strbuf.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "string-list.h"
   4 #include "utf8.h"
   5
   6 int starts_with(const char *str, const char *prefix)
   7 {
   8         for (; ; str++, prefix++)
   9                 if (!*prefix)
  10                         return 1;
  11                 else if (*str != *prefix)
  12                         return 0;
  13 }
  14
  15 int skip_to_optional_arg_default(const char *str, const char *prefix,
  16                                  const char **arg, const char *def)
  17 {
  18         const char *p;
  19
  20         if (!skip_prefix(str, prefix, &p))
  21                 return 0;
  22
  23         if (!*p) {
  24                 if (arg)
  25                         *arg = def;
  26                 return 1;
  27         }
  28
  29         if (*p != '=')
  30                 return 0;
  31
  32         if (arg)
  33                 *arg = p + 1;
  34         return 1;
  35 }
  36
  37 /*
  38  * Used as the default ->buf value, so that people can always assume
  39  * buf is non NULL and ->buf is NUL terminated even for a freshly
  40  * initialized strbuf.
  41  */
  42 char strbuf_slopbuf[1];
  43
  44 void strbuf_init(struct strbuf *sb, size_t hint)
  45 {
  46         sb->alloc = sb->len = 0;
  47         sb->buf = strbuf_slopbuf;
  48         if (hint)
  49                 strbuf_grow(sb, hint);
  50 }
  51
  52 void strbuf_release(struct strbuf *sb)
  53 {
  54         if (sb->alloc) {
  55                 free(sb->buf);
  56                 strbuf_init(sb, 0);
  57         }
  58 }
  59
  60 char *strbuf_detach(struct strbuf *sb, size_t *sz)
  61 {
  62         char *res;
  63         strbuf_grow(sb, 0);
  64         res = sb->buf;
  65         if (sz)
  66                 *sz = sb->len;
  67         strbuf_init(sb, 0);
  68         return res;
  69 }
  70
  71 void strbuf_attach(struct strbuf *sb, void *buf, size_t len, size_t alloc)
  72 {
  73         strbuf_release(sb);
  74         sb->buf   = buf;
  75         sb->len   = len;
  76         sb->alloc = alloc;
  77         strbuf_grow(sb, 0);
  78         sb->buf[sb->len] = '\0';
  79 }
  80
  81 void strbuf_grow(struct strbuf *sb, size_t extra)
  82 {
  83         int new_buf = !sb->alloc;
  84         if (unsigned_add_overflows(extra, 1) ||
  85             unsigned_add_overflows(sb->len, extra + 1))
  86                 die("you want to use way too much memory");
  87         if (new_buf)
  88                 sb->buf = NULL;
  89         ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
  90         if (new_buf)
  91                 sb->buf[0] = '\0';
  92 }
  93
  94 void strbuf_trim(struct strbuf *sb)
  95 {
  96         strbuf_rtrim(sb);
  97         strbuf_ltrim(sb);
  98 }
  99 void strbuf_rtrim(struct strbuf *sb)
 100 {
 101         while (sb->len > 0 && isspace((unsigned char)sb->buf[sb->len - 1]))
 102                 sb->len--;
 103         sb->buf[sb->len] = '\0';
 104 }
 105
 106 void strbuf_ltrim(struct strbuf *sb)
 107 {
 108         char *b = sb->buf;
 109         while (sb->len > 0 && isspace(*b)) {
 110                 b++;
 111                 sb->len--;
 112         }
 113         memmove(sb->buf, b, sb->len);
 114         sb->buf[sb->len] = '\0';
 115 }
 116
 117 int strbuf_reencode(struct strbuf *sb, const char *from, const char *to)
 118 {
 119         char *out;
 120         int len;
 121
 122         if (same_encoding(from, to))
 123                 return 0;
 124
 125         out = reencode_string_len(sb->buf, sb->len, to, from, &len);
 126         if (!out)
 127                 return -1;
 128
 129         strbuf_attach(sb, out, len, len);
 130         return 0;
 131 }
 132
 133 void strbuf_tolower(struct strbuf *sb)
 134 {
 135         char *p = sb->buf, *end = sb->buf + sb->len;
 136         for (; p < end; p++)
 137                 *p = tolower(*p);
 138 }
 139
 140 struct strbuf **strbuf_split_buf(const char *str, size_t slen,
 141                                  int terminator, int max)
 142 {
 143         struct strbuf **ret = NULL;
