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