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
 100 void strbuf_rtrim(struct strbuf *sb)
 101 {
 102         while (sb->len > 0 && isspace((unsigned char)sb->buf[sb->len - 1]))
 103                 sb->len--;
 104         sb->buf[sb->len] = '\0';
 105 }
 106
 107 void strbuf_trim_trailing_dir_sep(struct strbuf *sb)
 108 {
 109         while (sb->len > 0 && is_dir_sep((unsigned char)sb->buf[sb->len - 1]))
 110                 sb->len--;
 111         sb->buf[sb->len] = '\0';
 112 }
 113
 114 void strbuf_ltrim(struct strbuf *sb)
 115 {
 116         char *b = sb->buf;
 117         while (sb->len > 0 && isspace(*b)) {
 118                 b++;
 119                 sb->len--;
 120         }
 121         memmove(sb->buf, b, sb->len);
 122         sb->buf[sb->len] = '\0';
 123 }
 124
 125 int strbuf_reencode(struct strbuf *sb, const char *from, const char *to)
 126 {
 127         char *out;
 128         int len;
 129
 130         if (same_encoding(from, to))
 131                 return 0;
 132
 133         out = reencode_string_len(sb->buf, sb->len, to, from, &len);
 134         if (!out)
 135                 return -1;
 136
 137         strbuf_attach(sb, out, len, len);
 138         return 0;
 139 }
 140
 141 void strbuf_tolower(struct strbuf *sb)
 142 {
 143         char *p = sb->buf, *end = sb->buf + sb->len;
 144         for (; p < end; p++)
 145                 *p = tolower(*p);
 146 }
 147
 148 struct strbuf **strbuf_split_buf(const char *str, size_t slen,
 149                                  int terminator, int max)
 150 {
 151         struct strbuf **ret = NULL;
 152         size_t nr = 0, alloc = 0;
 153         struct strbuf *t;
 154
 155         while (slen) {
 156                 int len = slen;
 157                 if (max <= 0 || nr + 1 < max) {
 158                         const char *end = memchr(str, terminator, slen);
 159                         if (end)
 160                                 len = end - str + 1;
 161                 }
 162                 t = xmalloc(sizeof(struct strbuf));
 163                 strbuf_init(t, len);
 164                 strbuf_add(t, str, len);
 165                 ALLOC_GROW(ret, nr + 2, alloc);
 166                 ret[nr++] = t;
 167                 str += len;
 168                 slen -= len;
 169         }
 170         ALLOC_GROW(ret, nr + 1, alloc); /* In case string was empty */
 171         ret[nr] = NULL;
 172         return ret;
 173 }
 174
 175 void strbuf_add_separated_string_list(struct strbuf *str,
 176                                       const char *sep,
 177                                       struct string_list *slist)
 178 {
 179         struct string_list_item *item;
 180         int sep_needed = 0;
 181
 182         for_each_string_list_item(item, slist) {
 183                 if (sep_needed)
 184                         strbuf_addstr(str, sep);
 185                 strbuf_addstr(str, item->string);
 186                 sep_needed = 1;
 187         }
 188 }
 189
 190 void strbuf_list_free(struct strbuf **sbs)
 191 {
 192         struct strbuf **s = sbs;
 193
 194         while (*s) {
 195                 strbuf_release(*s);
 196                 free(*s++);
 197         }
 198         free(sbs);
 199 }
 200
 201 int strbuf_cmp(const struct strbuf *a, const struct strbuf *b)
 202 {
 203         int len = a->len < b->len ? a->len: b->len;
 204         int cmp = memcmp(a->buf, b->buf, len);
 205         if (cmp)
 206                 return cmp;
 207         return a->len < b->len ? -1: a->len != b->len;
 208 }
 209
 210 void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
 211                                    const void *data, size_t dlen)
 212 {
 213         if (unsigned_add_overflows(pos, len))
 214                 die("you want to use way too much memory");
 215         if (pos > sb->len)
 216                 die("`pos' is too far after the end of the buffer");
 217         if (pos + len > sb->len)
 218                 die("`pos + len' is too far after the end of the buffer");
 219
 220         if (dlen >= len)
 221                 strbuf_grow(sb, dlen - len);
 222         memmove(sb->buf + pos + dlen,
 223                         sb->buf + pos + len,
 224                         sb->len - pos - len);
 225         memcpy(sb->buf + pos, data, dlen);
 226         strbuf_setlen(sb, sb->len + dlen - len);
 227 }
 228
 229 void strbuf_insert(struct strbuf *sb, size_t pos, const void *data, size_t len)
 230 {
 231         strbuf_splice(sb, pos, 0, data, len);
 232 }
 233
 234 void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
