mailinfo.c

   1 /*
   2  * Another stupid program, this one parsing the headers of an
   3  * email to figure out authorship and subject
   4  */
   5 #define _GNU_SOURCE
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <ctype.h>
  10 #ifndef NO_ICONV
  11 #include <iconv.h>
  12 #endif
  13 #include "git-compat-util.h"
  14 #include "cache.h"
  15
  16 static FILE *cmitmsg, *patchfile;
  17
  18 static int keep_subject = 0;
  19 static char *metainfo_charset = NULL;
  20 static char line[1000];
  21 static char date[1000];
  22 static char name[1000];
  23 static char email[1000];
  24 static char subject[1000];
  25
  26 static enum  {
  27         TE_DONTCARE, TE_QP, TE_BASE64,
  28 } transfer_encoding;
  29 static char charset[256];
  30
  31 static char multipart_boundary[1000];
  32 static int multipart_boundary_len;
  33 static int patch_lines = 0;
  34
  35 static char *sanity_check(char *name, char *email)
  36 {
  37         int len = strlen(name);
  38         if (len < 3 || len > 60)
  39                 return email;
  40         if (strchr(name, '@') || strchr(name, '<') || strchr(name, '>'))
  41                 return email;
  42         return name;
  43 }
  44
  45 static int bogus_from(char *line)
  46 {
  47         /* John Doe <johndoe> */
  48         char *bra, *ket, *dst, *cp;
  49
  50         /* This is fallback, so do not bother if we already have an
  51          * e-mail address.
  52          */
  53         if (*email)
  54                 return 0;
  55
  56         bra = strchr(line, '<');
  57         if (!bra)
  58                 return 0;
  59         ket = strchr(bra, '>');
  60         if (!ket)
  61                 return 0;
  62
  63         for (dst = email, cp = bra+1; cp < ket; )
  64                 *dst++ = *cp++;
  65         *dst = 0;
  66         for (cp = line; isspace(*cp); cp++)
  67                 ;
  68         for (bra--; isspace(*bra); bra--)
  69                 *bra = 0;
  70         cp = sanity_check(cp, email);
  71         strcpy(name, cp);
  72         return 1;
  73 }
  74
  75 static int handle_from(char *in_line)
  76 {
  77         char line[1000];
  78         char *at;
  79         char *dst;
  80
  81         strcpy(line, in_line);
  82         at = strchr(line, '@');
  83         if (!at)
  84                 return bogus_from(line);
  85
  86         /*
  87          * If we already have one email, don't take any confusing lines
  88          */
  89         if (*email && strchr(at+1, '@'))
  90                 return 0;
  91
  92         /* Pick up the string around '@', possibly delimited with <>
  93          * pair; that is the email part.  White them out while copying.
  94          */
  95         while (at > line) {
  96                 char c = at[-1];
  97                 if (isspace(c))
  98                         break;
  99                 if (c == '<') {
 100                         at[-1] = ' ';
 101                         break;
 102                 }
 103                 at--;
 104         }
 105         dst = email;
 106         for (;;) {
 107                 unsigned char c = *at;
 108                 if (!c || c == '>' || isspace(c)) {
 109                         if (c == '>')
 110                                 *at = ' ';
 111                         break;
 112                 }
 113                 *at++ = ' ';
 114                 *dst++ = c;
 115         }
 116         *dst++ = 0;
 117
 118         /* The remainder is name.  It could be "John Doe <john.doe@xz>"
 119          * or "john.doe@xz (John Doe)", but we have whited out the
 120          * email part, so trim from both ends, possibly removing
 121          * the () pair at the end.
