readline/examples/rlfe.c

   1 /* A front-end using readline to "cook" input lines for Kawa.
   2  *
   3  * Copyright (C) 1999  Per Bothner
   4  *
   5  * This front-end program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as published
   7  * by the Free Software Foundation; either version 2, or (at your option)
   8  * any later version.
   9  *
  10  * Some code from Johnson & Troan: "Linux Application Development"
  11  * (Addison-Wesley, 1998) was used directly or for inspiration.
  12  */
  13
  14 /* PROBLEMS/TODO:
  15  *
  16  * Only tested under Linux;  needs to be ported.
  17  *
  18  * When running mc -c under the Linux console, mc does not recognize
  19  * mouse clicks, which mc does when not running under fep.
  20  *
  21  * Pasting selected text containing tabs is like hitting the tab character,
  22  * which invokes readline completion.  We don't want this.  I don't know
  23  * if this is fixable without integrating fep into a terminal emulator.
  24  *
  25  * Echo suppression is a kludge, but can only be avoided with better kernel
  26  * support: We need a tty mode to disable "real" echoing, while still
  27  * letting the inferior think its tty driver to doing echoing.
  28  * Stevens's book claims SCR$ and BSD4.3+ have TIOCREMOTE.
  29  *
  30  * The latest readline may have some hooks we can use to avoid having
  31  * to back up the prompt.
  32  *
  33  * Desirable readline feature:  When in cooked no-echo mode (e.g. password),
  34  * echo characters are they are types with '*', but remove them when done.
  35  *
  36  * A synchronous output while we're editing an input line should be
  37  * inserted in the output view *before* the input line, so that the
  38  * lines being edited (with the prompt) float at the end of the input.
  39  *
  40  * A "page mode" option to emulate more/less behavior:  At each page of
  41  * output, pause for a user command.  This required parsing the output
  42  * to keep track of line lengths.  It also requires remembering the
  43  * output, if we want an option to scroll back, which suggests that
  44  * this should be integrated with a terminal emulator like xterm.
  45  */
  46
  47 #ifdef HAVE_CONFIG_H
  48 #  include <config.h>
  49 #endif
  50
  51 #include <stdio.h>
  52 #include <fcntl.h>
  53 #include <sys/types.h>
  54 #include <sys/socket.h>
  55 #include <netinet/in.h>
  56 #include <arpa/inet.h>
  57 #include <signal.h>
  58 #include <netdb.h>
  59 #include <stdlib.h>
  60 #include <errno.h>
  61 #include <grp.h>
  62 #include <string.h>
  63 #include <sys/stat.h>
  64 #include <unistd.h>
  65 #include <sys/ioctl.h>
  66 #include <termios.h>
  67 #include <limits.h>
  68 #include <dirent.h>
  69
  70 #ifdef READLINE_LIBRARY
  71 #  include "readline.h"
  72 #  include "history.h"
  73 #else
  74 #  include <readline/readline.h>
  75 #  include <readline/history.h>
  76 #endif
  77
  78 #ifndef COMMAND
  79 #define COMMAND "/bin/sh"
  80 #endif
  81 #ifndef COMMAND_ARGS
  82 #define COMMAND_ARGS COMMAND
  83 #endif
  84
  85 #ifndef HAVE_MEMMOVE
  86 #ifndef memmove
  87 #  if __GNUC__ > 1
  88 #    define memmove(d, s, n)    __builtin_memcpy(d, s, n)
  89 #  else
  90 #    define memmove(d, s, n)    memcpy(d, s, n)
  91 #  endif
  92 #else
  93 #  define memmove(d, s, n)      memcpy(d, s, n)
  94 #endif
  95 #endif
  96
  97 #define APPLICATION_NAME "Rlfe"
  98
  99 #ifndef errno
 100 extern int errno;
 101 #endif
 102
 103 extern int optind;
 104 extern char *optarg;
 105
 106 static char *progname;
 107 static char *progversion;
 108
 109 static int in_from_inferior_fd;
 110 static int out_to_inferior_fd;
 111
 112 /* Unfortunately, we cannot safely display echo from the inferior process.
 113    The reason is that the echo bit in the pty is "owned" by the inferior,
 114    and if we try to turn it off, we could confuse the inferior.
