Andrew's git / gitweb.git / strbuf.c
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strbuf.con commit range-diff: add filename to inner diff (444e096)
   1#include "cache.h"
   2#include "refs.h"
   3#include "string-list.h"
   4#include "utf8.h"
   5
   6int 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
  15int istarts_with(const char *str, const char *prefix)
  16{
  17        for (; ; str++, prefix++)
  18                if (!*prefix)
  19                        return 1;
  20                else if (tolower(*str) != tolower(*prefix))
  21                        return 0;
  22}
  23
  24int skip_to_optional_arg_default(const char *str, const char *prefix,
  25                                 const char **arg, const char *def)
  26{
  27        const char *p;
  28
  29        if (!skip_prefix(str, prefix, &p))
  30                return 0;
  31
  32        if (!*p) {
  33                if (arg)
  34                        *arg = def;
  35                return 1;
  36        }
  37
  38        if (*p != '=')
  39                return 0;
  40
  41        if (arg)
  42                *arg = p + 1;
  43        return 1;
  44}
  45
  46/*
  47 * Used as the default ->buf value, so that people can always assume
  48 * buf is non NULL and ->buf is NUL terminated even for a freshly
  49 * initialized strbuf.
  50 */
  51char strbuf_slopbuf[1];
  52
  53void strbuf_init(struct strbuf *sb, size_t hint)
  54{
  55        sb->alloc = sb->len = 0;
  56        sb->buf = strbuf_slopbuf;
  57        if (hint)
  58                strbuf_grow(sb, hint);
  59}
  60
  61void strbuf_release(struct strbuf *sb)
  62{
  63        if (sb->alloc) {
  64                free(sb->buf);
  65                strbuf_init(sb, 0);
  66        }
  67}
  68
  69char *strbuf_detach(struct strbuf *sb, size_t *sz)
  70{
  71        char *res;
  72        strbuf_grow(sb, 0);
  73        res = sb->buf;
  74        if (sz)
  75                *sz = sb->len;
  76        strbuf_init(sb, 0);
  77        return res;
  78}
  79
  80void strbuf_attach(struct strbuf *sb, void *buf, size_t len, size_t alloc)
  81{
  82        strbuf_release(sb);
  83        sb->buf   = buf;
  84        sb->len   = len;
  85        sb->alloc = alloc;
  86        strbuf_grow(sb, 0);
  87        sb->buf[sb->len] = '\0';
  88}
  89
  90void strbuf_grow(struct strbuf *sb, size_t extra)
  91{
  92        int new_buf = !sb->alloc;
  93        if (unsigned_add_overflows(extra, 1) ||
  94            unsigned_add_overflows(sb->len, extra + 1))
  95                die("you want to use way too much memory");
  96        if (new_buf)
  97                sb->buf = NULL;
  98        ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
  99        if (new_buf)
 100                sb->buf[0] = '\0';
 101}
 102
 103void strbuf_trim(struct strbuf *sb)
 104{
 105        strbuf_rtrim(sb);
 106        strbuf_ltrim(sb);
 107}
 108
 109void strbuf_rtrim(struct strbuf *sb)
 110{
 111        while (sb->len > 0 && isspace((unsigned char)sb->buf[sb->len - 1]))
 112                sb->len--;
 113        sb->buf[sb->len] = '\0';
 114}
 115
 116void strbuf_trim_trailing_dir_sep(struct strbuf *sb)
 117{
 118        while (sb->len > 0 && is_dir_sep((unsigned char)sb->buf[sb->len - 1]))
 119                sb->len--;
 120        sb->buf[sb->len] = '\0';
 121}
 122
 123void strbuf_trim_trailing_newline(struct strbuf *sb)
 124{
 125        if (sb->len > 0 && sb->buf[sb->len - 1] == '\n') {
 126                if (--sb->len > 0 && sb->buf[sb->len - 1] == '\r')
 127                        --sb->len;
 128                sb->buf[sb->len] = '\0';
 129        }
 130}
 131
 132void strbuf_ltrim(struct strbuf *sb)
 133{
 134        char *b = sb->buf;
 135        while (sb->len > 0 && isspace(*b)) {
 136                b++;
 137                sb->len--;
 138        }
 139        memmove(sb->buf, b, sb->len);
 140        sb->buf[sb->len] = '\0';
 141}
 142
 143int strbuf_reencode(struct strbuf *sb, const char *from, const char *to)
 144{
 145        char *out;
 146        size_t len;
 147
 148        if (same_encoding(from, to))
 149                return 0;
 150
 151        out = reencode_string_len(sb->buf, sb->len, to, from, &len);
 152        if (!out)
 153                return -1;
 154
 155        strbuf_attach(sb, out, len, len);
 156        return 0;
 157}
 158
 159void strbuf_tolower(struct strbuf *sb)
 160{
