usr.bin/mail/collect.c

   1 /*
   2  * Copyright (c) 1980, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#)collect.c        8.2 (Berkeley) 4/19/94
  34  * $FreeBSD: src/usr.bin/mail/collect.c,v 1.4.6.3 2003/01/06 05:46:03 mikeh Exp $
  35  * $DragonFly: src/usr.bin/mail/collect.c,v 1.4 2004/09/08 03:01:11 joerg Exp $
  36  */
  37
  38 /*
  39  * Mail -- a mail program
  40  *
  41  * Collect input from standard input, handling
  42  * ~ escapes.
  43  */
  44
  45 #include "rcv.h"
  46 #include <fcntl.h>
  47 #include "extern.h"
  48
  49 /*
  50  * Read a message from standard output and return a read file to it
  51  * or NULL on error.
  52  */
  53
  54 /*
  55  * The following hokiness with global variables is so that on
  56  * receipt of an interrupt signal, the partial message can be salted
  57  * away on dead.letter.
  58  */
  59
  60 static  sig_t   saveint;                /* Previous SIGINT value */
  61 static  sig_t   savehup;                /* Previous SIGHUP value */
  62 static  sig_t   savetstp;               /* Previous SIGTSTP value */
  63 static  sig_t   savettou;               /* Previous SIGTTOU value */
  64 static  sig_t   savettin;               /* Previous SIGTTIN value */
  65 static  FILE    *collf;                 /* File for saving away */
  66 static  int     hadintr;                /* Have seen one SIGINT so far */
  67
  68 static  jmp_buf colljmp;                /* To get back to work */
  69 static  int     colljmp_p;              /* whether to long jump */
  70 static  jmp_buf collabort;              /* To end collection with error */
  71
  72 FILE *
  73 collect(struct header *hp, int printheaders)
  74 {
  75         FILE *fbuf;
  76         int lc, cc, escape, eofcount, fd, c, t;
  77         char linebuf[LINESIZE], tempname[PATHSIZE], *cp, getsub;
  78         sigset_t nset;
  79         int longline, lastlong, rc;     /* So we don't make 2 or more lines
  80                                            out of a long input line. */
  81
  82         collf = NULL;
  83         /*
  84          * Start catching signals from here, but we're still die on interrupts
  85          * until we're in the main loop.
  86          */
  87         sigemptyset(&nset);
  88         sigaddset(&nset, SIGINT);
  89         sigaddset(&nset, SIGHUP);
  90         sigprocmask(SIG_BLOCK, &nset, NULL);
  91         if ((saveint = signal(SIGINT, SIG_IGN)) != SIG_IGN)
  92                 signal(SIGINT, collint);
  93         if ((savehup = signal(SIGHUP, SIG_IGN)) != SIG_IGN)
  94                 signal(SIGHUP, collhup);
  95         savetstp = signal(SIGTSTP, collstop);
  96         savettou = signal(SIGTTOU, collstop);
  97         savettin = signal(SIGTTIN, collstop);
  98         if (setjmp(collabort) || setjmp(colljmp)) {
  99                 rm(tempname);
 100                 goto err;
 101         }
 102         sigprocmask(SIG_UNBLOCK, &nset, NULL);
 103
 104         noreset++;
 105         snprintf(tempname, sizeof(tempname), "%s/mail.RsXXXXXXXXXX", tmpdir);
 106         if ((fd = mkstemp(tempname)) == -1 ||
 107             (collf = Fdopen(fd, "w+")) == NULL) {
 108                 warn("%s", tempname);
 109                 goto err;
 110         }
 111         rm(tempname);
 112
 113         /*
 114          * If we are going to prompt for a subject,
 115          * refrain from printing a newline after
 116          * the headers (since some people mind).
