usr/src/cmd/cmd-inet/usr.bin/chat/chat.c

   1 /*
   2  * Copyright 2000 Sun Microsystems, Inc.  All rights reserved.
   3  * Use is subject to license terms.
   4  */
   5 /*
   6  *      Chat -- a program for automatic session establishment (i.e. dial
   7  *              the phone and log in).
   8  *
   9  * Standard termination codes:
  10  *  0 - successful completion of the script
  11  *  1 - invalid argument, expect string too large, etc.
  12  *  2 - error on an I/O operation or fatal error condition.
  13  *  3 - timeout waiting for a simple string.
  14  *  4 - the first string declared as "ABORT"
  15  *  5 - the second string declared as "ABORT"
  16  *  6 - ... and so on for successive ABORT strings.
  17  *
  18  *      This software is in the public domain.
  19  *
  20  * -----------------
  21  *      22-May-99 added environment substitutuion, enabled with -E switch.
  22  *      Andreas Arens <andras@cityweb.de>.
  23  *
  24  *      12-May-99 added a feature to read data to be sent from a file,
  25  *      if the send string starts with @.  Idea from gpk <gpk@onramp.net>.
  26  *
  27  *      added -T and -U option and \T and \U substitution to pass a phone
  28  *      number into chat script. Two are needed for some ISDN TA applications.
  29  *      Keith Dart <kdart@cisco.com>
  30  *
  31  *
  32  *      Added SAY keyword to send output to stderr.
  33  *      This allows to turn ECHO OFF and to output specific, user selected,
  34  *      text to give progress messages. This best works when stderr
  35  *      exists (i.e.: pppd in nodetach mode).
  36  *
  37  *      Added HANGUP directives to allow for us to be called
  38  *      back. When HANGUP is set to NO, chat will not hangup at HUP signal.
  39  *      We rely on timeouts in that case.
  40  *
  41  *      Added CLR_ABORT to clear previously set ABORT string. This has been
  42  *      dictated by the HANGUP above as "NO CARRIER" (for example) must be
  43  *      an ABORT condition until we know the other host is going to close
  44  *      the connection for call back. As soon as we have completed the
  45  *      first stage of the call back sequence, "NO CARRIER" is a valid, non
  46  *      fatal string. As soon as we got called back (probably get "CONNECT"),
  47  *      we should re-arm the ABORT "NO CARRIER". Hence the CLR_ABORT command.
  48  *      Note that CLR_ABORT packs the abort_strings[] array so that we do not
  49  *      have unused entries not being reclaimed.
  50  *
  51  *      In the same vein as above, added CLR_REPORT keyword.
  52  *
  53  *      Allow for comments. Line starting with '#' are comments and are
  54  *      ignored. If a '#' is to be expected as the first character, the
  55  *      expect string must be quoted.
  56  *
  57  *
  58  *              Francis Demierre <Francis@SwissMail.Com>
  59  *              Thu May 15 17:15:40 MET DST 1997
  60  *
  61  *
  62  *      Added -r "report file" switch & REPORT keyword.
  63  *              Robert Geer <bgeer@xmission.com>
  64  *
  65  *      Added -s "use stderr" and -S "don't use syslog" switches.
  66  *              June 18, 1997
  67  *              Karl O. Pinc <kop@meme.com>
  68  *
  69  *
  70  *      Added -e "echo" switch & ECHO keyword
  71  *              Dick Streefland <dicks@tasking.nl>
  72  *
  73  *
  74  *      Considerable updates and modifications by
  75  *              Al Longyear <longyear@pobox.com>
  76  *              Paul Mackerras <paulus@cs.anu.edu.au>
  77  *
  78  *
  79  *      The original author is:
  80  *
  81  *              Karl Fox <karl@MorningStar.Com>
  82  *              Morning Star Technologies, Inc.
  83  *              1760 Zollinger Road
  84  *              Columbus, OH  43221
  85  *              (614)451-1883
  86  *
  87  */
  88
  89 #ifndef __STDC__
  90 #define const
  91 #endif
  92
  93 #pragma ident   "%Z%%M% %I%     %E% SMI"
  94
  95 #ifndef lint
  96 static const char rcsid[] = "$Id: chat.c,v 1.26 1999/12/23 01:39:54 paulus Exp $";
  97 #endif
  98
  99 #include <stdio.h>
 100 #include <ctype.h>
 101 #include <time.h>
 102 #include <fcntl.h>
 103 #include <signal.h>
 104 #include <errno.h>
 105 #include <string.h>
 106 #include <stdlib.h>
 107 #include <unistd.h>
 108 #include <sys/types.h>
 109 #include <sys/stat.h>
 110 #include <syslog.h>
 111
 112 #ifndef TERMIO
 113 #undef  TERMIOS
 114 #define TERMIOS
 115 #endif
 116
 117 #ifdef TERMIO
 118 #include <termio.h>
 119 #endif
 120 #ifdef TERMIOS
 121 #include <termios.h>
 122 #endif
 123
 124 #define STR_LEN 1024
 125
 126 #ifndef SIGTYPE
 127 #define SIGTYPE void
 128 #endif
 129
 130 #undef __P
 131 #undef __V
 132
 133 #ifdef __STDC__
 134 #include <stdarg.h>
 135 #define __V(x)  x
 136 #define __P(x)  x
 137 #else
 138 #include <varargs.h>
 139 #define __V(x)  (va_alist) va_dcl
 140 #define __P(x)  ()
 141 #define const
 142 #endif
 143
 144 #ifndef O_NONBLOCK
 145 #define O_NONBLOCK      O_NDELAY
 146 #endif
 147
 148 #ifdef SUNOS
 149 extern int sys_nerr;
 150 extern char *sys_errlist[];
 151 #define memmove(to, from, n)    bcopy(from, to, n)
 152 #define strerror(n)             ((unsigned)(n) < sys_nerr? sys_errlist[(n)] :\
 153                                  "unknown error")
 154 #endif
 155
 156 /*************** Micro getopt() *********************************************/
 157 #define OPTION(c,v)     (_O&2&&**v?*(*v)++:!c||_O&4?0:(!(_O&1)&& \
 158                                 (--c,++v),_O=4,c&&**v=='-'&&v[0][1]?*++*v=='-'\
 159                                 &&!v[0][1]?(--c,++v,0):(_O=2,*(*v)++):0))
 160 #define OPTARG(c,v)     (_O&2?**v||(++v,--c)?(_O=1,--c,*v++): \
 161                                 (_O=4,(char*)0):(char*)0)
 162 #define OPTONLYARG(c,v) (_O&2&&**v?(_O=1,--c,*v++):(char*)0)
 163 #define ARG(c,v)        (c?(--c,*v++):(char*)0)
 164
 165 static int _O = 0;              /* Internal state */
 166 /*************** Micro getopt() *********************************************/
 167
 168 char *program_name;
 169
 170 #define MAX_ABORTS              50
 171 #define MAX_REPORTS             50
 172 #define DEFAULT_CHAT_TIMEOUT    45
 173
 174 int echo          = 0;
 175 int verbose       = 0;
 176 int to_log        = 1;
 177 int to_stderr     = 0;
 178 int Verbose       = 0;
 179 int quiet         = 0;
 180 int report        = 0;
 181 int use_env       = 0;
 182 int exit_code     = 0;
