quote.c

   1 #include "cache.h"
   2 #include "quote.h"
   3 #include "argv-array.h"
   4
   5 int quote_path_fully = 1;
   6
   7 /* Help to copy the thing properly quoted for the shell safety.
   8  * any single quote is replaced with '\'', any exclamation point
   9  * is replaced with '\!', and the whole thing is enclosed in a
  10  *
  11  * E.g.
  12  *  original     sq_quote     result
  13  *  name     ==> name      ==> 'name'
  14  *  a b      ==> a b       ==> 'a b'
  15  *  a'b      ==> a'\''b    ==> 'a'\''b'
  16  *  a!b      ==> a'\!'b    ==> 'a'\!'b'
  17  */
  18 static inline int need_bs_quote(char c)
  19 {
  20         return (c == '\'' || c == '!');
  21 }
  22
  23 void sq_quote_buf(struct strbuf *dst, const char *src)
  24 {
  25         char *to_free = NULL;
  26
  27         if (dst->buf == src)
  28                 to_free = strbuf_detach(dst, NULL);
  29
  30         strbuf_addch(dst, '\'');
  31         while (*src) {
  32                 size_t len = strcspn(src, "'!");
  33                 strbuf_add(dst, src, len);
  34                 src += len;
  35                 while (need_bs_quote(*src)) {
  36                         strbuf_addstr(dst, "'\\");
  37                         strbuf_addch(dst, *src++);
  38                         strbuf_addch(dst, '\'');
  39                 }
  40         }
  41         strbuf_addch(dst, '\'');
  42         free(to_free);
  43 }
  44
  45 void sq_quote_print(FILE *stream, const char *src)
  46 {
  47         char c;
  48
  49         fputc('\'', stream);
  50         while ((c = *src++)) {
  51                 if (need_bs_quote(c)) {
  52                         fputs("'\\", stream);
  53                         fputc(c, stream);
  54                         fputc('\'', stream);
  55                 } else {
  56                         fputc(c, stream);
  57                 }
  58         }
  59         fputc('\'', stream);
  60 }
  61
  62 void sq_quote_argv(struct strbuf *dst, const char** argv, size_t maxlen)
  63 {
  64         int i;
  65
  66         /* Copy into destination buffer. */
  67         strbuf_grow(dst, 255);
  68         for (i = 0; argv[i]; ++i) {
  69                 strbuf_addch(dst, ' ');
  70                 sq_quote_buf(dst, argv[i]);
  71                 if (maxlen && dst->len > maxlen)
  72                         die("Too many or long arguments");
  73         }
  74 }
  75
  76 static char *sq_dequote_step(char *arg, char **next)
  77 {
  78         char *dst = arg;
  79         char *src = arg;
  80         char c;
  81
  82         if (*src != '\'')
  83                 return NULL;
  84         for (;;) {
  85                 c = *++src;
  86                 if (!c)
  87                         return NULL;
  88                 if (c != '\'') {
  89                         *dst++ = c;
  90                         continue;
  91                 }
  92                 /* We stepped out of sq */
  93                 switch (*++src) {
  94                 case '\0':
  95                         *dst = 0;
  96                         if (next)
  97                                 *next = NULL;
  98                         return arg;
  99                 case '\\':
 100                         c = *++src;
 101                         if (need_bs_quote(c) && *++src == '\'') {
 102                                 *dst++ = c;
 103                                 continue;
 104                         }
 105                 /* Fallthrough */
 106                 default:
 107                         if (!next || !isspace(*src))
 108                                 return NULL;
 109                         do {
 110                                 c = *++src;
 111                         } while (isspace(c));
 112                         *dst = 0;
 113                         *next = src;
 114                         return arg;
 115                 }
 116         }
 117 }
 118
 119 char *sq_dequote(char *arg)
 120 {
 121         return sq_dequote_step(arg, NULL);
 122 }
 123
 124 static int sq_dequote_to_argv_internal(char *arg,
 125                                        const char ***argv, int *nr, int *alloc,
 126                                        struct argv_array *array)
 127 {
 128         char *next = arg;
 129
 130         if (!*arg)
 131                 return 0;
 132         do {
 133                 char *dequoted = sq_dequote_step(next, &next);
 134                 if (!dequoted)
 135                         return -1;
 136                 if (argv) {
 137                         ALLOC_GROW(*argv, *nr + 1, *alloc);
