh_fifo
, unix_error_string (errno
));
1047 mc_global
.tty
.use_subshell
= FALSE
;
1051 /* Opening the FIFO as O_RDONLY or O_WRONLY causes deadlock */
1053 if ((subshell_pipe
[READ
] = open (tcsh_fifo
, O_RDWR
)) == -1
1054 || (subshell_pipe
[WRITE
] = open (tcsh_fifo
, O_RDWR
)) == -1)
1056 fprintf (stderr
, _("Cannot open named pipe %s\n"), tcsh_fifo
);
1057 perror (__FILE__
": open");
1058 mc_global
.tty
.use_subshell
= FALSE
;
1062 else if (pipe (subshell_pipe
)) /* subshell_type is BASH, ASH_BUSYBOX, DASH or ZSH */
1064 perror (__FILE__
": couldn't create pipe");
1065 mc_global
.tty
.use_subshell
= FALSE
;
1070 /* Fork the subshell */
1072 subshell_alive
= TRUE
;
1073 subshell_stopped
= FALSE
;
1074 subshell_pid
= fork ();
1076 if (subshell_pid
== -1)
1078 fprintf (stderr
, "Cannot spawn the subshell process: %s\r\n", unix_error_string (errno
));
1079 /* We exit here because, if the process table is full, the */
1080 /* other method of running user commands won't work either */
1081 exit (EXIT_FAILURE
);
1084 if (subshell_pid
== 0)
1086 /* We are in the child process */
1087 init_subshell_child (pty_name
);
1090 init_subshell_precmd (precmd
, BUF_MEDIUM
);
1092 write_all (mc_global
.tty
.subshell_pty
, precmd
, strlen (precmd
));
1094 /* Wait until the subshell has started up and processed the command */
1096 subshell_state
= RUNNING_COMMAND
;
1097 tty_enable_interrupt_key ();
1098 if (!feed_subshell (QUIETLY
, TRUE
))
1100 mc_global
.tty
.use_subshell
= FALSE
;
1102 tty_disable_interrupt_key ();
1103 if (!subshell_alive
)
1104 mc_global
.tty
.use_subshell
= FALSE
; /* Subshell died instantly, so don't use it */
1107 /* --------------------------------------------------------------------------------------------- */
1110 invoke_subshell (const char *command
, int how
, vfs_path_t
** new_dir_vpath
)
1112 /* Make the MC terminal transparent */
1113 tcsetattr (STDOUT_FILENO
, TCSANOW
, &raw_mode
);
1115 /* Make the subshell change to MC's working directory */
1116 if (new_dir_vpath
!= NULL
)
1117 do_subshell_chdir (subshell_get_cwd_from_current_panel (), TRUE
);
1119 if (command
== NULL
) /* The user has done "C-o" from MC */
1121 if (subshell_state
== INACTIVE
)
1123 subshell_state
= ACTIVE
;
1124 /* FIXME: possibly take out this hack; the user can
1125 re-play it by hitting C-hyphen a few times! */
1127 write_all (mc_global
.tty
.subshell_pty
, " \b", 2); /* Hack to make prompt reappear */
1130 else /* MC has passed us a user command */
1133 write_all (mc_global
.tty
.subshell_pty
, " ", 1);
1134 /* FIXME: if command is long (>8KB ?) we go comma */
1135 write_all (mc_global
.tty
.subshell_pty
, command
, strlen (command
));
1136 write_all (mc_global
.tty
.subshell_pty
, "\n", 1);
1137 subshell_state
= RUNNING_COMMAND
;
1138 subshell_ready
= FALSE
;
1141 feed_subshell (how
, FALSE
);
1143 if (new_dir_vpath
!= NULL
&& subshell_alive
)
1147 pcwd
= vfs_translate_path (vfs_path_as_str (subshell_get_cwd_from_current_panel ()));
1148 if (strcmp (subshell_cwd
, pcwd
) != 0)
1149 *new_dir_vpath
= vfs_path_from_str (subshell_cwd
); /* Make MC change to the subshell's CWD */
1152 /* Restart the subshell if it has died by SIGHUP, SIGQUIT, etc. */
1153 while (!subshell_alive
&& subshell_get_mainloop_quit () == 0 && mc_global
.tty
.use_subshell
)
1156 return subshell_get_mainloop_quit ();