 117          */
 118         t = GTO|GSUBJECT|GCC|GNL;
 119         getsub = 0;
 120         if (hp->h_subject == NULL && value("interactive") != NULL &&
 121             (value("ask") != NULL || value("asksub") != NULL))
 122                 t &= ~GNL, getsub++;
 123         if (printheaders) {
 124                 puthead(hp, stdout, t);
 125                 fflush(stdout);
 126         }
 127         if ((cp = value("escape")) != NULL)
 128                 escape = *cp;
 129         else
 130                 escape = ESCAPE;
 131         eofcount = 0;
 132         hadintr = 0;
 133         lastlong = 0;
 134         longline = 0;
 135
 136         if (!setjmp(colljmp)) {
 137                 if (getsub)
 138                         grabh(hp, GSUBJECT);
 139         } else {
 140                 /*
 141                  * Come here for printing the after-signal message.
 142                  * Duplicate messages won't be printed because
 143                  * the write is aborted if we get a SIGTTOU.
 144                  */
 145 cont:
 146                 if (hadintr) {
 147                         fflush(stdout);
 148                         fprintf(stderr,
 149                         "\n(Interrupt -- one more to kill letter)\n");
 150                 } else {
 151                         printf("(continue)\n");
 152                         fflush(stdout);
 153                 }
 154         }
 155         for (;;) {
 156                 colljmp_p = 1;
 157                 c = readline(stdin, linebuf, LINESIZE);
 158                 colljmp_p = 0;
 159                 if (c < 0) {
 160                         if (value("interactive") != NULL &&
 161                             value("ignoreeof") != NULL && ++eofcount < 25) {
 162                                 printf("Use \".\" to terminate letter\n");
 163                                 continue;
 164                         }
 165                         break;
 166                 }
 167                 lastlong = longline;
 168                 longline = c == LINESIZE - 1;
 169                 eofcount = 0;
 170                 hadintr = 0;
 171                 if (linebuf[0] == '.' && linebuf[1] == '\0' &&
 172                     value("interactive") != NULL && !lastlong &&
 173                     (value("dot") != NULL || value("ignoreeof") != NULL))
 174                         break;
 175                 if (linebuf[0] != escape || value("interactive") == NULL ||
 176                     lastlong) {
 177                         if (putline(collf, linebuf, !longline) < 0)
 178                                 goto err;
 179                         continue;
 180                 }
 181                 c = linebuf[1];
 182                 switch (c) {
 183                 default:
 184                         /*
 185                          * On double escape, just send the single one.
 186                          * Otherwise, it's an error.
 187                          */
 188                         if (c == escape) {
 189                                 if (putline(collf, &linebuf[1], !longline) < 0)
 190                                         goto err;
 191                                 else
 192                                         break;
 193                         }
 194                         printf("Unknown tilde escape.\n");
 195                         break;
 196                 case 'C':
 197                         /*
 198                          * Dump core.
 199                          */
 200                         core();
 201                         break;
 202                 case '!':
 203                         /*
 204                          * Shell escape, send the balance of the
 205                          * line to sh -c.
 206                          */
 207                         shell(&linebuf[2]);
 208                         break;
 209                 case ':':
 210                 case '_':
 211                         /*
 212                          * Escape to command mode, but be nice!
 213                          */
 214                         execute(&linebuf[2], 1);
 215                         goto cont;
 216                 case '.':
 217                         /*
 218                          * Simulate end of file on input.
 219                          */
 220                         goto out;
 221                 case 'q':
 222                         /*
 223                          * Force a quit of sending mail.
 224                          * Act like an interrupt happened.
 225                          */
 226                         hadintr++;
 227                         collint(SIGINT);
 228                         exit(1);
 229                 case 'x':
 230                         /*
 231                          * Exit, do not save in dead.letter.
 232                          */
 233                         goto err;
 234                 case 'h':
 235                         /*
 236                          * Grab a bunch of headers.
 237                          */
 238                         grabh(hp, GTO|GSUBJECT|GCC|GBCC);
 239                         goto cont;
 240                 case 't':
 241                         /*
 242                          * Add to the To list.
 243                          */
 244                         hp->h_to = cat(hp->h_to, extract(&linebuf[2], GTO));
 245                         break;
 246                 case 's':
 247                         /*
 248                          * Set the Subject line.
