686 lines
17 KiB
C
686 lines
17 KiB
C
/* A front-end using readline to "cook" input lines for Kawa.
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*
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* Copyright (C) 1999 Per Bothner
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*
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* This front-end program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as published
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* by the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* Some code from Johnson & Troan: "Linux Application Development"
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* (Addison-Wesley, 1998) was used directly or for inspiration.
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*/
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/* PROBLEMS/TODO:
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*
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* Only tested under Linux; needs to be ported.
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*
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* When running mc -c under the Linux console, mc does not recognize
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* mouse clicks, which mc does when not running under fep.
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*
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* Pasting selected text containing tabs is like hitting the tab character,
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* which invokes readline completion. We don't want this. I don't know
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* if this is fixable without integrating fep into a terminal emulator.
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*
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* Echo suppression is a kludge, but can only be avoided with better kernel
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* support: We need a tty mode to disable "real" echoing, while still
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* letting the inferior think its tty driver to doing echoing.
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* Stevens's book claims SCR$ and BSD4.3+ have TIOCREMOTE.
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*
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* The latest readline may have some hooks we can use to avoid having
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* to back up the prompt.
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*
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* Desirable readline feature: When in cooked no-echo mode (e.g. password),
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* echo characters are they are types with '*', but remove them when done.
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*
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* A synchronous output while we're editing an input line should be
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* inserted in the output view *before* the input line, so that the
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* lines being edited (with the prompt) float at the end of the input.
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*
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* A "page mode" option to emulate more/less behavior: At each page of
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* output, pause for a user command. This required parsing the output
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* to keep track of line lengths. It also requires remembering the
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* output, if we want an option to scroll back, which suggests that
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* this should be integrated with a terminal emulator like xterm.
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*/
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <stdio.h>
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#include <fcntl.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <signal.h>
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#include <netdb.h>
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#include <stdlib.h>
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#include <errno.h>
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#include <grp.h>
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#include <string.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <sys/ioctl.h>
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#include <termios.h>
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#ifdef READLINE_LIBRARY
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# include "readline.h"
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# include "history.h"
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#else
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# include <readline/readline.h>
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# include <readline/history.h>
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#endif
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#ifndef COMMAND
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#define COMMAND "/bin/sh"
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#endif
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#ifndef COMMAND_ARGS
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#define COMMAND_ARGS COMMAND
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#endif
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#ifndef HAVE_MEMMOVE
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# if __GNUC__ > 1
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# define memmove(d, s, n) __builtin_memcpy(d, s, n)
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# else
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# define memmove(d, s, n) memcpy(d, s, n)
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# endif
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#else
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# define memmove(d, s, n) memcpy(d, s, n)
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#endif
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#define APPLICATION_NAME "Fep"
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static int in_from_inferior_fd;
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static int out_to_inferior_fd;
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/* Unfortunately, we cannot safely display echo from the inferior process.
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The reason is that the echo bit in the pty is "owned" by the inferior,
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and if we try to turn it off, we could confuse the inferior.
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Thus, when echoing, we get echo twice: First readline echoes while
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we're actually editing. Then we send the line to the inferior, and the
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terminal driver send back an extra echo.
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The work-around is to remember the input lines, and when we see that
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line come back, we supress the output.
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A better solution (supposedly available on SVR4) would be a smarter
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terminal driver, with more flags ... */
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#define ECHO_SUPPRESS_MAX 1024
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char echo_suppress_buffer[ECHO_SUPPRESS_MAX];
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int echo_suppress_start = 0;
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int echo_suppress_limit = 0;
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#define DEBUG
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#ifdef DEBUG
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FILE *logfile = NULL;
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#define DPRINT0(FMT) (fprintf(logfile, FMT), fflush(logfile))
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#define DPRINT1(FMT, V1) (fprintf(logfile, FMT, V1), fflush(logfile))
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#define DPRINT2(FMT, V1, V2) (fprintf(logfile, FMT, V1, V2), fflush(logfile))
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#else
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#define DPRINT0(FMT) /* Do nothing */
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#define DPRINT1(FMT, V1) /* Do nothing */
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#define DPRINT2(FMT, V1, V2) /* Do nothing */
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#endif
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struct termios orig_term;
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/* Pid of child process. */
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static pid_t child = -1;
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static void
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sig_child (int signo)
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{
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int status;
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wait (&status);
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DPRINT0 ("(Child process died.)\n");
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tcsetattr(STDIN_FILENO, TCSANOW, &orig_term);
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exit (0);
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}
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volatile int propagate_sigwinch = 0;
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/* sigwinch_handler
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* propagate window size changes from input file descriptor to
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* master side of pty.