 144         size_t nr = 0, alloc = 0;
 145         struct strbuf *t;
 146
 147         while (slen) {
 148                 int len = slen;
 149                 if (max <= 0 || nr + 1 < max) {
 150                         const char *end = memchr(str, terminator, slen);
 151                         if (end)
 152                                 len = end - str + 1;
 153                 }
 154                 t = xmalloc(sizeof(struct strbuf));
 155                 strbuf_init(t, len);
 156                 strbuf_add(t, str, len);
 157                 ALLOC_GROW(ret, nr + 2, alloc);
 158                 ret[nr++] = t;
 159                 str += len;
 160                 slen -= len;
 161         }
 162         ALLOC_GROW(ret, nr + 1, alloc); /* In case string was empty */
 163         ret[nr] = NULL;
 164         return ret;
 165 }
 166
 167 void strbuf_add_separated_string_list(struct strbuf *str,
 168                                       const char *sep,
 169                                       struct string_list *slist)
 170 {
 171         struct string_list_item *item;
 172         int sep_needed = 0;
 173
 174         for_each_string_list_item(item, slist) {
 175                 if (sep_needed)
 176                         strbuf_addstr(str, sep);
 177                 strbuf_addstr(str, item->string);
 178                 sep_needed = 1;
 179         }
 180 }
 181
 182 void strbuf_list_free(struct strbuf **sbs)
 183 {
 184         struct strbuf **s = sbs;
 185
 186         while (*s) {
 187                 strbuf_release(*s);
 188                 free(*s++);
 189         }
 190         free(sbs);
 191 }
 192
 193 int strbuf_cmp(const struct strbuf *a, const struct strbuf *b)
 194 {
 195         int len = a->len < b->len ? a->len: b->len;
 196         int cmp = memcmp(a->buf, b->buf, len);
 197         if (cmp)
 198                 return cmp;
 199         return a->len < b->len ? -1: a->len != b->len;
 200 }
 201
 202 void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
 203                                    const void *data, size_t dlen)
 204 {
 205         if (unsigned_add_overflows(pos, len))
 206                 die("you want to use way too much memory");
 207         if (pos > sb->len)
 208                 die("`pos' is too far after the end of the buffer");
 209         if (pos + len > sb->len)
 210                 die("`pos + len' is too far after the end of the buffer");
 211
 212         if (dlen >= len)
 213                 strbuf_grow(sb, dlen - len);
 214         memmove(sb->buf + pos + dlen,
 215                         sb->buf + pos + len,
 216                         sb->len - pos - len);
 217         memcpy(sb->buf + pos, data, dlen);
 218         strbuf_setlen(sb, sb->len + dlen - len);
 219 }
 220
 221 void strbuf_insert(struct strbuf *sb, size_t pos, const void *data, size_t len)
 222 {
 223         strbuf_splice(sb, pos, 0, data, len);
 224 }
 225
 226 void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
 227 {
 228         strbuf_splice(sb, pos, len, "", 0);
 229 }
 230
 231 void strbuf_add(struct strbuf *sb, const void *data, size_t len)
 232 {
 233         strbuf_grow(sb, len);
 234         memcpy(sb->buf + sb->len, data, len);
 235         strbuf_setlen(sb, sb->len + len);
 236 }
 237
 238 void strbuf_addbuf(struct strbuf *sb, const struct strbuf *sb2)
 239 {
 240         strbuf_grow(sb, sb2->len);
 241         memcpy(sb->buf + sb->len, sb2->buf, sb2->len);
 242         strbuf_setlen(sb, sb->len + sb2->len);
 243 }
 244
 245 void strbuf_addchars(struct strbuf *sb, int c, size_t n)
 246 {
 247         strbuf_grow(sb, n);
 248         memset(sb->buf + sb->len, c, n);
 249         strbuf_setlen(sb, sb->len + n);
 250 }
 251
 252 void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 253 {
 254         va_list ap;
 255         va_start(ap, fmt);
 256         strbuf_vaddf(sb, fmt, ap);
 257         va_end(ap);
 258 }
 259
 260 static void add_lines(struct strbuf *out,
 261                         const char *prefix1,