 249                          */
 250                         cp = &linebuf[2];
 251                         while (isspace((unsigned char)*cp))
 252                                 cp++;
 253                         hp->h_subject = savestr(cp);
 254                         break;
 255                 case 'R':
 256                         /*
 257                          * Set the Reply-To line.
 258                          */
 259                         cp = &linebuf[2];
 260                         while (isspace((unsigned char)*cp))
 261                                 cp++;
 262                         hp->h_replyto = savestr(cp);
 263                         break;
 264                 case 'c':
 265                         /*
 266                          * Add to the CC list.
 267                          */
 268                         hp->h_cc = cat(hp->h_cc, extract(&linebuf[2], GCC));
 269                         break;
 270                 case 'b':
 271                         /*
 272                          * Add to the BCC list.
 273                          */
 274                         hp->h_bcc = cat(hp->h_bcc, extract(&linebuf[2], GBCC));
 275                         break;
 276                 case 'i':
 277                 case 'A':
 278                 case 'a':
 279                         /*
 280                          * Insert named variable in message.
 281                          */
 282                         switch(c) {
 283                                 case 'i':
 284                                         cp = &linebuf[2];
 285                                         while(isspace((unsigned char)*cp))
 286                                                 cp++;
 287                                         break;
 288                                 case 'a':
 289                                         cp = "sign";
 290                                         break;
 291                                 case 'A':
 292                                         cp = "Sign";
 293                                         break;
 294                                 default:
 295                                         goto err;
 296                         }
 297
 298                         if(*cp != '\0' && (cp = value(cp)) != NULL) {
 299                                 printf("%s\n", cp);
 300                                 if(putline(collf, cp, 1) < 0)
 301                                         goto err;
 302                         }
 303
 304                         break;
 305                 case 'd':
 306                         /*
 307                          * Read in the dead letter file.
 308                          */
 309                         if (strlcpy(linebuf + 2, getdeadletter(),
 310                                 sizeof(linebuf) - 2)
 311                             >= sizeof(linebuf) - 2) {
 312                                 printf("Line buffer overflow\n");
 313                                 break;
 314                         }
 315                         /* FALLTHROUGH */
 316                 case 'r':
 317                 case '<':
 318                         /*
 319                          * Invoke a file:
 320                          * Search for the file name,
 321                          * then open it and copy the contents to collf.
 322                          */
 323                         cp = &linebuf[2];
 324                         while (isspace((unsigned char)*cp))
 325                                 cp++;
 326                         if (*cp == '\0') {
 327                                 printf("Interpolate what file?\n");
 328                                 break;
 329                         }
 330                         cp = expand(cp);
 331                         if (cp == NULL)
 332                                 break;
 333                         if (*cp == '!') {
 334                                 /*
 335                                  * Insert stdout of command.