 161        char *p = sb->buf, *end = sb->buf + sb->len;
 162        for (; p < end; p++)
 163                *p = tolower(*p);
 164}
 165
 166struct strbuf **strbuf_split_buf(const char *str, size_t slen,
 167                                 int terminator, int max)
 168{
 169        struct strbuf **ret = NULL;
 170        size_t nr = 0, alloc = 0;
 171        struct strbuf *t;
 172
 173        while (slen) {
 174                int len = slen;
 175                if (max <= 0 || nr + 1 < max) {
 176                        const char *end = memchr(str, terminator, slen);
 177                        if (end)
 178                                len = end - str + 1;
 179                }
 180                t = xmalloc(sizeof(struct strbuf));
 181                strbuf_init(t, len);
 182                strbuf_add(t, str, len);
 183                ALLOC_GROW(ret, nr + 2, alloc);
 184                ret[nr++] = t;
 185                str += len;
 186                slen -= len;
 187        }
 188        ALLOC_GROW(ret, nr + 1, alloc); /* In case string was empty */
 189        ret[nr] = NULL;
 190        return ret;
 191}
 192
 193void strbuf_add_separated_string_list(struct strbuf *str,
 194                                      const char *sep,
 195                                      struct string_list *slist)
 196{
 197        struct string_list_item *item;
 198        int sep_needed = 0;
 199
 200        for_each_string_list_item(item, slist) {
 201                if (sep_needed)
 202                        strbuf_addstr(str, sep);
 203                strbuf_addstr(str, item->string);
 204                sep_needed = 1;
 205        }
 206}
 207
 208void strbuf_list_free(struct strbuf **sbs)
 209{
 210        struct strbuf **s = sbs;
 211
 212        while (*s) {
 213                strbuf_release(*s);
 214                free(*s++);
 215        }
 216        free(sbs);
 217}
 218
 219int strbuf_cmp(const struct strbuf *a, const struct strbuf *b)
 220{
 221        size_t len = a->len < b->len ? a->len: b->len;
 222        int cmp = memcmp(a->buf, b->buf, len);
 223        if (cmp)
 224                return cmp;
 225        return a->len < b->len ? -1: a->len != b->len;
 226}
 227
 228void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
 229                                   const void *data, size_t dlen)
 230{
 231        if (unsigned_add_overflows(pos, len))
 232                die("you want to use way too much memory");
 233        if (pos > sb->len)
 234                die("`pos' is too far after the end of the buffer");
 235        if (pos + len > sb->len)
 236                die("`pos + len' is too far after the end of the buffer");
 237
 238        if (dlen >= len)
 239                strbuf_grow(sb, dlen - len);
 240        memmove(sb->buf + pos + dlen,
 241                        sb->buf + pos + len,
 242                        sb->len - pos - len);
 243        memcpy(sb->buf + pos, data, dlen);
 244        strbuf_setlen(sb, sb->len + dlen - len);
 245}
 246
 247void strbuf_insert(struct strbuf *sb, size_t pos, const void *data, size_t len)
 248{
 249        strbuf_splice(sb, pos, 0, data, len);
 250}
 251
 252void strbuf_vinsertf(struct strbuf *sb, size_t pos, const char *fmt, va_list ap)
 253{
 254        int len, len2;
 255        char save;
 256        va_list cp;
 257
 258        if (pos > sb->len)
 259                die("`pos' is too far after the end of the buffer");
 260        va_copy(cp, ap);
 261        len = vsnprintf(sb->buf + sb->len, 0, fmt, cp);
 262        va_end(cp);
 263        if (len < 0)
 264                BUG("your vsnprintf is broken (returned %d)", len);
 265        if (!len)
 266                return; /* nothing to do */
 267        if (unsigned_add_overflows(sb->len, len))
 268                die("you want to use way too much memory");
 269        strbuf_grow(sb, len);
 270        memmove(sb->buf + pos + len, sb->buf + pos, sb->len - pos);
 271        /* vsnprintf() will append a NUL, overwriting one of our characters */
 272        save = sb->buf[pos + len];
 273        len2 = vsnprintf(sb->buf + pos, len + 1, fmt, ap);
 274        sb->buf[pos + len] = save;
 275        if (len2 != len)
 276                BUG("your vsnprintf is broken (returns inconsistent lengths)");
 277        strbuf_setlen(sb, sb->len + len);
 278}
 279
 280void strbuf_insertf(struct strbuf *sb, size_t pos, const char *fmt, ...)