 262                         const char *prefix2,
 263                         const char *buf, size_t size)
 264 {
 265         while (size) {
 266                 const char *prefix;
 267                 const char *next = memchr(buf, '\n', size);
 268                 next = next ? (next + 1) : (buf + size);
 269
 270                 prefix = ((prefix2 && (buf[0] == '\n' || buf[0] == '\t'))
 271                           ? prefix2 : prefix1);
 272                 strbuf_addstr(out, prefix);
 273                 strbuf_add(out, buf, next - buf);
 274                 size -= next - buf;
 275                 buf = next;
 276         }
 277         strbuf_complete_line(out);
 278 }
 279
 280 void strbuf_add_commented_lines(struct strbuf *out, const char *buf, size_t size)
 281 {
 282         static char prefix1[3];
 283         static char prefix2[2];
 284
 285         if (prefix1[0] != comment_line_char) {
 286                 xsnprintf(prefix1, sizeof(prefix1), "%c ", comment_line_char);
 287                 xsnprintf(prefix2, sizeof(prefix2), "%c", comment_line_char);
 288         }
 289         add_lines(out, prefix1, prefix2, buf, size);
 290 }
 291
 292 void strbuf_commented_addf(struct strbuf *sb, const char *fmt, ...)
 293 {
 294         va_list params;
 295         struct strbuf buf = STRBUF_INIT;
 296         int incomplete_line = sb->len && sb->buf[sb->len - 1] != '\n';
 297
 298         va_start(params, fmt);
 299         strbuf_vaddf(&buf, fmt, params);
 300         va_end(params);
 301
 302         strbuf_add_commented_lines(sb, buf.buf, buf.len);
 303         if (incomplete_line)
 304                 sb->buf[--sb->len] = '\0';
 305
 306         strbuf_release(&buf);
 307 }
 308
 309 void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap)
 310 {
 311         int len;
 312         va_list cp;
 313
 314         if (!strbuf_avail(sb))
 315                 strbuf_grow(sb, 64);
 316         va_copy(cp, ap);
 317         len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, cp);
 318         va_end(cp);
 319         if (len < 0)
 320                 die("BUG: your vsnprintf is broken (returned %d)", len);
 321         if (len > strbuf_avail(sb)) {
 322                 strbuf_grow(sb, len);
 323                 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
 324                 if (len > strbuf_avail(sb))
 325                         die("BUG: your vsnprintf is broken (insatiable)");
 326         }
 327         strbuf_setlen(sb, sb->len + len);
 328 }
 329
 330 void strbuf_expand(struct strbuf *sb, const char *format, expand_fn_t fn,
 331                    void *context)
 332 {
 333         for (;;) {
 334                 const char *percent;
 335                 size_t consumed;
 336
 337                 percent = strchrnul(format, '%');
 338                 strbuf_add(sb, format, percent - format);
 339                 if (!*percent)
 340                         break;
 341                 format = percent + 1;
 342
 343                 if (*format == '%') {
 344                         strbuf_addch(sb, '%');
 345                         format++;
 346                         continue;
 347                 }
 348
 349                 consumed = fn(sb, format, context);
 350                 if (consumed)
 351                         format += consumed;
 352                 else
 353                         strbuf_addch(sb, '%');
 354         }
 355 }
 356
 357 size_t strbuf_expand_dict_cb(struct strbuf *sb, const char *placeholder,
 358                 void *context)
 359 {
 360         struct strbuf_expand_dict_entry *e = context;
 361         size_t len;
 362
 363         for (; e->placeholder && (len = strlen(e->placeholder)); e++) {
 364                 if (!strncmp(placeholder, e->placeholder, len)) {
 365                         if (e->value)
 366                                 strbuf_addstr(sb, e->value);
 367                         return len;
 368                 }
 369         }
 370         return 0;
 371 }
 372