 235 {
 236         strbuf_splice(sb, pos, len, "", 0);
 237 }
 238
 239 void strbuf_add(struct strbuf *sb, const void *data, size_t len)
 240 {
 241         strbuf_grow(sb, len);
 242         memcpy(sb->buf + sb->len, data, len);
 243         strbuf_setlen(sb, sb->len + len);
 244 }
 245
 246 void strbuf_addbuf(struct strbuf *sb, const struct strbuf *sb2)
 247 {
 248         strbuf_grow(sb, sb2->len);
 249         memcpy(sb->buf + sb->len, sb2->buf, sb2->len);
 250         strbuf_setlen(sb, sb->len + sb2->len);
 251 }
 252
 253 void strbuf_addchars(struct strbuf *sb, int c, size_t n)
 254 {
 255         strbuf_grow(sb, n);
 256         memset(sb->buf + sb->len, c, n);
 257         strbuf_setlen(sb, sb->len + n);
 258 }
 259
 260 void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 261 {
 262         va_list ap;
 263         va_start(ap, fmt);
 264         strbuf_vaddf(sb, fmt, ap);
 265         va_end(ap);
 266 }
 267
 268 static void add_lines(struct strbuf *out,
 269                         const char *prefix1,
 270                         const char *prefix2,
 271                         const char *buf, size_t size)
 272 {
 273         while (size) {
 274                 const char *prefix;
 275                 const char *next = memchr(buf, '\n', size);
 276                 next = next ? (next + 1) : (buf + size);
 277
 278                 prefix = ((prefix2 && (buf[0] == '\n' || buf[0] == '\t'))
 279                           ? prefix2 : prefix1);
 280                 strbuf_addstr(out, prefix);
 281                 strbuf_add(out, buf, next - buf);
 282                 size -= next - buf;
 283                 buf = next;
 284         }
 285         strbuf_complete_line(out);
 286 }
 287
 288 void strbuf_add_commented_lines(struct strbuf *out, const char *buf, size_t size)
 289 {
 290         static char prefix1[3];
 291         static char prefix2[2];
 292
 293         if (prefix1[0] != comment_line_char) {
 294                 xsnprintf(prefix1, sizeof(prefix1), "%c ", comment_line_char);
 295                 xsnprintf(prefix2, sizeof(prefix2), "%c", comment_line_char);
 296         }
 297         add_lines(out, prefix1, prefix2, buf, size);
 298 }
 299
 300 void strbuf_commented_addf(struct strbuf *sb, const char *fmt, ...)
 301 {
 302         va_list params;
 303         struct strbuf buf = STRBUF_INIT;
 304         int incomplete_line = sb->len && sb->buf[sb->len - 1] != '\n';
 305
 306         va_start(params, fmt);
 307         strbuf_vaddf(&buf, fmt, params);
 308         va_end(params);
 309
 310         strbuf_add_commented_lines(sb, buf.buf, buf.len);
 311         if (incomplete_line)
 312                 sb->buf[--sb->len] = '\0';
 313
 314         strbuf_release(&buf);
 315 }
 316
 317 void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap)
 318 {
 319         int len;
 320         va_list cp;
 321
 322         if (!strbuf_avail(sb))
 323                 strbuf_grow(sb, 64);
 324         va_copy(cp, ap);
 325         len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, cp);
 326         va_end(cp);
 327         if (len < 0)
 328                 die("BUG: your vsnprintf is broken (returned %d)", len);
 329         if (len > strbuf_avail(sb)) {
 330                 strbuf_grow(sb, len);
 331                 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
 332                 if (len > strbuf_avail(sb))
 333                         die("BUG: your vsnprintf is broken (insatiable)");
 334         }
 335         strbuf_setlen(sb, sb->len + len);
 336 }
 337
 338 void strbuf_expand(struct strbuf *sb, const char *format, expand_fn_t fn,
 339                    void *context)
 340 {
 341         for (;;) {
 342                 const char *percent;
 343                 size_t consumed;
 344
 345                 percent = strchrnul(format, '%');
 346                 strbuf_add(sb, format, percent - format);
 347                 if (!*percent)
 348                         break;
 349                 format = percent + 1;
 350
 351                 if (*format == '%') {
 352                         strbuf_addch(sb, '%');
 353                         format++;
 354                         continue;
 355                 }
 356
 357                 consumed = fn(sb, format, context);
 358                 if (consumed)
 359                         format += consumed;
 360                 else
 361                         strbuf_addch(sb, '%');
 362         }
 363 }
 364
 365 size_t strbuf_expand_dict_cb(struct strbuf *sb, const char *placeholder,
