strbuf.c

   1 #include "git-compat-util.h"
   2 #include "abspath.h"
   3 #include "alloc.h"
   4 #include "environment.h"
   5 #include "gettext.h"
   6 #include "hex.h"
   7 #include "object-name.h"
   8 #include "refs.h"
   9 #include "repository.h"
  10 #include "string-list.h"
  11 #include "utf8.h"
  12 #include "date.h"
  13 #include "wrapper.h"
  14
  15 int starts_with(const char *str, const char *prefix)
  16 {
  17         for (; ; str++, prefix++)
  18                 if (!*prefix)
  19                         return 1;
  20                 else if (*str != *prefix)
  21                         return 0;
  22 }
  23
  24 int istarts_with(const char *str, const char *prefix)
  25 {
  26         for (; ; str++, prefix++)
  27                 if (!*prefix)
  28                         return 1;
  29                 else if (tolower(*str) != tolower(*prefix))
  30                         return 0;
  31 }
  32
  33 int skip_to_optional_arg_default(const char *str, const char *prefix,
  34                                  const char **arg, const char *def)
  35 {
  36         const char *p;
  37
  38         if (!skip_prefix(str, prefix, &p))
  39                 return 0;
  40
  41         if (!*p) {
  42                 if (arg)
  43                         *arg = def;
  44                 return 1;
  45         }
  46
  47         if (*p != '=')
  48                 return 0;
  49
  50         if (arg)
  51                 *arg = p + 1;
  52         return 1;
  53 }
  54
  55 /*
  56  * Used as the default ->buf value, so that people can always assume
  57  * buf is non NULL and ->buf is NUL terminated even for a freshly
  58  * initialized strbuf.
  59  */
  60 char strbuf_slopbuf[1];
  61
  62 void strbuf_init(struct strbuf *sb, size_t hint)
  63 {
  64         struct strbuf blank = STRBUF_INIT;
  65         memcpy(sb, &blank, sizeof(*sb));
  66         if (hint)
  67                 strbuf_grow(sb, hint);
  68 }
  69
  70 void strbuf_release(struct strbuf *sb)
  71 {
  72         if (sb->alloc) {
  73                 free(sb->buf);
  74                 strbuf_init(sb, 0);
  75         }
  76 }
  77
  78 char *strbuf_detach(struct strbuf *sb, size_t *sz)
  79 {
  80         char *res;
  81         strbuf_grow(sb, 0);
  82         res = sb->buf;
  83         if (sz)
  84                 *sz = sb->len;
  85         strbuf_init(sb, 0);
  86         return res;
  87 }
  88
  89 void strbuf_attach(struct strbuf *sb, void *buf, size_t len, size_t alloc)
  90 {
  91         strbuf_release(sb);
  92         sb->buf   = buf;
  93         sb->len   = len;
  94         sb->alloc = alloc;
  95         strbuf_grow(sb, 0);
  96         sb->buf[sb->len] = '\0';
  97 }
  98
  99 void strbuf_grow(struct strbuf *sb, size_t extra)
 100 {
 101         int new_buf = !sb->alloc;
 102         if (unsigned_add_overflows(extra, 1) ||
 103             unsigned_add_overflows(sb->len, extra + 1))
 104                 die("you want to use way too much memory");
 105         if (new_buf)
 106                 sb->buf = NULL;
 107         ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
 108         if (new_buf)
 109                 sb->buf[0] = '\0';
 110 }
 111
 112 void strbuf_trim(struct strbuf *sb)
 113 {
 114         strbuf_rtrim(sb);
 115         strbuf_ltrim(sb);
 116 }
 117
 118 void strbuf_rtrim(struct strbuf *sb)
 119 {
 120         while (sb->len > 0 && isspace((unsigned char)sb->buf[sb->len - 1]))
 121                 sb->len--;
 122         sb->buf[sb->len] = '\0';
 123 }
 124
 125 void strbuf_trim_trailing_dir_sep(struct strbuf *sb)
 126 {
 127         while (sb->len > 0 && is_dir_sep((unsigned char)sb->buf[sb->len - 1]))
 128                 sb->len--;
 129         sb->buf[sb->len] = '\0';
 130 }
 131
 132 void strbuf_trim_trailing_newline(struct strbuf *sb)
 133 {
 134         if (sb->len > 0 && sb->buf[sb->len - 1] == '\n') {
 135                 if (--sb->len > 0 && sb->buf[sb->len - 1] == '\r')
 136                         --sb->len;
 137                 sb->buf[sb->len] = '\0';
 138         }
 139 }
 140
 141 void strbuf_ltrim(struct strbuf *sb)
 142 {
 143         char *b = sb->buf;
 144         while (sb->len > 0 && isspace(*b)) {
 145                 b++;
 146                 sb->len--;
 147         }
 148         memmove(sb->buf, b, sb->len);
 149         sb->buf[sb->len] = '\0';
 150 }
 151
 152 int strbuf_reencode(struct strbuf *sb, const char *from, const char *to)
 153 {
 154         char *out;
 155         size_t len;
 156
 157         if (same_encoding(from, to))
 158                 return 0;
 159
 160         out = reencode_string_len(sb->buf, sb->len, to, from, &len);
 161         if (!out)
 162                 return -1;