 373 void strbuf_addbuf_percentquote(struct strbuf *dst, const struct strbuf *src)
 374 {
 375         int i, len = src->len;
 376
 377         for (i = 0; i < len; i++) {
 378                 if (src->buf[i] == '%')
 379                         strbuf_addch(dst, '%');
 380                 strbuf_addch(dst, src->buf[i]);
 381         }
 382 }
 383
 384 size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f)
 385 {
 386         size_t res;
 387         size_t oldalloc = sb->alloc;
 388
 389         strbuf_grow(sb, size);
 390         res = fread(sb->buf + sb->len, 1, size, f);
 391         if (res > 0)
 392                 strbuf_setlen(sb, sb->len + res);
 393         else if (oldalloc == 0)
 394                 strbuf_release(sb);
 395         return res;
 396 }
 397
 398 ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
 399 {
 400         size_t oldlen = sb->len;
 401         size_t oldalloc = sb->alloc;
 402
 403         strbuf_grow(sb, hint ? hint : 8192);
 404         for (;;) {
 405                 ssize_t want = sb->alloc - sb->len - 1;
 406                 ssize_t got = read_in_full(fd, sb->buf + sb->len, want);
 407
 408                 if (got < 0) {
 409                         if (oldalloc == 0)
 410                                 strbuf_release(sb);
 411                         else
 412                                 strbuf_setlen(sb, oldlen);
 413                         return -1;
 414                 }
 415                 sb->len += got;
 416                 if (got < want)
 417                         break;
 418                 strbuf_grow(sb, 8192);
 419         }
 420
 421         sb->buf[sb->len] = '\0';
 422         return sb->len - oldlen;
 423 }
 424
 425 ssize_t strbuf_read_once(struct strbuf *sb, int fd, size_t hint)
 426 {
 427         size_t oldalloc = sb->alloc;
 428         ssize_t cnt;
 429
 430         strbuf_grow(sb, hint ? hint : 8192);
 431         cnt = xread(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
 432         if (cnt > 0)
 433                 strbuf_setlen(sb, sb->len + cnt);
 434         else if (oldalloc == 0)
 435                 strbuf_release(sb);
 436         return cnt;
 437 }
 438
 439 ssize_t strbuf_write(struct strbuf *sb, FILE *f)
 440 {
 441         return sb->len ? fwrite(sb->buf, 1, sb->len, f) : 0;
 442 }
 443
 444
 445 #define STRBUF_MAXLINK (2*PATH_MAX)
 446
 447 int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint)
 448 {
 449         size_t oldalloc = sb->alloc;
 450
 451         if (hint < 32)
 452                 hint = 32;
 453
 454         while (hint < STRBUF_MAXLINK) {
 455                 int len;
 456
 457                 strbuf_grow(sb, hint);
 458                 len = readlink(path, sb->buf, hint);
 459                 if (len < 0) {
 460                         if (errno != ERANGE)
 461                                 break;
 462                 } else if (len < hint) {
 463                         strbuf_setlen(sb, len);
 464                         return 0;
 465                 }
 466
 467                 /* .. the buffer was too small - try again */
 468                 hint *= 2;
 469         }
 470         if (oldalloc == 0)
 471                 strbuf_release(sb);
 472         return -1;
 473 }
 474
 475 int strbuf_getcwd(struct strbuf *sb)
 476 {
 477         size_t oldalloc = sb->alloc;
 478         size_t guessed_len = 128;
 479
 480         for (;; guessed_len *= 2) {
 481                 strbuf_grow(sb, guessed_len);
 482                 if (getcwd(sb->buf, sb->alloc)) {
 483                         strbuf_setlen(sb, strlen(sb->buf));
 484                         return 0;
 485                 }
 486
 487                 /*
 488                  * If getcwd(3) is implemented as a syscall that falls
 489                  * back to a regular lookup using readdir(3) etc. then
 490                  * we may be able to avoid EACCES by providing enough
 491                  * space to the syscall as it's not necessarily bound
 492                  * to the same restrictions as the fallback.
