| File: | src/gnu/lib/libreadline/tilde.c |
| Warning: | line 204, column 18 Although the value stored to 'result_size' is used in the enclosing expression, the value is never actually read from 'result_size' |
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| 1 | /* tilde.c -- Tilde expansion code (~/foo := $HOME/foo). */ |
| 2 | |
| 3 | /* Copyright (C) 1988,1989 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GNU Readline, a library for reading lines |
| 6 | of text with interactive input and history editing. |
| 7 | |
| 8 | Readline is free software; you can redistribute it and/or modify it |
| 9 | under the terms of the GNU General Public License as published by the |
| 10 | Free Software Foundation; either version 2, or (at your option) any |
| 11 | later version. |
| 12 | |
| 13 | Readline is distributed in the hope that it will be useful, but |
| 14 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with Readline; see the file COPYING. If not, write to the Free |
| 20 | Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */ |
| 21 | |
| 22 | #if defined (HAVE_CONFIG_H1) |
| 23 | # include <config.h> |
| 24 | #endif |
| 25 | |
| 26 | #if defined (HAVE_UNISTD_H1) |
| 27 | # ifdef _MINIX |
| 28 | # include <sys/types.h> |
| 29 | # endif |
| 30 | # include <unistd.h> |
| 31 | #endif |
| 32 | |
| 33 | #if defined (HAVE_STRING_H1) |
| 34 | # include <string.h> |
| 35 | #else /* !HAVE_STRING_H */ |
| 36 | # include <strings.h> |
| 37 | #endif /* !HAVE_STRING_H */ |
| 38 | |
| 39 | #if defined (HAVE_STDLIB_H1) |
| 40 | # include <stdlib.h> |
| 41 | #else |
| 42 | # include "ansi_stdlib.h" |
| 43 | #endif /* HAVE_STDLIB_H */ |
| 44 | |
| 45 | #include <sys/types.h> |
| 46 | #include <pwd.h> |
| 47 | |
| 48 | #include "tilde.h" |
| 49 | |
| 50 | #if defined (TEST) || defined (STATIC_MALLOC) |
| 51 | static void *xmalloc (), *xrealloc (); |
| 52 | #else |
| 53 | # include "xmalloc.h" |
| 54 | #endif /* TEST || STATIC_MALLOC */ |
| 55 | |
| 56 | #if !defined (HAVE_GETPW_DECLS1) |
| 57 | extern struct passwd *getpwuid PARAMS((uid_t))(uid_t); |
| 58 | extern struct passwd *getpwnam PARAMS((const char *))(const char *); |
| 59 | #endif /* !HAVE_GETPW_DECLS */ |
| 60 | |
| 61 | #if !defined (savestring) |
| 62 | #include <stdio.h> |
| 63 | static char * |
| 64 | xstrdup(const char *s) |
| 65 | { |
| 66 | char * cp; |
| 67 | cp = strdup(s); |
| 68 | if (cp == NULL((void *)0)) { |
| 69 | fprintf (stderr(&__sF[2]), "xstrdup: out of virtual memory\n"); |
| 70 | exit (2); |
| 71 | } |
| 72 | return(cp); |
| 73 | } |
| 74 | #define savestring(x)xstrdup(x) xstrdup(x) |
| 75 | #endif /* !savestring */ |
| 76 | |
| 77 | #if !defined (NULL((void *)0)) |
| 78 | # if defined (__STDC__1) |
| 79 | # define NULL((void *)0) ((void *) 0) |
| 80 | # else |
| 81 | # define NULL((void *)0) 0x0 |
| 82 | # endif /* !__STDC__ */ |
| 83 | #endif /* !NULL */ |
| 84 | |
| 85 | /* If being compiled as part of bash, these will be satisfied from |
| 86 | variables.o. If being compiled as part of readline, they will |
| 87 | be satisfied from shell.o. */ |
| 88 | extern char *sh_get_home_dir PARAMS((void))(void); |
| 89 | extern char *sh_get_env_value PARAMS((const char *))(const char *); |
| 90 | |
| 91 | /* The default value of tilde_additional_prefixes. This is set to |
| 92 | whitespace preceding a tilde so that simple programs which do not |
| 93 | perform any word separation get desired behaviour. */ |
| 94 | static const char *default_prefixes[] = |
| 95 | { " ~", "\t~", (const char *)NULL((void *)0) }; |
| 96 | |
| 97 | /* The default value of tilde_additional_suffixes. This is set to |
| 98 | whitespace or newline so that simple programs which do not |
| 99 | perform any word separation get desired behaviour. */ |