 115    Thus, when echoing, we get echo twice:  First readline echoes while
 116    we're actually editing. Then we send the line to the inferior, and the
 117    terminal driver send back an extra echo.
 118    The work-around is to remember the input lines, and when we see that
 119    line come back, we supress the output.
 120    A better solution (supposedly available on SVR4) would be a smarter
 121    terminal driver, with more flags ... */
 122 #define ECHO_SUPPRESS_MAX 1024
 123 char echo_suppress_buffer[ECHO_SUPPRESS_MAX];
 124 int echo_suppress_start = 0;
 125 int echo_suppress_limit = 0;
 126
 127 /* #define DEBUG */
 128
 129 static FILE *logfile = NULL;
 130
 131 #ifdef DEBUG
 132 FILE *debugfile = NULL;
 133 #define DPRINT0(FMT) (fprintf(debugfile, FMT), fflush(debugfile))
 134 #define DPRINT1(FMT, V1) (fprintf(debugfile, FMT, V1), fflush(debugfile))
 135 #define DPRINT2(FMT, V1, V2) (fprintf(debugfile, FMT, V1, V2), fflush(debugfile))
 136 #else
 137 #define DPRINT0(FMT) /* Do nothing */
 138 #define DPRINT1(FMT, V1) /* Do nothing */
 139 #define DPRINT2(FMT, V1, V2) /* Do nothing */
 140 #endif
 141
 142 struct termios orig_term;
 143
 144 static int rlfe_directory_completion_hook __P((char **));
 145 static int rlfe_directory_rewrite_hook __P((char **));
 146 static char *rlfe_filename_completion_function __P((const char *, int));
 147
 148 /* Pid of child process. */
 149 static pid_t child = -1;
 150
 151 static void
 152 sig_child (int signo)
 153 {
 154   int status;
 155   wait (&status);
 156   DPRINT0 ("(Child process died.)\n");
 157   tcsetattr(STDIN_FILENO, TCSANOW, &orig_term);
 158   exit (0);
 159 }
 160
 161 volatile int propagate_sigwinch = 0;
 162
 163 /* sigwinch_handler
 164  * propagate window size changes from input file descriptor to
 165  * master side of pty.
 166  */
 167 void sigwinch_handler(int signal) {
 168    propagate_sigwinch = 1;
 169 }
 170
 171 /* get_master_pty() takes a double-indirect character pointer in which
 172  * to put a slave name, and returns an integer file descriptor.
 173  * If it returns < 0, an error has occurred.
 174  * Otherwise, it has returned the master pty file descriptor, and fills
 175  * in *name with the name of the corresponding slave pty.
 176  * Once the slave pty has been opened, you are responsible to free *name.
 177  */
 178
 179 int get_master_pty(char **name) {
 180    int i, j;
 181    /* default to returning error */
 182    int master = -1;
 183
 184    /* create a dummy name to fill in */
 185    *name = strdup("/dev/ptyXX");
 186
 187    /* search for an unused pty */
 188    for (i=0; i<16 && master <= 0; i++) {
 189       for (j=0; j<16 && master <= 0; j++) {
 190          (*name)[5] = 'p';
 191          (*name)[8] = "pqrstuvwxyzPQRST"[i];
 192          (*name)[9] = "0123456789abcdef"[j];
 193          /* open the master pty */
 194          if ((master = open(*name, O_RDWR)) < 0) {
 195             if (errno == ENOENT) {
 196                /* we are out of pty devices */
 197                free (*name);
 198                return (master);
 199             }
 200          }
 201          else {
 202            /* By substituting a letter, we change the master pty
 203             * name into the slave pty name.
 204             */
 205            (*name)[5] = 't';
 206            if (access(*name, R_OK|W_OK) != 0)
 207              {
 208                close(master);
 209                master = -1;
 210              }
 211          }
 212       }
 213    }
 214    if ((master < 0) && (i == 16) && (j == 16)) {
 215       /* must have tried every pty unsuccessfully */
 216       free (*name);
 217       return (master);
 218    }
 219
 220    (*name)[5] = 't';
 221
 222    return (master);
 223 }
 224
 225 /* get_slave_pty() returns an integer file descriptor.
 226  * If it returns < 0, an error has occurred.
 227  * Otherwise, it has returned the slave file descriptor.
 228  */
 229
 230 int get_slave_pty(char *name) {
 231    struct group *gptr;
 232    gid_t gid;
 233    int slave = -1;
 234
 235    /* chown/chmod the corresponding pty, if possible.