 366                 void *context)
 367 {
 368         struct strbuf_expand_dict_entry *e = context;
 369         size_t len;
 370
 371         for (; e->placeholder && (len = strlen(e->placeholder)); e++) {
 372                 if (!strncmp(placeholder, e->placeholder, len)) {
 373                         if (e->value)
 374                                 strbuf_addstr(sb, e->value);
 375                         return len;
 376                 }
 377         }
 378         return 0;
 379 }
 380
 381 void strbuf_addbuf_percentquote(struct strbuf *dst, const struct strbuf *src)
 382 {
 383         int i, len = src->len;
 384
 385         for (i = 0; i < len; i++) {
 386                 if (src->buf[i] == '%')
 387                         strbuf_addch(dst, '%');
 388                 strbuf_addch(dst, src->buf[i]);
 389         }
 390 }
 391
 392 size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f)
 393 {
 394         size_t res;
 395         size_t oldalloc = sb->alloc;
 396
 397         strbuf_grow(sb, size);
 398         res = fread(sb->buf + sb->len, 1, size, f);
 399         if (res > 0)
 400                 strbuf_setlen(sb, sb->len + res);
 401         else if (oldalloc == 0)
 402                 strbuf_release(sb);
 403         return res;
 404 }
 405
 406 ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
 407 {
 408         size_t oldlen = sb->len;
 409         size_t oldalloc = sb->alloc;
 410
 411         strbuf_grow(sb, hint ? hint : 8192);
 412         for (;;) {
 413                 ssize_t want = sb->alloc - sb->len - 1;
 414                 ssize_t got = read_in_full(fd, sb->buf + sb->len, want);
 415
 416                 if (got < 0) {
 417                         if (oldalloc == 0)
 418                                 strbuf_release(sb);
 419                         else
 420                                 strbuf_setlen(sb, oldlen);
 421                         return -1;
 422                 }
 423                 sb->len += got;
 424                 if (got < want)
 425                         break;
 426                 strbuf_grow(sb, 8192);
 427         }
 428
 429         sb->buf[sb->len] = '\0';
 430         return sb->len - oldlen;
 431 }
 432
 433 ssize_t strbuf_read_once(struct strbuf *sb, int fd, size_t hint)
 434 {
 435         size_t oldalloc = sb->alloc;
 436         ssize_t cnt;
 437
 438         strbuf_grow(sb, hint ? hint : 8192);
 439         cnt = xread(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
 440         if (cnt > 0)
 441                 strbuf_setlen(sb, sb->len + cnt);
 442         else if (oldalloc == 0)
 443                 strbuf_release(sb);
 444         return cnt;
 445 }
 446
 447 ssize_t strbuf_write(struct strbuf *sb, FILE *f)
 448 {
 449         return sb->len ? fwrite(sb->buf, 1, sb->len, f) : 0;
 450 }
 451
 452
 453 #define STRBUF_MAXLINK (2*PATH_MAX)
 454
 455 int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint)
 456 {
 457         size_t oldalloc = sb->alloc;
 458
 459         if (hint < 32)
 460                 hint = 32;
 461
 462         while (hint < STRBUF_MAXLINK) {
 463                 int len;
 464
 465                 strbuf_grow(sb, hint);
 466                 len = readlink(path, sb->buf, hint);
 467                 if (len < 0) {
 468                         if (errno != ERANGE)
 469                                 break;
 470                 } else if (len < hint) {
 471                         strbuf_setlen(sb, len);
 472                         return 0;
 473                 }
 474
 475                 /* .. the buffer was too small - try again */
 476                 hint *= 2;
 477         }
 478         if (oldalloc == 0)
 479                 strbuf_release(sb);
 480         return -1;
 481 }
 482
 483 int strbuf_getcwd(struct strbuf *sb)
 484 {
 485         size_t oldalloc = sb->alloc;
 486         size_t guessed_len = 128;
 487
 488         for (;; guessed_len *= 2) {
 489                 strbuf_grow(sb, guessed_len);
 490                 if (getcwd(sb->buf, sb->alloc)) {
 491                         strbuf_setlen(sb, strlen(sb->buf));
 492                         return 0;
 493                 }
 494
 495                 /*
 496                  * If getcwd(3) is implemented as a syscall that falls
 497                  * back to a regular lookup using readdir(3) etc. then
 498                  * we may be able to avoid EACCES by providing enough
 499                  * space to the syscall as it's not necessarily bound
 500                  * to the same restrictions as the fallback.