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*/
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void sigwinch_handler(int signal) {
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propagate_sigwinch = 1;
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}
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/* get_master_pty() takes a double-indirect character pointer in which
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* to put a slave name, and returns an integer file descriptor.
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* If it returns < 0, an error has occurred.
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* Otherwise, it has returned the master pty file descriptor, and fills
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* in *name with the name of the corresponding slave pty.
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* Once the slave pty has been opened, you are responsible to free *name.
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*/
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int get_master_pty(char **name) {
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int i, j;
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/* default to returning error */
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int master = -1;
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/* create a dummy name to fill in */
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*name = strdup("/dev/ptyXX");
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/* search for an unused pty */
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for (i=0; i<16 && master <= 0; i++) {
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for (j=0; j<16 && master <= 0; j++) {
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(*name)[5] = 'p';
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(*name)[8] = "pqrstuvwxyzPQRST"[i];
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(*name)[9] = "0123456789abcdef"[j];
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/* open the master pty */
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if ((master = open(*name, O_RDWR)) < 0) {
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if (errno == ENOENT) {
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/* we are out of pty devices */
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free (*name);
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return (master);
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}
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}
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else {
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/* By substituting a letter, we change the master pty
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* name into the slave pty name.
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*/
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(*name)[5] = 't';
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if (access(*name, R_OK|W_OK) != 0)
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{
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close(master);
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master = -1;
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}
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}
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}
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}
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if ((master < 0) && (i == 16) && (j == 16)) {
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/* must have tried every pty unsuccessfully */
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free (*name);
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return (master);
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}
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(*name)[5] = 't';
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return (master);
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}
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/* get_slave_pty() returns an integer file descriptor.
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* If it returns < 0, an error has occurred.
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* Otherwise, it has returned the slave file descriptor.
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*/
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int get_slave_pty(char *name) {
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struct group *gptr;
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gid_t gid;
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int slave = -1;
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/* chown/chmod the corresponding pty, if possible.
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* This will only work if the process has root permissions.
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* Alternatively, write and exec a small setuid program that
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* does just this.
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*/
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if ((gptr = getgrnam("tty")) != 0) {
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gid = gptr->gr_gid;
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} else {
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/* if the tty group does not exist, don't change the
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* group on the slave pty, only the owner
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*/
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gid = -1;
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}
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/* Note that we do not check for errors here. If this is code
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* where these actions are critical, check for errors!
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*/
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chown(name, getuid(), gid);
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/* This code only makes the slave read/writeable for the user.
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* If this is for an interactive shell that will want to
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* receive "write" and "wall" messages, OR S_IWGRP into the
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* second argument below.
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*/
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chmod(name, S_IRUSR|S_IWUSR);
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/* open the corresponding slave pty */
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slave = open(name, O_RDWR);
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return (slave);
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}
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/* Certain special characters, such as ctrl/C, we want to pass directly
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to the inferior, rather than letting readline handle them. */
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static char special_chars[20];
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static int special_chars_count;
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static void
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add_special_char(int ch)
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{
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if (ch != 0)
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special_chars[special_chars_count++] = ch;
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}
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static int eof_char;
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static int
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is_special_char(int ch)
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{
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int i;
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#if 0
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if (ch == eof_char && rl_point == rl_end)
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return 1;
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#endif
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for (i = special_chars_count; --i >= 0; )
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if (special_chars[i] == ch)
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return 1;
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return 0;
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}
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static char buf[1024];
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/* buf[0 .. buf_count-1] is the what has been emitted on the current line.