 493                  */
 494                 if (errno == EACCES && guessed_len < PATH_MAX)
 495                         continue;
 496
 497                 if (errno != ERANGE)
 498                         break;
 499         }
 500         if (oldalloc == 0)
 501                 strbuf_release(sb);
 502         else
 503                 strbuf_reset(sb);
 504         return -1;
 505 }
 506
 507 #ifdef HAVE_GETDELIM
 508 int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
 509 {
 510         ssize_t r;
 511
 512         if (feof(fp))
 513                 return EOF;
 514
 515         strbuf_reset(sb);
 516
 517         /* Translate slopbuf to NULL, as we cannot call realloc on it */
 518         if (!sb->alloc)
 519                 sb->buf = NULL;
 520         errno = 0;
 521         r = getdelim(&sb->buf, &sb->alloc, term, fp);
 522
 523         if (r > 0) {
 524                 sb->len = r;
 525                 return 0;
 526         }
 527         assert(r == -1);
 528
 529         /*
 530          * Normally we would have called xrealloc, which will try to free
 531          * memory and recover. But we have no way to tell getdelim() to do so.
 532          * Worse, we cannot try to recover ENOMEM ourselves, because we have
 533          * no idea how many bytes were read by getdelim.
 534          *
 535          * Dying here is reasonable. It mirrors what xrealloc would do on
 536          * catastrophic memory failure. We skip the opportunity to free pack
 537          * memory and retry, but that's unlikely to help for a malloc small
 538          * enough to hold a single line of input, anyway.
 539          */
 540         if (errno == ENOMEM)
 541                 die("Out of memory, getdelim failed");
 542
 543         /*
 544          * Restore strbuf invariants; if getdelim left us with a NULL pointer,
 545          * we can just re-init, but otherwise we should make sure that our
 546          * length is empty, and that the result is NUL-terminated.
 547          */
 548         if (!sb->buf)
 549                 strbuf_init(sb, 0);
 550         else
 551                 strbuf_reset(sb);
 552         return EOF;
 553 }
 554 #else
 555 int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
 556 {
 557         int ch;
 558
 559         if (feof(fp))
 560                 return EOF;
 561
 562         strbuf_reset(sb);
 563         flockfile(fp);
 564         while ((ch = getc_unlocked(fp)) != EOF) {
 565                 if (!strbuf_avail(sb))
 566                         strbuf_grow(sb, 1);
 567                 sb->buf[sb->len++] = ch;
 568                 if (ch == term)
 569                         break;
 570         }
 571         funlockfile(fp);
 572         if (ch == EOF && sb->len == 0)
 573                 return EOF;
 574
 575         sb->buf[sb->len] = '\0';
 576         return 0;
 577 }
 578 #endif
 579
 580 static int strbuf_getdelim(struct strbuf *sb, FILE *fp, int term)
 581 {
 582         if (strbuf_getwholeline(sb, fp, term))
 583                 return EOF;
 584         if (sb->buf[sb->len - 1] == term)
 585                 strbuf_setlen(sb, sb->len - 1);
 586         return 0;
 587 }
 588
 589 int strbuf_getline(struct strbuf *sb, FILE *fp)
 590 {
 591         if (strbuf_getwholeline(sb, fp, '\n'))
 592                 return EOF;
 593         if (sb->buf[sb->len - 1] == '\n') {
 594                 strbuf_setlen(sb, sb->len - 1);
 595                 if (sb->len && sb->buf[sb->len - 1] == '\r')
 596                         strbuf_setlen(sb, sb->len - 1);
 597         }
 598         return 0;
 599 }
 600
 601 int strbuf_getline_lf(struct strbuf *sb, FILE *fp)
 602 {
 603         return strbuf_getdelim(sb, fp, '\n');
 604 }
 605
 606 int strbuf_getline_nul(struct strbuf *sb, FILE *fp)
 607 {
 608         return strbuf_getdelim(sb, fp, '\0');
 609 }
 610
 611 int strbuf_getwholeline_fd(struct strbuf *sb, int fd, int term)
 612 {
 613         strbuf_reset(sb);
 614
 615         while (1) {
 616                 char ch;
 617                 ssize_t len = xread(fd, &ch, 1);
 618                 if (len <= 0)
 619                         return EOF;
 620                 strbuf_addch(sb, ch);
 621                 if (ch == term)
 622                         break;
 623         }
 624         return 0;
 625 }
 626
 627 ssize_t strbuf_read_file(struct strbuf *sb, const char *path, size_t hint)
 628 {
 629         int fd;
 630         ssize_t len;
 631
 632         fd = open(path, O_RDONLY);
 633         if (fd < 0)
 634                 return -1;
 635         len = strbuf_read(sb, fd, hint);
 636         close(fd);
 637         if (len < 0)
 638                 return -1;
 639
 640         return len;
 641 }
 642
 643 void strbuf_add_lines(struct strbuf *out, const char *prefix,