 122          */
 123         at = line + strlen(line);
 124         while (at > line) {
 125                 unsigned char c = *--at;
 126                 if (!isspace(c)) {
 127                         at[(c == ')') ? 0 : 1] = 0;
 128                         break;
 129                 }
 130         }
 131
 132         at = line;
 133         for (;;) {
 134                 unsigned char c = *at;
 135                 if (!c || !isspace(c)) {
 136                         if (c == '(')
 137                                 at++;
 138                         break;
 139                 }
 140                 at++;
 141         }
 142         at = sanity_check(at, email);
 143         strcpy(name, at);
 144         return 1;
 145 }
 146
 147 static int handle_date(char *line)
 148 {
 149         strcpy(date, line);
 150         return 0;
 151 }
 152
 153 static int handle_subject(char *line)
 154 {
 155         strcpy(subject, line);
 156         return 0;
 157 }
 158
 159 /* NOTE NOTE NOTE.  We do not claim we do full MIME.  We just attempt
 160  * to have enough heuristics to grok MIME encoded patches often found
 161  * on our mailing lists.  For example, we do not even treat header lines
 162  * case insensitively.
 163  */
 164
 165 static int slurp_attr(const char *line, const char *name, char *attr)
 166 {
 167         char *ends, *ap = strcasestr(line, name);
 168         size_t sz;
 169
 170         if (!ap) {
 171                 *attr = 0;
 172                 return 0;
 173         }
 174         ap += strlen(name);
 175         if (*ap == '"') {
 176                 ap++;
 177                 ends = "\"";
 178         }
 179         else
 180                 ends = "; \t";
 181         sz = strcspn(ap, ends);
 182         memcpy(attr, ap, sz);
 183         attr[sz] = 0;
 184         return 1;
 185 }
 186
 187 static int handle_subcontent_type(char *line)
 188 {
 189         /* We do not want to mess with boundary.  Note that we do not
 190          * handle nested multipart.
 191          */
 192         if (strcasestr(line, "boundary=")) {
 193                 fprintf(stderr, "Not handling nested multipart message.\n");
 194                 exit(1);
 195         }
 196         slurp_attr(line, "charset=", charset);
 197         if (*charset) {
 198                 int i, c;
 199                 for (i = 0; (c = charset[i]) != 0; i++)
 200                         charset[i] = tolower(c);
 201         }
 202         return 0;
 203 }
 204
 205 static int handle_content_type(char *line)
 206 {
 207         *multipart_boundary = 0;
 208         if (slurp_attr(line, "boundary=", multipart_boundary + 2)) {
 209                 memcpy(multipart_boundary, "--", 2);
 210                 multipart_boundary_len = strlen(multipart_boundary);
 211         }
 212         slurp_attr(line, "charset=", charset);
 213         return 0;
 214 }
 215
 216 static int handle_content_transfer_encoding(char *line)
 217 {
 218         if (strcasestr(line, "base64"))
 219                 transfer_encoding = TE_BASE64;
 220         else if (strcasestr(line, "quoted-printable"))
 221                 transfer_encoding = TE_QP;
 222         else
 223                 transfer_encoding = TE_DONTCARE;
 224         return 0;
 225 }
 226
 227 static int is_multipart_boundary(const char *line)
 228 {
 229         return (!memcmp(line, multipart_boundary, multipart_boundary_len));
 230 }
 231
 232 static int eatspace(char *line)
 233 {
 234         int len = strlen(line);
 235         while (len > 0 && isspace(line[len-1]))
 236                 line[--len] = 0;
 237         return len;
 238 }
 239
 240 #define SEEN_FROM 01
 241 #define SEEN_DATE 02
 242 #define SEEN_SUBJECT 04
 243 #define SEEN_BOGUS_UNIX_FROM 010
 244 #define SEEN_PREFIX  020
 245
 246 /* First lines of body can have From:, Date:, and Subject: or empty */
 247 static void handle_inbody_header(int *seen, char *line)
 248 {
 249         if (*seen & SEEN_PREFIX)
 250                 return;
 251         if (isspace(*line)) {
 252                 char *cp;
 253                 for (cp = line + 1; *cp; cp++) {
 254                         if (!isspace(*cp))
 255                                 break;
 256                 }
 257                 if (!*cp)
 258                         return;