 183 FILE* report_fp   = (FILE *) 0;
 184 char *report_file = (char *) 0;
 185 char *chat_file   = (char *) 0;
 186 char *phone_num   = (char *) 0;
 187 char *phone_num2  = (char *) 0;
 188 int timeout       = DEFAULT_CHAT_TIMEOUT;
 189
 190 int have_tty_parameters = 0;
 191
 192 #ifdef TERMIO
 193 #define term_parms struct termio
 194 #define get_term_param(param) ioctl(0, TCGETA, param)
 195 #define set_term_param(param) ioctl(0, TCSETA, param)
 196 struct termio saved_tty_parameters;
 197 #endif
 198
 199 #ifdef TERMIOS
 200 #define term_parms struct termios
 201 #define get_term_param(param) tcgetattr(0, param)
 202 #define set_term_param(param) tcsetattr(0, TCSANOW, param)
 203 struct termios saved_tty_parameters;
 204 #endif
 205
 206 char *abort_string[MAX_ABORTS], *fail_reason = (char *)0,
 207         fail_buffer[50];
 208 int n_aborts = 0, abort_next = 0, timeout_next = 0, echo_next = 0;
 209 int clear_abort_next = 0;
 210
 211 char *report_string[MAX_REPORTS] ;
 212 char  report_buffer[50] ;
 213 int n_reports = 0, report_next = 0, report_gathering = 0 ;
 214 int clear_report_next = 0;
 215
 216 int say_next = 0, hup_next = 0;
 217
 218 void *dup_mem __P((void *b, size_t c));
 219 void *copy_of __P((char *s));
 220 void usage __P((void));
 221 void logf __P((const char *fmt, ...));
 222 void fatal __P((int code, const char *fmt, ...));
 223 SIGTYPE sigalrm __P((int signo));
 224 SIGTYPE sigint __P((int signo));
 225 SIGTYPE sigterm __P((int signo));
 226 SIGTYPE sighup __P((int signo));
 227 void unalarm __P((void));
 228 void init __P((void));
 229 void set_tty_parameters __P((void));
 230 void echo_stderr __P((int));
 231 void break_sequence __P((void));
 232 void terminate __P((int status));
 233 void do_file __P((char *chat_file));
 234 int  get_string __P((register char *string));
 235 int  put_string __P((register char *s));
 236 int  write_char __P((int c));
 237 int  put_char __P((int c));
 238 int  get_char __P((void));
 239 void chat_send __P((register char *s));
 240 char *character __P((int c));
 241 void chat_expect __P((register char *s));
 242 char *clean __P((register char *s, int sending));
 243 void break_sequence __P((void));
 244 void terminate __P((int status));
 245 void pack_array __P((char **array, int end));
 246 char *expect_strtok __P((char *, char *));
 247 int vfmtmsg __P((char *, int, const char *, va_list));  /* vsprintf++ */
 248
 249 int main __P((int, char *[]));
 250
 251 void *dup_mem(b, c)
 252 void *b;
 253 size_t c;
 254 {
 255     void *ans = malloc (c);
 256     if (!ans)
 257         fatal(2, "memory error!");
 258
 259     memcpy (ans, b, c);
 260     return ans;
 261 }
 262
 263 void *copy_of (s)
 264 char *s;
 265 {
 266     return dup_mem (s, strlen (s) + 1);
 267 }
 268
 269 /*
 270  * chat [ -v ] [ -E ] [ -T number ] [ -U number ] [ -t timeout ] [ -f chat-file ] \
 271  * [ -r report-file ] \
 272  *              [...[[expect[-say[-expect...]] say expect[-say[-expect]] ...]]]
 273  *
 274  *      Perform a UUCP-dialer-like chat script on stdin and stdout.
 275  */
 276 int
 277 main(argc, argv)
 278      int argc;
 279      char **argv;
 280 {
 281     int option;
 282     char *arg;
 283
 284     program_name = *argv;
 285     tzset();
 286
 287     while ((option = OPTION(argc, argv)) != 0) {
 288         switch (option) {
 289         case 'e':
 290             ++echo;
 291             break;
 292
 293         case 'E':
 294             ++use_env;
 295             break;
 296
 297         case 'v':
 298             ++verbose;
 299             break;
 300
 301         case 'V':
 302             ++Verbose;
 303             break;
 304
 305         case 's':
 306             ++to_stderr;
 307             break;
 308
 309         case 'S':
 310             to_log = 0;
 311             break;
 312
 313         case 'f':
 314             if ((arg = OPTARG(argc, argv)) != NULL)
 315                     chat_file = copy_of(arg);
 316             else
 317                 usage();
 318             break;
 319
 320         case 't':
 321             if ((arg = OPTARG(argc, argv)) != NULL)
 322                 timeout = atoi(arg);
 323             else
 324                 usage();
 325             break;
 326
 327         case 'r':
 328             arg = OPTARG (argc, argv);
 329             if (arg) {
 330                 if (report_fp != NULL)
 331                     fclose (report_fp);
 332                 report_file = copy_of (arg);
 333                 report_fp   = fopen (report_file, "a");
 334                 if (report_fp != NULL) {
 335                     if (verbose)
 336                         fprintf (report_fp, "Opening \"%s\"...\n",
 337                                  report_file);
 338                     report = 1;
 339                 }
 340             }
 341             break;
 342
 343         case 'T':
 344             if ((arg = OPTARG(argc, argv)) != NULL)
 345                 phone_num = copy_of(arg);
 346             else
 347                 usage();
 348             break;
 349
 350         case 'U':
 351             if ((arg = OPTARG(argc, argv)) != NULL)
 352                 phone_num2 = copy_of(arg);
 353             else
 354                 usage();
 355             break;
 356
 357         default:
 358             usage();
 359             break;
 360         }
 361     }
 362 /*
 363  * Default the report file to the stderr location
 364  */
 365     if (report_fp == NULL)
 366         report_fp = stderr;
 367
 368     if (to_log) {
 369 #ifdef ultrix
 370         openlog("chat", LOG_PID);
 371 #else
 372         openlog("chat", LOG_PID | LOG_NDELAY, LOG_LOCAL2);
 373
 374         if (verbose)
 375             setlogmask(LOG_UPTO(LOG_INFO));
 376         else
 377             setlogmask(LOG_UPTO(LOG_WARNING));
 378 #endif
 379     }
 380
 381     init();
 382
 383     if (chat_file != NULL) {
 384         arg = ARG(argc, argv);
 385         if (arg != NULL)
 386             usage();
 387         else
 388             do_file (chat_file);
 389     } else {
 390         while ((arg = ARG(argc, argv)) != NULL) {
 391             chat_expect(arg);
 392
 393             if ((arg = ARG(argc, argv)) != NULL)
 394                 chat_send(arg);
 395         }
 396     }
 397
 398     terminate(0);
 399     return 0;
 400 }
 401
 402 /*
 403  *  Process a chat script when read from a file.