 163
 164         strbuf_attach(sb, out, len, len);
 165         return 0;
 166 }
 167
 168 void strbuf_tolower(struct strbuf *sb)
 169 {
 170         char *p = sb->buf, *end = sb->buf + sb->len;
 171         for (; p < end; p++)
 172                 *p = tolower(*p);
 173 }
 174
 175 struct strbuf **strbuf_split_buf(const char *str, size_t slen,
 176                                  int terminator, int max)
 177 {
 178         struct strbuf **ret = NULL;
 179         size_t nr = 0, alloc = 0;
 180         struct strbuf *t;
 181
 182         while (slen) {
 183                 int len = slen;
 184                 if (max <= 0 || nr + 1 < max) {
 185                         const char *end = memchr(str, terminator, slen);
 186                         if (end)
 187                                 len = end - str + 1;
 188                 }
 189                 t = xmalloc(sizeof(struct strbuf));
 190                 strbuf_init(t, len);
 191                 strbuf_add(t, str, len);
 192                 ALLOC_GROW(ret, nr + 2, alloc);
 193                 ret[nr++] = t;
 194                 str += len;
 195                 slen -= len;
 196         }
 197         ALLOC_GROW(ret, nr + 1, alloc); /* In case string was empty */
 198         ret[nr] = NULL;
 199         return ret;
 200 }
 201
 202 void strbuf_add_separated_string_list(struct strbuf *str,
 203                                       const char *sep,
 204                                       struct string_list *slist)
 205 {
 206         struct string_list_item *item;
 207         int sep_needed = 0;
 208
 209         for_each_string_list_item(item, slist) {
 210                 if (sep_needed)
 211                         strbuf_addstr(str, sep);
 212                 strbuf_addstr(str, item->string);
 213                 sep_needed = 1;
 214         }
 215 }
 216
 217 void strbuf_list_free(struct strbuf **sbs)
 218 {
 219         struct strbuf **s = sbs;
 220
 221         if (!s)
 222                 return;
 223         while (*s) {
 224                 strbuf_release(*s);
 225                 free(*s++);
 226         }
 227         free(sbs);
 228 }
 229
 230 int strbuf_cmp(const struct strbuf *a, const struct strbuf *b)
 231 {
 232         size_t len = a->len < b->len ? a->len: b->len;
 233         int cmp = memcmp(a->buf, b->buf, len);
 234         if (cmp)
 235                 return cmp;
 236         return a->len < b->len ? -1: a->len != b->len;
 237 }
 238
 239 void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
 240                                    const void *data, size_t dlen)
 241 {
 242         if (unsigned_add_overflows(pos, len))
 243                 die("you want to use way too much memory");
 244         if (pos > sb->len)
 245                 die("`pos' is too far after the end of the buffer");
 246         if (pos + len > sb->len)
 247                 die("`pos + len' is too far after the end of the buffer");
 248
 249         if (dlen >= len)
 250                 strbuf_grow(sb, dlen - len);
 251         memmove(sb->buf + pos + dlen,
 252                         sb->buf + pos + len,
 253                         sb->len - pos - len);
 254         memcpy(sb->buf + pos, data, dlen);
 255         strbuf_setlen(sb, sb->len + dlen - len);
 256 }
 257
 258 void strbuf_insert(struct strbuf *sb, size_t pos, const void *data, size_t len)
 259 {
 260         strbuf_splice(sb, pos, 0, data, len);
 261 }
 262
 263 void strbuf_vinsertf(struct strbuf *sb, size_t pos, const char *fmt, va_list ap)
 264 {
 265         int len, len2;
 266         char save;
 267         va_list cp;
 268
 269         if (pos > sb->len)
 270                 die("`pos' is too far after the end of the buffer");
 271         va_copy(cp, ap);
 272         len = vsnprintf(sb->buf + sb->len, 0, fmt, cp);
 273         va_end(cp);
 274         if (len < 0)
 275                 BUG("your vsnprintf is broken (returned %d)", len);
 276         if (!len)
 277                 return; /* nothing to do */
 278         if (unsigned_add_overflows(sb->len, len))
 279                 die("you want to use way too much memory");
 280         strbuf_grow(sb, len);
 281         memmove(sb->buf + pos + len, sb->buf + pos, sb->len - pos);
 282         /* vsnprintf() will append a NUL, overwriting one of our characters */
 283         save = sb->buf[pos + len];
 284         len2 = vsnprintf(sb->buf + pos, len + 1, fmt, ap);
 285         sb->buf[pos + len] = save;
 286         if (len2 != len)
 287                 BUG("your vsnprintf is broken (returns inconsistent lengths)");
 288         strbuf_setlen(sb, sb->len + len);
 289 }
 290
 291 void strbuf_insertf(struct strbuf *sb, size_t pos, const char *fmt, ...)