 336                                  */
 337                                 char *sh;
 338                                 int nullfd, tempfd, rc;
 339                                 char tempname2[PATHSIZE];
 340
 341                                 if ((nullfd = open("/dev/null", O_RDONLY, 0))
 342                                     == -1) {
 343                                         warn("/dev/null");
 344                                         break;
 345                                 }
 346
 347                                 snprintf(tempname2, sizeof(tempname2),
 348                                          "%s/mail.ReXXXXXXXXXX", tmpdir);
 349                                 if ((tempfd = mkstemp(tempname2)) == -1 ||
 350                                     (fbuf = Fdopen(tempfd, "w+")) == NULL) {
 351                                         warn("%s", tempname2);
 352                                         break;
 353                                 }
 354                                 unlink(tempname2);
 355
 356                                 if ((sh = value("SHELL")) == NULL)
 357                                         sh = _PATH_CSHELL;
 358
 359                                 rc = run_command(sh, 0, nullfd, fileno(fbuf),
 360                                     "-c", cp+1, NULL);
 361
 362                                 close(nullfd);
 363
 364                                 if (rc < 0) {
 365                                         Fclose(fbuf);
 366                                         break;
 367                                 }
 368
 369                                 if (fsize(fbuf) == 0) {
 370                                         fprintf(stderr,
 371                                             "No bytes from command \"%s\"\n",
 372                                             cp+1);
 373                                         Fclose(fbuf);
 374                                         break;
 375                                 }
 376
 377                                 rewind(fbuf);
 378                         } else if (isdir(cp)) {
 379                                 printf("%s: Directory\n", cp);
 380                                 break;
 381                         } else if ((fbuf = Fopen(cp, "r")) == NULL) {
 382                                 warn("%s", cp);
 383                                 break;
 384                         }
 385                         printf("\"%s\" ", cp);
 386                         fflush(stdout);
 387                         lc = 0;
 388                         cc = 0;
 389                         while ((rc = readline(fbuf, linebuf, LINESIZE)) >= 0) {
 390                                 if (rc != LINESIZE - 1)
 391                                         lc++;
 392                                 if ((t = putline(collf, linebuf,
 393                                          rc != LINESIZE - 1)) < 0) {
 394                                         Fclose(fbuf);
 395                                         goto err;
 396                                 }
 397                                 cc += t;
 398                         }
 399                         Fclose(fbuf);
 400                         printf("%d/%d\n", lc, cc);
 401                         break;
 402                 case 'w':
 403                         /*
 404                          * Write the message on a file.
 405                          */
 406                         cp = &linebuf[2];
 407                         while (*cp == ' ' || *cp == '\t')
 408                                 cp++;
 409                         if (*cp == '\0') {
 410                                 fprintf(stderr, "Write what file!?\n");
 411                                 break;
 412                         }
 413                         if ((cp = expand(cp)) == NULL)
 414                                 break;
 415                         rewind(collf);
 416                         exwrite(cp, collf, 1);
 417                         break;
 418                 case 'm':
 419                 case 'M':
 420                 case 'f':
 421                 case 'F':
 422                         /*
 423                          * Interpolate the named messages, if we
 424                          * are in receiving mail mode.  Does the
 425                          * standard list processing garbage.
 426                          * If ~f is given, we don't shift over.
 427                          */
 428                         if (forward(linebuf + 2, collf, tempname, c) < 0)
 429                                 goto err;
 430                         goto cont;
 431                 case '?':
 432                         if ((fbuf = Fopen(_PATH_TILDE, "r")) == NULL) {
 433                                 warn("%s", _PATH_TILDE);
 434                                 break;
 435                         }
 436                         while ((t = getc(fbuf)) != EOF)
 437                                 putchar(t);
 438                         Fclose(fbuf);
 439                         break;
 440                 case 'p':
 441                         /*
 442                          * Print out the current state of the
 443                          * message without altering anything.
 444                          */
 445                         rewind(collf);
 446                         printf("-------\nMessage contains:\n");
 447                         puthead(hp, stdout, GTO|GSUBJECT|GCC|GBCC|GNL);
 448                         while ((t = getc(collf)) != EOF)
 449                                 putchar(t);
 450                         goto cont;
 451                 case '|':
 452                         /*
 453                          * Pipe message through command.
 454                          * Collect output as new message.
 455                          */
 456                         rewind(collf);
 457                         mespipe(collf, &linebuf[2]);
 458                         goto cont;
 459                 case 'v':
 460                 case 'e':
 461                         /*
 462                          * Edit the current message.
 463                          * 'e' means to use EDITOR
 464                          * 'v' means to use VISUAL
 465                          */
 466                         rewind(collf);
 467                         mesedit(collf, c);
 468                         goto cont;
 469                 }
 470         }
 471         goto out;
 472 err:
 473         if (collf != NULL) {
 474                 Fclose(collf);
 475                 collf = NULL;
 476         }
 477 out:
 478         if (collf != NULL)
 479                 rewind(collf);
 480         noreset--;
 481         sigprocmask(SIG_BLOCK, &nset, NULL);
 482         signal(SIGINT, saveint);
 483         signal(SIGHUP, savehup);
 484         signal(SIGTSTP, savetstp);
 485         signal(SIGTTOU, savettou);
 486         signal(SIGTTIN, savettin);
 487         sigprocmask(SIG_UNBLOCK, &nset, NULL);
 488         return (collf);
 489 }
 490
 491 /*
 492  * Write a file, ex-like if f set.