 404  */
 405
 406 void do_file (chat_file)
 407 char *chat_file;
 408 {
 409     int linect, sendflg;
 410     char *sp, *arg, quote;
 411     char buf [STR_LEN];
 412     FILE *cfp;
 413
 414     cfp = fopen (chat_file, "r");
 415     if (cfp == NULL)
 416         fatal(1, "%s -- open failed: %m", chat_file);
 417
 418     linect = 0;
 419     sendflg = 0;
 420
 421     while (fgets(buf, STR_LEN, cfp) != NULL) {
 422         sp = strchr (buf, '\n');
 423         if (sp)
 424             *sp = '\0';
 425
 426         linect++;
 427         sp = buf;
 428
 429         /* lines starting with '#' are comments. If a real '#'
 430            is to be expected, it should be quoted .... */
 431         if ( *sp == '#' )
 432             continue;
 433
 434         while (*sp != '\0') {
 435             if (*sp == ' ' || *sp == '\t') {
 436                 ++sp;
 437                 continue;
 438             }
 439
 440             if (*sp == '"' || *sp == '\'') {
 441                 quote = *sp++;
 442                 arg = sp;
 443                 while (*sp != quote) {
 444                     if (*sp == '\0')
 445                         fatal(1, "unterminated quote (line %d)", linect);
 446
 447                     if (*sp++ == '\\') {
 448                         if (*sp != '\0')
 449                             ++sp;
 450                     }
 451                 }
 452             }
 453             else {
 454                 arg = sp;
 455                 while (*sp != '\0' && *sp != ' ' && *sp != '\t')
 456                     ++sp;
 457             }
 458
 459             if (*sp != '\0')
 460                 *sp++ = '\0';
 461
 462             if (sendflg)
 463                 chat_send (arg);
 464             else
 465                 chat_expect (arg);
 466             sendflg = !sendflg;
 467         }
 468     }
 469     fclose (cfp);
 470 }
 471
 472 /*
 473  *      We got an error parsing the command line.
 474  */
 475 void usage()
 476 {
 477     fprintf(stderr, "\
 478 Usage: %s [-e] [-E] [-v] [-V] [-t timeout] [-r report-file]\n\
 479      [-T phone-number] [-U phone-number2] {-f chat-file | chat-script}\n", program_name);
 480     exit(1);
 481 }
 482
 483 char line[1024];
 484
 485 /*
 486  * Send a message to syslog and/or stderr.
 487  */
 488 void logf __V((const char *fmt, ...))
 489 {
 490     va_list args;
 491
 492 #ifdef __STDC__
 493     va_start(args, fmt);
 494 #else
 495     char *fmt;
 496     va_start(args);
 497     fmt = va_arg(args, char *);
 498 #endif
 499
 500     vfmtmsg(line, sizeof(line), fmt, args);
 501     if (to_log)
 502         syslog(LOG_INFO, "%s", line);
 503     if (to_stderr)
 504         fprintf(stderr, "%s\n", line);
 505 }
 506
 507 /*
 508  *      Print an error message and terminate.
 509  */
 510
 511 void fatal __V((int code, const char *fmt, ...))
 512 {
 513     va_list args;
 514
 515 #ifdef __STDC__
 516     va_start(args, fmt);
 517 #else
 518     int code;
 519     char *fmt;
 520     va_start(args);
 521     code = va_arg(args, int);
 522     fmt = va_arg(args, char *);
 523 #endif
 524
 525     vfmtmsg(line, sizeof(line), fmt, args);
 526     if (to_log)
 527         syslog(LOG_ERR, "%s", line);
 528     if (to_stderr)
 529         fprintf(stderr, "%s\n", line);
 530     terminate(code);
 531 }
 532
 533 int alarmed = 0;
 534
 535 SIGTYPE sigalrm(signo)
 536 int signo;
 537 {
 538     int flags;
 539
 540     alarm(1);
 541     alarmed = 1;                /* Reset alarm to avoid race window */
 542     signal(SIGALRM, sigalrm);   /* that can cause hanging in read() */
 543
 544     if ((flags = fcntl(0, F_GETFL, 0)) == -1)
 545         fatal(2, "Can't get file mode flags on stdin: %m");
 546
 547     if (fcntl(0, F_SETFL, flags | O_NONBLOCK) == -1)
 548         fatal(2, "Can't set file mode flags on stdin: %m");
 549
 550     if (verbose)
 551         logf("alarm");
 552 }
 553
 554 void unalarm()
 555 {
 556     int flags;
 557
 558     if ((flags = fcntl(0, F_GETFL, 0)) == -1)
 559         fatal(2, "Can't get file mode flags on stdin: %m");
 560
 561     if (fcntl(0, F_SETFL, flags & ~O_NONBLOCK) == -1)
 562         fatal(2, "Can't set file mode flags on stdin: %m");
 563 }
 564
 565 SIGTYPE sigint(signo)
 566 int signo;
 567 {
 568     fatal(2, "SIGINT");
 569 }
 570
 571 SIGTYPE sigterm(signo)
 572 int signo;
 573 {
 574     fatal(2, "SIGTERM");
 575 }
 576
 577 SIGTYPE sighup(signo)
 578 int signo;
 579 {
 580     fatal(2, "SIGHUP");
 581 }
 582
 583 void init()
 584 {
 585     signal(SIGINT, sigint);
 586     signal(SIGTERM, sigterm);
 587     signal(SIGHUP, sighup);
 588
 589     set_tty_parameters();
 590     signal(SIGALRM, sigalrm);
 591     alarm(0);
 592     alarmed = 0;
 593 }
 594
 595 void set_tty_parameters()
 596 {
 597 #if defined(get_term_param)
 598     term_parms t;
 599
 600     if (get_term_param (&t) < 0)
 601         fatal(2, "Can't get terminal parameters: %m");
 602
 603     saved_tty_parameters = t;
 604     have_tty_parameters  = 1;
 605
 606     t.c_iflag     |= IGNBRK | ISTRIP | IGNPAR;
 607     t.c_oflag      = 0;
 608     t.c_lflag      = 0;
 609     t.c_cc[VERASE] =
 610     t.c_cc[VKILL]  = 0;
 611     t.c_cc[VMIN]   = 1;
 612     t.c_cc[VTIME]  = 0;
 613
 614     if (set_term_param (&t) < 0)
 615         fatal(2, "Can't set terminal parameters: %m");
 616 #endif
 617 }
 618
 619 void break_sequence()
 620 {
 621 #ifdef TERMIOS
 622     tcsendbreak (0, 0);
 623 #endif
 624 }
 625
 626 void terminate(status)
 627 int status;
 628 {
 629     static int terminating = 0;
 630
 631     if (terminating)
 632         exit(status);
 633     terminating = 1;
 634     echo_stderr(-1);
 635 /*
 636  * Allow the last of the report string to be gathered before we terminate.