 292 {
 293         va_list ap;
 294         va_start(ap, fmt);
 295         strbuf_vinsertf(sb, pos, fmt, ap);
 296         va_end(ap);
 297 }
 298
 299 void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
 300 {
 301         strbuf_splice(sb, pos, len, "", 0);
 302 }
 303
 304 void strbuf_add(struct strbuf *sb, const void *data, size_t len)
 305 {
 306         strbuf_grow(sb, len);
 307         memcpy(sb->buf + sb->len, data, len);
 308         strbuf_setlen(sb, sb->len + len);
 309 }
 310
 311 void strbuf_addbuf(struct strbuf *sb, const struct strbuf *sb2)
 312 {
 313         strbuf_grow(sb, sb2->len);
 314         memcpy(sb->buf + sb->len, sb2->buf, sb2->len);
 315         strbuf_setlen(sb, sb->len + sb2->len);
 316 }
 317
 318 const char *strbuf_join_argv(struct strbuf *buf,
 319                              int argc, const char **argv, char delim)
 320 {
 321         if (!argc)
 322                 return buf->buf;
 323
 324         strbuf_addstr(buf, *argv);
 325         while (--argc) {
 326                 strbuf_addch(buf, delim);
 327                 strbuf_addstr(buf, *(++argv));
 328         }
 329
 330         return buf->buf;
 331 }
 332
 333 void strbuf_addchars(struct strbuf *sb, int c, size_t n)
 334 {
 335         strbuf_grow(sb, n);
 336         memset(sb->buf + sb->len, c, n);
 337         strbuf_setlen(sb, sb->len + n);
 338 }
 339
 340 void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 341 {
 342         va_list ap;
 343         va_start(ap, fmt);
 344         strbuf_vaddf(sb, fmt, ap);
 345         va_end(ap);
 346 }
 347
 348 static void add_lines(struct strbuf *out,
 349                         const char *prefix1,
 350                         const char *prefix2,
 351                         const char *buf, size_t size)
 352 {
 353         while (size) {
 354                 const char *prefix;
 355                 const char *next = memchr(buf, '\n', size);
 356                 next = next ? (next + 1) : (buf + size);
 357
 358                 prefix = ((prefix2 && (buf[0] == '\n' || buf[0] == '\t'))
 359                           ? prefix2 : prefix1);
 360                 strbuf_addstr(out, prefix);
 361                 strbuf_add(out, buf, next - buf);
 362                 size -= next - buf;
 363                 buf = next;
 364         }
 365         strbuf_complete_line(out);
 366 }
 367
 368 void strbuf_add_commented_lines(struct strbuf *out, const char *buf, size_t size)
 369 {
 370         static char prefix1[3];
 371         static char prefix2[2];
 372
 373         if (prefix1[0] != comment_line_char) {
 374                 xsnprintf(prefix1, sizeof(prefix1), "%c ", comment_line_char);
 375                 xsnprintf(prefix2, sizeof(prefix2), "%c", comment_line_char);
 376         }
 377         add_lines(out, prefix1, prefix2, buf, size);
 378 }
 379
 380 void strbuf_commented_addf(struct strbuf *sb, const char *fmt, ...)
 381 {
 382         va_list params;
 383         struct strbuf buf = STRBUF_INIT;
 384         int incomplete_line = sb->len && sb->buf[sb->len - 1] != '\n';
 385
 386         va_start(params, fmt);
 387         strbuf_vaddf(&buf, fmt, params);
 388         va_end(params);
 389
 390         strbuf_add_commented_lines(sb, buf.buf, buf.len);
 391         if (incomplete_line)
 392                 sb->buf[--sb->len] = '\0';
 393
 394         strbuf_release(&buf);
 395 }
 396
 397 void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap)
 398 {
 399         int len;
 400         va_list cp;
 401
 402         if (!strbuf_avail(sb))
 403                 strbuf_grow(sb, 64);
 404         va_copy(cp, ap);
 405         len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, cp);
 406         va_end(cp);
 407         if (len < 0)
 408                 BUG("your vsnprintf is broken (returned %d)", len);
 409         if (len > strbuf_avail(sb)) {
 410                 strbuf_grow(sb, len);
 411                 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
 412                 if (len > strbuf_avail(sb))
 413                         BUG("your vsnprintf is broken (insatiable)");
 414         }
 415         strbuf_setlen(sb, sb->len + len);
 416 }
 417
 418 int strbuf_expand_step(struct strbuf *sb, const char **formatp)
 419 {
 420         const char *format = *formatp;
 421         const char *percent = strchrnul(format, '%');
 422
 423         strbuf_add(sb, format, percent - format);
 424         if (!*percent)
 425                 return 0;
 426         *formatp = percent + 1;
 427         return 1;
 428 }
 429
 430 size_t strbuf_expand_literal(struct strbuf *sb, const char *placeholder)
 431 {
 432         int ch;
 433
 434         switch (placeholder[0]) {
 435         case 'n':               /* newline */
 436                 strbuf_addch(sb, '\n');
 437                 return 1;
 438         case 'x':
 439                 /* %x00 == NUL, %x0a == LF, etc. */
 440                 ch = hex2chr(placeholder + 1);