 281{
 282        va_list ap;
 283        va_start(ap, fmt);
 284        strbuf_vinsertf(sb, pos, fmt, ap);
 285        va_end(ap);
 286}
 287
 288void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
 289{
 290        strbuf_splice(sb, pos, len, "", 0);
 291}
 292
 293void strbuf_add(struct strbuf *sb, const void *data, size_t len)
 294{
 295        strbuf_grow(sb, len);
 296        memcpy(sb->buf + sb->len, data, len);
 297        strbuf_setlen(sb, sb->len + len);
 298}
 299
 300void strbuf_addbuf(struct strbuf *sb, const struct strbuf *sb2)
 301{
 302        strbuf_grow(sb, sb2->len);
 303        memcpy(sb->buf + sb->len, sb2->buf, sb2->len);
 304        strbuf_setlen(sb, sb->len + sb2->len);
 305}
 306
 307const char *strbuf_join_argv(struct strbuf *buf,
 308                             int argc, const char **argv, char delim)
 309{
 310        if (!argc)
 311                return buf->buf;
 312
 313        strbuf_addstr(buf, *argv);
 314        while (--argc) {
 315                strbuf_addch(buf, delim);
 316                strbuf_addstr(buf, *(++argv));
 317        }
 318
 319        return buf->buf;
 320}
 321
 322void strbuf_addchars(struct strbuf *sb, int c, size_t n)
 323{
 324        strbuf_grow(sb, n);
 325        memset(sb->buf + sb->len, c, n);
 326        strbuf_setlen(sb, sb->len + n);
 327}
 328
 329void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 330{
 331        va_list ap;
 332        va_start(ap, fmt);
 333        strbuf_vaddf(sb, fmt, ap);
 334        va_end(ap);
 335}
 336
 337static void add_lines(struct strbuf *out,
 338                        const char *prefix1,
 339                        const char *prefix2,
 340                        const char *buf, size_t size)
 341{
 342        while (size) {
 343                const char *prefix;
 344                const char *next = memchr(buf, '\n', size);
 345                next = next ? (next + 1) : (buf + size);
 346
 347                prefix = ((prefix2 && (buf[0] == '\n' || buf[0] == '\t'))
 348                          ? prefix2 : prefix1);
 349                strbuf_addstr(out, prefix);
 350                strbuf_add(out, buf, next - buf);
 351                size -= next - buf;
 352                buf = next;
 353        }
 354        strbuf_complete_line(out);
 355}
 356
 357void strbuf_add_commented_lines(struct strbuf *out, const char *buf, size_t size)
 358{
 359        static char prefix1[3];
 360        static char prefix2[2];
 361
 362        if (prefix1[0] != comment_line_char) {
 363                xsnprintf(prefix1, sizeof(prefix1), "%c ", comment_line_char);
 364                xsnprintf(prefix2, sizeof(prefix2), "%c", comment_line_char);
 365        }
 366        add_lines(out, prefix1, prefix2, buf, size);
 367}
 368
 369void strbuf_commented_addf(struct strbuf *sb, const char *fmt, ...)