 259         }
 260         if (!memcmp(">From", line, 5) && isspace(line[5])) {
 261                 if (!(*seen & SEEN_BOGUS_UNIX_FROM)) {
 262                         *seen |= SEEN_BOGUS_UNIX_FROM;
 263                         return;
 264                 }
 265         }
 266         if (!memcmp("From:", line, 5) && isspace(line[5])) {
 267                 if (!(*seen & SEEN_FROM) && handle_from(line+6)) {
 268                         *seen |= SEEN_FROM;
 269                         return;
 270                 }
 271         }
 272         if (!memcmp("Date:", line, 5) && isspace(line[5])) {
 273                 if (!(*seen & SEEN_DATE)) {
 274                         handle_date(line+6);
 275                         *seen |= SEEN_DATE;
 276                         return;
 277                 }
 278         }
 279         if (!memcmp("Subject:", line, 8) && isspace(line[8])) {
 280                 if (!(*seen & SEEN_SUBJECT)) {
 281                         handle_subject(line+9);
 282                         *seen |= SEEN_SUBJECT;
 283                         return;
 284                 }
 285         }
 286         if (!memcmp("[PATCH]", line, 7) && isspace(line[7])) {
 287                 if (!(*seen & SEEN_SUBJECT)) {
 288                         handle_subject(line);
 289                         *seen |= SEEN_SUBJECT;
 290                         return;
 291                 }
 292         }
 293         *seen |= SEEN_PREFIX;
 294 }
 295
 296 static char *cleanup_subject(char *subject)
 297 {
 298         if (keep_subject)
 299                 return subject;
 300         for (;;) {
 301                 char *p;
 302                 int len, remove;
 303                 switch (*subject) {
 304                 case 'r': case 'R':
 305                         if (!memcmp("e:", subject+1, 2)) {
 306                                 subject +=3;
 307                                 continue;
 308                         }
 309                         break;
 310                 case ' ': case '\t': case ':':
 311                         subject++;
 312                         continue;
 313
 314                 case '[':
 315                         p = strchr(subject, ']');
 316                         if (!p) {
 317                                 subject++;
 318                                 continue;
 319                         }
 320                         len = strlen(p);
 321                         remove = p - subject;
 322                         if (remove <= len *2) {
 323                                 subject = p+1;
 324                                 continue;
 325                         }
 326                         break;
 327                 }
 328                 eatspace(subject);
 329                 return subject;
 330         }
 331 }
 332
 333 static void cleanup_space(char *buf)
 334 {
 335         unsigned char c;
 336         while ((c = *buf) != 0) {
 337                 buf++;
 338                 if (isspace(c)) {
 339                         buf[-1] = ' ';
 340                         c = *buf;
 341                         while (isspace(c)) {
 342                                 int len = strlen(buf);
 343                                 memmove(buf, buf+1, len);
 344                                 c = *buf;
 345                         }
 346                 }
 347         }
 348 }
 349
 350 static void decode_header_bq(char *it);
 351 typedef int (*header_fn_t)(char *);
 352 struct header_def {
 353         const char *name;
 354         header_fn_t func;
 355         int namelen;
 356 };
 357
 358 static void check_header(char *line, struct header_def *header)
 359 {
 360         int i;
 361
 362         if (header[0].namelen <= 0) {
 363                 for (i = 0; header[i].name; i++)
 364                         header[i].namelen = strlen(header[i].name);
 365         }
 366         for (i = 0; header[i].name; i++) {
 367                 int len = header[i].namelen;
 368                 if (!strncasecmp(line, header[i].name, len) &&
 369                     line[len] == ':' && isspace(line[len + 1])) {
 370                         /* Unwrap inline B and Q encoding, and optionally
 371                          * normalize the meta information to utf8.