 441                 if (ch < 0)
 442                         return 0;
 443                 strbuf_addch(sb, ch);
 444                 return 3;
 445         }
 446         return 0;
 447 }
 448
 449 void strbuf_addbuf_percentquote(struct strbuf *dst, const struct strbuf *src)
 450 {
 451         size_t i, len = src->len;
 452
 453         for (i = 0; i < len; i++) {
 454                 if (src->buf[i] == '%')
 455                         strbuf_addch(dst, '%');
 456                 strbuf_addch(dst, src->buf[i]);
 457         }
 458 }
 459
 460 #define URL_UNSAFE_CHARS " <>\"%{}|\\^`:?#[]@!$&'()*+,;="
 461
 462 void strbuf_add_percentencode(struct strbuf *dst, const char *src, int flags)
 463 {
 464         size_t i, len = strlen(src);
 465
 466         for (i = 0; i < len; i++) {
 467                 unsigned char ch = src[i];
 468                 if (ch <= 0x1F || ch >= 0x7F ||
 469                     (ch == '/' && (flags & STRBUF_ENCODE_SLASH)) ||
 470                     strchr(URL_UNSAFE_CHARS, ch))
 471                         strbuf_addf(dst, "%%%02X", (unsigned char)ch);
 472                 else
 473                         strbuf_addch(dst, ch);
 474         }
 475 }
 476
 477 size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f)
 478 {
 479         size_t res;
 480         size_t oldalloc = sb->alloc;
 481
 482         strbuf_grow(sb, size);
 483         res = fread(sb->buf + sb->len, 1, size, f);
 484         if (res > 0)
 485                 strbuf_setlen(sb, sb->len + res);
 486         else if (oldalloc == 0)
 487                 strbuf_release(sb);
 488         return res;
 489 }
 490
 491 ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
 492 {
 493         size_t oldlen = sb->len;
 494         size_t oldalloc = sb->alloc;
 495
 496         strbuf_grow(sb, hint ? hint : 8192);
 497         for (;;) {
 498                 ssize_t want = sb->alloc - sb->len - 1;
 499                 ssize_t got = read_in_full(fd, sb->buf + sb->len, want);
 500
 501                 if (got < 0) {
 502                         if (oldalloc == 0)
 503                                 strbuf_release(sb);
 504                         else
 505                                 strbuf_setlen(sb, oldlen);
 506                         return -1;
 507                 }
 508                 sb->len += got;
 509                 if (got < want)
 510                         break;
 511                 strbuf_grow(sb, 8192);
 512         }
 513
 514         sb->buf[sb->len] = '\0';
 515         return sb->len - oldlen;
 516 }
 517
 518 ssize_t strbuf_read_once(struct strbuf *sb, int fd, size_t hint)
 519 {
 520         size_t oldalloc = sb->alloc;
 521         ssize_t cnt;
 522
 523         strbuf_grow(sb, hint ? hint : 8192);
 524         cnt = xread(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
 525         if (cnt > 0)
 526                 strbuf_setlen(sb, sb->len + cnt);
 527         else if (oldalloc == 0)
 528                 strbuf_release(sb);
 529         return cnt;
 530 }
 531
 532 ssize_t strbuf_write(struct strbuf *sb, FILE *f)
 533 {
 534         return sb->len ? fwrite(sb->buf, 1, sb->len, f) : 0;
 535 }
 536
 537 #define STRBUF_MAXLINK (2*PATH_MAX)
 538
 539 int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint)
 540 {
 541         size_t oldalloc = sb->alloc;
 542
 543         if (hint < 32)
 544                 hint = 32;
 545
 546         while (hint < STRBUF_MAXLINK) {
 547                 ssize_t len;
 548
 549                 strbuf_grow(sb, hint);
 550                 len = readlink(path, sb->buf, hint);
 551                 if (len < 0) {
 552                         if (errno != ERANGE)
 553                                 break;
 554                 } else if (len < hint) {
 555                         strbuf_setlen(sb, len);
 556                         return 0;
 557                 }
 558
 559                 /* .. the buffer was too small - try again */
 560                 hint *= 2;
 561         }
 562         if (oldalloc == 0)
 563                 strbuf_release(sb);
 564         return -1;
 565 }
 566
 567 int strbuf_getcwd(struct strbuf *sb)
 568 {
 569         size_t oldalloc = sb->alloc;
 570         size_t guessed_len = 128;
 571
 572         for (;; guessed_len *= 2) {
 573                 strbuf_grow(sb, guessed_len);
 574                 if (getcwd(sb->buf, sb->alloc)) {
 575                         strbuf_setlen(sb, strlen(sb->buf));
 576                         return 0;
 577                 }
 578
 579                 /*
 580                  * If getcwd(3) is implemented as a syscall that falls
 581                  * back to a regular lookup using readdir(3) etc. then
 582                  * we may be able to avoid EACCES by providing enough
 583                  * space to the syscall as it's not necessarily bound
 584                  * to the same restrictions as the fallback.