 637  */
 638     if (report_gathering) {
 639         int c, rep_len;
 640
 641         rep_len = strlen(report_buffer);
 642         while (rep_len + 1 <= sizeof(report_buffer)) {
 643             alarm(1);
 644             c = get_char();
 645             alarm(0);
 646             if (c < 0 || iscntrl(c))
 647                 break;
 648             report_buffer[rep_len] = c;
 649             ++rep_len;
 650         }
 651         report_buffer[rep_len] = 0;
 652         fprintf (report_fp, "chat:  %s\n", report_buffer);
 653     }
 654     if (report_file != (char *) 0 && report_fp != (FILE *) NULL) {
 655         if (verbose)
 656             fprintf (report_fp, "Closing \"%s\".\n", report_file);
 657         fclose (report_fp);
 658         report_fp = (FILE *) NULL;
 659     }
 660
 661 #if defined(get_term_param)
 662     if (have_tty_parameters) {
 663         if (set_term_param (&saved_tty_parameters) < 0)
 664             fatal(2, "Can't restore terminal parameters: %m");
 665     }
 666 #endif
 667
 668     exit(status);
 669 }
 670
 671 /*
 672  *      'Clean up' this string.
 673  */
 674 char *clean(s, sending)
 675 register char *s;
 676 int sending;  /* set to 1 when sending (putting) this string. */
 677 {
 678     char temp[STR_LEN], env_str[STR_LEN], cur_chr;
 679     register char *s1, *phchar;
 680     int add_return = sending;
 681 #define isoctal(chr)    (((chr) >= '0') && ((chr) <= '7'))
 682 #define isalnumx(chr)   ((((chr) >= '0') && ((chr) <= '9')) \
 683                          || (((chr) >= 'a') && ((chr) <= 'z')) \
 684                          || (((chr) >= 'A') && ((chr) <= 'Z')) \
 685                          || (chr) == '_')
 686
 687     s1 = temp;
 688     while (*s) {
 689         cur_chr = *s++;
 690         if (cur_chr == '^') {
 691             cur_chr = *s++;
 692             if (cur_chr == '\0') {
 693                 *s1++ = '^';
 694                 break;
 695             }
 696             cur_chr &= 0x1F;
 697             if (cur_chr != 0) {
 698                 *s1++ = cur_chr;
 699             }
 700             continue;
 701         }
 702
 703         if (use_env && cur_chr == '$') {                /* ARI */
 704             phchar = env_str;
 705             while (isalnumx(*s))
 706                 *phchar++ = *s++;
 707             *phchar = '\0';
 708             phchar = getenv(env_str);
 709             if (phchar)
 710                 while (*phchar)
 711                     *s1++ = *phchar++;
 712             continue;
 713         }
 714
 715         if (cur_chr != '\\') {
 716             *s1++ = cur_chr;
 717             continue;
 718         }
 719
 720         cur_chr = *s++;
 721         if (cur_chr == '\0') {
 722             if (sending) {
 723                 *s1++ = '\\';
 724                 *s1++ = '\\';
 725             }
 726             break;
 727         }
 728
 729         switch (cur_chr) {
 730         case 'b':
 731             *s1++ = '\b';
 732             break;
 733
 734         case 'c':
 735             if (sending && *s == '\0')
 736                 add_return = 0;
 737             else
 738                 *s1++ = cur_chr;
 739             break;
 740
 741         case '\\':
 742         case 'K':
 743         case 'p':
 744         case 'd':
 745             if (sending)
 746                 *s1++ = '\\';
 747             *s1++ = cur_chr;
 748             break;
 749
 750         case 'T':
 751             if (sending && phone_num) {
 752                 for (phchar = phone_num; *phchar != '\0'; phchar++)
 753                     *s1++ = *phchar;
 754             }
 755             else {
 756                 *s1++ = '\\';
 757                 *s1++ = 'T';
 758             }
 759             break;
 760
 761         case 'U':
 762             if (sending && phone_num2) {
 763                 for (phchar = phone_num2; *phchar != '\0'; phchar++)
 764                     *s1++ = *phchar;
 765             }
 766             else {
 767                 *s1++ = '\\';
 768                 *s1++ = 'U';
 769             }
 770             break;
 771
 772         case 'q':
 773             quiet = 1;
 774             break;
 775
 776         case 'r':
 777             *s1++ = '\r';
 778             break;
 779
 780         case 'n':
 781             *s1++ = '\n';
 782             break;
 783
 784         case 's':
 785             *s1++ = ' ';
 786             break;
 787
 788         case 't':
 789             *s1++ = '\t';
 790             break;
 791
 792         case 'N':
 793             if (sending) {
 794                 *s1++ = '\\';
 795                 *s1++ = '\0';
 796             }
 797             else
 798                 *s1++ = 'N';
 799             break;
 800
 801         case '$':                       /* ARI */
 802             if (use_env) {
 803                 *s1++ = cur_chr;
 804                 break;
 805             }
 806             /* FALL THROUGH */
 807
 808         default:
 809             if (isoctal (cur_chr)) {
 810                 cur_chr &= 0x07;
 811                 if (isoctal (*s)) {
 812                     cur_chr <<= 3;
 813                     cur_chr |= *s++ - '0';
 814                     if (isoctal (*s)) {
 815                         cur_chr <<= 3;
 816                         cur_chr |= *s++ - '0';
 817                     }
 818                 }
 819
 820                 if (cur_chr != 0 || sending) {
 821                     if (sending && (cur_chr == '\\' || cur_chr == 0))
 822                         *s1++ = '\\';
 823                     *s1++ = cur_chr;
 824                 }
 825                 break;
 826             }
 827
 828             if (sending)
 829                 *s1++ = '\\';
 830             *s1++ = cur_chr;
 831             break;
 832         }
 833     }
 834
 835     if (add_return)
 836         *s1++ = '\r';
 837
 838     *s1++ = '\0'; /* guarantee closure */
 839     *s1++ = '\0'; /* terminate the string */
 840     return dup_mem (temp, (size_t) (s1 - temp)); /* may have embedded nuls */
 841 }
 842
 843 /*
 844  * A modified version of 'strtok'. This version skips \ sequences.