 236     * This will only work if the process has root permissions.
 237     * Alternatively, write and exec a small setuid program that
 238     * does just this.
 239     */
 240    if ((gptr = getgrnam("tty")) != 0) {
 241       gid = gptr->gr_gid;
 242    } else {
 243       /* if the tty group does not exist, don't change the
 244        * group on the slave pty, only the owner
 245        */
 246       gid = -1;
 247    }
 248
 249    /* Note that we do not check for errors here.  If this is code
 250     * where these actions are critical, check for errors!
 251     */
 252    chown(name, getuid(), gid);
 253    /* This code only makes the slave read/writeable for the user.
 254     * If this is for an interactive shell that will want to
 255     * receive "write" and "wall" messages, OR S_IWGRP into the
 256     * second argument below.
 257     */
 258    chmod(name, S_IRUSR|S_IWUSR);
 259
 260    /* open the corresponding slave pty */
 261    slave = open(name, O_RDWR);
 262    return (slave);
 263 }
 264
 265 /* Certain special characters, such as ctrl/C, we want to pass directly
 266    to the inferior, rather than letting readline handle them. */
 267
 268 static char special_chars[20];
 269 static int special_chars_count;
 270
 271 static void
 272 add_special_char(int ch)
 273 {
 274   if (ch != 0)
 275     special_chars[special_chars_count++] = ch;
 276 }
 277
 278 static int eof_char;
 279
 280 static int
 281 is_special_char(int ch)
 282 {
 283   int i;
 284 #if 0
 285   if (ch == eof_char && rl_point == rl_end)
 286     return 1;
 287 #endif
 288   for (i = special_chars_count;  --i >= 0; )
 289     if (special_chars[i] == ch)
 290       return 1;
 291   return 0;
 292 }
 293
 294 static char buf[1024];
 295 /* buf[0 .. buf_count-1] is the what has been emitted on the current line.
 296    It is used as the readline prompt. */
 297 static int buf_count = 0;
 298
 299 int num_keys = 0;
 300
 301 static void
 302 null_prep_terminal (int meta)
 303 {
 304 }
 305
 306 static void
 307 null_deprep_terminal ()
 308 {
 309 }
 310
 311 char pending_special_char;
 312
 313 static void
 314 line_handler (char *line)
 315 {
 316   if (line == NULL)
 317     {
 318       char buf[1];
 319       DPRINT0("saw eof!\n");
 320       buf[0] = '\004'; /* ctrl/d */
 321       write (out_to_inferior_fd, buf, 1);
 322     }
 323   else
 324     {
 325       static char enter[] = "\r";
 326       /*  Send line to inferior: */
 327       int length = strlen (line);
 328       if (length > ECHO_SUPPRESS_MAX-2)
 329         {
 330           echo_suppress_start = 0;
 331           echo_suppress_limit = 0;
 332         }
 333       else
 334         {
 335           if (echo_suppress_limit + length > ECHO_SUPPRESS_MAX - 2)
 336             {
 337               if (echo_suppress_limit - echo_suppress_start + length
 338                   <= ECHO_SUPPRESS_MAX - 2)
 339                 {
 340                   memmove (echo_suppress_buffer,
 341                            echo_suppress_buffer + echo_suppress_start,
 342                            echo_suppress_limit - echo_suppress_start);
 343                   echo_suppress_limit -= echo_suppress_start;
 344                   echo_suppress_start = 0;
 345                 }
 346               else
 347                 {
 348                   echo_suppress_limit = 0;
 349                 }
 350               echo_suppress_start = 0;
 351             }
 352           memcpy (echo_suppress_buffer + echo_suppress_limit,
 353                   line, length);
 354           echo_suppress_limit += length;
 355           echo_suppress_buffer[echo_suppress_limit++] = '\r';
 356           echo_suppress_buffer[echo_suppress_limit++] = '\n';
 357         }
 358       write (out_to_inferior_fd, line, length);
 359       if (pending_special_char == 0)
 360         {
 361           write (out_to_inferior_fd, enter, sizeof(enter)-1);
 362           if (*line)
 363             add_history (line);
 364         }
 365       free (line);
 366     }
 367   rl_callback_handler_remove ();
 368   buf_count = 0;
 369   num_keys = 0;
 370   if (pending_special_char != 0)
 371     {
 372       write (out_to_inferior_fd, &pending_special_char, 1);
 373       pending_special_char = 0;
 374     }
 375 }
 376
 377 /* Value of rl_getc_function.