 585                  */
 586                 if (errno == EACCES && guessed_len < PATH_MAX)
 587                         continue;
 588
 589                 if (errno != ERANGE)
 590                         break;
 591         }
 592         if (oldalloc == 0)
 593                 strbuf_release(sb);
 594         else
 595                 strbuf_reset(sb);
 596         return -1;
 597 }
 598
 599 #ifdef HAVE_GETDELIM
 600 int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
 601 {
 602         ssize_t r;
 603
 604         if (feof(fp))
 605                 return EOF;
 606
 607         strbuf_reset(sb);
 608
 609         /* Translate slopbuf to NULL, as we cannot call realloc on it */
 610         if (!sb->alloc)
 611                 sb->buf = NULL;
 612         errno = 0;
 613         r = getdelim(&sb->buf, &sb->alloc, term, fp);
 614
 615         if (r > 0) {
 616                 sb->len = r;
 617                 return 0;
 618         }
 619         assert(r == -1);
 620
 621         /*
 622          * Normally we would have called xrealloc, which will try to free
 623          * memory and recover. But we have no way to tell getdelim() to do so.
 624          * Worse, we cannot try to recover ENOMEM ourselves, because we have
 625          * no idea how many bytes were read by getdelim.
 626          *
 627          * Dying here is reasonable. It mirrors what xrealloc would do on
 628          * catastrophic memory failure. We skip the opportunity to free pack
 629          * memory and retry, but that's unlikely to help for a malloc small
 630          * enough to hold a single line of input, anyway.
 631          */
 632         if (errno == ENOMEM)
 633                 die("Out of memory, getdelim failed");
 634
 635         /*
 636          * Restore strbuf invariants; if getdelim left us with a NULL pointer,
 637          * we can just re-init, but otherwise we should make sure that our
 638          * length is empty, and that the result is NUL-terminated.
 639          */
 640         if (!sb->buf)
 641                 strbuf_init(sb, 0);
 642         else
 643                 strbuf_reset(sb);
 644         return EOF;
 645 }
 646 #else
 647 int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
 648 {
 649         int ch;
 650
 651         if (feof(fp))
 652                 return EOF;
 653
 654         strbuf_reset(sb);
 655         flockfile(fp);
 656         while ((ch = getc_unlocked(fp)) != EOF) {
 657                 if (!strbuf_avail(sb))
 658                         strbuf_grow(sb, 1);
 659                 sb->buf[sb->len++] = ch;
 660                 if (ch == term)
 661                         break;
 662         }
 663         funlockfile(fp);
 664         if (ch == EOF && sb->len == 0)
 665                 return EOF;
 666
 667         sb->buf[sb->len] = '\0';
 668         return 0;
 669 }
 670 #endif
 671
 672 int strbuf_appendwholeline(struct strbuf *sb, FILE *fp, int term)
 673 {
 674         struct strbuf line = STRBUF_INIT;
 675         if (strbuf_getwholeline(&line, fp, term))
 676                 return EOF;
 677         strbuf_addbuf(sb, &line);
 678         strbuf_release(&line);
 679         return 0;
 680 }
 681
 682 static int strbuf_getdelim(struct strbuf *sb, FILE *fp, int term)
 683 {
 684         if (strbuf_getwholeline(sb, fp, term))
 685                 return EOF;
 686         if (sb->buf[sb->len - 1] == term)
 687                 strbuf_setlen(sb, sb->len - 1);
 688         return 0;
 689 }
 690
 691 int strbuf_getline(struct strbuf *sb, FILE *fp)
 692 {
 693         if (strbuf_getwholeline(sb, fp, '\n'))
 694                 return EOF;
 695         if (sb->buf[sb->len - 1] == '\n') {
 696                 strbuf_setlen(sb, sb->len - 1);
 697                 if (sb->len && sb->buf[sb->len - 1] == '\r')
 698                         strbuf_setlen(sb, sb->len - 1);
 699         }
 700         return 0;
 701 }
 702
 703 int strbuf_getline_lf(struct strbuf *sb, FILE *fp)
 704 {
 705         return strbuf_getdelim(sb, fp, '\n');
 706 }
 707
 708 int strbuf_getline_nul(struct strbuf *sb, FILE *fp)
 709 {
 710         return strbuf_getdelim(sb, fp, '\0');
 711 }
 712
 713 int strbuf_getwholeline_fd(struct strbuf *sb, int fd, int term)
 714 {
 715         strbuf_reset(sb);
 716
 717         while (1) {
 718                 char ch;
 719                 ssize_t len = xread(fd, &ch, 1);
 720                 if (len <= 0)
 721                         return EOF;
 722                 strbuf_addch(sb, ch);
 723                 if (ch == term)
 724                         break;
 725         }
 726         return 0;
 727 }
 728
 729 ssize_t strbuf_read_file(struct strbuf *sb, const char *path, size_t hint)
 730 {
 731         int fd;
 732         ssize_t len;
 733         int saved_errno;
 734
 735         fd = open(path, O_RDONLY);