 845  */
 846
 847 char *expect_strtok (s, term)
 848      char *s, *term;
 849 {
 850     static  char *str   = "";
 851     int     escape_flag = 0;
 852     char   *result;
 853
 854 /*
 855  * If a string was specified then do initial processing.
 856  */
 857     if (s)
 858         str = s;
 859
 860 /*
 861  * If this is the escape flag then reset it and ignore the character.
 862  */
 863     if (*str)
 864         result = str;
 865     else
 866         result = (char *) 0;
 867
 868     while (*str) {
 869         if (escape_flag) {
 870             escape_flag = 0;
 871             ++str;
 872             continue;
 873         }
 874
 875         if (*str == '\\') {
 876             ++str;
 877             escape_flag = 1;
 878             continue;
 879         }
 880
 881 /*
 882  * If this is not in the termination string, continue.
 883  */
 884         if (strchr (term, *str) == (char *) 0) {
 885             ++str;
 886             continue;
 887         }
 888
 889 /*
 890  * This is the terminator. Mark the end of the string and stop.
 891  */
 892         *str++ = '\0';
 893         break;
 894     }
 895     return (result);
 896 }
 897
 898 /*
 899  * Process the expect string
 900  */
 901
 902 void chat_expect (s)
 903 char *s;
 904 {
 905     char *expect;
 906     char *reply;
 907
 908     if (strcmp(s, "HANGUP") == 0) {
 909         ++hup_next;
 910         return;
 911     }
 912
 913     if (strcmp(s, "ABORT") == 0) {
 914         ++abort_next;
 915         return;
 916     }
 917
 918     if (strcmp(s, "CLR_ABORT") == 0) {
 919         ++clear_abort_next;
 920         return;
 921     }
 922
 923     if (strcmp(s, "REPORT") == 0) {
 924         ++report_next;
 925         return;
 926     }
 927
 928     if (strcmp(s, "CLR_REPORT") == 0) {
 929         ++clear_report_next;
 930         return;
 931     }
 932
 933     if (strcmp(s, "TIMEOUT") == 0) {
 934         ++timeout_next;
 935         return;
 936     }
 937
 938     if (strcmp(s, "ECHO") == 0) {
 939         ++echo_next;
 940         return;
 941     }
 942
 943     if (strcmp(s, "SAY") == 0) {
 944         ++say_next;
 945         return;
 946     }
 947
 948 /*
 949  * Fetch the expect and reply string.
 950  */
 951     for (;;) {
 952         expect = expect_strtok (s, "-");
 953         s      = (char *) 0;
 954
 955         if (expect == (char *) 0)
 956             return;
 957
 958         reply = expect_strtok (s, "-");
 959
 960 /*
 961  * Handle the expect string. If successful then exit.
 962  */
 963         if (get_string (expect))
 964             return;
 965
 966 /*
 967  * If there is a sub-reply string then send it. Otherwise any condition
 968  * is terminal.
 969  */
 970         if (reply == (char *) 0 || exit_code != 3)
 971             break;
 972
 973         chat_send (reply);
 974     }
 975
 976 /*
 977  * The expectation did not occur. This is terminal.
 978  */
 979     if (fail_reason)
 980         logf("Failed (%s)", fail_reason);
 981     else
 982         logf("Failed");
 983     terminate(exit_code);
 984 }
 985
 986 /*
 987  * Translate the input character to the appropriate string for printing
 988  * the data.
 989  */
 990
 991 char *character(c)
 992 int c;
 993 {
 994     static char string[10];
 995     char *meta;
 996
 997     meta = (c & 0x80) ? "M-" : "";
 998     c &= 0x7F;
 999
1000     if (c < 32)
1001         sprintf(string, "%s^%c", meta, (int)c + '@');
1002     else if (c == 127)
1003         sprintf(string, "%s^?", meta);
1004     else
1005         sprintf(string, "%s%c", meta, c);
1006
1007     return (string);
1008 }
1009
1010 /*
1011  *  process the reply string
1012  */
1013 void chat_send (s)
1014 register char *s;
1015 {
1016     char file_data[STR_LEN];
1017
1018     if (say_next) {
1019         say_next = 0;
1020         s = clean(s, 1);
1021         write(2, s, strlen(s));
1022         free(s);
1023         return;
1024     }
1025
1026     if (hup_next) {
1027         hup_next = 0;
1028         if (strcmp(s, "OFF") == 0)
1029            signal(SIGHUP, SIG_IGN);
1030         else
1031            signal(SIGHUP, sighup);
1032         return;
1033     }
1034
1035     if (echo_next) {
1036         echo_next = 0;
1037         echo = (strcmp(s, "ON") == 0);
1038         return;
1039     }
1040
1041     if (abort_next) {
1042         char *s1;
1043
1044         abort_next = 0;
1045
1046         if (n_aborts >= MAX_ABORTS)
1047             fatal(2, "Too many ABORT strings");
1048
1049         s1 = clean(s, 0);
1050
1051         if (strlen(s1) > strlen(s)
1052             || strlen(s1) + 1 > sizeof(fail_buffer))
1053             fatal(1, "Illegal or too-long ABORT string ('%v')", s);
1054
1055         abort_string[n_aborts++] = s1;
1056
1057         if (verbose)
1058             logf("abort on (%v)", s);
1059         return;
1060     }
1061
1062     if (clear_abort_next) {
1063         char *s1;
1064         int   i;
1065         int   old_max;
1066         int   pack = 0;
1067
1068         clear_abort_next = 0;
1069
1070         s1 = clean(s, 0);
1071
1072         if (strlen(s1) > strlen(s)
1073             || strlen(s1) + 1 > sizeof(fail_buffer))
1074             fatal(1, "Illegal or too-long CLR_ABORT string ('%v')", s);
1075
1076         old_max = n_aborts;
1077         for (i=0; i < n_aborts; i++) {
1078             if ( strcmp(s1,abort_string[i]) == 0 ) {
1079                 free(abort_string[i]);
1080                 abort_string[i] = NULL;
1081                 pack++;
1082                 n_aborts--;
1083                 if (verbose)
1084                     logf("clear abort on (%v)", s);
1085             }
1086         }
1087         free(s1);
1088         if (pack)
1089             pack_array(abort_string,old_max);
1090         return;
1091     }
1092
1093     if (report_next) {
1094         char *s1;
1095
1096         report_next = 0;
1097         if (n_reports >= MAX_REPORTS)
1098             fatal(2, "Too many REPORT strings");