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It is used as the readline prompt. */
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static int buf_count = 0;
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int num_keys = 0;
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static void
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null_prep_terminal (int meta)
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{
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}
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static void
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null_deprep_terminal ()
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{
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}
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char pending_special_char;
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static void
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line_handler (char *line)
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{
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if (line == NULL)
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{
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char buf[1];
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DPRINT0("saw eof!\n");
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buf[0] = '\004'; /* ctrl/d */
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write (out_to_inferior_fd, buf, 1);
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}
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else
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{
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static char enter[] = "\r";
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/* Send line to inferior: */
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int length = strlen (line);
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if (length > ECHO_SUPPRESS_MAX-2)
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{
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echo_suppress_start = 0;
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echo_suppress_limit = 0;
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}
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else
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{
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if (echo_suppress_limit + length > ECHO_SUPPRESS_MAX - 2)
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{
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if (echo_suppress_limit - echo_suppress_start + length
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<= ECHO_SUPPRESS_MAX - 2)
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{
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memmove (echo_suppress_buffer,
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echo_suppress_buffer + echo_suppress_start,
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echo_suppress_limit - echo_suppress_start);
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echo_suppress_limit -= echo_suppress_start;
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echo_suppress_start = 0;
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}
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else
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{
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echo_suppress_limit = 0;
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}
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echo_suppress_start = 0;
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}
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memcpy (echo_suppress_buffer + echo_suppress_limit,
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line, length);
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echo_suppress_limit += length;
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echo_suppress_buffer[echo_suppress_limit++] = '\r';
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echo_suppress_buffer[echo_suppress_limit++] = '\n';
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}
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write (out_to_inferior_fd, line, length);
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if (pending_special_char == 0)
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{
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write (out_to_inferior_fd, enter, sizeof(enter)-1);
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if (*line)
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add_history (line);
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}
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free (line);
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}
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rl_callback_handler_remove ();
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buf_count = 0;
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num_keys = 0;
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if (pending_special_char != 0)
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{
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write (out_to_inferior_fd, &pending_special_char, 1);
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pending_special_char = 0;
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}
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}
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/* Value of rl_getc_function.
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Use this because readline should read from stdin, not rl_instream,
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points to the pty (so readline has monitor its terminal modes). */
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int
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my_rl_getc (FILE *dummy)
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{
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int ch = rl_getc (stdin);
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if (is_special_char (ch))
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{
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pending_special_char = ch;
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return '\r';
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}
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return ch;
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}
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int
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main(int argc, char** argv)
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{
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char *path;
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int i;
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int master;
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char *name;
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int in_from_tty_fd;
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struct sigaction act;
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struct winsize ws;
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struct termios t;
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int maxfd;
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fd_set in_set;
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static char empty_string[1] = "";
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char *prompt = empty_string;
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int ioctl_err = 0;
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#ifdef DEBUG
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logfile = fopen("LOG", "w");
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#endif
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rl_readline_name = APPLICATION_NAME;
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if ((master = get_master_pty(&name)) < 0)
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{
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perror("ptypair: could not open master pty");
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exit(1);
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}
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DPRINT1("pty name: '%s'\n", name);
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/* set up SIGWINCH handler */
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act.sa_handler = sigwinch_handler;
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sigemptyset(&(act.sa_mask));
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act.sa_flags = 0;
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if (sigaction(SIGWINCH, &act, NULL) < 0)
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{
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perror("ptypair: could not handle SIGWINCH ");
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exit(1);
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}
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if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) < 0)
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{
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perror("ptypair: could not get window size");
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exit(1);
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}
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if ((child = fork()) < 0)
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{
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perror("cannot fork");
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exit(1);
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}
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if (child == 0)
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{
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int slave; /* file descriptor for slave pty */
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/* We are in the child process */
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close(master);
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#ifdef TIOCSCTTY
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if ((slave = get_slave_pty(name)) < 0)
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{
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perror("ptypair: could not open slave pty");
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exit(1);
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}
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free(name);
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#endif
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/* We need to make this process a session group leader, because
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* it is on a new PTY, and things like job control simply will
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* not work correctly unless there is a session group leader
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* and process group leader (which a session group leader
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* automatically is). This also disassociates us from our old
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* controlling tty.