 644                       const char *buf, size_t size)
 645 {
 646         add_lines(out, prefix, NULL, buf, size);
 647 }
 648
 649 void strbuf_addstr_xml_quoted(struct strbuf *buf, const char *s)
 650 {
 651         while (*s) {
 652                 size_t len = strcspn(s, "\"<>&");
 653                 strbuf_add(buf, s, len);
 654                 s += len;
 655                 switch (*s) {
 656                 case '"':
 657                         strbuf_addstr(buf, "&quot;");
 658                         break;
 659                 case '<':
 660                         strbuf_addstr(buf, "&lt;");
 661                         break;
 662                 case '>':
 663                         strbuf_addstr(buf, "&gt;");
 664                         break;
 665                 case '&':
 666                         strbuf_addstr(buf, "&amp;");
 667                         break;
 668                 case 0:
 669                         return;
 670                 }
 671                 s++;
 672         }
 673 }
 674
 675 static int is_rfc3986_reserved(char ch)
 676 {
 677         switch (ch) {
 678                 case '!': case '*': case '\'': case '(': case ')': case ';':
 679                 case ':': case '@': case '&': case '=': case '+': case '$':
 680                 case ',': case '/': case '?': case '#': case '[': case ']':
 681                         return 1;
 682         }
 683         return 0;
 684 }
 685
 686 static int is_rfc3986_unreserved(char ch)
 687 {
 688         return isalnum(ch) ||
 689                 ch == '-' || ch == '_' || ch == '.' || ch == '~';
 690 }
 691
 692 static void strbuf_add_urlencode(struct strbuf *sb, const char *s, size_t len,
 693                                  int reserved)
 694 {
 695         strbuf_grow(sb, len);
 696         while (len--) {
 697                 char ch = *s++;
 698                 if (is_rfc3986_unreserved(ch) ||
 699                     (!reserved && is_rfc3986_reserved(ch)))
 700                         strbuf_addch(sb, ch);
 701                 else
 702                         strbuf_addf(sb, "%%%02x", (unsigned char)ch);
 703         }
 704 }
 705
 706 void strbuf_addstr_urlencode(struct strbuf *sb, const char *s,
 707                              int reserved)
 708 {
 709         strbuf_add_urlencode(sb, s, strlen(s), reserved);
 710 }
 711
 712 void strbuf_humanise_bytes(struct strbuf *buf, off_t bytes)
 713 {
 714         if (bytes > 1 << 30) {
 715                 strbuf_addf(buf, "%u.%2.2u GiB",
 716                             (int)(bytes >> 30),
 717                             (int)(bytes & ((1 << 30) - 1)) / 10737419);
 718         } else if (bytes > 1 << 20) {
 719                 int x = bytes + 5243;  /* for rounding */
 720                 strbuf_addf(buf, "%u.%2.2u MiB",
 721                             x >> 20, ((x & ((1 << 20) - 1)) * 100) >> 20);
 722         } else if (bytes > 1 << 10) {
 723                 int x = bytes + 5;  /* for rounding */
 724                 strbuf_addf(buf, "%u.%2.2u KiB",
 725                             x >> 10, ((x & ((1 << 10) - 1)) * 100) >> 10);
 726         } else {
 727                 strbuf_addf(buf, "%u bytes", (int)bytes);
 728         }
 729 }
 730
 731 void strbuf_add_absolute_path(struct strbuf *sb, const char *path)
 732 {
 733         if (!*path)
 734                 die("The empty string is not a valid path");
 735         if (!is_absolute_path(path)) {
 736                 struct stat cwd_stat, pwd_stat;
 737                 size_t orig_len = sb->len;
 738                 char *cwd = xgetcwd();
 739                 char *pwd = getenv("PWD");
 740                 if (pwd && strcmp(pwd, cwd) &&
 741                     !stat(cwd, &cwd_stat) &&
 742                     (cwd_stat.st_dev || cwd_stat.st_ino) &&
 743                     !stat(pwd, &pwd_stat) &&
 744                     pwd_stat.st_dev == cwd_stat.st_dev &&
 745                     pwd_stat.st_ino == cwd_stat.st_ino)
 746                         strbuf_addstr(sb, pwd);
 747                 else
 748                         strbuf_addstr(sb, cwd);
 749                 if (sb->len > orig_len && !is_dir_sep(sb->buf[sb->len - 1]))
 750                         strbuf_addch(sb, '/');
 751                 free(cwd);
 752         }
 753         strbuf_addstr(sb, path);
 754 }
 755
 756 void strbuf_add_real_path(struct strbuf *sb, const char *path)
 757 {
 758         if (sb->len) {
 759                 struct strbuf resolved = STRBUF_INIT;
 760                 strbuf_realpath(&resolved, path, 1);
 761                 strbuf_addbuf(sb, &resolved);
 762                 strbuf_release(&resolved);
 763         } else
 764                 strbuf_realpath(sb, path, 1);
 765 }
 766
 767 int printf_ln(const char *fmt, ...)