1099
1100         s1 = clean(s, 0);
1101
1102         if (strlen(s1) > strlen(s) || strlen(s1) > sizeof fail_buffer - 1)
1103             fatal(1, "Illegal or too-long REPORT string ('%v')", s);
1104
1105         report_string[n_reports++] = s1;
1106
1107         if (verbose)
1108             logf("report (%v)", s);
1109         return;
1110     }
1111
1112     if (clear_report_next) {
1113         char *s1;
1114         int   i;
1115         int   old_max;
1116         int   pack = 0;
1117
1118         clear_report_next = 0;
1119
1120         s1 = clean(s, 0);
1121
1122         if (strlen(s1) > strlen(s) || strlen(s1) > sizeof fail_buffer - 1)
1123             fatal(1, "Illegal or too-long REPORT string ('%v')", s);
1124
1125         old_max = n_reports;
1126         for (i=0; i < n_reports; i++) {
1127             if ( strcmp(s1,report_string[i]) == 0 ) {
1128                 free(report_string[i]);
1129                 report_string[i] = NULL;
1130                 pack++;
1131                 n_reports--;
1132                 if (verbose)
1133                     logf("clear report (%v)", s);
1134             }
1135         }
1136         free(s1);
1137         if (pack)
1138             pack_array(report_string,old_max);
1139
1140         return;
1141     }
1142
1143     if (timeout_next) {
1144         timeout_next = 0;
1145         timeout = atoi(s);
1146
1147         if (timeout <= 0)
1148             timeout = DEFAULT_CHAT_TIMEOUT;
1149
1150         if (verbose)
1151             logf("timeout set to %d seconds", timeout);
1152
1153         return;
1154     }
1155
1156     /*
1157      * The syntax @filename means read the string to send from the
1158      * file `filename'.
1159      */
1160     if (s[0] == '@') {
1161         /* skip the @ and any following white-space */
1162         char *fn = s;
1163         while (*++fn == ' ' || *fn == '\t')
1164             ;
1165
1166         if (*fn != 0) {
1167             FILE *f;
1168             int n = 0;
1169
1170             /* open the file and read until STR_LEN-1 bytes or end-of-file */
1171             f = fopen(fn, "r");
1172             if (f == NULL)
1173                 fatal(1, "%s -- open failed: %m", fn);
1174             while (n < STR_LEN - 1) {
1175                 int nr = fread(&file_data[n], 1, STR_LEN - 1 - n, f);
1176                 if (nr < 0)
1177                     fatal(1, "%s -- read error", fn);
1178                 if (nr == 0)
1179                     break;
1180                 n += nr;
1181             }
1182             fclose(f);
1183
1184             /* use the string we got as the string to send,
1185                but trim off the final newline if any. */
1186             if (n > 0 && file_data[n-1] == '\n')
1187                 --n;
1188             file_data[n] = 0;
1189             s = file_data;
1190         }
1191     }
1192
1193     if (strcmp(s, "EOT") == 0)
1194         s = "^D\\c";
1195     else if (strcmp(s, "BREAK") == 0)
1196         s = "\\K\\c";
1197
1198     if (!put_string(s))
1199         fatal(1, "Failed");
1200 }
1201
1202 int get_char()
1203 {
1204     int status;
1205     char c;
1206
1207     status = read(0, &c, 1);
1208
1209     switch (status) {
1210     case 1:
1211         return ((int)c & 0x7F);
1212
1213     default:
1214         logf("warning: read() on stdin returned %d", status);
1215
1216     case -1:
1217         if ((status = fcntl(0, F_GETFL, 0)) == -1)
1218             fatal(2, "Can't get file mode flags on stdin: %m");
1219
1220         if (fcntl(0, F_SETFL, status & ~O_NONBLOCK) == -1)
1221             fatal(2, "Can't set file mode flags on stdin: %m");
1222
1223         return (-1);
1224     }
1225 }
1226
1227 int put_char(c)
1228 int c;
1229 {
1230     int status;
1231     char ch = c;
1232
1233     usleep(10000);              /* inter-character typing delay (?) */
1234
1235     status = write(1, &ch, 1);
1236
1237     switch (status) {
1238     case 1:
1239         return (0);
1240
1241     default:
1242         logf("warning: write() on stdout returned %d", status);
1243
1244     case -1:
1245         if ((status = fcntl(0, F_GETFL, 0)) == -1)
1246             fatal(2, "Can't get file mode flags on stdin, %m");
1247
1248         if (fcntl(0, F_SETFL, status & ~O_NONBLOCK) == -1)
1249             fatal(2, "Can't set file mode flags on stdin: %m");
1250
1251         return (-1);
1252     }
1253 }
1254
1255 int write_char (c)
1256 int c;
1257 {
1258     if (alarmed || put_char(c) < 0) {
1259         alarm(0);
1260         alarmed = 0;
1261
1262         if (verbose) {
1263             if (errno == EINTR || errno == EWOULDBLOCK)
1264                 logf(" -- write timed out");
1265             else
1266                 logf(" -- write failed: %m");
1267         }
1268         return (0);
1269     }
1270     return (1);
1271 }
1272
1273 int put_string (s)
1274 register char *s;
1275 {
1276     quiet = 0;
1277     s = clean(s, 1);
1278
1279     if (verbose) {
1280         if (quiet)
1281             logf("send (??????)");
1282         else
1283             logf("send (%v)", s);
1284     }
1285
1286     alarm(timeout); alarmed = 0;
1287
1288     while (*s) {
1289         register char c = *s++;
1290
1291         if (c != '\\') {
1292             if (!write_char (c))
1293                 return 0;
1294             continue;
1295         }
1296
1297         c = *s++;
1298         switch (c) {
1299         case 'd':
1300             sleep(1);
1301             break;
1302
1303         case 'K':
1304             break_sequence();
1305             break;
1306
1307         case 'p':
1308             usleep(10000);      /* 1/100th of a second (arg is microseconds) */
1309             break;
1310
1311         default:
1312             if (!write_char (c))
1313                 return 0;
1314             break;
1315         }
1316     }
1317
1318     alarm(0);
1319     alarmed = 0;
1320     return (1);
1321 }
1322
1323 /*
1324  *      Echo a character to stderr.