 370{
 371        va_list params;
 372        struct strbuf buf = STRBUF_INIT;
 373        int incomplete_line = sb->len && sb->buf[sb->len - 1] != '\n';
 374
 375        va_start(params, fmt);
 376        strbuf_vaddf(&buf, fmt, params);
 377        va_end(params);
 378
 379        strbuf_add_commented_lines(sb, buf.buf, buf.len);
 380        if (incomplete_line)
 381                sb->buf[--sb->len] = '\0';
 382
 383        strbuf_release(&buf);
 384}
 385
 386void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap)
 387{
 388        int len;
 389        va_list cp;
 390
 391        if (!strbuf_avail(sb))
 392                strbuf_grow(sb, 64);
 393        va_copy(cp, ap);
 394        len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, cp);
 395        va_end(cp);
 396        if (len < 0)
 397                BUG("your vsnprintf is broken (returned %d)", len);
 398        if (len > strbuf_avail(sb)) {
 399                strbuf_grow(sb, len);
 400                len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
 401                if (len > strbuf_avail(sb))
 402                        BUG("your vsnprintf is broken (insatiable)");
 403        }
 404        strbuf_setlen(sb, sb->len + len);
 405}
 406
 407void strbuf_expand(struct strbuf *sb, const char *format, expand_fn_t fn,
 408                   void *context)
 409{
 410        for (;;) {
 411                const char *percent;
 412                size_t consumed;
 413
 414                percent = strchrnul(format, '%');
 415                strbuf_add(sb, format, percent - format);
 416                if (!*percent)
 417                        break;
 418                format = percent + 1;
 419
 420                if (*format == '%') {
 421                        strbuf_addch(sb, '%');
 422                        format++;
 423                        continue;
 424                }
 425
 426                consumed = fn(sb, format, context);
 427                if (consumed)
 428                        format += consumed;
 429                else
 430                        strbuf_addch(sb, '%');
 431        }
 432}
 433
 434size_t strbuf_expand_literal_cb(struct strbuf *sb,
 435                                const char *placeholder,
 436                                void *context)
 437{
 438        int ch;
 439
 440        switch (placeholder[0]) {
 441        case 'n':               /* newline */
 442                strbuf_addch(sb, '\n');
 443                return 1;
 444        case 'x':
 445                /* %x00 == NUL, %x0a == LF, etc. */
 446                ch = hex2chr(placeholder + 1);
 447                if (ch < 0)
 448                        return 0;
 449                strbuf_addch(sb, ch);
 450                return 3;
 451        }
 452        return 0;
 453}
 454
 455size_t strbuf_expand_dict_cb(struct strbuf *sb, const char *placeholder,
 456                void *context)
 457{
 458        struct strbuf_expand_dict_entry *e = context;
 459        size_t len;
 460
 461        for (; e->placeholder && (len = strlen(e->placeholder)); e++) {
 462                if (!strncmp(placeholder, e->placeholder, len)) {
 463                        if (e->value)
 464                                strbuf_addstr(sb, e->value);
 465                        return len;
 466                }
 467        }
 468        return 0;
 469}
 470
 471void strbuf_addbuf_percentquote(struct strbuf *dst, const struct strbuf *src)
 472{
 473        size_t i, len = src->len;
 474
 475        for (i = 0; i < len; i++) {
 476                if (src->buf[i] == '%')
 477                        strbuf_addch(dst, '%');
 478                strbuf_addch(dst, src->buf[i]);
 479        }
 480}
 481
 482size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f)
 483{
 484        size_t res;
 485        size_t oldalloc = sb->alloc;
 486
 487        strbuf_grow(sb, size);
 488        res = fread(sb->buf + sb->len, 1, size, f);
 489        if (res > 0)
 490                strbuf_setlen(sb, sb->len + res);
 491        else if (oldalloc == 0)
 492                strbuf_release(sb);
 493        return res;
 494}
 495
 496ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
 497{
 498        size_t oldlen = sb->len;
 499        size_t oldalloc = sb->alloc;
 500
 501        strbuf_grow(sb, hint ? hint : 8192);
 502        for (;;) {
 503                ssize_t want = sb->alloc - sb->len - 1;
 504                ssize_t got = read_in_full(fd, sb->buf + sb->len, want);
 505
 506                if (got < 0) {
 507                        if (oldalloc == 0)
 508                                strbuf_release(sb);
 509                        else
 510                                strbuf_setlen(sb, oldlen);
 511                        return -1;
 512                }
 513                sb->len += got;
 514                if (got < want)
 515                        break;
 516                strbuf_grow(sb, 8192);
 517        }
 518
 519        sb->buf[sb->len] = '\0';
 520        return sb->len - oldlen;
 521}
 522
 523ssize_t strbuf_read_once(struct strbuf *sb, int fd, size_t hint)
 524{
 525        size_t oldalloc = sb->alloc;
 526        ssize_t cnt;
 527
 528        strbuf_grow(sb, hint ? hint : 8192);
 529        cnt = xread(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
 530        if (cnt > 0)
 531                strbuf_setlen(sb, sb->len + cnt);
 532        else if (oldalloc == 0)
 533                strbuf_release(sb);
 534        return cnt;
 535}
 536
 537ssize_t strbuf_write(struct strbuf *sb, FILE *f)
 538{
 539        return sb->len ? fwrite(sb->buf, 1, sb->len, f) : 0;
 540}
 541
 542
 543#define STRBUF_MAXLINK (2*PATH_MAX)
 544
 545int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint)
 546{
 547        size_t oldalloc = sb->alloc;
 548
 549        if (hint < 32)
 550                hint = 32;
 551
 552        while (hint < STRBUF_MAXLINK) {
 553                ssize_t len;
 554
 555                strbuf_grow(sb, hint);
 556                len = readlink(path, sb->buf, hint);
 557                if (len < 0) {
 558                        if (errno != ERANGE)
 559                                break;
 560                } else if (len < hint) {
 561                        strbuf_setlen(sb, len);
 562                        return 0;
 563                }
 564
 565                /* .. the buffer was too small - try again */
 566                hint *= 2;
 567        }
 568        if (oldalloc == 0)
 569                strbuf_release(sb);
 570        return -1;
 571}
 572
 573int strbuf_getcwd(struct strbuf *sb)
 574{
 575        size_t oldalloc = sb->alloc;
 576        size_t guessed_len = 128;
 577
 578        for (;; guessed_len *= 2) {
 579                strbuf_grow(sb, guessed_len);
 580                if (getcwd(sb->buf, sb->alloc)) {
 581                        strbuf_setlen(sb, strlen(sb->buf));
 582                        return 0;
 583                }
 584
 585                /*
 586                 * If getcwd(3) is implemented as a syscall that falls
 587                 * back to a regular lookup using readdir(3) etc. then
 588                 * we may be able to avoid EACCES by providing enough
 589                 * space to the syscall as it's not necessarily bound
 590                 * to the same restrictions as the fallback.