 768 {
 769         int ret;
 770         va_list ap;
 771         va_start(ap, fmt);
 772         ret = vprintf(fmt, ap);
 773         va_end(ap);
 774         if (ret < 0 || putchar('\n') == EOF)
 775                 return -1;
 776         return ret + 1;
 777 }
 778
 779 int fprintf_ln(FILE *fp, const char *fmt, ...)
 780 {
 781         int ret;
 782         va_list ap;
 783         va_start(ap, fmt);
 784         ret = vfprintf(fp, fmt, ap);
 785         va_end(ap);
 786         if (ret < 0 || putc('\n', fp) == EOF)
 787                 return -1;
 788         return ret + 1;
 789 }
 790
 791 char *xstrdup_tolower(const char *string)
 792 {
 793         char *result;
 794         size_t len, i;
 795
 796         len = strlen(string);
 797         result = xmallocz(len);
 798         for (i = 0; i < len; i++)
 799                 result[i] = tolower(string[i]);
 800         result[i] = '\0';
 801         return result;
 802 }
 803
 804 char *xstrvfmt(const char *fmt, va_list ap)
 805 {
 806         struct strbuf buf = STRBUF_INIT;
 807         strbuf_vaddf(&buf, fmt, ap);
 808         return strbuf_detach(&buf, NULL);
 809 }
 810
 811 char *xstrfmt(const char *fmt, ...)
 812 {
 813         va_list ap;
 814         char *ret;
 815
 816         va_start(ap, fmt);
 817         ret = xstrvfmt(fmt, ap);
 818         va_end(ap);
 819
 820         return ret;
 821 }
 822
 823 void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm,
 824                      int tz_offset, int suppress_tz_name)
 825 {
 826         struct strbuf munged_fmt = STRBUF_INIT;
 827         size_t hint = 128;
 828         size_t len;
 829
 830         if (!*fmt)
 831                 return;
 832
 833         /*
 834          * There is no portable way to pass timezone information to
 835          * strftime, so we handle %z and %Z here.
 836          */
 837         for (;;) {
 838                 const char *percent = strchrnul(fmt, '%');
 839                 strbuf_add(&munged_fmt, fmt, percent - fmt);
 840                 if (!*percent)
 841                         break;
 842                 fmt = percent + 1;
 843                 switch (*fmt) {
 844                 case '%':
 845                         strbuf_addstr(&munged_fmt, "%%");
 846                         fmt++;
 847                         break;
 848                 case 'z':
 849                         strbuf_addf(&munged_fmt, "%+05d", tz_offset);
 850                         fmt++;
 851                         break;
 852                 case 'Z':
 853                         if (suppress_tz_name) {
 854                                 fmt++;
 855                                 break;
 856                         }
 857                         /* FALLTHROUGH */
 858                 default:
 859                         strbuf_addch(&munged_fmt, '%');
 860                 }
 861         }
 862         fmt = munged_fmt.buf;
 863
 864         strbuf_grow(sb, hint);
 865         len = strftime(sb->buf + sb->len, sb->alloc - sb->len, fmt, tm);
 866
 867         if (!len) {
 868                 /*
 869                  * strftime reports "0" if it could not fit the result in the buffer.