1325  *      When called with -1, a '\n' character is generated when
1326  *      the cursor is not at the beginning of a line.
1327  */
1328 void echo_stderr(n)
1329 int n;
1330 {
1331     static int need_lf;
1332     char *s;
1333
1334     switch (n) {
1335     case '\r':          /* ignore '\r' */
1336         break;
1337     case -1:
1338         if (need_lf == 0)
1339             break;
1340         /* fall through */
1341     case '\n':
1342         write(2, "\n", 1);
1343         need_lf = 0;
1344         break;
1345     default:
1346         s = character(n);
1347         write(2, s, strlen(s));
1348         need_lf = 1;
1349         break;
1350     }
1351 }
1352
1353 /*
1354  *      'Wait for' this string to appear on this file descriptor.
1355  */
1356 int get_string(string)
1357 register char *string;
1358 {
1359     char temp[STR_LEN];
1360     int c, printed = 0, len, minlen;
1361     register char *s = temp, *end = s + STR_LEN;
1362     char *logged = temp;
1363
1364     fail_reason = (char *)0;
1365     string = clean(string, 0);
1366     len = strlen(string);
1367     minlen = (len > sizeof(fail_buffer)? len: sizeof(fail_buffer)) - 1;
1368
1369     if (verbose)
1370         logf("expect (%v)", string);
1371
1372     if (len > STR_LEN) {
1373         logf("expect string is too long");
1374         exit_code = 1;
1375         return 0;
1376     }
1377
1378     if (len == 0) {
1379         if (verbose)
1380             logf("got it");
1381         return (1);
1382     }
1383
1384     alarm(timeout);
1385     alarmed = 0;
1386
1387     while ( ! alarmed && (c = get_char()) >= 0) {
1388         int n, abort_len, report_len;
1389
1390         if (echo)
1391             echo_stderr(c);
1392         if (verbose && c == '\n') {
1393             if (s == logged)
1394                 logf("");       /* blank line */
1395             else
1396                 logf("%0.*v", s - logged, logged);
1397             logged = s + 1;
1398         }
1399
1400         *s++ = c;
1401
1402         if (verbose && s >= logged + 80) {
1403             logf("%0.*v", s - logged, logged);
1404             logged = s;
1405         }
1406
1407         if (Verbose) {
1408            if (c == '\n')
1409                fputc( '\n', stderr );
1410            else if (c != '\r')
1411                fprintf( stderr, "%s", character(c) );
1412         }
1413
1414         if (!report_gathering) {
1415             for (n = 0; n < n_reports; ++n) {
1416                 if ((report_string[n] != (char*) NULL) &&
1417                     s - temp >= (report_len = strlen(report_string[n])) &&
1418                     strncmp(s - report_len, report_string[n], report_len) == 0) {
1419                     time_t time_now   = time ((time_t*) NULL);
1420                     struct tm* tm_now = localtime (&time_now);
1421
1422                     strftime (report_buffer, 20, "%b %d %H:%M:%S ", tm_now);
1423                     strcat (report_buffer, report_string[n]);
1424
1425                     report_string[n] = (char *) NULL;
1426                     report_gathering = 1;
1427                     break;
1428                 }
1429             }
1430         }
1431         else {
1432             if (!iscntrl (c)) {
1433                 int rep_len = strlen (report_buffer);
1434                 report_buffer[rep_len]     = c;
1435                 report_buffer[rep_len + 1] = '\0';
1436             }
1437             else {
1438                 report_gathering = 0;
1439                 fprintf (report_fp, "chat:  %s\n", report_buffer);
1440             }
1441         }
1442
1443         if (s - temp >= len &&
1444             c == string[len - 1] &&
1445             strncmp(s - len, string, len) == 0) {
1446             if (verbose) {
1447                 if (s > logged)
1448                     logf("%0.*v", s - logged, logged);
1449                 logf(" -- got it\n");
1450             }
1451
1452             alarm(0);
1453             alarmed = 0;
1454             return (1);
1455         }
1456
1457         for (n = 0; n < n_aborts; ++n) {
1458             if (s - temp >= (abort_len = strlen(abort_string[n])) &&
1459                 strncmp(s - abort_len, abort_string[n], abort_len) == 0) {
1460                 if (verbose) {
1461                     if (s > logged)
1462                         logf("%0.*v", s - logged, logged);
1463                     logf(" -- failed");
1464                 }
1465
1466                 alarm(0);
1467                 alarmed = 0;
1468                 exit_code = n + 4;
1469                 strcpy(fail_reason = fail_buffer, abort_string[n]);
1470                 return (0);
1471             }
1472         }
1473
1474         if (s >= end) {
1475             if (logged < s - minlen) {
1476                 if (verbose)
1477                     logf("%0.*v", s - logged, logged);
1478                 logged = s;
1479             }
1480             s -= minlen;
1481             memmove(temp, s, minlen);
1482             logged = temp + (logged - s);
1483             s = temp + minlen;
1484         }
1485
1486         if (alarmed && verbose)
1487             logf("warning: alarm synchronization problem");
1488     }
1489
1490     alarm(0);
1491
1492     if (verbose && printed) {
1493         if (alarmed)
1494             logf(" -- read timed out");
1495         else
1496             logf(" -- read failed: %m");
1497     }
1498
1499     exit_code = 3;
1500     alarmed   = 0;
1501     return (0);
1502 }
1503
1504 /*
1505  * Gross kludge to handle Solaris versions >= 2.6 having usleep.
1506  */
1507 #ifdef SOL2
1508 #include <sys/param.h>
1509 #if MAXUID > 65536              /* then this is Solaris 2.6 or later */
1510 #undef NO_USLEEP
1511 #endif
1512 #endif /* SOL2 */
1513
1514 #ifdef NO_USLEEP
1515 #include <sys/types.h>
1516 #include <sys/time.h>
1517
1518 /*
1519   usleep -- support routine for 4.2BSD system call emulations
1520   last edit:  29-Oct-1984     D A Gwyn
1521   */
1522
1523 extern int        select();
1524
1525 int
1526 usleep( usec )                            /* returns 0 if ok, else -1 */
1527     long                usec;           /* delay in microseconds */
1528 {
1529     static struct {             /* `timeval' */
1530         long    tv_sec;         /* seconds */
1531         long    tv_usec;        /* microsecs */
1532     } delay;                    /* _select() timeout */
1533
1534     delay.tv_sec  = usec / 1000000L;
1535     delay.tv_usec = usec % 1000000L;
1536
1537     return select(0, (long *)0, (long *)0, (long *)0, &delay);
1538 }
1539 #endif
1540
1541 void
1542 pack_array (array, end)
1543     char **array; /* The address of the array of string pointers */
1544     int    end;   /* The index of the next free entry before CLR_ */
1545 {
1546     int i, j;
1547
1548     for (i = 0; i < end; i++) {
1549         if (array[i] == NULL) {
1550             for (j = i+1; j < end; ++j)
1551                 if (array[j] != NULL)
1552                     array[i++] = array[j];
1553             for (; i < end; ++i)
1554                 array[i] = NULL;
1555             break;
1556         }
1557     }
1558 }
1559
1560 /*
1561  * vfmtmsg - format a message into a buffer.  Like vsprintf except we
1562  * also specify the length of the output buffer, and we handle the
1563  * %m (error message) format.
