quote.c

   1 #include "cache.h"
   2 #include "quote.h"
   3 #include "argv-array.h"
   4
   5 int quote_path_fully = 1;
   6
   7 static inline int need_bs_quote(char c)
   8 {
   9         return (c == '\'' || c == '!');
  10 }
  11
  12 /* Help to copy the thing properly quoted for the shell safety.
  13  * any single quote is replaced with '\'', any exclamation point
  14  * is replaced with '\!', and the whole thing is enclosed in a
  15  * single quote pair.
  16  *
  17  * E.g.
  18  *  original     sq_quote     result
  19  *  name     ==> name      ==> 'name'
  20  *  a b      ==> a b       ==> 'a b'
  21  *  a'b      ==> a'\''b    ==> 'a'\''b'
  22  *  a!b      ==> a'\!'b    ==> 'a'\!'b'
  23  */
  24 void sq_quote_buf(struct strbuf *dst, const char *src)
  25 {
  26         char *to_free = NULL;
  27
  28         if (dst->buf == src)
  29                 to_free = strbuf_detach(dst, NULL);
  30
  31         strbuf_addch(dst, '\'');
  32         while (*src) {
  33                 size_t len = strcspn(src, "'!");
  34                 strbuf_add(dst, src, len);
  35                 src += len;
  36                 while (need_bs_quote(*src)) {
  37                         strbuf_addstr(dst, "'\\");
  38                         strbuf_addch(dst, *src++);
  39                         strbuf_addch(dst, '\'');
  40                 }
  41         }
  42         strbuf_addch(dst, '\'');
  43         free(to_free);
  44 }
  45
  46 void sq_quote_buf_pretty(struct strbuf *dst, const char *src)
  47 {
  48         static const char ok_punct[] = "+,-./:=@_^";
  49         const char *p;
  50
  51         for (p = src; *p; p++) {
  52                 if (!isalpha(*p) && !isdigit(*p) && !strchr(ok_punct, *p)) {
  53                         sq_quote_buf(dst, src);
  54                         return;
  55                 }
  56         }
  57
  58         /* if we get here, we did not need quoting */
  59         strbuf_addstr(dst, src);
  60 }
  61
  62 void sq_quotef(struct strbuf *dst, const char *fmt, ...)
  63 {
  64         struct strbuf src = STRBUF_INIT;
  65
  66         va_list ap;
  67         va_start(ap, fmt);
  68         strbuf_vaddf(&src, fmt, ap);
  69         va_end(ap);
  70
  71         sq_quote_buf(dst, src.buf);
  72         strbuf_release(&src);
  73 }
  74
  75 void sq_quote_argv(struct strbuf *dst, const char **argv)
  76 {
  77         int i;
  78
  79         /* Copy into destination buffer. */
  80         strbuf_grow(dst, 255);
  81         for (i = 0; argv[i]; ++i) {
  82                 strbuf_addch(dst, ' ');
  83                 sq_quote_buf(dst, argv[i]);
  84         }
  85 }
  86
  87 /*
  88  * Legacy function to append each argv value, quoted as necessasry,
  89  * with whitespace before each value.  This results in a leading
  90  * space in the result.
  91  */
  92 void sq_quote_argv_pretty(struct strbuf *dst, const char **argv)
  93 {
  94         if (argv[0])
  95                 strbuf_addch(dst, ' ');
  96         sq_append_quote_argv_pretty(dst, argv);
  97 }
  98
  99 /*
 100  * Append each argv value, quoted as necessary, with whitespace between them.
 101  */
 102 void sq_append_quote_argv_pretty(struct strbuf *dst, const char **argv)
 103 {
 104         int i;
 105
 106         for (i = 0; argv[i]; i++) {
 107                 if (i > 0)
 108                         strbuf_addch(dst, ' ');
 109                 sq_quote_buf_pretty(dst, argv[i]);
 110         }
 111 }
 112
 113 static char *sq_dequote_step(char *arg, char **next)
 114 {
 115         char *dst = arg;
 116         char *src = arg;
 117         char c;
 118
 119         if (*src != '\'')
 120                 return NULL;
 121         for (;;) {
 122                 c = *++src;
 123                 if (!c)
 124                         return NULL;
 125                 if (c != '\'') {
 126                         *dst++ = c;
 127                         continue;
 128                 }
 129                 /* We stepped out of sq */
 130                 switch (*++src) {
 131                 case '\0':
 132                         *dst = 0;
 133                         if (next)
 134                                 *next = NULL;
 135                         return arg;
 136                 case '\\':
 137                         /*
 138                          * Allow backslashed characters outside of
 139                          * single-quotes only if they need escaping,
 140                          * and only if we resume the single-quoted part
 141                          * afterward.