 736         if (fd < 0)
 737                 return -1;
 738         len = strbuf_read(sb, fd, hint);
 739         saved_errno = errno;
 740         close(fd);
 741         if (len < 0) {
 742                 errno = saved_errno;
 743                 return -1;
 744         }
 745
 746         return len;
 747 }
 748
 749 void strbuf_add_lines(struct strbuf *out, const char *prefix,
 750                       const char *buf, size_t size)
 751 {
 752         add_lines(out, prefix, NULL, buf, size);
 753 }
 754
 755 void strbuf_addstr_xml_quoted(struct strbuf *buf, const char *s)
 756 {
 757         while (*s) {
 758                 size_t len = strcspn(s, "\"<>&");
 759                 strbuf_add(buf, s, len);
 760                 s += len;
 761                 switch (*s) {
 762                 case '"':
 763                         strbuf_addstr(buf, "&quot;");
 764                         break;
 765                 case '<':
 766                         strbuf_addstr(buf, "&lt;");
 767                         break;
 768                 case '>':
 769                         strbuf_addstr(buf, "&gt;");
 770                         break;
 771                 case '&':
 772                         strbuf_addstr(buf, "&amp;");
 773                         break;
 774                 case 0:
 775                         return;
 776                 }
 777                 s++;
 778         }
 779 }
 780
 781 int is_rfc3986_reserved_or_unreserved(char ch)
 782 {
 783         if (is_rfc3986_unreserved(ch))
 784                 return 1;
 785         switch (ch) {
 786                 case '!': case '*': case '\'': case '(': case ')': case ';':
 787                 case ':': case '@': case '&': case '=': case '+': case '$':
 788                 case ',': case '/': case '?': case '#': case '[': case ']':
 789                         return 1;
 790         }
 791         return 0;
 792 }
 793
 794 int is_rfc3986_unreserved(char ch)
 795 {
 796         return isalnum(ch) ||
 797                 ch == '-' || ch == '_' || ch == '.' || ch == '~';
 798 }
 799
 800 static void strbuf_add_urlencode(struct strbuf *sb, const char *s, size_t len,
 801                                  char_predicate allow_unencoded_fn)
 802 {
 803         strbuf_grow(sb, len);
 804         while (len--) {
 805                 char ch = *s++;
 806                 if (allow_unencoded_fn(ch))
 807                         strbuf_addch(sb, ch);
 808                 else
 809                         strbuf_addf(sb, "%%%02x", (unsigned char)ch);
 810         }
 811 }
 812
 813 void strbuf_addstr_urlencode(struct strbuf *sb, const char *s,
 814                              char_predicate allow_unencoded_fn)
 815 {
 816         strbuf_add_urlencode(sb, s, strlen(s), allow_unencoded_fn);
 817 }
 818
 819 static void strbuf_humanise(struct strbuf *buf, off_t bytes,
 820                                  int humanise_rate)
 821 {
 822         if (bytes > 1 << 30) {
 823                 strbuf_addf(buf,
 824                                 humanise_rate == 0 ?
 825                                         /* TRANSLATORS: IEC 80000-13:2008 gibibyte */
 826                                         _("%u.%2.2u GiB") :
 827                                         /* TRANSLATORS: IEC 80000-13:2008 gibibyte/second */
 828                                         _("%u.%2.2u GiB/s"),
 829                             (unsigned)(bytes >> 30),
 830                             (unsigned)(bytes & ((1 << 30) - 1)) / 10737419);
 831         } else if (bytes > 1 << 20) {
 832                 unsigned x = bytes + 5243;  /* for rounding */
 833                 strbuf_addf(buf,
 834                                 humanise_rate == 0 ?
 835                                         /* TRANSLATORS: IEC 80000-13:2008 mebibyte */
 836                                         _("%u.%2.2u MiB") :
 837                                         /* TRANSLATORS: IEC 80000-13:2008 mebibyte/second */
 838                                         _("%u.%2.2u MiB/s"),
 839                             x >> 20, ((x & ((1 << 20) - 1)) * 100) >> 20);
 840         } else if (bytes > 1 << 10) {
 841                 unsigned x = bytes + 5;  /* for rounding */
 842                 strbuf_addf(buf,
 843                                 humanise_rate == 0 ?
 844                                         /* TRANSLATORS: IEC 80000-13:2008 kibibyte */
 845                                         _("%u.%2.2u KiB") :
 846                                         /* TRANSLATORS: IEC 80000-13:2008 kibibyte/second */
 847                                         _("%u.%2.2u KiB/s"),
 848                             x >> 10, ((x & ((1 << 10) - 1)) * 100) >> 10);
 849         } else {
 850                 strbuf_addf(buf,
 851                                 humanise_rate == 0 ?