| 100 | static const char *default_suffixes[] = |
| 101 | { " ", "\n", (const char *)NULL((void *)0) }; |
| 102 | |
| 103 | /* If non-null, this contains the address of a function that the application |
| 104 | wants called before trying the standard tilde expansions. The function |
| 105 | is called with the text sans tilde, and returns a malloc()'ed string |
| 106 | which is the expansion, or a NULL pointer if the expansion fails. */ |
| 107 | tilde_hook_func_t *tilde_expansion_preexpansion_hook = (tilde_hook_func_t *)NULL((void *)0); |
| 108 | |
| 109 | /* If non-null, this contains the address of a function to call if the |
| 110 | standard meaning for expanding a tilde fails. The function is called |
| 111 | with the text (sans tilde, as in "foo"), and returns a malloc()'ed string |
| 112 | which is the expansion, or a NULL pointer if there is no expansion. */ |
| 113 | tilde_hook_func_t *tilde_expansion_failure_hook = (tilde_hook_func_t *)NULL((void *)0); |
| 114 | |
| 115 | /* When non-null, this is a NULL terminated array of strings which |
| 116 | are duplicates for a tilde prefix. Bash uses this to expand |
| 117 | `=~' and `:~'. */ |
| 118 | char **tilde_additional_prefixes = (char **)default_prefixes; |
| 119 | |
| 120 | /* When non-null, this is a NULL terminated array of strings which match |
| 121 | the end of a username, instead of just "/". Bash sets this to |
| 122 | `:' and `=~'. */ |
| 123 | char **tilde_additional_suffixes = (char **)default_suffixes; |
| 124 | |
| 125 | static int tilde_find_prefix PARAMS((const char *, int *))(const char *, int *); |
| 126 | static int tilde_find_suffix PARAMS((const char *))(const char *); |
| 127 | static char *isolate_tilde_prefix PARAMS((const char *, int *))(const char *, int *); |
| 128 | static char *glue_prefix_and_suffix PARAMS((char *, const char *, int))(char *, const char *, int); |
| 129 | |
| 130 | /* Find the start of a tilde expansion in STRING, and return the index of |
| 131 | the tilde which starts the expansion. Place the length of the text |
| 132 | which identified this tilde starter in LEN, excluding the tilde itself. */ |
| 133 | static int |
| 134 | tilde_find_prefix (string, len) |
| 135 | const char *string; |
| 136 | int *len; |
| 137 | { |
| 138 | register int i, j, string_len; |
| 139 | register char **prefixes; |
| 140 | |
| 141 | prefixes = tilde_additional_prefixes; |
| 142 | |
| 143 | string_len = strlen (string); |
| 144 | *len = 0; |
| 145 | |
| 146 | if (*string == '\0' || *string == '~') |
| 147 | return (0); |
| 148 | |
| 149 | if (prefixes) |
| 150 | { |
| 151 | for (i = 0; i < string_len; i++) |
| 152 | { |
| 153 | for (j = 0; prefixes[j]; j++) |
| 154 | { |
| 155 | if (strncmp (string + i, prefixes[j], strlen (prefixes[j])) == 0) |
| 156 | { |
| 157 | *len = strlen (prefixes[j]) - 1; |
| 158 | return (i + *len); |
| 159 | } |
| 160 | } |
| 161 | } |
| 162 | } |
| 163 | return (string_len); |
| 164 | } |
| 165 | |
| 166 | /* Find the end of a tilde expansion in STRING, and return the index of |
| 167 | the character which ends the tilde definition. */ |
| 168 | static int |
| 169 | tilde_find_suffix (string) |
| 170 | const char *string; |
| 171 | { |
| 172 | register int i, j, string_len; |
| 173 | register char **suffixes; |
| 174 | |
| 175 | suffixes = tilde_additional_suffixes; |
| 176 | string_len = strlen (string); |
| 177 | |
| 178 | for (i = 0; i < string_len; i++) |
| 179 | { |
| 180 | #if defined (__MSDOS__) |
| 181 | if (string[i] == '/' || string[i] == '\\' /* || !string[i] */) |
| 182 | #else |
| 183 | if (string[i] == '/' /* || !string[i] */) |
| 184 | #endif |
| 185 | break; |
| 186 | |
| 187 | for (j = 0; suffixes && suffixes[j]; j++) |
| 188 | { |
| 189 | if (strncmp (string + i, suffixes[j], strlen (suffixes[j])) == 0) |