 870                  * Unfortunately, it also reports "0" if the requested time string
 871                  * takes 0 bytes. So our strategy is to munge the format so that the
 872                  * output contains at least one character, and then drop the extra
 873                  * character before returning.
 874                  */
 875                 strbuf_addch(&munged_fmt, ' ');
 876                 while (!len) {
 877                         hint *= 2;
 878                         strbuf_grow(sb, hint);
 879                         len = strftime(sb->buf + sb->len, sb->alloc - sb->len,
 880                                        munged_fmt.buf, tm);
 881                 }
 882                 len--; /* drop munged space */
 883         }
 884         strbuf_release(&munged_fmt);
 885         strbuf_setlen(sb, sb->len + len);
 886 }
 887
 888 void strbuf_add_unique_abbrev(struct strbuf *sb, const unsigned char *sha1,
 889                               int abbrev_len)
 890 {
 891         int r;
 892         strbuf_grow(sb, GIT_SHA1_HEXSZ + 1);
 893         r = find_unique_abbrev_r(sb->buf + sb->len, sha1, abbrev_len);
 894         strbuf_setlen(sb, sb->len + r);
 895 }
 896
 897 /*
 898  * Returns the length of a line, without trailing spaces.
 899  *
 900  * If the line ends with newline, it will be removed too.
 901  */
 902 static size_t cleanup(char *line, size_t len)
 903 {
 904         while (len) {
 905                 unsigned char c = line[len - 1];
 906                 if (!isspace(c))
 907                         break;
 908                 len--;
 909         }
 910
 911         return len;
 912 }
 913
 914 /*
 915  * Remove empty lines from the beginning and end
 916  * and also trailing spaces from every line.
 917  *
 918  * Turn multiple consecutive empty lines between paragraphs
 919  * into just one empty line.
 920  *
 921  * If the input has only empty lines and spaces,
 922  * no output will be produced.
 923  *
 924  * If last line does not have a newline at the end, one is added.
 925  *
 926  * Enable skip_comments to skip every line starting with comment
 927  * character.
 928  */
 929 void strbuf_stripspace(struct strbuf *sb, int skip_comments)
 930 {
 931         int empties = 0;
 932         size_t i, j, len, newlen;
 933         char *eol;
 934
 935         /* We may have to add a newline. */
 936         strbuf_grow(sb, 1);
 937
 938         for (i = j = 0; i < sb->len; i += len, j += newlen) {
 939                 eol = memchr(sb->buf + i, '\n', sb->len - i);
 940                 len = eol ? eol - (sb->buf + i) + 1 : sb->len - i;
 941
 942                 if (skip_comments && len && sb->buf[i] == comment_line_char) {
 943                         newlen = 0;
 944                         continue;
 945                 }
 946                 newlen = cleanup(sb->buf + i, len);
 947
 948                 /* Not just an empty line? */
 949                 if (newlen) {
 950                         if (empties > 0 && j > 0)
 951                                 sb->buf[j++] = '\n';
 952                         empties = 0;
 953                         memmove(sb->buf + j, sb->buf + i, newlen);
 954                         sb->buf[newlen + j++] = '\n';
 955                 } else {
 956                         empties++;
 957                 }
 958         }
 959
 960         strbuf_setlen(sb, j);
 961 }
 962
 963 int strbuf_normalize_path(struct strbuf *src)
 964 {
 965         struct strbuf dst = STRBUF_INIT;
 966
 967         strbuf_grow(&dst, src->len);
 968         if (normalize_path_copy(dst.buf, src->buf) < 0) {
 969                 strbuf_release(&dst);
 970                 return -1;
 971         }
 972
 973         /*
 974          * normalize_path does not tell us the new length, so we have to
 975          * compute it by looking for the new NUL it placed
 976          */
 977         strbuf_setlen(&dst, strlen(dst.buf));
 978         strbuf_swap(src, &dst);
 979         strbuf_release(&dst);
 980         return 0;
 981 }