 852                                         /* TRANSLATORS: IEC 80000-13:2008 byte */
 853                                         Q_("%u byte", "%u bytes", bytes) :
 854                                         /* TRANSLATORS: IEC 80000-13:2008 byte/second */
 855                                         Q_("%u byte/s", "%u bytes/s", bytes),
 856                                 (unsigned)bytes);
 857         }
 858 }
 859
 860 void strbuf_humanise_bytes(struct strbuf *buf, off_t bytes)
 861 {
 862         strbuf_humanise(buf, bytes, 0);
 863 }
 864
 865 void strbuf_humanise_rate(struct strbuf *buf, off_t bytes)
 866 {
 867         strbuf_humanise(buf, bytes, 1);
 868 }
 869
 870 void strbuf_add_absolute_path(struct strbuf *sb, const char *path)
 871 {
 872         if (!*path)
 873                 die("The empty string is not a valid path");
 874         if (!is_absolute_path(path)) {
 875                 struct stat cwd_stat, pwd_stat;
 876                 size_t orig_len = sb->len;
 877                 char *cwd = xgetcwd();
 878                 char *pwd = getenv("PWD");
 879                 if (pwd && strcmp(pwd, cwd) &&
 880                     !stat(cwd, &cwd_stat) &&
 881                     (cwd_stat.st_dev || cwd_stat.st_ino) &&
 882                     !stat(pwd, &pwd_stat) &&
 883                     pwd_stat.st_dev == cwd_stat.st_dev &&
 884                     pwd_stat.st_ino == cwd_stat.st_ino)
 885                         strbuf_addstr(sb, pwd);
 886                 else
 887                         strbuf_addstr(sb, cwd);
 888                 if (sb->len > orig_len && !is_dir_sep(sb->buf[sb->len - 1]))
 889                         strbuf_addch(sb, '/');
 890                 free(cwd);
 891         }
 892         strbuf_addstr(sb, path);
 893 }
 894
 895 void strbuf_add_real_path(struct strbuf *sb, const char *path)
 896 {
 897         if (sb->len) {
 898                 struct strbuf resolved = STRBUF_INIT;
 899                 strbuf_realpath(&resolved, path, 1);
 900                 strbuf_addbuf(sb, &resolved);
 901                 strbuf_release(&resolved);
 902         } else
 903                 strbuf_realpath(sb, path, 1);
 904 }
 905
 906 int printf_ln(const char *fmt, ...)
 907 {
 908         int ret;
 909         va_list ap;
 910         va_start(ap, fmt);
 911         ret = vprintf(fmt, ap);
 912         va_end(ap);
 913         if (ret < 0 || putchar('\n') == EOF)
 914                 return -1;
 915         return ret + 1;
 916 }
 917
 918 int fprintf_ln(FILE *fp, const char *fmt, ...)
 919 {
 920         int ret;
 921         va_list ap;
 922         va_start(ap, fmt);
 923         ret = vfprintf(fp, fmt, ap);
 924         va_end(ap);
 925         if (ret < 0 || putc('\n', fp) == EOF)
 926                 return -1;
 927         return ret + 1;
 928 }
 929
 930 char *xstrdup_tolower(const char *string)
 931 {
 932         char *result;
 933         size_t len, i;
 934
 935         len = strlen(string);
 936         result = xmallocz(len);
 937         for (i = 0; i < len; i++)
 938                 result[i] = tolower(string[i]);
 939         return result;
 940 }
 941
 942 char *xstrdup_toupper(const char *string)
 943 {
 944         char *result;
 945         size_t len, i;
 946
 947         len = strlen(string);
 948         result = xmallocz(len);
 949         for (i = 0; i < len; i++)
 950                 result[i] = toupper(string[i]);
 951         return result;
 952 }
 953
 954 char *xstrvfmt(const char *fmt, va_list ap)
 955 {
 956         struct strbuf buf = STRBUF_INIT;
 957         strbuf_vaddf(&buf, fmt, ap);
 958         return strbuf_detach(&buf, NULL);
 959 }
 960
 961 char *xstrfmt(const char *fmt, ...)
 962 {
 963         va_list ap;
 964         char *ret;
 965
 966         va_start(ap, fmt);
 967         ret = xstrvfmt(fmt, ap);
 968         va_end(ap);
 969
 970         return ret;
 971 }
 972
 973 void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm,
 974                      int tz_offset, int suppress_tz_name)
 975 {
 976         struct strbuf munged_fmt = STRBUF_INIT;
 977         size_t hint = 128;
 978         size_t len;
 979
 980         if (!*fmt)
 981                 return;
 982
 983         /*
 984          * There is no portable way to pass timezone information to
 985          * strftime, so we handle %z and %Z here. Likewise '%s', because
 986          * going back to an epoch time requires knowing the zone.
 987          *
 988          * Note that tz_offset is in the "[-+]HHMM" decimal form; this is what
 989          * we want for %z, but the computation for %s has to convert to number
 990          * of seconds.
 991          */
 992         while (strbuf_expand_step(&munged_fmt, &fmt)) {
 993                 switch (*fmt) {
 994                 case '%':
 995                         strbuf_addstr(&munged_fmt, "%%");
 996                         fmt++;
 997                         break;
 998                 case 's':
 999                         strbuf_addf(&munged_fmt, "%"PRItime,
1000                                     (timestamp_t)tm_to_time_t(tm) -
1001                                     3600 * (tz_offset / 100) -
1002                                     60 * (tz_offset % 100));
1003                         fmt++;
1004                         break;
1005                 case 'z':
1006                         strbuf_addf(&munged_fmt, "%+05d", tz_offset);
1007                         fmt++;
1008                         break;
1009                 case 'Z':
1010                         if (suppress_tz_name) {
1011                                 fmt++;
1012                                 break;
1013                         }
1014                         /* FALLTHROUGH */
1015                 default:
1016                         strbuf_addch(&munged_fmt, '%');
1017                 }
1018         }
1019         fmt = munged_fmt.buf;
1020
1021         strbuf_grow(sb, hint);
1022         len = strftime(sb->buf + sb->len, sb->alloc - sb->len, fmt, tm);
1023
1024         if (!len) {
1025                 /*
1026                  * strftime reports "0" if it could not fit the result in the buffer.