 591                 */
 592                if (errno == EACCES && guessed_len < PATH_MAX)
 593                        continue;
 594
 595                if (errno != ERANGE)
 596                        break;
 597        }
 598        if (oldalloc == 0)
 599                strbuf_release(sb);
 600        else
 601                strbuf_reset(sb);
 602        return -1;
 603}
 604
 605#ifdef HAVE_GETDELIM
 606int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
 607{
 608        ssize_t r;
 609
 610        if (feof(fp))
 611                return EOF;
 612
 613        strbuf_reset(sb);
 614
 615        /* Translate slopbuf to NULL, as we cannot call realloc on it */
 616        if (!sb->alloc)
 617                sb->buf = NULL;
 618        errno = 0;
 619        r = getdelim(&sb->buf, &sb->alloc, term, fp);
 620
 621        if (r > 0) {
 622                sb->len = r;
 623                return 0;
 624        }
 625        assert(r == -1);
 626
 627        /*
 628         * Normally we would have called xrealloc, which will try to free
 629         * memory and recover. But we have no way to tell getdelim() to do so.
 630         * Worse, we cannot try to recover ENOMEM ourselves, because we have
 631         * no idea how many bytes were read by getdelim.
 632         *
 633         * Dying here is reasonable. It mirrors what xrealloc would do on
 634         * catastrophic memory failure. We skip the opportunity to free pack
 635         * memory and retry, but that's unlikely to help for a malloc small
 636         * enough to hold a single line of input, anyway.
 637         */
 638        if (errno == ENOMEM)
 639                die("Out of memory, getdelim failed");
 640
 641        /*
 642         * Restore strbuf invariants; if getdelim left us with a NULL pointer,
 643         * we can just re-init, but otherwise we should make sure that our
 644         * length is empty, and that the result is NUL-terminated.
 645         */
 646        if (!sb->buf)
 647                strbuf_init(sb, 0);
 648        else
 649                strbuf_reset(sb);
 650        return EOF;
 651}
 652#else
 653int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
 654{
 655        int ch;
 656
 657        if (feof(fp))
 658                return EOF;
 659
 660        strbuf_reset(sb);
 661        flockfile(fp);
 662        while ((ch = getc_unlocked(fp)) != EOF) {
 663                if (!strbuf_avail(sb))
 664                        strbuf_grow(sb, 1);
 665                sb->buf[sb->len++] = ch;
 666                if (ch == term)
 667                        break;
 668        }
 669        funlockfile(fp);
 670        if (ch == EOF && sb->len == 0)
 671                return EOF;
 672
 673        sb->buf[sb->len] = '\0';
 674        return 0;
 675}
 676#endif
 677
 678static int strbuf_getdelim(struct strbuf *sb, FILE *fp, int term)
 679{
 680        if (strbuf_getwholeline(sb, fp, term))
 681                return EOF;
 682        if (sb->buf[sb->len - 1] == term)
 683                strbuf_setlen(sb, sb->len - 1);
 684        return 0;
 685}
 686
 687int strbuf_getline(struct strbuf *sb, FILE *fp)
 688{
 689        if (strbuf_getwholeline(sb, fp, '\n'))
 690                return EOF;
 691        if (sb->buf[sb->len - 1] == '\n') {
 692                strbuf_setlen(sb, sb->len - 1);
 693                if (sb->len && sb->buf[sb->len - 1] == '\r')
 694                        strbuf_setlen(sb, sb->len - 1);
 695        }
 696        return 0;
 697}
 698
 699int strbuf_getline_lf(struct strbuf *sb, FILE *fp)
 700{
 701        return strbuf_getdelim(sb, fp, '\n');
 702}
 703
 704int strbuf_getline_nul(struct strbuf *sb, FILE *fp)
 705{
 706        return strbuf_getdelim(sb, fp, '\0');
 707}
 708
 709int strbuf_getwholeline_fd(struct strbuf *sb, int fd, int term)
 710{
 711        strbuf_reset(sb);