 372                          */
 373                         decode_header_bq(line + len + 2);
 374                         header[i].func(line + len + 2);
 375                         break;
 376                 }
 377         }
 378 }
 379
 380 static void check_subheader_line(char *line)
 381 {
 382         static struct header_def header[] = {
 383                 { "Content-Type", handle_subcontent_type },
 384                 { "Content-Transfer-Encoding",
 385                   handle_content_transfer_encoding },
 386                 { NULL },
 387         };
 388         check_header(line, header);
 389 }
 390 static void check_header_line(char *line)
 391 {
 392         static struct header_def header[] = {
 393                 { "From", handle_from },
 394                 { "Date", handle_date },
 395                 { "Subject", handle_subject },
 396                 { "Content-Type", handle_content_type },
 397                 { "Content-Transfer-Encoding",
 398                   handle_content_transfer_encoding },
 399                 { NULL },
 400         };
 401         check_header(line, header);
 402 }
 403
 404 static int is_rfc2822_header(char *line)
 405 {
 406         /*
 407          * The section that defines the loosest possible
 408          * field name is "3.6.8 Optional fields".
 409          *
 410          * optional-field = field-name ":" unstructured CRLF
 411          * field-name = 1*ftext
 412          * ftext = %d33-57 / %59-126
 413          */
 414         int ch;
 415         char *cp = line;
 416         while ((ch = *cp++)) {
 417                 if (ch == ':')
 418                         return cp != line;
 419                 if ((33 <= ch && ch <= 57) ||
 420                     (59 <= ch && ch <= 126))
 421                         continue;
 422                 break;
 423         }
 424         return 0;
 425 }
 426
 427 static int read_one_header_line(char *line, int sz, FILE *in)
 428 {
 429         int ofs = 0;
 430         while (ofs < sz) {
 431                 int peek, len;
 432                 if (fgets(line + ofs, sz - ofs, in) == NULL)
 433                         break;
 434                 len = eatspace(line + ofs);
 435                 if ((len == 0) || !is_rfc2822_header(line)) {
 436                         /* Re-add the newline */
 437                         line[ofs + len] = '\n';
 438                         line[ofs + len + 1] = '\0';
 439                         break;
 440                 }
 441                 ofs += len;
 442                 /* Yuck, 2822 header "folding" */
 443                 peek = fgetc(in); ungetc(peek, in);
 444                 if (peek != ' ' && peek != '\t')
 445                         break;
 446         }
 447         /* Count mbox From headers as headers */
 448         if (!ofs && !memcmp(line, "From ", 5))
 449                 ofs = 1;
 450         return ofs;
 451 }
 452
 453 static unsigned hexval(int c)
 454 {
 455         if (c >= '0' && c <= '9')
 456                 return c - '0';
 457         if (c >= 'a' && c <= 'f')
 458                 return c - 'a' + 10;
 459         if (c >= 'A' && c <= 'F')
 460                 return c - 'A' + 10;
 461         return ~0;
 462 }
 463
 464 static int decode_q_segment(char *in, char *ot, char *ep, int rfc2047)
 465 {
 466         int c;
 467         while ((c = *in++) != 0 && (in <= ep)) {
 468                 if (c == '=') {
 469                         int d = *in++;
 470                         if (d == '\n' || !d)
 471                                 break; /* drop trailing newline */
 472                         *ot++ = ((hexval(d) << 4) | hexval(*in++));
 473                         continue;
 474                 }
 475                 if (rfc2047 && c == '_') /* rfc2047 4.2 (2) */
 476                         c = 0x20;
 477                 *ot++ = c;
 478         }
 479         *ot = 0;
 480         return 0;
 481 }
 482
 483 static int decode_b_segment(char *in, char *ot, char *ep)
 484 {
 485         /* Decode in..ep, possibly in-place to ot */
 486         int c, pos = 0, acc = 0;
 487
 488         while ((c = *in++) != 0 && (in <= ep)) {
 489                 if (c == '+')
 490                         c = 62;
 491                 else if (c == '/')
 492                         c = 63;
 493                 else if ('A' <= c && c <= 'Z')
 494                         c -= 'A';
 495                 else if ('a' <= c && c <= 'z')
 496                         c -= 'a' - 26;
 497                 else if ('0' <= c && c <= '9')
 498                         c -= '0' - 52;
 499                 else if (c == '=') {
 500                         /* padding is almost like (c == 0), except we do
 501                          * not output NUL resulting only from it;
 502                          * for now we just trust the data.