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*/
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if (setsid() < 0)
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{
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perror("could not set session leader");
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}
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/* Tie us to our new controlling tty. */
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#ifdef TIOCSCTTY
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if (ioctl(slave, TIOCSCTTY, NULL))
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{
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perror("could not set new controlling tty");
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}
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#else
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if ((slave = get_slave_pty(name)) < 0)
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{
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perror("ptypair: could not open slave pty");
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exit(1);
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}
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free(name);
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#endif
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/* make slave pty be standard in, out, and error */
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dup2(slave, STDIN_FILENO);
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dup2(slave, STDOUT_FILENO);
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dup2(slave, STDERR_FILENO);
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/* at this point the slave pty should be standard input */
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if (slave > 2)
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{
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close(slave);
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}
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/* Try to restore window size; failure isn't critical */
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if (ioctl(STDOUT_FILENO, TIOCSWINSZ, &ws) < 0)
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{
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perror("could not restore window size");
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}
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/* now start the shell */
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{
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static char* command_args[] = { COMMAND_ARGS, NULL };
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if (argc <= 1)
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execvp(COMMAND, command_args);
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else
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execvp(argv[1], &argv[1]);
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}
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/* should never be reached */
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exit(1);
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}
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/* parent */
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signal (SIGCHLD, sig_child);
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free(name);
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/* Note that we only set termios settings for standard input;
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* the master side of a pty is NOT a tty.
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*/
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tcgetattr(STDIN_FILENO, &orig_term);
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t = orig_term;
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eof_char = t.c_cc[VEOF];
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/* add_special_char(t.c_cc[VEOF]);*/
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add_special_char(t.c_cc[VINTR]);
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add_special_char(t.c_cc[VQUIT]);
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add_special_char(t.c_cc[VSUSP]);
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#if defined (VDISCARD)
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add_special_char(t.c_cc[VDISCARD]);
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#endif
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#if 0
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t.c_lflag |= (ICANON | ISIG | ECHO | ECHOCTL | ECHOE | \
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ECHOK | ECHOKE | ECHONL | ECHOPRT );
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#else
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t.c_lflag &= ~(ICANON | ISIG | ECHO | ECHOCTL | ECHOE | \
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ECHOK | ECHOKE | ECHONL | ECHOPRT );