 712
 713        while (1) {
 714                char ch;
 715                ssize_t len = xread(fd, &ch, 1);
 716                if (len <= 0)
 717                        return EOF;
 718                strbuf_addch(sb, ch);
 719                if (ch == term)
 720                        break;
 721        }
 722        return 0;
 723}
 724
 725ssize_t strbuf_read_file(struct strbuf *sb, const char *path, size_t hint)
 726{
 727        int fd;
 728        ssize_t len;
 729        int saved_errno;
 730
 731        fd = open(path, O_RDONLY);
 732        if (fd < 0)
 733                return -1;
 734        len = strbuf_read(sb, fd, hint);
 735        saved_errno = errno;
 736        close(fd);
 737        if (len < 0) {
 738                errno = saved_errno;
 739                return -1;
 740        }
 741
 742        return len;
 743}
 744
 745void strbuf_add_lines(struct strbuf *out, const char *prefix,
 746                      const char *buf, size_t size)
 747{
 748        add_lines(out, prefix, NULL, buf, size);
 749}
 750
 751void strbuf_addstr_xml_quoted(struct strbuf *buf, const char *s)
 752{
 753        while (*s) {
 754                size_t len = strcspn(s, "\"<>&");
 755                strbuf_add(buf, s, len);
 756                s += len;
 757                switch (*s) {
 758                case '"':
 759                        strbuf_addstr(buf, "&quot;");
 760                        break;
 761                case '<':
 762                        strbuf_addstr(buf, "&lt;");
 763                        break;
 764                case '>':
 765                        strbuf_addstr(buf, "&gt;");
 766                        break;
 767                case '&':
 768                        strbuf_addstr(buf, "&amp;");
 769                        break;
 770                case 0:
 771                        return;
 772                }
 773                s++;
 774        }
 775}
 776
 777static int is_rfc3986_reserved(char ch)
 778{
 779        switch (ch) {
 780                case '!': case '*': case '\'': case '(': case ')': case ';':
 781                case ':': case '@': case '&': case '=': case '+': case '$':
 782                case ',': case '/': case '?': case '#': case '[': case ']':
 783                        return 1;
 784        }
 785        return 0;
 786}
 787
 788static int is_rfc3986_unreserved(char ch)
 789{
 790        return isalnum(ch) ||
 791                ch == '-' || ch == '_' || ch == '.' || ch == '~';
 792}
 793
 794static void strbuf_add_urlencode(struct strbuf *sb, const char *s, size_t len,
 795                                 int reserved)
 796{
 797        strbuf_grow(sb, len);
 798        while (len--) {
 799                char ch = *s++;
 800                if (is_rfc3986_unreserved(ch) ||
 801                    (!reserved && is_rfc3986_reserved(ch)))
 802                        strbuf_addch(sb, ch);
 803                else
 804                        strbuf_addf(sb, "%%%02x", (unsigned char)ch);
 805        }
 806}
 807
 808void strbuf_addstr_urlencode(struct strbuf *sb, const char *s,
 809                             int reserved)
 810{
 811        strbuf_add_urlencode(sb, s, strlen(s), reserved);
 812}
 813
 814void strbuf_humanise_bytes(struct strbuf *buf, off_t bytes)
 815{
 816        if (bytes > 1 << 30) {
 817                strbuf_addf(buf, "%u.%2.2u GiB",
 818                            (unsigned)(bytes >> 30),
 819                            (unsigned)(bytes & ((1 << 30) - 1)) / 10737419);
 820        } else if (bytes > 1 << 20) {
 821                unsigned x = bytes + 5243;  /* for rounding */
 822                strbuf_addf(buf, "%u.%2.2u MiB",
 823                            x >> 20, ((x & ((1 << 20) - 1)) * 100) >> 20);
 824        } else if (bytes > 1 << 10) {
 825                unsigned x = bytes + 5;  /* for rounding */
