strbuf.c

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