 503                          */
 504                         c = 0;
 505                 }
 506                 else
 507                         continue; /* garbage */
 508                 switch (pos++) {
 509                 case 0:
 510                         acc = (c << 2);
 511                         break;
 512                 case 1:
 513                         *ot++ = (acc | (c >> 4));
 514                         acc = (c & 15) << 4;
 515                         break;
 516                 case 2:
 517                         *ot++ = (acc | (c >> 2));
 518                         acc = (c & 3) << 6;
 519                         break;
 520                 case 3:
 521                         *ot++ = (acc | c);
 522                         acc = pos = 0;
 523                         break;
 524                 }
 525         }
 526         *ot = 0;
 527         return 0;
 528 }
 529
 530 static void convert_to_utf8(char *line, char *charset)
 531 {
 532 #ifndef NO_ICONV
 533         char *in, *out;
 534         size_t insize, outsize, nrc;
 535         char outbuf[4096]; /* cheat */
 536         static char latin_one[] = "latin1";
 537         char *input_charset = *charset ? charset : latin_one;
 538         iconv_t conv = iconv_open(metainfo_charset, input_charset);
 539
 540         if (conv == (iconv_t) -1) {
 541                 static int warned_latin1_once = 0;
 542                 if (input_charset != latin_one) {
 543                         fprintf(stderr, "cannot convert from %s to %s\n",
 544                                 input_charset, metainfo_charset);
 545                         *charset = 0;
 546                 }
 547                 else if (!warned_latin1_once) {
 548                         warned_latin1_once = 1;
 549                         fprintf(stderr, "tried to convert from %s to %s, "
 550                                 "but your iconv does not work with it.\n",
 551                                 input_charset, metainfo_charset);
 552                 }
 553                 return;
 554         }
 555         in = line;
 556         insize = strlen(in);
 557         out = outbuf;
 558         outsize = sizeof(outbuf);
 559         nrc = iconv(conv, &in, &insize, &out, &outsize);
 560         iconv_close(conv);
 561         if (nrc == (size_t) -1)
 562                 return;
 563         *out = 0;
 564         strcpy(line, outbuf);
 565 #endif
 566 }
 567
 568 static void decode_header_bq(char *it)
 569 {
 570         char *in, *out, *ep, *cp, *sp;
 571         char outbuf[1000];
 572
 573         in = it;
 574         out = outbuf;
 575         while ((ep = strstr(in, "=?")) != NULL) {
 576                 int sz, encoding;
 577                 char charset_q[256], piecebuf[256];
 578                 if (in != ep) {
 579                         sz = ep - in;
 580                         memcpy(out, in, sz);
 581                         out += sz;
 582                         in += sz;
 583                 }
 584                 /* E.g.
 585                  * ep : "=?iso-2022-jp?B?GyR...?= foo"
 586                  * ep : "=?ISO-8859-1?Q?Foo=FCbar?= baz"
 587                  */
 588                 ep += 2;
 589                 cp = strchr(ep, '?');
 590                 if (!cp)
 591                         return; /* no munging */
 592                 for (sp = ep; sp < cp; sp++)
 593                         charset_q[sp - ep] = tolower(*sp);
 594                 charset_q[cp - ep] = 0;
 595                 encoding = cp[1];
 596                 if (!encoding || cp[2] != '?')