 501                  */
 502                 if (errno == EACCES && guessed_len < PATH_MAX)
 503                         continue;
 504
 505                 if (errno != ERANGE)
 506                         break;
 507         }
 508         if (oldalloc == 0)
 509                 strbuf_release(sb);
 510         else
 511                 strbuf_reset(sb);
 512         return -1;
 513 }
 514
 515 #ifdef HAVE_GETDELIM
 516 int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
 517 {
 518         ssize_t r;
 519
 520         if (feof(fp))
 521                 return EOF;
 522
 523         strbuf_reset(sb);
 524
 525         /* Translate slopbuf to NULL, as we cannot call realloc on it */
 526         if (!sb->alloc)
 527                 sb->buf = NULL;
 528         errno = 0;
 529         r = getdelim(&sb->buf, &sb->alloc, term, fp);
 530
 531         if (r > 0) {
 532                 sb->len = r;
 533                 return 0;
 534         }
 535         assert(r == -1);
 536
 537         /*
 538          * Normally we would have called xrealloc, which will try to free
 539          * memory and recover. But we have no way to tell getdelim() to do so.
 540          * Worse, we cannot try to recover ENOMEM ourselves, because we have
 541          * no idea how many bytes were read by getdelim.
 542          *
 543          * Dying here is reasonable. It mirrors what xrealloc would do on
 544          * catastrophic memory failure. We skip the opportunity to free pack
 545          * memory and retry, but that's unlikely to help for a malloc small
 546          * enough to hold a single line of input, anyway.
 547          */
 548         if (errno == ENOMEM)
 549                 die("Out of memory, getdelim failed");
 550
 551         /*
 552          * Restore strbuf invariants; if getdelim left us with a NULL pointer,
 553          * we can just re-init, but otherwise we should make sure that our
 554          * length is empty, and that the result is NUL-terminated.
 555          */
 556         if (!sb->buf)
 557                 strbuf_init(sb, 0);
 558         else
 559                 strbuf_reset(sb);
 560         return EOF;
 561 }
 562 #else
 563 int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
 564 {
 565         int ch;
 566
 567         if (feof(fp))
 568                 return EOF;
 569
 570         strbuf_reset(sb);
 571         flockfile(fp);
 572         while ((ch = getc_unlocked(fp)) != EOF) {
 573                 if (!strbuf_avail(sb))
 574                         strbuf_grow(sb, 1);
 575                 sb->buf[sb->len++] = ch;
 576                 if (ch == term)
 577                         break;
 578         }
 579         funlockfile(fp);
 580         if (ch == EOF && sb->len == 0)
 581                 return EOF;
 582
 583         sb->buf[sb->len] = '\0';
 584         return 0;
 585 }
 586 #endif
 587
 588 static int strbuf_getdelim(struct strbuf *sb, FILE *fp, int term)
 589 {
 590         if (strbuf_getwholeline(sb, fp, term))
 591                 return EOF;
 592         if (sb->buf[sb->len - 1] == term)
 593                 strbuf_setlen(sb, sb->len - 1);
 594         return 0;
 595 }
 596
 597 int strbuf_getline(struct strbuf *sb, FILE *fp)
 598 {
 599         if (strbuf_getwholeline(sb, fp, '\n'))
 600                 return EOF;
 601         if (sb->buf[sb->len - 1] == '\n') {
 602                 strbuf_setlen(sb, sb->len - 1);
 603                 if (sb->len && sb->buf[sb->len - 1] == '\r')
 604                         strbuf_setlen(sb, sb->len - 1);
 605         }
 606         return 0;
 607 }
 608
 609 int strbuf_getline_lf(struct strbuf *sb, FILE *fp)
 610 {
 611         return strbuf_getdelim(sb, fp, '\n');
 612 }
 613
 614 int strbuf_getline_nul(struct strbuf *sb, FILE *fp)
 615 {
 616         return strbuf_getdelim(sb, fp, '\0');
 617 }
 618
 619 int strbuf_getwholeline_fd(struct strbuf *sb, int fd, int term)
 620 {
 621         strbuf_reset(sb);
 622
 623         while (1) {
 624                 char ch;
 625                 ssize_t len = xread(fd, &ch, 1);
 626                 if (len <= 0)
 627                         return EOF;
 628                 strbuf_addch(sb, ch);
 629                 if (ch == term)
 630                         break;
 631         }