 138                         (*argv)[(*nr)++] = dequoted;
 139                 }
 140                 if (array)
 141                         argv_array_push(array, dequoted);
 142         } while (next);
 143
 144         return 0;
 145 }
 146
 147 int sq_dequote_to_argv(char *arg, const char ***argv, int *nr, int *alloc)
 148 {
 149         return sq_dequote_to_argv_internal(arg, argv, nr, alloc, NULL);
 150 }
 151
 152 int sq_dequote_to_argv_array(char *arg, struct argv_array *array)
 153 {
 154         return sq_dequote_to_argv_internal(arg, NULL, NULL, NULL, array);
 155 }
 156
 157 /* 1 means: quote as octal
 158  * 0 means: quote as octal if (quote_path_fully)
 159  * -1 means: never quote
 160  * c: quote as "\\c"
 161  */
 162 #define X8(x)   x, x, x, x, x, x, x, x
 163 #define X16(x)  X8(x), X8(x)
 164 static signed char const sq_lookup[256] = {
 165         /*           0    1    2    3    4    5    6    7 */
 166         /* 0x00 */   1,   1,   1,   1,   1,   1,   1, 'a',
 167         /* 0x08 */ 'b', 't', 'n', 'v', 'f', 'r',   1,   1,
 168         /* 0x10 */ X16(1),
 169         /* 0x20 */  -1,  -1, '"',  -1,  -1,  -1,  -1,  -1,
 170         /* 0x28 */ X16(-1), X16(-1), X16(-1),
 171         /* 0x58 */  -1,  -1,  -1,  -1,'\\',  -1,  -1,  -1,
 172         /* 0x60 */ X16(-1), X8(-1),
 173         /* 0x78 */  -1,  -1,  -1,  -1,  -1,  -1,  -1,   1,
 174         /* 0x80 */ /* set to 0 */
 175 };
 176
 177 static inline int sq_must_quote(char c)
 178 {
 179         return sq_lookup[(unsigned char)c] + quote_path_fully > 0;
 180 }
 181
 182 /* returns the longest prefix not needing a quote up to maxlen if positive.
 183    This stops at the first \0 because it's marked as a character needing an
 184    escape */
 185 static size_t next_quote_pos(const char *s, ssize_t maxlen)
 186 {
 187         size_t len;
 188         if (maxlen < 0) {
 189                 for (len = 0; !sq_must_quote(s[len]); len++);
 190         } else {
 191                 for (len = 0; len < maxlen && !sq_must_quote(s[len]); len++);
 192         }
 193         return len;
 194 }
 195
 196 /*
 197  * C-style name quoting.
 198  *
 199  * (1) if sb and fp are both NULL, inspect the input name and counts the
 200  *     number of bytes that are needed to hold c_style quoted version of name,
 201  *     counting the double quotes around it but not terminating NUL, and
 202  *     returns it.
 203  *     However, if name does not need c_style quoting, it returns 0.
 204  *
 205  * (2) if sb or fp are not NULL, it emits the c_style quoted version
 206  *     of name, enclosed with double quotes if asked and needed only.
 207  *     Return value is the same as in (1).
 208  */
 209 static size_t quote_c_style_counted(const char *name, ssize_t maxlen,
 210                                     struct strbuf *sb, FILE *fp, int no_dq)
 211 {
 212 #undef EMIT
 213 #define EMIT(c)                                 \
 214         do {                                        \
 215                 if (sb) strbuf_addch(sb, (c));          \
 216                 if (fp) fputc((c), fp);                 \
 217                 count++;                                \
 218         } while (0)
 219 #define EMITBUF(s, l)                           \
 220         do {                                        \
 221                 if (sb) strbuf_add(sb, (s), (l));       \
 222                 if (fp) fwrite((s), (l), 1, fp);        \
 223                 count += (l);                           \
 224         } while (0)
 225
 226         size_t len, count = 0;
 227         const char *p = name;
 228
 229         for (;;) {
 230                 int ch;
 231
 232                 len = next_quote_pos(p, maxlen);
 233                 if (len == maxlen || (maxlen < 0 && !p[len]))
 234                         break;
 235
 236                 if (!no_dq && p == name)
 237                         EMIT('"');
 238
 239                 EMITBUF(p, len);
 240                 EMIT('\\');
 241                 p += len;
 242                 ch = (unsigned char)*p++;
 243                 if (maxlen >= 0)
 244                         maxlen -= len + 1;
 245                 if (sq_lookup[ch] >= ' ') {
 246                         EMIT(sq_lookup[ch]);
 247                 } else {
 248                         EMIT(((ch >> 6) & 03) + '0');
 249                         EMIT(((ch >> 3) & 07) + '0');
 250                         EMIT(((ch >> 0) & 07) + '0');
 251                 }
 252         }
 253
 254         EMITBUF(p, len);
 255         if (p == name)   /* no ending quote needed */