 597                         return; /* no munging */
 598                 ep = strstr(cp + 3, "?=");
 599                 if (!ep)
 600                         return; /* no munging */
 601                 switch (tolower(encoding)) {
 602                 default:
 603                         return; /* no munging */
 604                 case 'b':
 605                         sz = decode_b_segment(cp + 3, piecebuf, ep);
 606                         break;
 607                 case 'q':
 608                         sz = decode_q_segment(cp + 3, piecebuf, ep, 1);
 609                         break;
 610                 }
 611                 if (sz < 0)
 612                         return;
 613                 if (metainfo_charset)
 614                         convert_to_utf8(piecebuf, charset_q);
 615                 strcpy(out, piecebuf);
 616                 out += strlen(out);
 617                 in = ep + 2;
 618         }
 619         strcpy(out, in);
 620         strcpy(it, outbuf);
 621 }
 622
 623 static void decode_transfer_encoding(char *line)
 624 {
 625         char *ep;
 626
 627         switch (transfer_encoding) {
 628         case TE_QP:
 629                 ep = line + strlen(line);
 630                 decode_q_segment(line, line, ep, 0);
 631                 break;
 632         case TE_BASE64:
 633                 ep = line + strlen(line);
 634                 decode_b_segment(line, line, ep);
 635                 break;
 636         case TE_DONTCARE:
 637                 break;
 638         }
 639 }
 640
 641 static void handle_info(void)
 642 {
 643         char *sub;
 644
 645         sub = cleanup_subject(subject);
 646         cleanup_space(name);
 647         cleanup_space(date);
 648         cleanup_space(email);
 649         cleanup_space(sub);
 650
 651         printf("Author: %s\nEmail: %s\nSubject: %s\nDate: %s\n\n",
 652                name, email, sub, date);
 653 }
 654
 655 /* We are inside message body and have read line[] already.
 656  * Spit out the commit log.
 657  */
 658 static int handle_commit_msg(int *seen)
 659 {
 660         if (!cmitmsg)
 661                 return 0;
 662         do {
 663                 if (!memcmp("diff -", line, 6) ||
 664                     !memcmp("---", line, 3) ||
 665                     !memcmp("Index: ", line, 7))
 666                         break;
 667                 if ((multipart_boundary[0] && is_multipart_boundary(line))) {
 668                         /* We come here when the first part had only
 669                          * the commit message without any patch.  We
 670                          * pretend we have not seen this line yet, and
 671                          * go back to the loop.
 672                          */
 673                         return 1;
 674                 }
 675
 676                 /* Unwrap transfer encoding and optionally
 677                  * normalize the log message to UTF-8.
 678                  */
 679                 decode_transfer_encoding(line);
 680                 if (metainfo_charset)
 681                         convert_to_utf8(line, charset);
 682
 683                 handle_inbody_header(seen, line);
 684                 if (!(*seen & SEEN_PREFIX))
 685                         continue;
 686
 687                 fputs(line, cmitmsg);
 688         } while (fgets(line, sizeof(line), stdin) != NULL);
 689         fclose(cmitmsg);
 690         cmitmsg = NULL;
 691         return 0;
 692 }
 693
 694 /* We have done the commit message and have the first
 695  * line of the patch in line[].
 696  */
 697 static void handle_patch(void)
 698 {
 699         do {
 700                 if (multipart_boundary[0] && is_multipart_boundary(line))
 701                         break;
 702                 /* Only unwrap transfer encoding but otherwise do not
 703                  * do anything.  We do *NOT* want UTF-8 conversion
 704                  * here; we are dealing with the user payload.