 378    Use this because readline should read from stdin, not rl_instream,
 379    points to the pty (so readline has monitor its terminal modes). */
 380
 381 int
 382 my_rl_getc (FILE *dummy)
 383 {
 384   int ch = rl_getc (stdin);
 385   if (is_special_char (ch))
 386     {
 387       pending_special_char = ch;
 388       return '\r';
 389     }
 390   return ch;
 391 }
 392
 393 static void
 394 usage()
 395 {
 396   fprintf (stderr, "%s: usage: %s [-l filename] [-a] [-n appname] [-hv] [command [arguments...]]\n",
 397                    progname, progname);
 398 }
 399
 400 int
 401 main(int argc, char** argv)
 402 {
 403   char *path;
 404   int i, append;
 405   int master;
 406   char *name, *logfname, *appname;
 407   int in_from_tty_fd;
 408   struct sigaction act;
 409   struct winsize ws;
 410   struct termios t;
 411   int maxfd;
 412   fd_set in_set;
 413   static char empty_string[1] = "";
 414   char *prompt = empty_string;
 415   int ioctl_err = 0;
 416
 417   if ((progname = strrchr (argv[0], '/')) == 0)
 418     progname = argv[0];
 419   else
 420     progname++;
 421   progversion = RL_LIBRARY_VERSION;
 422
 423   append = 0;
 424   appname = APPLICATION_NAME;
 425   logfname = (char *)NULL;
 426
 427   while ((i = getopt (argc, argv, "ahl:n:v")) != EOF)
 428     {
 429       switch (i)
 430         {
 431         case 'l':
 432           logfname = optarg;
 433           break;
 434         case 'n':
 435           appname = optarg;
 436           break;
 437         case 'a':
 438           append = 1;
 439           break;
 440         case 'h':
 441           usage ();
 442           exit (0);
 443         case 'v':
 444           fprintf (stderr, "%s version %s\n", progname, progversion);
 445           exit (0);
 446         default:
 447           usage ();
 448           exit (2);
 449         }
 450     }
 451
 452   argc -= optind;
 453   argv += optind;
 454
 455   if (logfname)
 456     {
 457       logfile = fopen (logfname, append ? "a" : "w");
 458       if (logfile == 0)
 459         fprintf (stderr, "%s: warning: could not open log file %s: %s\n",
 460                          progname, logfname, strerror (errno));
 461     }
 462
 463   rl_readline_name = appname;
 464
 465 #ifdef DEBUG
 466   debugfile = fopen("LOG", "w");
 467 #endif
 468
 469   if ((master = get_master_pty(&name)) < 0)
 470     {
 471       perror("ptypair: could not open master pty");
 472       exit(1);
 473     }
 474
 475   DPRINT1("pty name: '%s'\n", name);
 476
 477   /* set up SIGWINCH handler */
 478   act.sa_handler = sigwinch_handler;
 479   sigemptyset(&(act.sa_mask));
 480   act.sa_flags = 0;
 481   if (sigaction(SIGWINCH, &act, NULL) < 0)
 482     {
 483       perror("ptypair: could not handle SIGWINCH ");
 484       exit(1);
 485     }
 486
 487   if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) < 0)
 488     {
 489       perror("ptypair: could not get window size");
 490       exit(1);
 491     }
 492
 493   if ((child = fork()) < 0)
 494     {
 495       perror("cannot fork");
 496       exit(1);
 497     }
 498
 499   if (child == 0)
 500     {
 501       int slave;  /* file descriptor for slave pty */
 502
 503       /* We are in the child process */
 504       close(master);
 505
 506 #ifdef TIOCSCTTY
 507       if ((slave = get_slave_pty(name)) < 0)
 508         {
 509           perror("ptypair: could not open slave pty");
 510           exit(1);
 511         }
 512       free(name);
 513 #endif
 514
 515       /* We need to make this process a session group leader, because
 516        * it is on a new PTY, and things like job control simply will
 517        * not work correctly unless there is a session group leader
 518        * and process group leader (which a session group leader
 519        * automatically is). This also disassociates us from our old
 520        * controlling tty.