 142                          */
 143                         if (need_bs_quote(src[1]) && src[2] == '\'') {
 144                                 *dst++ = src[1];
 145                                 src += 2;
 146                                 continue;
 147                         }
 148                 /* Fallthrough */
 149                 default:
 150                         if (!next || !isspace(*src))
 151                                 return NULL;
 152                         do {
 153                                 c = *++src;
 154                         } while (isspace(c));
 155                         *dst = 0;
 156                         *next = src;
 157                         return arg;
 158                 }
 159         }
 160 }
 161
 162 char *sq_dequote(char *arg)
 163 {
 164         return sq_dequote_step(arg, NULL);
 165 }
 166
 167 static int sq_dequote_to_argv_internal(char *arg,
 168                                        const char ***argv, int *nr, int *alloc,
 169                                        struct argv_array *array)
 170 {
 171         char *next = arg;
 172
 173         if (!*arg)
 174                 return 0;
 175         do {
 176                 char *dequoted = sq_dequote_step(next, &next);
 177                 if (!dequoted)
 178                         return -1;
 179                 if (argv) {
 180                         ALLOC_GROW(*argv, *nr + 1, *alloc);
 181                         (*argv)[(*nr)++] = dequoted;
 182                 }
 183                 if (array)
 184                         argv_array_push(array, dequoted);
 185         } while (next);
 186
 187         return 0;
 188 }
 189
 190 int sq_dequote_to_argv(char *arg, const char ***argv, int *nr, int *alloc)
 191 {
 192         return sq_dequote_to_argv_internal(arg, argv, nr, alloc, NULL);
 193 }
 194
 195 int sq_dequote_to_argv_array(char *arg, struct argv_array *array)
 196 {
 197         return sq_dequote_to_argv_internal(arg, NULL, NULL, NULL, array);
 198 }
 199
 200 /* 1 means: quote as octal
 201  * 0 means: quote as octal if (quote_path_fully)
 202  * -1 means: never quote
 203  * c: quote as "\\c"
 204  */
 205 #define X8(x)   x, x, x, x, x, x, x, x
 206 #define X16(x)  X8(x), X8(x)
 207 static signed char const sq_lookup[256] = {
 208         /*           0    1    2    3    4    5    6    7 */
 209         /* 0x00 */   1,   1,   1,   1,   1,   1,   1, 'a',
 210         /* 0x08 */ 'b', 't', 'n', 'v', 'f', 'r',   1,   1,
 211         /* 0x10 */ X16(1),
 212         /* 0x20 */  -1,  -1, '"',  -1,  -1,  -1,  -1,  -1,
 213         /* 0x28 */ X16(-1), X16(-1), X16(-1),
 214         /* 0x58 */  -1,  -1,  -1,  -1,'\\',  -1,  -1,  -1,
 215         /* 0x60 */ X16(-1), X8(-1),
 216         /* 0x78 */  -1,  -1,  -1,  -1,  -1,  -1,  -1,   1,
 217         /* 0x80 */ /* set to 0 */
 218 };
 219
 220 static inline int sq_must_quote(char c)
 221 {
 222         return sq_lookup[(unsigned char)c] + quote_path_fully > 0;
 223 }
 224
 225 /* returns the longest prefix not needing a quote up to maxlen if positive.
 226    This stops at the first \0 because it's marked as a character needing an
 227    escape */
 228 static size_t next_quote_pos(const char *s, ssize_t maxlen)
 229 {
 230         size_t len;
 231         if (maxlen < 0) {
 232                 for (len = 0; !sq_must_quote(s[len]); len++);
 233         } else {
 234                 for (len = 0; len < maxlen && !sq_must_quote(s[len]); len++);
 235         }
 236         return len;
 237 }
 238
 239 /*
 240  * C-style name quoting.
 241  *
 242  * (1) if sb and fp are both NULL, inspect the input name and counts the
 243  *     number of bytes that are needed to hold c_style quoted version of name,
 244  *     counting the double quotes around it but not terminating NUL, and
 245  *     returns it.
 246  *     However, if name does not need c_style quoting, it returns 0.
 247  *
 248  * (2) if sb or fp are not NULL, it emits the c_style quoted version
 249  *     of name, enclosed with double quotes if asked and needed only.
 250  *     Return value is the same as in (1).