 705                  */
 706                 decode_transfer_encoding(line);
 707                 fputs(line, patchfile);
 708                 patch_lines++;
 709         } while (fgets(line, sizeof(line), stdin) != NULL);
 710 }
 711
 712 /* multipart boundary and transfer encoding are set up for us, and we
 713  * are at the end of the sub header.  do equivalent of handle_body up
 714  * to the next boundary without closing patchfile --- we will expect
 715  * that the first part to contain commit message and a patch, and
 716  * handle other parts as pure patches.
 717  */
 718 static int handle_multipart_one_part(int *seen)
 719 {
 720         int n = 0;
 721
 722         while (fgets(line, sizeof(line), stdin) != NULL) {
 723         again:
 724                 n++;
 725                 if (is_multipart_boundary(line))
 726                         break;
 727                 if (handle_commit_msg(seen))
 728                         goto again;
 729                 handle_patch();
 730                 break;
 731         }
 732         if (n == 0)
 733                 return -1;
 734         return 0;
 735 }
 736
 737 static void handle_multipart_body(void)
 738 {
 739         int seen = 0;
 740         int part_num = 0;
 741
 742         /* Skip up to the first boundary */
 743         while (fgets(line, sizeof(line), stdin) != NULL)
 744                 if (is_multipart_boundary(line)) {
 745                         part_num = 1;
 746                         break;
 747                 }
 748         if (!part_num)
 749                 return;
 750         /* We are on boundary line.  Start slurping the subhead. */
 751         while (1) {
 752                 int hdr = read_one_header_line(line, sizeof(line), stdin);
 753                 if (!hdr) {
 754                         if (handle_multipart_one_part(&seen) < 0)
 755                                 return;
 756                         /* Reset per part headers */
 757                         transfer_encoding = TE_DONTCARE;
 758                         charset[0] = 0;
 759                 }
 760                 else
 761                         check_subheader_line(line);
 762         }
 763         fclose(patchfile);
 764         if (!patch_lines) {
 765                 fprintf(stderr, "No patch found\n");
 766                 exit(1);
 767         }
 768 }
 769
 770 /* Non multipart message */
 771 static void handle_body(void)
 772 {
 773         int seen = 0;
 774
 775         handle_commit_msg(&seen);
 776         handle_patch();
 777         fclose(patchfile);
 778         if (!patch_lines) {
 779                 fprintf(stderr, "No patch found\n");
 780                 exit(1);
 781         }
 782 }
 783
 784 static const char mailinfo_usage[] =
 785         "git-mailinfo [-k] [-u | --encoding=<encoding>] msg patch <mail >info";
 786
 787 int main(int argc, char **argv)
 788 {
 789         /* NEEDSWORK: might want to do the optional .git/ directory
 790          * discovery
 791          */
 792         git_config(git_default_config);
 793
 794         while (1 < argc && argv[1][0] == '-') {
 795                 if (!strcmp(argv[1], "-k"))
 796                         keep_subject = 1;
 797                 else if (!strcmp(argv[1], "-u"))
 798                         metainfo_charset = git_commit_encoding;
 799                 else if (!strncmp(argv[1], "--encoding=", 11))
 800                         metainfo_charset = argv[1] + 11;
 801                 else
 802                         usage(mailinfo_usage);
 803                 argc--; argv++;
 804         }
 805
 806         if (argc != 3)
 807                 usage(mailinfo_usage);
 808         cmitmsg = fopen(argv[1], "w");
 809         if (!cmitmsg) {
 810                 perror(argv[1]);
 811                 exit(1);
 812         }
 813         patchfile = fopen(argv[2], "w");
 814         if (!patchfile) {
 815                 perror(argv[2]);
 816                 exit(1);
 817         }
 818         while (1) {
 819                 int hdr = read_one_header_line(line, sizeof(line), stdin);
 820                 if (!hdr) {
 821                         if (multipart_boundary[0])
 822                                 handle_multipart_body();
 823                         else
 824                                 handle_body();
 825                         handle_info();
 826                         break;
 827                 }
 828                 check_header_line(line);
 829         }
 830         return 0;
 831 }