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#endif
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t.c_iflag |= IGNBRK;
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t.c_cc[VMIN] = 1;
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t.c_cc[VTIME] = 0;
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tcsetattr(STDIN_FILENO, TCSANOW, &t);
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in_from_inferior_fd = master;
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out_to_inferior_fd = master;
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rl_instream = fdopen (master, "r");
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rl_getc_function = my_rl_getc;
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rl_prep_term_function = null_prep_terminal;
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rl_deprep_term_function = null_deprep_terminal;
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rl_callback_handler_install (prompt, line_handler);
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in_from_tty_fd = STDIN_FILENO;
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FD_ZERO (&in_set);
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maxfd = in_from_inferior_fd > in_from_tty_fd ? in_from_inferior_fd
|
|
: in_from_tty_fd;
|
|
for (;;)
|
|
{
|
|
int num;
|
|
FD_SET (in_from_inferior_fd, &in_set);
|
|
FD_SET (in_from_tty_fd, &in_set);
|
|
|
|
num = select(maxfd+1, &in_set, NULL, NULL, NULL);
|
|
|
|
if (propagate_sigwinch)
|
|
{
|
|
struct winsize ws;
|
|
if (ioctl (STDIN_FILENO, TIOCGWINSZ, &ws) >= 0)
|
|
{
|
|
ioctl (master, TIOCSWINSZ, &ws);
|
|
}
|
|
propagate_sigwinch = 0;
|
|
continue;
|
|
}
|
|
|
|
if (num <= 0)
|
|
{
|
|
perror ("select");
|
|
exit (-1);
|
|
}
|
|
if (FD_ISSET (in_from_tty_fd, &in_set))
|
|
{
|
|
extern int readline_echoing_p;
|
|
struct termios term_master;
|
|
int do_canon = 1;
|
|
int ioctl_ret;
|
|
|
|
DPRINT1("[tty avail num_keys:%d]\n", num_keys);
|
|
|
|
/* If we can't get tty modes for the master side of the pty, we
|
|
can't handle non-canonical-mode programs. Always assume the
|
|
master is in canonical echo mode if we can't tell. */
|
|
ioctl_ret = tcgetattr(master, &term_master);
|
|
|
|
if (ioctl_ret >= 0)
|
|
{
|
|
DPRINT2 ("echo:%d, canon:%d\n",
|
|
(term_master.c_lflag & ECHO) != 0,
|
|
(term_master.c_lflag & ICANON) != 0);
|
|
do_canon = (term_master.c_lflag & ICANON) != 0;
|
|
readline_echoing_p = (term_master.c_lflag & ECHO) != 0;
|
|
}
|
|
else
|
|
{
|
|
if (ioctl_err == 0)
|
|
DPRINT1("tcgetattr on master fd failed: errno = %d\n", errno);
|
|
ioctl_err = 1;
|
|
}
|
|
|
|
if (do_canon == 0 && num_keys == 0)
|
|
{
|
|
char ch[10];
|
|
int count = read (STDIN_FILENO, ch, sizeof(ch));
|
|
write (out_to_inferior_fd, ch, count);
|
|
}
|
|
else
|
|
{
|
|
if (num_keys == 0)
|
|
{
|
|
int i;
|
|
/* Re-install callback handler for new prompt. */
|
|
if (prompt != empty_string)
|
|
free (prompt);
|
|
prompt = malloc (buf_count + 1);
|
|
if (prompt == NULL)
|
|
prompt = empty_string;
|
|
else
|
|
{
|
|
memcpy (prompt, buf, buf_count);
|
|
prompt[buf_count] = '\0';
|
|
DPRINT1("New prompt '%s'\n", prompt);
|
|
#if 0 /* ifdef HAVE_RL_ALREADY_PROMPTED -- doesn't work */
|
|
rl_already_prompted = buf_count > 0;
|
|
#else
|
|
if (buf_count > 0)
|
|
write (1, "\r", 1);
|
|
#endif
|
|
}
|
|
rl_callback_handler_install (prompt, line_handler);
|
|
}
|
|
num_keys++;
|
|
rl_callback_read_char ();
|
|
}
|
|
}
|
|
else /* input from inferior. */
|
|
{
|
|
int i;
|
|
int count;
|
|
int old_count;
|
|
if (buf_count > (sizeof(buf) >> 2))
|
|
buf_count = 0;
|
|
count = read (in_from_inferior_fd, buf+buf_count,
|
|
sizeof(buf) - buf_count);
|
|
if (count <= 0)
|
|
{
|
|
DPRINT0 ("(Connection closed by foreign host.)\n");
|
|
tcsetattr(STDIN_FILENO, TCSANOW, &orig_term);
|
|
exit (0);
|
|
}
|
|
old_count = buf_count;
|
|
|
|
/* Look for any pending echo that we need to suppress. */
|
|
while (echo_suppress_start < echo_suppress_limit
|
|
&& count > 0
|
|
&& buf[buf_count] == echo_suppress_buffer[echo_suppress_start])
|
|
{
|
|
count--;
|
|
buf_count++;
|
|
echo_suppress_start++;
|
|
}
|
|
|
|
/* Write to the terminal anything that was not suppressed. */
|
|
if (count > 0)
|
|
write (1, buf + buf_count, count);
|
|
|
|
/* Finally, look for a prompt candidate.
|
|
* When we get around to going input (from the keyboard),
|
|
* we will consider the prompt to be anything since the last
|
|
* line terminator. So we need to save that text in the
|
|
* initial part of buf. However, anything before the
|
|
* most recent end-of-line is not interesting. */
|
|
buf_count += count;
|
|
#if 1
|
|
for (i = buf_count; --i >= old_count; )
|
|
#else
|
|
for (i = buf_count - 1; i-- >= buf_count - count; )
|
|
#endif
|
|
{
|
|
if (buf[i] == '\n' || buf[i] == '\r')
|
|
{
|
|
i++;
|
|
memmove (buf, buf+i, buf_count - i);
|
|
buf_count -= i;
|
|
break;
|
|
}
|
|
}
|
|
DPRINT2("-> i: %d, buf_count: %d\n", i, buf_count);
|
|
}
|
|
}
|
|
}
|