 251  */
 252 static size_t quote_c_style_counted(const char *name, ssize_t maxlen,
 253                                     struct strbuf *sb, FILE *fp, int no_dq)
 254 {
 255 #undef EMIT
 256 #define EMIT(c)                                 \
 257         do {                                        \
 258                 if (sb) strbuf_addch(sb, (c));          \
 259                 if (fp) fputc((c), fp);                 \
 260                 count++;                                \
 261         } while (0)
 262 #define EMITBUF(s, l)                           \
 263         do {                                        \
 264                 if (sb) strbuf_add(sb, (s), (l));       \
 265                 if (fp) fwrite((s), (l), 1, fp);        \
 266                 count += (l);                           \
 267         } while (0)
 268
 269         size_t len, count = 0;
 270         const char *p = name;
 271
 272         for (;;) {
 273                 int ch;
 274
 275                 len = next_quote_pos(p, maxlen);
 276                 if (len == maxlen || (maxlen < 0 && !p[len]))
 277                         break;
 278
 279                 if (!no_dq && p == name)
 280                         EMIT('"');
 281
 282                 EMITBUF(p, len);
 283                 EMIT('\\');
 284                 p += len;
 285                 ch = (unsigned char)*p++;
 286                 if (maxlen >= 0)
 287                         maxlen -= len + 1;
 288                 if (sq_lookup[ch] >= ' ') {
 289                         EMIT(sq_lookup[ch]);
 290                 } else {
 291                         EMIT(((ch >> 6) & 03) + '0');
 292                         EMIT(((ch >> 3) & 07) + '0');
 293                         EMIT(((ch >> 0) & 07) + '0');
 294                 }
 295         }
 296
 297         EMITBUF(p, len);
 298         if (p == name)   /* no ending quote needed */
 299                 return 0;
 300
 301         if (!no_dq)
 302                 EMIT('"');
 303         return count;
 304 }
 305
 306 size_t quote_c_style(const char *name, struct strbuf *sb, FILE *fp, int nodq)
 307 {
 308         return quote_c_style_counted(name, -1, sb, fp, nodq);
 309 }
 310
 311 void quote_two_c_style(struct strbuf *sb, const char *prefix, const char *path, int nodq)
 312 {
 313         if (quote_c_style(prefix, NULL, NULL, 0) ||
 314             quote_c_style(path, NULL, NULL, 0)) {
 315                 if (!nodq)
 316                         strbuf_addch(sb, '"');
 317                 quote_c_style(prefix, sb, NULL, 1);
 318                 quote_c_style(path, sb, NULL, 1);
 319                 if (!nodq)
 320                         strbuf_addch(sb, '"');
 321         } else {
 322                 strbuf_addstr(sb, prefix);
 323                 strbuf_addstr(sb, path);
 324         }
 325 }
 326
 327 void write_name_quoted(const char *name, FILE *fp, int terminator)
 328 {
 329         if (terminator) {
 330                 quote_c_style(name, NULL, fp, 0);
 331         } else {
 332                 fputs(name, fp);
 333         }
 334         fputc(terminator, fp);
 335 }
 336
 337 void write_name_quoted_relative(const char *name, const char *prefix,
 338                                 FILE *fp, int terminator)
 339 {
 340         struct strbuf sb = STRBUF_INIT;
 341
 342         name = relative_path(name, prefix, &sb);
 343         write_name_quoted(name, fp, terminator);
 344
 345         strbuf_release(&sb);
 346 }
 347
 348 /* quote path as relative to the given prefix */
 349 char *quote_path_relative(const char *in, const char *prefix,
 350                           struct strbuf *out)
 351 {
 352         struct strbuf sb = STRBUF_INIT;
 353         const char *rel = relative_path(in, prefix, &sb);
 354         strbuf_reset(out);
 355         quote_c_style_counted(rel, strlen(rel), out, NULL, 0);
 356         strbuf_release(&sb);
 357
 358         return out->buf;
 359 }
 360
 361 /*
 362  * C-style name unquoting.
 363  *
 364  * Quoted should point at the opening double quote.
 365  * + Returns 0 if it was able to unquote the string properly, and appends the
 366  *   result in the strbuf `sb'.
 367  * + Returns -1 in case of error, and doesn't touch the strbuf. Though note
 368  *   that this function will allocate memory in the strbuf, so calling
 369  *   strbuf_release is mandatory whichever result unquote_c_style returns.
 370  *
 371  * Updates endp pointer to point at one past the ending double quote if given.