 632         return 0;
 633 }
 634
 635 ssize_t strbuf_read_file(struct strbuf *sb, const char *path, size_t hint)
 636 {
 637         int fd;
 638         ssize_t len;
 639         int saved_errno;
 640
 641         fd = open(path, O_RDONLY);
 642         if (fd < 0)
 643                 return -1;
 644         len = strbuf_read(sb, fd, hint);
 645         saved_errno = errno;
 646         close(fd);
 647         if (len < 0) {
 648                 errno = saved_errno;
 649                 return -1;
 650         }
 651
 652         return len;
 653 }
 654
 655 void strbuf_add_lines(struct strbuf *out, const char *prefix,
 656                       const char *buf, size_t size)
 657 {
 658         add_lines(out, prefix, NULL, buf, size);
 659 }
 660
 661 void strbuf_addstr_xml_quoted(struct strbuf *buf, const char *s)
 662 {
 663         while (*s) {
 664                 size_t len = strcspn(s, "\"<>&");
 665                 strbuf_add(buf, s, len);
 666                 s += len;
 667                 switch (*s) {
 668                 case '"':
 669                         strbuf_addstr(buf, "&quot;");
 670                         break;
 671                 case '<':
 672                         strbuf_addstr(buf, "&lt;");
 673                         break;
 674                 case '>':
 675                         strbuf_addstr(buf, "&gt;");
 676                         break;
 677                 case '&':
 678                         strbuf_addstr(buf, "&amp;");
 679                         break;
 680                 case 0:
 681                         return;
 682                 }
 683                 s++;
 684         }
 685 }
 686
 687 static int is_rfc3986_reserved(char ch)
 688 {
 689         switch (ch) {
 690                 case '!': case '*': case '\'': case '(': case ')': case ';':
 691                 case ':': case '@': case '&': case '=': case '+': case '$':
 692                 case ',': case '/': case '?': case '#': case '[': case ']':
 693                         return 1;
 694         }
 695         return 0;
 696 }
 697
 698 static int is_rfc3986_unreserved(char ch)
 699 {
 700         return isalnum(ch) ||
 701                 ch == '-' || ch == '_' || ch == '.' || ch == '~';
 702 }
 703
 704 static void strbuf_add_urlencode(struct strbuf *sb, const char *s, size_t len,
 705                                  int reserved)
 706 {
 707         strbuf_grow(sb, len);
 708         while (len--) {
 709                 char ch = *s++;
 710                 if (is_rfc3986_unreserved(ch) ||
 711                     (!reserved && is_rfc3986_reserved(ch)))
 712                         strbuf_addch(sb, ch);
 713                 else
 714                         strbuf_addf(sb, "%%%02x", (unsigned char)ch);
 715         }
 716 }
 717
 718 void strbuf_addstr_urlencode(struct strbuf *sb, const char *s,
 719                              int reserved)
 720 {
 721         strbuf_add_urlencode(sb, s, strlen(s), reserved);
 722 }
 723
 724 void strbuf_humanise_bytes(struct strbuf *buf, off_t bytes)
 725 {
 726         if (bytes > 1 << 30) {
 727                 strbuf_addf(buf, "%u.%2.2u GiB",
 728                             (int)(bytes >> 30),
 729                             (int)(bytes & ((1 << 30) - 1)) / 10737419);
 730         } else if (bytes > 1 << 20) {
 731                 int x = bytes + 5243;  /* for rounding */
 732                 strbuf_addf(buf, "%u.%2.2u MiB",
 733                             x >> 20, ((x & ((1 << 20) - 1)) * 100) >> 20);
 734         } else if (bytes > 1 << 10) {
 735                 int x = bytes + 5;  /* for rounding */
 736                 strbuf_addf(buf, "%u.%2.2u KiB",
 737                             x >> 10, ((x & ((1 << 10) - 1)) * 100) >> 10);
 738         } else {
 739                 strbuf_addf(buf, "%u bytes", (int)bytes);
 740         }
 741 }
 742
 743 void strbuf_add_absolute_path(struct strbuf *sb, const char *path)
 744 {
 745         if (!*path)
 746                 die("The empty string is not a valid path");
 747         if (!is_absolute_path(path)) {
 748                 struct stat cwd_stat, pwd_stat;
 749                 size_t orig_len = sb->len;
 750                 char *cwd = xgetcwd();
 751                 char *pwd = getenv("PWD");
 752                 if (pwd && strcmp(pwd, cwd) &&