1027                  * Unfortunately, it also reports "0" if the requested time string
1028                  * takes 0 bytes. So our strategy is to munge the format so that the
1029                  * output contains at least one character, and then drop the extra
1030                  * character before returning.
1031                  */
1032                 strbuf_addch(&munged_fmt, ' ');
1033                 while (!len) {
1034                         hint *= 2;
1035                         strbuf_grow(sb, hint);
1036                         len = strftime(sb->buf + sb->len, sb->alloc - sb->len,
1037                                        munged_fmt.buf, tm);
1038                 }
1039                 len--; /* drop munged space */
1040         }
1041         strbuf_release(&munged_fmt);
1042         strbuf_setlen(sb, sb->len + len);
1043 }
1044
1045 void strbuf_repo_add_unique_abbrev(struct strbuf *sb, struct repository *repo,
1046                                    const struct object_id *oid, int abbrev_len)
1047 {
1048         int r;
1049         strbuf_grow(sb, GIT_MAX_HEXSZ + 1);
1050         r = repo_find_unique_abbrev_r(repo, sb->buf + sb->len, oid, abbrev_len);
1051         strbuf_setlen(sb, sb->len + r);
1052 }
1053
1054 void strbuf_add_unique_abbrev(struct strbuf *sb, const struct object_id *oid,
1055                               int abbrev_len)
1056 {
1057         strbuf_repo_add_unique_abbrev(sb, the_repository, oid, abbrev_len);
1058 }
1059
1060 /*
1061  * Returns the length of a line, without trailing spaces.
1062  *
1063  * If the line ends with newline, it will be removed too.
1064  */
1065 static size_t cleanup(char *line, size_t len)
1066 {
1067         while (len) {
1068                 unsigned char c = line[len - 1];
1069                 if (!isspace(c))
1070                         break;
1071                 len--;
1072         }
1073
1074         return len;
1075 }
1076
1077 /*
1078  * Remove empty lines from the beginning and end
1079  * and also trailing spaces from every line.
1080  *
1081  * Turn multiple consecutive empty lines between paragraphs
1082  * into just one empty line.
1083  *
1084  * If the input has only empty lines and spaces,
1085  * no output will be produced.
1086  *
1087  * If last line does not have a newline at the end, one is added.
1088  *
1089  * Enable skip_comments to skip every line starting with comment
1090  * character.
1091  */
1092 void strbuf_stripspace(struct strbuf *sb, int skip_comments)
1093 {
1094         size_t empties = 0;
1095         size_t i, j, len, newlen;
1096         char *eol;
1097
1098         /* We may have to add a newline. */
1099         strbuf_grow(sb, 1);
1100
1101         for (i = j = 0; i < sb->len; i += len, j += newlen) {
1102                 eol = memchr(sb->buf + i, '\n', sb->len - i);
1103                 len = eol ? eol - (sb->buf + i) + 1 : sb->len - i;
1104
1105                 if (skip_comments && len && sb->buf[i] == comment_line_char) {
1106                         newlen = 0;
1107                         continue;
1108                 }
1109                 newlen = cleanup(sb->buf + i, len);
1110
1111                 /* Not just an empty line? */
1112                 if (newlen) {
1113                         if (empties > 0 && j > 0)
1114                                 sb->buf[j++] = '\n';
1115                         empties = 0;
1116                         memmove(sb->buf + j, sb->buf + i, newlen);
1117                         sb->buf[newlen + j++] = '\n';
1118                 } else {
1119                         empties++;
1120                 }
1121         }
1122
1123         strbuf_setlen(sb, j);
1124 }
1125
1126 int strbuf_normalize_path(struct strbuf *src)
1127 {
1128         struct strbuf dst = STRBUF_INIT;
1129
1130         strbuf_grow(&dst, src->len);
1131         if (normalize_path_copy(dst.buf, src->buf) < 0) {
1132                 strbuf_release(&dst);
1133                 return -1;
1134         }
1135
1136         /*
1137          * normalize_path does not tell us the new length, so we have to
1138          * compute it by looking for the new NUL it placed
1139          */
1140         strbuf_setlen(&dst, strlen(dst.buf));
1141         strbuf_swap(src, &dst);
1142         strbuf_release(&dst);
1143         return 0;
1144 }
1145
1146 void strbuf_strip_file_from_path(struct strbuf *sb)
1147 {
1148         char *path_sep = find_last_dir_sep(sb->buf);
1149         strbuf_setlen(sb, path_sep ? path_sep - sb->buf + 1 : 0);
1150 }