 521        */
 522       if (setsid() < 0)
 523         {
 524           perror("could not set session leader");
 525         }
 526
 527       /* Tie us to our new controlling tty. */
 528 #ifdef TIOCSCTTY
 529       if (ioctl(slave, TIOCSCTTY, NULL))
 530         {
 531           perror("could not set new controlling tty");
 532         }
 533 #else
 534       if ((slave = get_slave_pty(name)) < 0)
 535         {
 536           perror("ptypair: could not open slave pty");
 537           exit(1);
 538         }
 539       free(name);
 540 #endif
 541
 542       /* make slave pty be standard in, out, and error */
 543       dup2(slave, STDIN_FILENO);
 544       dup2(slave, STDOUT_FILENO);
 545       dup2(slave, STDERR_FILENO);
 546
 547       /* at this point the slave pty should be standard input */
 548       if (slave > 2)
 549         {
 550           close(slave);
 551         }
 552
 553       /* Try to restore window size; failure isn't critical */
 554       if (ioctl(STDOUT_FILENO, TIOCSWINSZ, &ws) < 0)
 555         {
 556           perror("could not restore window size");
 557         }
 558
 559       /* now start the shell */
 560       {
 561         static char* command_args[] = { COMMAND_ARGS, NULL };
 562         if (argc < 1)
 563           execvp(COMMAND, command_args);
 564         else
 565           execvp(argv[0], &argv[0]);
 566       }
 567
 568       /* should never be reached */
 569       exit(1);
 570     }
 571
 572   /* parent */
 573   signal (SIGCHLD, sig_child);
 574   free(name);
 575
 576   /* Note that we only set termios settings for standard input;
 577    * the master side of a pty is NOT a tty.
 578    */
 579   tcgetattr(STDIN_FILENO, &orig_term);
 580
 581   t = orig_term;
 582   eof_char = t.c_cc[VEOF];
 583   /*  add_special_char(t.c_cc[VEOF]);*/
 584   add_special_char(t.c_cc[VINTR]);
 585   add_special_char(t.c_cc[VQUIT]);
 586   add_special_char(t.c_cc[VSUSP]);
 587 #if defined (VDISCARD)
 588   add_special_char(t.c_cc[VDISCARD]);
 589 #endif
 590
 591 #if 0
 592   t.c_lflag |= (ICANON | ISIG | ECHO | ECHOCTL | ECHOE | \
 593                 ECHOK | ECHOKE | ECHONL | ECHOPRT );
 594 #else
 595   t.c_lflag &= ~(ICANON | ISIG | ECHO | ECHOCTL | ECHOE | \
 596                  ECHOK | ECHOKE | ECHONL | ECHOPRT );
 597 #endif
 598   t.c_iflag |= IGNBRK;
 599   t.c_cc[VMIN] = 1;
 600   t.c_cc[VTIME] = 0;
 601   tcsetattr(STDIN_FILENO, TCSANOW, &t);
 602   in_from_inferior_fd = master;
 603   out_to_inferior_fd = master;
 604   rl_instream = fdopen (master, "r");
 605   rl_getc_function = my_rl_getc;
 606
 607   rl_prep_term_function = null_prep_terminal;
 608   rl_deprep_term_function = null_deprep_terminal;
 609   rl_callback_handler_install (prompt, line_handler);
 610
 611 #if 1
 612   rl_directory_completion_hook = rlfe_directory_completion_hook;
 613   rl_completion_entry_function = rlfe_filename_completion_function;
 614 #else
 615   rl_directory_rewrite_hook = rlfe_directory_rewrite_hook;
 616 #endif
 617
 618   in_from_tty_fd = STDIN_FILENO;
 619   FD_ZERO (&in_set);
 620   maxfd = in_from_inferior_fd > in_from_tty_fd ? in_from_inferior_fd
 621     : in_from_tty_fd;
 622   for (;;)
 623     {
 624       int num;
 625       FD_SET (in_from_inferior_fd, &in_set);
 626       FD_SET (in_from_tty_fd, &in_set);
 627
 628       num = select(maxfd+1, &in_set, NULL, NULL, NULL);
 629
 630       if (propagate_sigwinch)
 631         {
 632           struct winsize ws;
 633           if (ioctl (STDIN_FILENO, TIOCGWINSZ, &ws) >= 0)
 634             {
 635               ioctl (master, TIOCSWINSZ, &ws);
 636             }
 637           propagate_sigwinch = 0;
 638           continue;
 639         }
 640
 641       if (num <= 0)
 642         {
 643           perror ("select");
 644           exit (-1);
 645         }
 646       if (FD_ISSET (in_from_tty_fd, &in_set))
 647         {
 648           extern int readline_echoing_p;
 649           struct termios term_master;
 650           int do_canon = 1;
 651           int ioctl_ret;
 652
 653           DPRINT1("[tty avail num_keys:%d]\n", num_keys);
 654
 655           /* If we can't get tty modes for the master side of the pty, we
 656              can't handle non-canonical-mode programs.  Always assume the
 657              master is in canonical echo mode if we can't tell. */
 658           ioctl_ret = tcgetattr(master, &term_master);
 659
 660           if (ioctl_ret >= 0)
 661             {
