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_argv(struct strbuf *dst, const char** argv, size_t maxlen)
  46 {
  47         int i;
  48
  49         /* Copy into destination buffer. */
  50         strbuf_grow(dst, 255);
  51         for (i = 0; argv[i]; ++i) {
  52                 strbuf_addch(dst, ' ');
  53                 sq_quote_buf(dst, argv[i]);
  54                 if (maxlen && dst->len > maxlen)
  55                         die("Too many or long arguments");
  56         }
  57 }
  58
  59 static char *sq_dequote_step(char *arg, char **next)
  60 {
  61         char *dst = arg;
  62         char *src = arg;
  63         char c;
  64
  65         if (*src != '\'')
  66                 return NULL;
  67         for (;;) {
  68                 c = *++src;
  69                 if (!c)
  70                         return NULL;
  71                 if (c != '\'') {
  72                         *dst++ = c;
  73                         continue;
  74                 }
  75                 /* We stepped out of sq */
  76                 switch (*++src) {
  77                 case '\0':
  78                         *dst = 0;
  79                         if (next)
  80                                 *next = NULL;
  81                         return arg;
  82                 case '\\':
  83                         c = *++src;
  84                         if (need_bs_quote(c) && *++src == '\'') {
  85                                 *dst++ = c;
  86                                 continue;
  87                         }
  88                 /* Fallthrough */
  89                 default:
  90                         if (!next || !isspace(*src))
  91                                 return NULL;
  92                         do {
  93                                 c = *++src;
  94                         } while (isspace(c));
  95                         *dst = 0;
  96                         *next = src;
  97                         return arg;
  98                 }
  99         }
 100 }
 101
 102 char *sq_dequote(char *arg)
 103 {
 104         return sq_dequote_step(arg, NULL);
 105 }
 106
 107 static int sq_dequote_to_argv_internal(char *arg,
 108                                        const char ***argv, int *nr, int *alloc,
 109                                        struct argv_array *array)
 110 {
 111         char *next = arg;
 112
 113         if (!*arg)
 114                 return 0;
 115         do {
 116                 char *dequoted = sq_dequote_step(next, &next);
 117                 if (!dequoted)
 118                         return -1;
 119                 if (argv) {
 120                         ALLOC_GROW(*argv, *nr + 1, *alloc);
 121                         (*argv)[(*nr)++] = dequoted;
 122                 }
 123                 if (array)
 124                         argv_array_push(array, dequoted);
 125         } while (next);
 126
 127         return 0;
 128 }
 129
 130 int sq_dequote_to_argv(char *arg, const char ***argv, int *nr, int *alloc)
 131 {
 132         return sq_dequote_to_argv_internal(arg, argv, nr, alloc, NULL);
 133 }
 134
 135 int sq_dequote_to_argv_array(char *arg, struct argv_array *array)
 136 {
 137         return sq_dequote_to_argv_internal(arg, NULL, NULL, NULL, array);
 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 || (maxlen < 0 && !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 (maxlen >= 0)
 227                         maxlen -= len + 1;
 228                 if (sq_lookup[ch] >= ' ') {
 229                         EMIT(sq_lookup[ch]);
 230                 } else {
 231                         EMIT(((ch >> 6) & 03) + '0');
 232                         EMIT(((ch >> 3) & 07) + '0');
 233                         EMIT(((ch >> 0) & 07) + '0');
 234                 }
 235         }
 236
 237         EMITBUF(p, len);
 238         if (p == name)   /* no ending quote needed */
 239                 return 0;
 240
 241         if (!no_dq)
 242                 EMIT('"');
 243         return count;
 244 }
 245
 246 size_t quote_c_style(const char *name, struct strbuf *sb, FILE *fp, int nodq)
 247 {
 248         return quote_c_style_counted(name, -1, sb, fp, nodq);
 249 }
 250
 251 void quote_two_c_style(struct strbuf *sb, const char *prefix, const char *path, int nodq)
 252 {
 253         if (quote_c_style(prefix, NULL, NULL, 0) ||
 254             quote_c_style(path, NULL, NULL, 0)) {
 255                 if (!nodq)
 256                         strbuf_addch(sb, '"');
 257                 quote_c_style(prefix, sb, NULL, 1);
 258                 quote_c_style(path, sb, NULL, 1);
 259                 if (!nodq)
 260                         strbuf_addch(sb, '"');
 261         } else {
 262                 strbuf_addstr(sb, prefix);
 263                 strbuf_addstr(sb, path);
 264         }
 265 }
 266
 267 void write_name_quoted(const char *name, FILE *fp, int terminator)
 268 {
 269         if (terminator) {
 270                 quote_c_style(name, NULL, fp, 0);
 271         } else {
 272                 fputs(name, fp);
 273         }
 274         fputc(terminator, fp);
 275 }
 276
 277 void write_name_quoted_relative(const char *name, const char *prefix,
 278                                 FILE *fp, int terminator)
 279 {
 280         struct strbuf sb = STRBUF_INIT;
 281
 282         name = relative_path(name, prefix, &sb);
 283         write_name_quoted(name, fp, terminator);
 284
 285         strbuf_release(&sb);
 286 }
 287
 288 /* quote path as relative to the given prefix */
 289 char *quote_path_relative(const char *in, const char *prefix,
 290                           struct strbuf *out)
 291 {
 292         struct strbuf sb = STRBUF_INIT;
 293         const char *rel = relative_path(in, prefix, &sb);
 294         strbuf_reset(out);
 295         quote_c_style_counted(rel, strlen(rel), out, NULL, 0);
 296         strbuf_release(&sb);
 297
 298         return out->buf;
 299 }
 300
 301 /*
 302  * C-style name unquoting.