 372  */
 373 int unquote_c_style(struct strbuf *sb, const char *quoted, const char **endp)
 374 {
 375         size_t oldlen = sb->len, len;
 376         int ch, ac;
 377
 378         if (*quoted++ != '"')
 379                 return -1;
 380
 381         for (;;) {
 382                 len = strcspn(quoted, "\"\\");
 383                 strbuf_add(sb, quoted, len);
 384                 quoted += len;
 385
 386                 switch (*quoted++) {
 387                   case '"':
 388                         if (endp)
 389                                 *endp = quoted;
 390                         return 0;
 391                   case '\\':
 392                         break;
 393                   default:
 394                         goto error;
 395                 }
 396
 397                 switch ((ch = *quoted++)) {
 398                 case 'a': ch = '\a'; break;
 399                 case 'b': ch = '\b'; break;
 400                 case 'f': ch = '\f'; break;
 401                 case 'n': ch = '\n'; break;
 402                 case 'r': ch = '\r'; break;
 403                 case 't': ch = '\t'; break;
 404                 case 'v': ch = '\v'; break;
 405
 406                 case '\\': case '"':
 407                         break; /* verbatim */
 408
 409                 /* octal values with first digit over 4 overflow */
 410                 case '0': case '1': case '2': case '3':
 411                                         ac = ((ch - '0') << 6);
 412                         if ((ch = *quoted++) < '0' || '7' < ch)
 413                                 goto error;
 414                                         ac |= ((ch - '0') << 3);
 415                         if ((ch = *quoted++) < '0' || '7' < ch)
 416                                 goto error;
 417                                         ac |= (ch - '0');
 418                                         ch = ac;
 419                                         break;
 420                                 default:
 421                         goto error;
 422                         }
 423                 strbuf_addch(sb, ch);
 424                 }
 425
 426   error:
 427         strbuf_setlen(sb, oldlen);
 428         return -1;
 429 }
 430
 431 /* quoting as a string literal for other languages */
 432
 433 void perl_quote_buf(struct strbuf *sb, const char *src)
 434 {
 435         const char sq = '\'';
 436         const char bq = '\\';
 437         char c;
 438
 439         strbuf_addch(sb, sq);
 440         while ((c = *src++)) {
 441                 if (c == sq || c == bq)
 442                         strbuf_addch(sb, bq);
 443                 strbuf_addch(sb, c);
 444         }
 445         strbuf_addch(sb, sq);
 446 }
 447
 448 void python_quote_buf(struct strbuf *sb, const char *src)
 449 {
 450         const char sq = '\'';
 451         const char bq = '\\';
 452         const char nl = '\n';
 453         char c;
 454
 455         strbuf_addch(sb, sq);
 456         while ((c = *src++)) {
 457                 if (c == nl) {
 458                         strbuf_addch(sb, bq);
 459                         strbuf_addch(sb, 'n');
 460                         continue;
 461                 }
 462                 if (c == sq || c == bq)
 463                         strbuf_addch(sb, bq);
 464                 strbuf_addch(sb, c);
 465         }
 466         strbuf_addch(sb, sq);
 467 }
 468
 469 void tcl_quote_buf(struct strbuf *sb, const char *src)
 470 {
 471         char c;
 472
 473         strbuf_addch(sb, '"');
 474         while ((c = *src++)) {
 475                 switch (c) {
 476                 case '[': case ']':
 477                 case '{': case '}':
 478                 case '$': case '\\': case '"':
 479                         strbuf_addch(sb, '\\');
 480                         /* fallthrough */
 481                 default:
 482                         strbuf_addch(sb, c);
 483                         break;
 484                 case '\f':
 485                         strbuf_addstr(sb, "\\f");
 486                         break;
 487                 case '\r':
 488                         strbuf_addstr(sb, "\\r");
 489                         break;
 490                 case '\n':
 491                         strbuf_addstr(sb, "\\n");
 492                         break;
 493                 case '\t':
 494                         strbuf_addstr(sb, "\\t");
 495                         break;
 496                 case '\v':
 497                         strbuf_addstr(sb, "\\v");
 498                         break;
 499                 }
 500         }
 501         strbuf_addch(sb, '"');
 502 }
 503
 504 void basic_regex_quote_buf(struct strbuf *sb, const char *src)
 505 {
 506         char c;
 507
 508         if (*src == '^') {
 509                 /* only beginning '^' is special and needs quoting */
 510                 strbuf_addch(sb, '\\');
 511                 strbuf_addch(sb, *src++);
 512         }
 513         if (*src == '*')
 514                 /* beginning '*' is not special, no quoting */
 515                 strbuf_addch(sb, *src++);
 516
 517         while ((c = *src++)) {
 518                 switch (c) {
 519                 case '[':
 520                 case '.':
 521                 case '\\':
 522                 case '*':
 523                         strbuf_addch(sb, '\\');
 524                         strbuf_addch(sb, c);
 525                         break;
 526
 527                 case '$':
 528                         /* only the end '$' is special and needs quoting */
 529                         if (*src == '\0')
 530                                 strbuf_addch(sb, '\\');
 531                         strbuf_addch(sb, c);
 532                         break;
 533
 534                 default:
 535                         strbuf_addch(sb, c);
 536                         break;
 537                 }
 538         }
 539 }