 662               DPRINT2 ("echo:%d, canon:%d\n",
 663                         (term_master.c_lflag & ECHO) != 0,
 664                         (term_master.c_lflag & ICANON) != 0);
 665               do_canon = (term_master.c_lflag & ICANON) != 0;
 666               readline_echoing_p = (term_master.c_lflag & ECHO) != 0;
 667             }
 668           else
 669             {
 670               if (ioctl_err == 0)
 671                 DPRINT1("tcgetattr on master fd failed: errno = %d\n", errno);
 672               ioctl_err = 1;
 673             }
 674
 675           if (do_canon == 0 && num_keys == 0)
 676             {
 677               char ch[10];
 678               int count = read (STDIN_FILENO, ch, sizeof(ch));
 679               write (out_to_inferior_fd, ch, count);
 680             }
 681           else
 682             {
 683               if (num_keys == 0)
 684                 {
 685                   int i;
 686                   /* Re-install callback handler for new prompt. */
 687                   if (prompt != empty_string)
 688                     free (prompt);
 689                   prompt = malloc (buf_count + 1);
 690                   if (prompt == NULL)
 691                     prompt = empty_string;
 692                   else
 693                     {
 694                       memcpy (prompt, buf, buf_count);
 695                       prompt[buf_count] = '\0';
 696                       DPRINT1("New prompt '%s'\n", prompt);
 697 #if 0 /* ifdef HAVE_RL_ALREADY_PROMPTED -- doesn't work */
 698                       rl_already_prompted = buf_count > 0;
 699 #else
 700                       if (buf_count > 0)
 701                         write (1, "\r", 1);
 702 #endif
 703                     }
 704                   rl_callback_handler_install (prompt, line_handler);
 705                 }
 706               num_keys++;
 707               rl_callback_read_char ();
 708             }
 709         }
 710       else /* input from inferior. */
 711         {
 712           int i;
 713           int count;
 714           int old_count;
 715           if (buf_count > (sizeof(buf) >> 2))
 716             buf_count = 0;
 717           count = read (in_from_inferior_fd, buf+buf_count,
 718                         sizeof(buf) - buf_count);
 719           if (count <= 0)
 720             {
 721               DPRINT0 ("(Connection closed by foreign host.)\n");
 722               tcsetattr(STDIN_FILENO, TCSANOW, &orig_term);
 723               exit (0);
 724             }
 725           old_count = buf_count;
 726
 727           /* Do some minimal carriage return translation and backspace
 728              processing before logging the input line. */
 729           if (logfile)
 730             {
 731 #ifndef __GNUC__
 732               char *b;
 733 #else
 734               char b[count + 1];
 735 #endif
 736               int i, j;
 737
 738 #ifndef __GNUC__
 739               b = malloc (count + 1);
 740               if (b) {
 741 #endif
 742               for (i = 0; i < count; i++)
 743                 b[i] = buf[buf_count + i];
 744               b[i] = '\0';
 745               for (i = j = 0; i <= count; i++)
 746                 {
 747                   if (b[i] == '\r')
 748                     {
 749                       if (b[i+1] != '\n')
 750                         b[j++] = '\n';
 751                     }
 752                   else if (b[i] == '\b')
 753                     {
 754                       if (i)
 755                         j--;
 756                     }
 757                   else
 758                     b[j++] = b[i];
 759                 }
 760               fprintf (logfile, "%s", b);
 761
 762 #ifndef __GNUC__
 763               free (b);
 764               }
 765 #endif
 766             }
 767
 768           /* Look for any pending echo that we need to suppress. */
 769           while (echo_suppress_start < echo_suppress_limit
 770                  && count > 0
 771                  && buf[buf_count] == echo_suppress_buffer[echo_suppress_start])
 772             {
 773               count--;
 774               buf_count++;
 775               echo_suppress_start++;
 776             }
 777
 778           /* Write to the terminal anything that was not suppressed. */
 779           if (count > 0)
 780             write (1, buf + buf_count, count);
 781
 782           /* Finally, look for a prompt candidate.