1160 /* --------------------------------------------------------------------------------------------- */
1163 read_subshell_prompt (void)
1167 struct timeval timeleft
= { 0, 0 };
1169 gboolean prompt_was_reset
= FALSE
;
1173 FD_SET (mc_global
.tty
.subshell_pty
, &tmp
);
1175 /* First time through */
1176 if (subshell_prompt
== NULL
)
1177 subshell_prompt
= g_string_sized_new (INITIAL_PROMPT_SIZE
);
1179 p
= g_string_sized_new (INITIAL_PROMPT_SIZE
);
1181 while (subshell_alive
1182 && (rc
= select (mc_global
.tty
.subshell_pty
+ 1, &tmp
, NULL
, NULL
, &timeleft
)) != 0)
1186 /* Check for 'select' errors */
1191 if (mc_global
.tty
.winch_flag
!= 0)
1192 tty_change_screen_size ();
1197 fprintf (stderr
, "select (FD_SETSIZE, &tmp...): %s\r\n", unix_error_string (errno
));
1198 exit (EXIT_FAILURE
);
1201 bytes
= read (mc_global
.tty
.subshell_pty
, pty_buffer
, sizeof (pty_buffer
));
1203 /* Extract the prompt from the shell output */
1204 for (i
= 0; i
< bytes
; i
++)
1205 if (pty_buffer
[i
] == '\n' || pty_buffer
[i
] == '\r')
1207 g_string_set_size (p
, 0);
1208 prompt_was_reset
= TRUE
;
1210 else if (pty_buffer
[i
] != '\0')
1211 g_string_append_c (p
, pty_buffer
[i
]);
1214 if (p
->len
!= 0 || prompt_was_reset
)
1215 g_string_assign (subshell_prompt
, p
->str
);
1217 g_string_free (p
, TRUE
);
1219 return (rc
!= 0 || bytes
!= 0);
1222 /* --------------------------------------------------------------------------------------------- */
1225 do_update_prompt (void)
1227 if (update_subshell_prompt
)
1229 printf ("\r\n%s", subshell_prompt
->str
);
1231 update_subshell_prompt
= FALSE
;
1235 /* --------------------------------------------------------------------------------------------- */
1238 exit_subshell (void)
1240 gboolean subshell_quit
= TRUE
;
1242 if (subshell_state
!= INACTIVE
&& subshell_alive
)
1244 query_dialog (_("Warning"),
1245 _("The shell is still active. Quit anyway?"),
1246 D_NORMAL
, 2, _("&Yes"), _("&No")) == 0;
1250 if (mc_global
.shell
->type
== SHELL_TCSH
)
1252 if (unlink (tcsh_fifo
) == -1)
1253 fprintf (stderr
, "Cannot remove named pipe %s: %s\r\n",
1254 tcsh_fifo
, unix_error_string (errno
));
1257 g_string_free (subshell_prompt
, TRUE
);
1258 subshell_prompt
= NULL
;
1259 pty_buffer
[0] = '\0';
1262 return subshell_quit
;
1265 /* --------------------------------------------------------------------------------------------- */
1267 /** If it actually changed the directory it returns true */
1269 do_subshell_chdir (const vfs_path_t
* vpath
, gboolean update_prompt
)
1273 pcwd
= vfs_path_to_str_flags (subshell_get_cwd_from_current_panel (), 0, VPF_RECODE
);
1275 if (!(subshell_state
== INACTIVE
&& strcmp (subshell_cwd
, pcwd
) != 0))
1277 /* We have to repaint the subshell prompt if we read it from
1278 * the main program. Please note that in the code after this
1279 * if, the cd command that is sent will make the subshell
1280 * repaint the prompt, so we don't have to paint it. */
1282 do_update_prompt ();
1287 /* The initial space keeps this out of the command history (in bash
1288 because we set "HISTCONTROL=ignorespace") */
1289 write_all (mc_global
.tty
.subshell_pty
, " cd ", 4);
1293 const char *translate
;
1295 translate
= vfs_translate_path (vfs_path_as_str (vpath
));
1296 if (translate
!= NULL
)
1300 temp
= subshell_name_quote (translate
);
1301 write_all (mc_global
.tty
.subshell_pty
, temp
->str
, temp
->len
);
1302 g_string_free (temp
