quote.c

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