 753                     !stat(cwd, &cwd_stat) &&
 754                     (cwd_stat.st_dev || cwd_stat.st_ino) &&
 755                     !stat(pwd, &pwd_stat) &&
 756                     pwd_stat.st_dev == cwd_stat.st_dev &&
 757                     pwd_stat.st_ino == cwd_stat.st_ino)
 758                         strbuf_addstr(sb, pwd);
 759                 else
 760                         strbuf_addstr(sb, cwd);
 761                 if (sb->len > orig_len && !is_dir_sep(sb->buf[sb->len - 1]))
 762                         strbuf_addch(sb, '/');
 763                 free(cwd);
 764         }
 765         strbuf_addstr(sb, path);
 766 }
 767
 768 void strbuf_add_real_path(struct strbuf *sb, const char *path)
 769 {
 770         if (sb->len) {
 771                 struct strbuf resolved = STRBUF_INIT;
 772                 strbuf_realpath(&resolved, path, 1);
 773                 strbuf_addbuf(sb, &resolved);
 774                 strbuf_release(&resolved);
 775         } else
 776                 strbuf_realpath(sb, path, 1);
 777 }
 778
 779 int printf_ln(const char *fmt, ...)
 780 {
 781         int ret;
 782         va_list ap;
 783         va_start(ap, fmt);
 784         ret = vprintf(fmt, ap);
 785         va_end(ap);
 786         if (ret < 0 || putchar('\n') == EOF)
 787                 return -1;
 788         return ret + 1;
 789 }
 790
 791 int fprintf_ln(FILE *fp, const char *fmt, ...)
 792 {
 793         int ret;
 794         va_list ap;
 795         va_start(ap, fmt);
 796         ret = vfprintf(fp, fmt, ap);
 797         va_end(ap);
 798         if (ret < 0 || putc('\n', fp) == EOF)
 799                 return -1;
 800         return ret + 1;
 801 }
 802
 803 char *xstrdup_tolower(const char *string)
 804 {
 805         char *result;
 806         size_t len, i;
 807
 808         len = strlen(string);
 809         result = xmallocz(len);
 810         for (i = 0; i < len; i++)
 811                 result[i] = tolower(string[i]);
 812         result[i] = '\0';
 813         return result;
 814 }
 815
 816 char *xstrvfmt(const char *fmt, va_list ap)
 817 {
 818         struct strbuf buf = STRBUF_INIT;
 819         strbuf_vaddf(&buf, fmt, ap);
 820         return strbuf_detach(&buf, NULL);
 821 }
 822
 823 char *xstrfmt(const char *fmt, ...)
 824 {
 825         va_list ap;
 826         char *ret;
 827
 828         va_start(ap, fmt);
 829         ret = xstrvfmt(fmt, ap);
 830         va_end(ap);
 831
 832         return ret;
 833 }
 834
 835 void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm,
 836                      int tz_offset, int suppress_tz_name)
 837 {
 838         struct strbuf munged_fmt = STRBUF_INIT;
 839         size_t hint = 128;
 840         size_t len;
 841
 842         if (!*fmt)
 843                 return;
 844
 845         /*
 846          * There is no portable way to pass timezone information to
 847          * strftime, so we handle %z and %Z here.
 848          */
 849         for (;;) {
 850                 const char *percent = strchrnul(fmt, '%');
 851                 strbuf_add(&munged_fmt, fmt, percent - fmt);
 852                 if (!*percent)
 853                         break;
 854                 fmt = percent + 1;
 855                 switch (*fmt) {
 856                 case '%':
 857                         strbuf_addstr(&munged_fmt, "%%");
 858                         fmt++;
 859                         break;
 860                 case 'z':
 861                         strbuf_addf(&munged_fmt, "%+05d", tz_offset);
 862                         fmt++;
 863                         break;
 864                 case 'Z':
 865                         if (suppress_tz_name) {
 866                                 fmt++;
 867                                 break;
 868                         }
 869                         /* FALLTHROUGH */
 870                 default:
 871                         strbuf_addch(&munged_fmt, '%');
 872                 }
 873         }
 874         fmt = munged_fmt.buf;
 875
 876         strbuf_grow(sb, hint);
 877         len = strftime(sb->buf + sb->len, sb->alloc - sb->len, fmt, tm);
 878
 879         if (!len) {
 880                 /*
 881                  * strftime reports "0" if it could not fit the result in the buffer.