 826                strbuf_addf(buf, "%u.%2.2u KiB",
 827                            x >> 10, ((x & ((1 << 10) - 1)) * 100) >> 10);
 828        } else {
 829                strbuf_addf(buf, "%u bytes", (unsigned)bytes);
 830        }
 831}
 832
 833void strbuf_add_absolute_path(struct strbuf *sb, const char *path)
 834{
 835        if (!*path)
 836                die("The empty string is not a valid path");
 837        if (!is_absolute_path(path)) {
 838                struct stat cwd_stat, pwd_stat;
 839                size_t orig_len = sb->len;
 840                char *cwd = xgetcwd();
 841                char *pwd = getenv("PWD");
 842                if (pwd && strcmp(pwd, cwd) &&
 843                    !stat(cwd, &cwd_stat) &&
 844                    (cwd_stat.st_dev || cwd_stat.st_ino) &&
 845                    !stat(pwd, &pwd_stat) &&
 846                    pwd_stat.st_dev == cwd_stat.st_dev &&
 847                    pwd_stat.st_ino == cwd_stat.st_ino)
 848                        strbuf_addstr(sb, pwd);
 849                else
 850                        strbuf_addstr(sb, cwd);
 851                if (sb->len > orig_len && !is_dir_sep(sb->buf[sb->len - 1]))
 852                        strbuf_addch(sb, '/');
 853                free(cwd);
 854        }
 855        strbuf_addstr(sb, path);
 856}
 857
 858void strbuf_add_real_path(struct strbuf *sb, const char *path)
 859{
 860        if (sb->len) {
 861                struct strbuf resolved = STRBUF_INIT;
 862                strbuf_realpath(&resolved, path, 1);
 863                strbuf_addbuf(sb, &resolved);
 864                strbuf_release(&resolved);
 865        } else
 866                strbuf_realpath(sb, path, 1);
 867}
 868
 869int printf_ln(const char *fmt, ...)
 870{
 871        int ret;
 872        va_list ap;
 873        va_start(ap, fmt);
 874        ret = vprintf(fmt, ap);
 875        va_end(ap);
 876        if (ret < 0 || putchar('\n') == EOF)
 877                return -1;
 878        return ret + 1;
 879}
 880
 881int fprintf_ln(FILE *fp, const char *fmt, ...)
 882{
 883        int ret;
 884        va_list ap;
 885        va_start(ap, fmt);
 886        ret = vfprintf(fp, fmt, ap);
 887        va_end(ap);
 888        if (ret < 0 || putc('\n', fp) == EOF)
 889                return -1;
 890        return ret + 1;
 891}
 892
 893char *xstrdup_tolower(const char *string)
 894{
 895        char *result;
 896        size_t len, i;
 897
 898        len = strlen(string);
 899        result = xmallocz(len);
 900        for (i = 0; i < len; i++)
 901                result[i] = tolower(string[i]);
 902        return result;
 903}
 904
 905char *xstrdup_toupper(const char *string)
 906{
 907        char *result;
 908        size_t len, i;
 909
 910        len = strlen(string);
 911        result = xmallocz(len);
 912        for (i = 0; i < len; i++)
 913                result[i] = toupper(string[i]);
 914        return result;
 915}
 916
 917char *xstrvfmt(const char *fmt, va_list ap)
 918{
 919        struct strbuf buf = STRBUF_INIT;
 920        strbuf_vaddf(&buf, fmt, ap);
 921        return strbuf_detach(&buf, NULL);
 922}
 923
 924char *xstrfmt(const char *fmt, ...)
 925{
 926        va_list ap;
 927        char *ret;
 928
 929        va_start(ap, fmt);
 930        ret = xstrvfmt(fmt, ap);
 931        va_end(ap);
 932
 933        return ret;
 934}
 935
 936void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm,
 937                     int tz_offset, int suppress_tz_name)
 938{
 939        struct strbuf munged_fmt = STRBUF_INIT;
 940        size_t hint = 128;
 941        size_t len;
 942
 943        if (!*fmt)
 944                return;
 945
 946        /*
 947         * There is no portable way to pass timezone information to
 948         * strftime, so we handle %z and %Z here.