, TRUE
);
1306 write_all (mc_global
.tty
.subshell_pty
, ".", 1);
1311 write_all (mc_global
.tty
.subshell_pty
, "/", 1);
1313 write_all (mc_global
.tty
.subshell_pty
, "\n", 1);
1315 subshell_state
= RUNNING_COMMAND
;
1316 feed_subshell (QUIETLY
, FALSE
);
1320 gboolean bPathNotEq
;
1322 bPathNotEq
= strcmp (subshell_cwd
, pcwd
) != 0;
1324 if (bPathNotEq
&& mc_global
.shell
->type
== SHELL_TCSH
)
1326 char rp_subshell_cwd
[PATH_MAX
];
1327 char rp_current_panel_cwd
[PATH_MAX
];
1328 char *p_subshell_cwd
, *p_current_panel_cwd
;
1330 p_subshell_cwd
= mc_realpath (subshell_cwd
, rp_subshell_cwd
);
1331 p_current_panel_cwd
= mc_realpath (pcwd
, rp_current_panel_cwd
);
1333 if (p_subshell_cwd
== NULL
)
1334 p_subshell_cwd
= subshell_cwd
;
1335 if (p_current_panel_cwd
== NULL
)
1336 p_current_panel_cwd
= pcwd
;
1337 bPathNotEq
= strcmp (p_subshell_cwd
, p_current_panel_cwd
) != 0;
1340 if (bPathNotEq
&& !DIR_IS_DOT (pcwd
))
1345 vfs_path_to_str_flags (subshell_get_cwd_from_current_panel (), 0,
1346 VPF_STRIP_PASSWORD
);
1347 vfs_print_message (_("Warning: Cannot change to %s.\n"), cwd
);
1352 /* Really escape Zsh history */
1353 if (mc_global
.shell
->type
== SHELL_ZSH
)
1355 /* Per Zsh documentation last command prefixed with space lingers in the internal history
1356 * until the next command is entered before it vanishes. To make it vanish right away,
1357 * type a space and press return. */
1358 write_all (mc_global
.tty
.subshell_pty
, " \n", 2);
1359 subshell_state
= RUNNING_COMMAND
;
1360 feed_subshell (QUIETLY
, FALSE
);
1363 update_subshell_prompt
= FALSE
;
1366 /* Make sure that MC never stores the CWD in a silly format */
1367 /* like /usr////lib/../bin, or the strcmp() above will fail */
1370 /* --------------------------------------------------------------------------------------------- */
1373 subshell_get_console_attributes (void)
1375 /* Get our current terminal modes */
1377 if (tcgetattr (STDOUT_FILENO
, &shell_mode
))
1379 fprintf (stderr
, "Cannot get terminal settings: %s\r\n", unix_error_string (errno
));
1380 mc_global
.tty
.use_subshell
= FALSE
;
1384 /* --------------------------------------------------------------------------------------------- */
1386 * Figure out whether the subshell has stopped, exited or been killed
1387 * Possibly modifies: 'subshell_alive', 'subshell_stopped' and 'quit' */
1390 sigchld_handler (int sig
)
1397 pid
= waitpid (subshell_pid
, &status
, WUNTRACED
| WNOHANG
);
1399 if (pid
== subshell_pid
)
1401 /* Figure out what has happened to the subshell */
1403 if (WIFSTOPPED (status
))
1405 if (WSTOPSIG (status
) == SIGSTOP
)
1407 /* The subshell has received a SIGSTOP signal */
1408 subshell_stopped
= TRUE
;
1412 /* The user has suspended the subshell. Revive it */
1413 kill (subshell_pid
, SIGCONT
);
1418 /* The subshell has either exited normally or been killed */
1419 subshell_alive
= FALSE
;
1420 delete_select_channel (mc_global
.tty
.subshell_pty
);
1421 if (WIFEXITED (status
) && WEXITSTATUS (status
) != FORK_FAILURE
)
1424 subshell_quit
= subshell_get_mainloop_quit () | SUBSHELL_EXIT
; /* Exited normally */
1425 subshell_set_mainloop_quit (subshell_quit
);
1429 subshell_handle_cons_saver ();
1431 /* If we got here, some other child exited; ignore it */
1434 /* --------------------------------------------------------------------------------------------- */