 783            * When we get around to going input (from the keyboard),
 784            * we will consider the prompt to be anything since the last
 785            * line terminator.  So we need to save that text in the
 786            * initial part of buf.  However, anything before the
 787            * most recent end-of-line is not interesting. */
 788           buf_count += count;
 789 #if 1
 790           for (i = buf_count;  --i >= old_count; )
 791 #else
 792           for (i = buf_count - 1;  i-- >= buf_count - count; )
 793 #endif
 794             {
 795               if (buf[i] == '\n' || buf[i] == '\r')
 796                 {
 797                   i++;
 798                   memmove (buf, buf+i, buf_count - i);
 799                   buf_count -= i;
 800                   break;
 801                 }
 802             }
 803           DPRINT2("-> i: %d, buf_count: %d\n", i, buf_count);
 804         }
 805     }
 806 }
 807
 808 /*
 809  *
 810  * FILENAME COMPLETION FOR RLFE
 811  *
 812  */
 813
 814 #ifndef PATH_MAX
 815 #  define PATH_MAX 1024
 816 #endif
 817
 818 #define DIRSEP          '/'
 819 #define ISDIRSEP(x)     ((x) == '/')
 820 #define PATHSEP(x)      (ISDIRSEP(x) || (x) == 0)
 821
 822 #define DOT_OR_DOTDOT(x) \
 823         ((x)[0] == '.' && (PATHSEP((x)[1]) || \
 824                           ((x)[1] == '.' && PATHSEP((x)[2]))))
 825
 826 #define FREE(x)         if (x) free(x)
 827
 828 #define STRDUP(s, x)    do { \
 829                           s = strdup (x);\
 830                           if (s == 0) \
 831                             return ((char *)NULL); \
 832                         } while (0)
 833
 834 static int
 835 get_inferior_cwd (path, psize)
 836      char *path;
 837      size_t psize;
 838 {
 839   int n;
 840   static char procfsbuf[PATH_MAX] = { '\0' };
 841
 842   if (procfsbuf[0] == '\0')
 843     sprintf (procfsbuf, "/proc/%d/cwd", (int)child);
 844   n = readlink (procfsbuf, path, psize);
 845   if (n < 0)
 846     return n;
 847   if (n > psize)
 848     return -1;
 849   path[n] = '\0';
 850   return n;
 851 }
 852
 853 static int
 854 rlfe_directory_rewrite_hook (dirnamep)
 855      char **dirnamep;
 856 {
 857   char *ldirname, cwd[PATH_MAX], *retdir, *ld;
 858   int n, ldlen;
 859
 860   ldirname = *dirnamep;
 861
 862   if (*ldirname == '/')
 863     return 0;
 864
 865   n = get_inferior_cwd (cwd, sizeof(cwd) - 1);
 866   if (n < 0)
 867     return 0;
 868   if (n == 0)   /* current directory */
 869     {
 870       cwd[0] = '.';
 871       cwd[1] = '\0';
 872       n = 1;
 873     }
 874
 875   /* Minimally canonicalize ldirname by removing leading `./' */
 876   for (ld = ldirname; *ld; )
 877     {
 878       if (ISDIRSEP (ld[0]))
 879         ld++;
 880       else if (ld[0] == '.' && PATHSEP(ld[1]))
 881         ld++;
 882       else
 883         break;
 884     }
 885   ldlen = (ld && *ld) ? strlen (ld) : 0;
 886
 887   retdir = (char *)malloc (n + ldlen + 3);
 888   if (retdir == 0)
 889     return 0;
 890   if (ldlen)
 891     sprintf (retdir, "%s/%s", cwd, ld);
 892   else
 893     strcpy (retdir, cwd);
 894   free (ldirname);
 895
 896   *dirnamep = retdir;
 897
 898   DPRINT1("rl_directory_rewrite_hook returns %s\n", retdir);
 899   return 1;
 900 }
 901
 902 /* Translate *DIRNAMEP to be relative to the inferior's CWD.  Leave a trailing
 903    slash on the result. */
 904 static int
 905 rlfe_directory_completion_hook (dirnamep)
 906      char **dirnamep;
 907 {