 303  *
 304  * Quoted should point at the opening double quote.
 305  * + Returns 0 if it was able to unquote the string properly, and appends the
 306  *   result in the strbuf `sb'.
 307  * + Returns -1 in case of error, and doesn't touch the strbuf. Though note
 308  *   that this function will allocate memory in the strbuf, so calling
 309  *   strbuf_release is mandatory whichever result unquote_c_style returns.
 310  *
 311  * Updates endp pointer to point at one past the ending double quote if given.
 312  */
 313 int unquote_c_style(struct strbuf *sb, const char *quoted, const char **endp)
 314 {
 315         size_t oldlen = sb->len, len;
 316         int ch, ac;
 317
 318         if (*quoted++ != '"')
 319                 return -1;
 320
 321         for (;;) {
 322                 len = strcspn(quoted, "\"\\");
 323                 strbuf_add(sb, quoted, len);
 324                 quoted += len;
 325
 326                 switch (*quoted++) {
 327                   case '"':
 328                         if (endp)
 329                                 *endp = quoted;
 330                         return 0;
 331                   case '\\':
 332                         break;
 333                   default:
 334                         goto error;
 335                 }
 336
 337                 switch ((ch = *quoted++)) {
 338                 case 'a': ch = '\a'; break;
 339                 case 'b': ch = '\b'; break;
 340                 case 'f': ch = '\f'; break;
 341                 case 'n': ch = '\n'; break;
 342                 case 'r': ch = '\r'; break;
 343                 case 't': ch = '\t'; break;
 344                 case 'v': ch = '\v'; break;
 345
 346                 case '\\': case '"':
 347                         break; /* verbatim */
 348
 349                 /* octal values with first digit over 4 overflow */
 350                 case '0': case '1': case '2': case '3':
 351                                         ac = ((ch - '0') << 6);
 352                         if ((ch = *quoted++) < '0' || '7' < ch)
 353                                 goto error;
 354                                         ac |= ((ch - '0') << 3);
 355                         if ((ch = *quoted++) < '0' || '7' < ch)
 356                                 goto error;
 357                                         ac |= (ch - '0');
 358                                         ch = ac;
 359                                         break;
 360                                 default:
 361                         goto error;
 362                         }
 363                 strbuf_addch(sb, ch);
 364                 }
 365
 366   error:
 367         strbuf_setlen(sb, oldlen);
 368         return -1;
 369 }
 370
 371 /* quoting as a string literal for other languages */
 372
 373 void perl_quote_buf(struct strbuf *sb, const char *src)
 374 {
 375         const char sq = '\'';
 376         const char bq = '\\';
 377         char c;
 378
 379         strbuf_addch(sb, sq);
 380         while ((c = *src++)) {
 381                 if (c == sq || c == bq)
 382                         strbuf_addch(sb, bq);
 383                 strbuf_addch(sb, c);
 384         }
 385         strbuf_addch(sb, sq);
 386 }
 387
 388 void python_quote_buf(struct strbuf *sb, const char *src)
 389 {
 390         const char sq = '\'';
 391         const char bq = '\\';
 392         const char nl = '\n';
 393         char c;
 394
 395         strbuf_addch(sb, sq);
 396         while ((c = *src++)) {
 397                 if (c == nl) {
 398                         strbuf_addch(sb, bq);
 399                         strbuf_addch(sb, 'n');
 400                         continue;
 401                 }
 402                 if (c == sq || c == bq)
 403                         strbuf_addch(sb, bq);
 404                 strbuf_addch(sb, c);
 405         }
 406         strbuf_addch(sb, sq);
 407 }
 408
 409 void tcl_quote_buf(struct strbuf *sb, const char *src)
 410 {
 411         char c;
 412
 413         strbuf_addch(sb, '"');
 414         while ((c = *src++)) {
 415                 switch (c) {
 416                 case '[': case ']':
 417                 case '{': case '}':
 418                 case '$': case '\\': case '"':
 419                         strbuf_addch(sb, '\\');
 420                 default:
 421                         strbuf_addch(sb, c);
 422                         break;
 423                 case '\f':
 424                         strbuf_addstr(sb, "\\f");
 425                         break;
 426                 case '\r':
 427                         strbuf_addstr(sb, "\\r");
 428                         break;
 429                 case '\n':
 430                         strbuf_addstr(sb, "\\n");
 431                         break;
 432                 case '\t':
 433                         strbuf_addstr(sb, "\\t");
 434                         break;
 435                 case '\v':
 436                         strbuf_addstr(sb, "\\v");
 437                         break;
 438                 }
 439         }
 440         strbuf_addch(sb, '"');
 441 }