 256                 return 0;
 257
 258         if (!no_dq)
 259                 EMIT('"');
 260         return count;
 261 }
 262
 263 size_t quote_c_style(const char *name, struct strbuf *sb, FILE *fp, int nodq)
 264 {
 265         return quote_c_style_counted(name, -1, sb, fp, nodq);
 266 }
 267
 268 void quote_two_c_style(struct strbuf *sb, const char *prefix, const char *path, int nodq)
 269 {
 270         if (quote_c_style(prefix, NULL, NULL, 0) ||
 271             quote_c_style(path, NULL, NULL, 0)) {
 272                 if (!nodq)
 273                         strbuf_addch(sb, '"');
 274                 quote_c_style(prefix, sb, NULL, 1);
 275                 quote_c_style(path, sb, NULL, 1);
 276                 if (!nodq)
 277                         strbuf_addch(sb, '"');
 278         } else {
 279                 strbuf_addstr(sb, prefix);
 280                 strbuf_addstr(sb, path);
 281         }
 282 }
 283
 284 void write_name_quoted(const char *name, FILE *fp, int terminator)
 285 {
 286         if (terminator) {
 287                 quote_c_style(name, NULL, fp, 0);
 288         } else {
 289                 fputs(name, fp);
 290         }
 291         fputc(terminator, fp);
 292 }
 293
 294 void write_name_quotedpfx(const char *pfx, size_t pfxlen,
 295                           const char *name, FILE *fp, int terminator)
 296 {
 297         int needquote = 0;
 298
 299         if (terminator) {
 300                 needquote = next_quote_pos(pfx, pfxlen) < pfxlen
 301                         || name[next_quote_pos(name, -1)];
 302         }
 303         if (needquote) {
 304                 fputc('"', fp);
 305                 quote_c_style_counted(pfx, pfxlen, NULL, fp, 1);
 306                 quote_c_style(name, NULL, fp, 1);
 307                 fputc('"', fp);
 308         } else {
 309                 fwrite(pfx, pfxlen, 1, fp);
 310                 fputs(name, fp);
 311         }
 312         fputc(terminator, fp);
 313 }
 314
 315 static const char *path_relative(const char *in, int len,
 316                                  struct strbuf *sb, const char *prefix,
 317                                  int prefix_len);
 318
 319 void write_name_quoted_relative(const char *name, size_t len,
 320                                 const char *prefix, size_t prefix_len,
 321                                 FILE *fp, int terminator)
 322 {
 323         struct strbuf sb = STRBUF_INIT;
 324
 325         name = path_relative(name, len, &sb, prefix, prefix_len);
 326         write_name_quoted(name, fp, terminator);
 327
 328         strbuf_release(&sb);
 329 }
 330
 331 /*
 332  * Give path as relative to prefix.
 333  *
 334  * The strbuf may or may not be used, so do not assume it contains the
 335  * returned path.
 336  */
 337 static const char *path_relative(const char *in, int len,
 338                                  struct strbuf *sb, const char *prefix,
 339                                  int prefix_len)
 340 {
 341         int off, i;
 342
 343         if (len < 0)
 344                 len = strlen(in);
 345         if (prefix_len < 0) {
 346                 if (prefix)
 347                         prefix_len = strlen(prefix);
 348                 else
 349                         prefix_len = 0;
 350         }
 351
 352         off = 0;
 353         i = 0;
 354         while (i < prefix_len && i < len && prefix[i] == in[i]) {
 355                 if (prefix[i] == '/')
 356                         off = i + 1;
 357                 i++;
 358         }
 359         in += off;
 360         len -= off;
 361
 362         if (i >= prefix_len)
 363                 return in;
 364
 365         strbuf_reset(sb);
 366         strbuf_grow(sb, len);
 367
 368         while (i < prefix_len) {
 369                 if (prefix[i] == '/')
 370                         strbuf_addstr(sb, "../");
 371                 i++;
 372         }
 373         strbuf_add(sb, in, len);
 374
 375         return sb->buf;
 376 }
 377
 378 /* quote path as relative to the given prefix */
 379 char *quote_path_relative(const char *in, int len,
 380                           struct strbuf *out, const char *prefix)
 381 {
 382         struct strbuf sb = STRBUF_INIT;
 383         const char *rel = path_relative(in, len, &sb, prefix, -1);
 384         strbuf_reset(out);
 385         quote_c_style_counted(rel, strlen(rel), out, NULL, 0);
 386         strbuf_release(&sb);
 387
 388         if (!out->len)
 389                 strbuf_addstr(out, "./");
 390
 391         return out->buf;
 392 }
 393
 394 /*
 395  * C-style name unquoting.