 908   char *ldirname, *retdir;
 909   int n, ldlen;
 910
 911   ldirname = *dirnamep;
 912
 913   if (*ldirname == '/')
 914     return 0;
 915
 916   n = rlfe_directory_rewrite_hook (dirnamep);
 917   if (n == 0)
 918     return 0;
 919
 920   ldirname = *dirnamep;
 921   ldlen = (ldirname && *ldirname) ? strlen (ldirname) : 0;
 922
 923   if (ldlen == 0 || ldirname[ldlen - 1] != '/')
 924     {
 925       retdir = (char *)malloc (ldlen + 3);
 926       if (retdir == 0)
 927         return 0;
 928       if (ldlen)
 929         strcpy (retdir, ldirname);
 930       else
 931         retdir[ldlen++] = '.';
 932       retdir[ldlen] = '/';
 933       retdir[ldlen+1] = '\0';
 934       free (ldirname);
 935
 936       *dirnamep = retdir;
 937     }
 938
 939   DPRINT1("rl_directory_completion_hook returns %s\n", retdir);
 940   return 1;
 941 }
 942
 943 static char *
 944 rlfe_filename_completion_function (text, state)
 945      const char *text;
 946      int state;
 947 {
 948   static DIR *directory;
 949   static char *filename = (char *)NULL;
 950   static char *dirname = (char *)NULL, *ud = (char *)NULL;
 951   static int flen, udlen;
 952   char *temp;
 953   struct dirent *dentry;
 954
 955   if (state == 0)
 956     {
 957       if (directory)
 958         {
 959           closedir (directory);
 960           directory = 0;
 961         }
 962       FREE (dirname);
 963       FREE (filename);
 964       FREE (ud);
 965
 966       if (text && *text)
 967         STRDUP (filename, text);
 968       else
 969         {
 970           filename = malloc(1);
 971           if (filename == 0)
 972             return ((char *)NULL);
 973           filename[0] = '\0';
 974         }
 975       dirname = (text && *text) ? strdup (text) : strdup (".");
 976       if (dirname == 0)
 977         return ((char *)NULL);
 978
 979       temp = strrchr (dirname, '/');
 980       if (temp)
 981         {
 982           strcpy (filename, ++temp);
 983           *temp = '\0';
 984         }
 985       else
 986         {
 987           dirname[0] = '.';
 988           dirname[1] = '\0';
 989         }
 990
 991       STRDUP (ud, dirname);
 992       udlen = strlen (ud);
 993
 994       rlfe_directory_completion_hook (&dirname);
 995
 996       directory = opendir (dirname);
 997       flen = strlen (filename);
 998
 999       rl_filename_completion_desired = 1;
1000     }
1001
1002   dentry = 0;
1003   while (directory && (dentry = readdir (directory)))
1004     {
1005       if (flen == 0)
1006         {
1007           if (DOT_OR_DOTDOT(dentry->d_name) == 0)
1008             break;
1009         }
1010       else
1011         {
1012           if ((dentry->d_name[0] == filename[0]) &&
1013               (strlen (dentry->d_name) >= flen) &&
1014               (strncmp (filename, dentry->d_name, flen) == 0))
1015             break;
1016         }
1017     }
1018
1019   if (dentry == 0)
1020     {
1021       if (directory)
1022         {
1023           closedir (directory);
1024           directory = 0;
1025         }
1026       FREE (dirname);
1027       FREE (filename);
1028       FREE (ud);
1029       dirname = filename = ud = 0;
1030       return ((char *)NULL);
1031     }
1032
1033   if (ud == 0 || (ud[0] == '.' && ud[1] == '\0'))
1034     temp = strdup (dentry->d_name);
1035   else
1036     {
1037       temp = malloc (1 + udlen + strlen (dentry->d_name));
1038       strcpy (temp, ud);
1039       strcpy (temp + udlen, dentry->d_name);
1040     }
1041   return (temp);
1042 }