 882                  * Unfortunately, it also reports "0" if the requested time string
 883                  * takes 0 bytes. So our strategy is to munge the format so that the
 884                  * output contains at least one character, and then drop the extra
 885                  * character before returning.
 886                  */
 887                 strbuf_addch(&munged_fmt, ' ');
 888                 while (!len) {
 889                         hint *= 2;
 890                         strbuf_grow(sb, hint);
 891                         len = strftime(sb->buf + sb->len, sb->alloc - sb->len,
 892                                        munged_fmt.buf, tm);
 893                 }
 894                 len--; /* drop munged space */
 895         }
 896         strbuf_release(&munged_fmt);
 897         strbuf_setlen(sb, sb->len + len);
 898 }
 899
 900 void strbuf_add_unique_abbrev(struct strbuf *sb, const struct object_id *oid,
 901                               int abbrev_len)
 902 {
 903         int r;
 904         strbuf_grow(sb, GIT_SHA1_HEXSZ + 1);
 905         r = find_unique_abbrev_r(sb->buf + sb->len, oid, abbrev_len);
 906         strbuf_setlen(sb, sb->len + r);
 907 }
 908
 909 /*
 910  * Returns the length of a line, without trailing spaces.
 911  *
 912  * If the line ends with newline, it will be removed too.
 913  */
 914 static size_t cleanup(char *line, size_t len)
 915 {
 916         while (len) {
 917                 unsigned char c = line[len - 1];
 918                 if (!isspace(c))
 919                         break;
 920                 len--;
 921         }
 922
 923         return len;
 924 }
 925
 926 /*
 927  * Remove empty lines from the beginning and end
 928  * and also trailing spaces from every line.
 929  *
 930  * Turn multiple consecutive empty lines between paragraphs
 931  * into just one empty line.
 932  *
 933  * If the input has only empty lines and spaces,
 934  * no output will be produced.
 935  *
 936  * If last line does not have a newline at the end, one is added.
 937  *
 938  * Enable skip_comments to skip every line starting with comment
 939  * character.
 940  */
 941 void strbuf_stripspace(struct strbuf *sb, int skip_comments)
 942 {
 943         int empties = 0;
 944         size_t i, j, len, newlen;
 945         char *eol;
 946
 947         /* We may have to add a newline. */
 948         strbuf_grow(sb, 1);
 949
 950         for (i = j = 0; i < sb->len; i += len, j += newlen) {
 951                 eol = memchr(sb->buf + i, '\n', sb->len - i);
 952                 len = eol ? eol - (sb->buf + i) + 1 : sb->len - i;
 953
 954                 if (skip_comments && len && sb->buf[i] == comment_line_char) {
 955                         newlen = 0;
 956                         continue;
 957                 }
 958                 newlen = cleanup(sb->buf + i, len);
 959
 960                 /* Not just an empty line? */
 961                 if (newlen) {
 962                         if (empties > 0 && j > 0)
 963                                 sb->buf[j++] = '\n';
 964                         empties = 0;
 965                         memmove(sb->buf + j, sb->buf + i, newlen);
 966                         sb->buf[newlen + j++] = '\n';
 967                 } else {
 968                         empties++;
 969                 }
 970         }
 971
 972         strbuf_setlen(sb, j);
 973 }
 974
 975 int strbuf_normalize_path(struct strbuf *src)
 976 {
 977         struct strbuf dst = STRBUF_INIT;
 978
 979         strbuf_grow(&dst, src->len);
 980         if (normalize_path_copy(dst.buf, src->buf) < 0) {
 981                 strbuf_release(&dst);
 982                 return -1;
 983         }
 984
 985         /*
 986          * normalize_path does not tell us the new length, so we have to
 987          * compute it by looking for the new NUL it placed
 988          */
 989         strbuf_setlen(&dst, strlen(dst.buf));
 990         strbuf_swap(src, &dst);
 991         strbuf_release(&dst);
 992         return 0;
 993 }