1564  * Doesn't do floating-point formats.
1565  * Returns the number of chars put into buf.
1566  */
1567 #define OUTCHAR(c)      (buflen > 0? (--buflen, *buf++ = (c)): 0)
1568
1569 int
1570 vfmtmsg(buf, buflen, fmt, args)
1571     char *buf;
1572     int buflen;
1573     const char *fmt;
1574     va_list args;
1575 {
1576     int c, i, n;
1577     int width, prec, fillch;
1578     int base, len, neg, quoted;
1579     unsigned long val = 0;
1580     char *str, *buf0;
1581     const char *f;
1582     unsigned char *p;
1583     char num[32];
1584     static char hexchars[] = "0123456789abcdef";
1585
1586     buf0 = buf;
1587     --buflen;
1588     while (buflen > 0) {
1589         for (f = fmt; *f != '%' && *f != 0; ++f)
1590             ;
1591         if (f > fmt) {
1592             len = f - fmt;
1593             if (len > buflen)
1594                 len = buflen;
1595             memcpy(buf, fmt, len);
1596             buf += len;
1597             buflen -= len;
1598             fmt = f;
1599         }
1600         if (*fmt == 0)
1601             break;
1602         c = *++fmt;
1603         width = prec = 0;
1604         fillch = ' ';
1605         if (c == '0') {
1606             fillch = '0';
1607             c = *++fmt;
1608         }
1609         if (c == '*') {
1610             width = va_arg(args, int);
1611             c = *++fmt;
1612         } else {
1613             while (isdigit(c)) {
1614                 width = width * 10 + c - '0';
1615                 c = *++fmt;
1616             }
1617         }
1618         if (c == '.') {
1619             c = *++fmt;
1620             if (c == '*') {
1621                 prec = va_arg(args, int);
1622                 c = *++fmt;
1623             } else {
1624                 while (isdigit(c)) {
1625                     prec = prec * 10 + c - '0';
1626                     c = *++fmt;
1627                 }
1628             }
1629         }
1630         str = 0;
1631         base = 0;
1632         neg = 0;
1633         ++fmt;
1634         switch (c) {
1635         case 'd':
1636             i = va_arg(args, int);
1637             if (i < 0) {
1638                 neg = 1;
1639                 val = -i;
1640             } else
1641                 val = i;
1642             base = 10;
1643             break;
1644         case 'o':
1645             val = va_arg(args, unsigned int);
1646             base = 8;
1647             break;
1648         case 'x':
1649             val = va_arg(args, unsigned int);
1650             base = 16;
1651             break;
1652         case 'p':
1653             val = (unsigned long) va_arg(args, void *);
1654             base = 16;
1655             neg = 2;
1656             break;
1657         case 's':
1658             str = va_arg(args, char *);
1659             break;
1660         case 'c':
1661             num[0] = va_arg(args, int);
1662             num[1] = 0;
1663             str = num;
1664             break;
1665         case 'm':
1666             str = strerror(errno);
1667             break;
1668         case 'v':               /* "visible" string */
1669         case 'q':               /* quoted string */
1670             quoted = c == 'q';
1671             p = va_arg(args, unsigned char *);
1672             if (fillch == '0' && prec > 0) {
1673                 n = prec;
1674             } else {
1675                 n = strlen((char *)p);
1676                 if (prec > 0 && prec < n)
1677                     n = prec;
1678             }
1679             while (n > 0 && buflen > 0) {
1680                 c = *p++;
1681                 --n;
1682                 if (!quoted && c >= 0x80) {
1683                     OUTCHAR('M');
1684                     OUTCHAR('-');
1685                     c -= 0x80;
1686                 }
1687                 if (quoted && (c == '"' || c == '\\'))
1688                     OUTCHAR('\\');
1689                 if (c < 0x20 || (0x7f <= c && c < 0xa0)) {
1690                     if (quoted) {
1691                         OUTCHAR('\\');
1692                         switch (c) {
1693                         case '\t':      OUTCHAR('t');   break;
1694                         case '\n':      OUTCHAR('n');   break;
1695                         case '\b':      OUTCHAR('b');   break;
1696                         case '\f':      OUTCHAR('f');   break;
1697                         default:
1698                             OUTCHAR('x');
1699                             OUTCHAR(hexchars[c >> 4]);
1700                             OUTCHAR(hexchars[c & 0xf]);
1701                         }
1702                     } else {
1703                         if (c == '\t')
1704                             OUTCHAR(c);
1705                         else {
1706                             OUTCHAR('^');
1707                             OUTCHAR(c ^ 0x40);
1708                         }
1709                     }
1710                 } else
1711                     OUTCHAR(c);
1712             }
1713             continue;
1714         default:
1715             *buf++ = '%';
1716             if (c != '%')
1717                 --fmt;          /* so %z outputs %z etc. */
1718             --buflen;
1719             continue;
1720         }
1721         if (base != 0) {
1722             str = num + sizeof(num);
1723             *--str = 0;
1724             while (str > num + neg) {
1725                 *--str = hexchars[val % base];
1726                 val = val / base;
1727                 if (--prec <= 0 && val == 0)
1728                     break;
1729             }
1730             switch (neg) {
1731             case 1:
1732                 *--str = '-';
1733                 break;
1734             case 2:
1735                 *--str = 'x';
1736                 *--str = '0';
1737                 break;
1738             }
1739             len = num + sizeof(num) - 1 - str;
1740         } else {
1741             len = strlen(str);
1742             if (prec > 0 && len > prec)
1743                 len = prec;
1744         }
1745         if (width > 0) {
1746             if (width > buflen)
1747                 width = buflen;
1748             if ((n = width - len) > 0) {
1749                 buflen -= n;
1750                 for (; n > 0; --n)
1751                     *buf++ = fillch;
1752             }
1753         }
1754         if (len > buflen)
1755             len = buflen;
1756         memcpy(buf, str, len);
1757         buf += len;
1758         buflen -= len;
1759     }
1760     *buf = 0;
1761     return buf - buf0;
1762 }