 396  *
 397  * Quoted should point at the opening double quote.
 398  * + Returns 0 if it was able to unquote the string properly, and appends the
 399  *   result in the strbuf `sb'.
 400  * + Returns -1 in case of error, and doesn't touch the strbuf. Though note
 401  *   that this function will allocate memory in the strbuf, so calling
 402  *   strbuf_release is mandatory whichever result unquote_c_style returns.
 403  *
 404  * Updates endp pointer to point at one past the ending double quote if given.
 405  */
 406 int unquote_c_style(struct strbuf *sb, const char *quoted, const char **endp)
 407 {
 408         size_t oldlen = sb->len, len;
 409         int ch, ac;
 410
 411         if (*quoted++ != '"')
 412                 return -1;
 413
 414         for (;;) {
 415                 len = strcspn(quoted, "\"\\");
 416                 strbuf_add(sb, quoted, len);
 417                 quoted += len;
 418
 419                 switch (*quoted++) {
 420                   case '"':
 421                         if (endp)
 422                                 *endp = quoted;
 423                         return 0;
 424                   case '\\':
 425                         break;
 426                   default:
 427                         goto error;
 428                 }
 429
 430                 switch ((ch = *quoted++)) {
 431                 case 'a': ch = '\a'; break;
 432                 case 'b': ch = '\b'; break;
 433                 case 'f': ch = '\f'; break;
 434                 case 'n': ch = '\n'; break;
 435                 case 'r': ch = '\r'; break;
 436                 case 't': ch = '\t'; break;
 437                 case 'v': ch = '\v'; break;
 438
 439                 case '\\': case '"':
 440                         break; /* verbatim */
 441
 442                 /* octal values with first digit over 4 overflow */
 443                 case '0': case '1': case '2': case '3':
 444                                         ac = ((ch - '0') << 6);
 445                         if ((ch = *quoted++) < '0' || '7' < ch)
 446                                 goto error;
 447                                         ac |= ((ch - '0') << 3);
 448                         if ((ch = *quoted++) < '0' || '7' < ch)
 449                                 goto error;
 450                                         ac |= (ch - '0');
 451                                         ch = ac;
 452                                         break;
 453                                 default:
 454                         goto error;
 455                         }
 456                 strbuf_addch(sb, ch);
 457                 }
 458
 459   error:
 460         strbuf_setlen(sb, oldlen);
 461         return -1;
 462 }
 463
 464 /* quoting as a string literal for other languages */
 465
 466 void perl_quote_print(FILE *stream, const char *src)
 467 {
 468         const char sq = '\'';
 469         const char bq = '\\';
 470         char c;
 471
 472         fputc(sq, stream);
 473         while ((c = *src++)) {
 474                 if (c == sq || c == bq)
 475                         fputc(bq, stream);
 476                 fputc(c, stream);
 477         }
 478         fputc(sq, stream);
 479 }
 480
 481 void python_quote_print(FILE *stream, const char *src)
 482 {
 483         const char sq = '\'';
 484         const char bq = '\\';
 485         const char nl = '\n';
 486         char c;
 487
 488         fputc(sq, stream);
 489         while ((c = *src++)) {
 490                 if (c == nl) {
 491                         fputc(bq, stream);
 492                         fputc('n', stream);
 493                         continue;
 494                 }
 495                 if (c == sq || c == bq)
 496                         fputc(bq, stream);
 497                 fputc(c, stream);
 498         }
 499         fputc(sq, stream);
 500 }
 501
 502 void tcl_quote_print(FILE *stream, const char *src)
 503 {
 504         char c;
 505
 506         fputc('"', stream);
 507         while ((c = *src++)) {
 508                 switch (c) {
 509                 case '[': case ']':
 510                 case '{': case '}':
 511                 case '$': case '\\': case '"':
 512                         fputc('\\', stream);
 513                 default:
 514                         fputc(c, stream);
 515                         break;
 516                 case '\f':
 517                         fputs("\\f", stream);
 518                         break;
 519                 case '\r':
 520                         fputs("\\r", stream);
 521                         break;
 522                 case '\n':
 523                         fputs("\\n", stream);
 524                         break;
 525                 case '\t':
 526                         fputs("\\t", stream);
 527                         break;
 528                 case '\v':
 529                         fputs("\\v", stream);
 530                         break;
 531                 }
 532         }
 533         fputc('"', stream);
 534 }