 949         */
 950        for (;;) {
 951                const char *percent = strchrnul(fmt, '%');
 952                strbuf_add(&munged_fmt, fmt, percent - fmt);
 953                if (!*percent)
 954                        break;
 955                fmt = percent + 1;
 956                switch (*fmt) {
 957                case '%':
 958                        strbuf_addstr(&munged_fmt, "%%");
 959                        fmt++;
 960                        break;
 961                case 'z':
 962                        strbuf_addf(&munged_fmt, "%+05d", tz_offset);
 963                        fmt++;
 964                        break;
 965                case 'Z':
 966                        if (suppress_tz_name) {
 967                                fmt++;
 968                                break;
 969                        }
 970                        /* FALLTHROUGH */
 971                default:
 972                        strbuf_addch(&munged_fmt, '%');
 973                }
 974        }
 975        fmt = munged_fmt.buf;
 976
 977        strbuf_grow(sb, hint);
 978        len = strftime(sb->buf + sb->len, sb->alloc - sb->len, fmt, tm);
 979
 980        if (!len) {
 981                /*
 982                 * strftime reports "0" if it could not fit the result in the buffer.
 983                 * Unfortunately, it also reports "0" if the requested time string
 984                 * takes 0 bytes. So our strategy is to munge the format so that the
 985                 * output contains at least one character, and then drop the extra
 986                 * character before returning.
 987                 */
 988                strbuf_addch(&munged_fmt, ' ');
 989                while (!len) {
 990                        hint *= 2;
 991                        strbuf_grow(sb, hint);
 992                        len = strftime(sb->buf + sb->len, sb->alloc - sb->len,
 993                                       munged_fmt.buf, tm);
 994                }
 995                len--; /* drop munged space */
 996        }
 997        strbuf_release(&munged_fmt);
 998        strbuf_setlen(sb, sb->len + len);
 999}
1000
1001void strbuf_add_unique_abbrev(struct strbuf *sb, const struct object_id *oid,
1002                              int abbrev_len)
1003{
1004        int r;
1005        strbuf_grow(sb, GIT_MAX_HEXSZ + 1);
1006        r = find_unique_abbrev_r(sb->buf + sb->len, oid, abbrev_len);
1007        strbuf_setlen(sb, sb->len + r);
1008}
1009
1010/*
1011 * Returns the length of a line, without trailing spaces.
1012 *
1013 * If the line ends with newline, it will be removed too.
1014 */
1015static size_t cleanup(char *line, size_t len)
1016{
1017        while (len) {
1018                unsigned char c = line[len - 1];
1019                if (!isspace(c))
1020                        break;
1021                len--;
1022        }
1023
1024        return len;
1025}
1026
1027/*
1028 * Remove empty lines from the beginning and end
1029 * and also trailing spaces from every line.
1030 *
1031 * Turn multiple consecutive empty lines between paragraphs
1032 * into just one empty line.
1033 *
1034 * If the input has only empty lines and spaces,
1035 * no output will be produced.
1036 *
1037 * If last line does not have a newline at the end, one is added.
1038 *
1039 * Enable skip_comments to skip every line starting with comment
1040 * character.
1041 */
1042void strbuf_stripspace(struct strbuf *sb, int skip_comments)
1043{
1044        size_t empties = 0;
1045        size_t i, j, len, newlen;
1046        char *eol;
1047
1048        /* We may have to add a newline. */
1049        strbuf_grow(sb, 1);
1050
1051        for (i = j = 0; i < sb->len; i += len, j += newlen) {
1052                eol = memchr(sb->buf + i, '\n', sb->len - i);
1053                len = eol ? eol - (sb->buf + i) + 1 : sb->len - i;
1054
1055                if (skip_comments && len && sb->buf[i] == comment_line_char) {
1056                        newlen = 0;
1057                        continue;
1058                }
1059                newlen = cleanup(sb->buf + i, len);
1060
1061                /* Not just an empty line? */
1062                if (newlen) {
1063                        if (empties > 0 && j > 0)
1064                                sb->buf[j++] = '\n';
1065                        empties = 0;
1066                        memmove(sb->buf + j, sb->buf + i, newlen);
1067                        sb->buf[newlen + j++] = '\n';
1068                } else {
1069                        empties++;
1070                }
1071        }
1072
1073        strbuf_setlen(sb, j);
1074}
1075
1076int strbuf_normalize_path(struct strbuf *src)
1077{
1078        struct strbuf dst = STRBUF_INIT;
1079
1080        strbuf_grow(&dst, src->len);
1081        if (normalize_path_copy(dst.buf, src->buf) < 0) {
1082                strbuf_release(&dst);
1083                return -1;
1084        }
1085
1086        /*
1087         * normalize_path does not tell us the new length, so we have to
1088         * compute it by looking for the new NUL it placed
1089         */
1090        strbuf_setlen(&dst, strlen(dst.buf));
1091        strbuf_swap(src, &dst);
1092        strbuf_release(&dst);
1093        return 0;
1094}