 493  */
 494 int
 495 exwrite(char *name, FILE *fp, int f)
 496 {
 497         FILE *of;
 498         int c, lc;
 499         long cc;
 500         struct stat junk;
 501
 502         if (f) {
 503                 printf("\"%s\" ", name);
 504                 fflush(stdout);
 505         }
 506         if (stat(name, &junk) >= 0 && S_ISREG(junk.st_mode)) {
 507                 if (!f)
 508                         fprintf(stderr, "%s: ", name);
 509                 fprintf(stderr, "File exists\n");
 510                 return (-1);
 511         }
 512         if ((of = Fopen(name, "w")) == NULL) {
 513                 warn((char *)NULL);
 514                 return (-1);
 515         }
 516         lc = 0;
 517         cc = 0;
 518         while ((c = getc(fp)) != EOF) {
 519                 cc++;
 520                 if (c == '\n')
 521                         lc++;
 522                 putc(c, of);
 523                 if (ferror(of)) {
 524                         warnx("%s", name);
 525                         Fclose(of);
 526                         return (-1);
 527                 }
 528         }
 529         Fclose(of);
 530         printf("%d/%ld\n", lc, cc);
 531         fflush(stdout);
 532         return (0);
 533 }
 534
 535 /*
 536  * Edit the message being collected on fp.
 537  * On return, make the edit file the new temp file.
 538  */
 539 void
 540 mesedit(FILE *fp, int c)
 541 {
 542         sig_t sigint = signal(SIGINT, SIG_IGN);
 543         FILE *nf = run_editor(fp, (off_t)-1, c, 0);
 544
 545         if (nf != NULL) {
 546                 fseeko(nf, (off_t)0, SEEK_END);
 547                 collf = nf;
 548                 Fclose(fp);
 549         }
 550         signal(SIGINT, sigint);
 551 }
 552
 553 /*
 554  * Pipe the message through the command.
 555  * Old message is on stdin of command;
 556  * New message collected from stdout.
 557  * Sh -c must return 0 to accept the new message.
 558  */
 559 void
 560 mespipe(FILE *fp, char *cmd)
 561 {
 562         FILE *nf;
 563         int fd;
 564         sig_t sigint = signal(SIGINT, SIG_IGN);
 565         char *sh, tempname[PATHSIZE];
 566
 567         snprintf(tempname, sizeof(tempname), "%s/mail.ReXXXXXXXXXX", tmpdir);
 568         if ((fd = mkstemp(tempname)) == -1 ||
 569             (nf = Fdopen(fd, "w+")) == NULL) {
 570                 warn("%s", tempname);
 571                 goto out;
 572         }
 573         rm(tempname);
 574         /*
 575          * stdin = current message.
 576          * stdout = new message.
 577          */
 578         if ((sh = value("SHELL")) == NULL)
 579                 sh = _PATH_CSHELL;
 580         if (run_command(sh, 0, fileno(fp), fileno(nf), "-c", cmd, NULL) < 0) {
 581                 Fclose(nf);
 582                 goto out;
 583         }
 584         if (fsize(nf) == 0) {
 585                 fprintf(stderr, "No bytes from \"%s\" !?\n", cmd);
 586                 Fclose(nf);
 587                 goto out;
 588         }
 589         /*
 590          * Take new files.
 591          */
 592         fseeko(nf, (off_t)0, SEEK_END);
 593         collf = nf;
 594         Fclose(fp);
 595 out:
 596         signal(SIGINT, sigint);
 597 }
 598
 599 /*
 600  * Interpolate the named messages into the current
 601  * message, preceding each line with a tab.
 602  * Return a count of the number of characters now in
 603  * the message, or -1 if an error is encountered writing
 604  * the message temporary.  The flag argument is 'm' if we
 605  * should shift over and 'f' if not.
 606  */
 607 int
 608 forward(char *ms, FILE *fp, char *fn, int f)
 609 {
 610         int *msgvec;
 611         struct ignoretab *ig;
 612         char *tabst;
 613
 614         msgvec = (int *)salloc((msgCount+1) * sizeof(*msgvec));
 615         if (msgvec == NULL)
 616                 return (0);
 617         if (getmsglist(ms, msgvec, 0) < 0)
 618                 return (0);
 619         if (*msgvec == 0) {
 620                 *msgvec = first(0, MMNORM);
 621                 if (*msgvec == 0) {
 622                         printf("No appropriate messages\n");
 623                         return (0);
 624                 }
 625                 msgvec[1] = 0;
 626         }
 627         if (f == 'f' || f == 'F')
 628                 tabst = NULL;
 629         else if ((tabst = value("indentprefix")) == NULL)
 630                 tabst = "\t";
 631         ig = isupper((unsigned char)f) ? NULL : ignore;
 632         printf("Interpolating:");
 633         for (; *msgvec != 0; msgvec++) {
 634                 struct message *mp = message + *msgvec - 1;
 635
 636                 touch(mp);
 637                 printf(" %d", *msgvec);
 638                 if (sendmessage(mp, fp, ig, tabst) < 0) {
 639                         warnx("%s", fn);
 640                         return (-1);
 641                 }
 642         }
 643         printf("\n");
 644         return (0);
 645 }
 646
 647 /*
 648  * Print (continue) when continued after ^Z.
 649  */
 650 /*ARGSUSED*/
 651 void
 652 collstop(int s)
 653 {
 654         sig_t old_action = signal(s, SIG_DFL);
 655         sigset_t nset;
 656
 657         sigemptyset(&nset);
 658         sigaddset(&nset, s);
 659         sigprocmask(SIG_UNBLOCK, &nset, NULL);
 660         kill(0, s);
 661         sigprocmask(SIG_BLOCK, &nset, NULL);
 662         signal(s, old_action);
 663         if (colljmp_p) {
 664                 colljmp_p = 0;
 665                 hadintr = 0;
 666                 longjmp(colljmp, 1);
 667         }
 668 }
 669
 670 /*
 671  * On interrupt, come here to save the partial message in ~/dead.letter.
 672  * Then jump out of the collection loop.
 673  */
 674 /*ARGSUSED*/
 675 void
 676 collint(int s)
 677 {
 678         /*
 679          * the control flow is subtle, because we can be called from ~q.
 680          */
 681         if (!hadintr) {
 682                 if (value("ignore") != NULL) {
 683                         printf("@");
 684                         fflush(stdout);
 685                         clearerr(stdin);
 686                         return;
 687                 }
 688                 hadintr = 1;
 689                 longjmp(colljmp, 1);
 690         }
 691         rewind(collf);
 692         if (value("nosave") == NULL)
 693                 savedeadletter(collf);
 694         longjmp(collabort, 1);
 695 }
 696
 697 /*ARGSUSED*/
 698 void
 699 collhup(int s)
 700 {
 701         rewind(collf);
 702         savedeadletter(collf);
 703         /*
 704          * Let's pretend nobody else wants to clean up,
 705          * a true statement at this time.
 706          */
 707         exit(1);
 708 }
 709
 710 void
 711 savedeadletter(FILE *fp)
 712 {
 713         FILE *dbuf;
 714         int c;
 715         char *cp;
 716
 717         if (fsize(fp) == 0)
 718                 return;
 719         cp = getdeadletter();
 720         c = umask(077);
 721         dbuf = Fopen(cp, "a");
 722         umask(c);
 723         if (dbuf == NULL)
 724                 return;
 725         while ((c = getc(fp)) != EOF)
 726                 putc(c, dbuf);
 727         Fclose(dbuf);
 728         rewind(fp);
 729 }