| 190 | return (i); |
| 191 | } |
| 192 | } |
| 193 | return (i); |
| 194 | } |
| 195 | |
| 196 | /* Return a new string which is the result of tilde expanding STRING. */ |
| 197 | char * |
| 198 | tilde_expand (string) |
| 199 | const char *string; |
| 200 | { |
| 201 | char *result; |
| 202 | int result_size, result_index; |
| 203 | |
| 204 | result_index = result_size = 0; |
Although the value stored to 'result_size' is used in the enclosing expression, the value is never actually read from 'result_size' | |
| 205 | if ((result = strchr (string, '~'))) |
| 206 | result = (char *)xmalloc (result_size = (strlen (string) + 16)); |
| 207 | else |
| 208 | result = (char *)xmalloc (result_size = (strlen (string) + 1)); |
| 209 | |
| 210 | /* Scan through STRING expanding tildes as we come to them. */ |
| 211 | while (1) |
| 212 | { |
| 213 | register int start, end; |
| 214 | char *tilde_word, *expansion; |
| 215 | int len; |
| 216 | |
| 217 | /* Make START point to the tilde which starts the expansion. */ |
| 218 | start = tilde_find_prefix (string, &len); |
| 219 | |
| 220 | /* Copy the skipped text into the result. */ |
| 221 | if ((result_index + start + 1) > result_size) |
| 222 | result = (char *)xrealloc (result, 1 + (result_size += (start + 20))); |
| 223 | |
| 224 | strncpy (result + result_index, string, start); |
| 225 | result_index += start; |
| 226 | |
| 227 | /* Advance STRING to the starting tilde. */ |
| 228 | string += start; |
| 229 | |
| 230 | /* Make END be the index of one after the last character of the |
| 231 | username. */ |
| 232 | end = tilde_find_suffix (string); |
| 233 | |
| 234 | /* If both START and END are zero, we are all done. */ |
| 235 | if (!start && !end) |
| 236 | break; |
| 237 | |
| 238 | /* Expand the entire tilde word, and copy it into RESULT. */ |
| 239 | tilde_word = (char *)xmalloc (1 + end); |
| 240 | strncpy (tilde_word, string, end); |
| 241 | tilde_word[end] = '\0'; |
| 242 | string += end; |
| 243 | |
| 244 | expansion = tilde_expand_word (tilde_word); |
| 245 | free (tilde_word); |
| 246 | |
| 247 | len = strlen (expansion); |
| 248 | #ifdef __CYGWIN__ |
| 249 | /* Fix for Cygwin to prevent ~user/xxx from expanding to //xxx when |
| 250 | $HOME for `user' is /. On cygwin, // denotes a network drive. */ |
| 251 | if (len > 1 || *expansion != '/' || *string != '/') |
| 252 | #endif |
| 253 | { |
| 254 | if ((result_index + len + 1) > result_size) |
| 255 | result = (char *)xrealloc (result, 1 + (result_size += (len + 20))); |
| 256 | |
| 257 | strlcpy (result + result_index, expansion, |
| 258 | result_size - result_index); |
| 259 | result_index += len; |
| 260 | } |
| 261 | free (expansion); |
| 262 | } |
| 263 | |
| 264 | result[result_index] = '\0'; |
| 265 | |
| 266 | return (result); |
| 267 | } |
| 268 | |
| 269 | /* Take FNAME and return the tilde prefix we want expanded. If LENP is |
| 270 | non-null, the index of the end of the prefix into FNAME is returned in |
| 271 | the location it points to. */ |
| 272 | static char * |
| 273 | isolate_tilde_prefix (fname, lenp) |
| 274 | const char *fname; |
| 275 | int *lenp; |
| 276 | { |
| 277 | char *ret; |
| 278 | int i; |
| 279 | |
| 280 | ret = (char *)xmalloc (strlen (fname)); |
| 281 | #if defined (__MSDOS__) |
| 282 | for (i = 1; fname[i] && fname[i] != '/' && fname[i] != '\\'; i++) |
| 283 | #else |
| 284 | for (i = 1; fname[i] && fname[i] != '/'; i++) |
| 285 | #endif |
| 286 | ret[i - 1] = fname[i]; |
| 287 | ret[i - 1] = '\0'; |
| 288 | if (lenp) |
| 289 | *lenp = i; |
| 290 | return ret; |
| 291 | } |
| 292 | |
| 293 | /* Return a string that is PREFIX concatenated with SUFFIX starting at |
| 294 | SUFFIND. */ |
| 295 | static char * |
| 296 | glue_prefix_and_suffix (prefix, suffix, suffind) |
| 297 | char *prefix; |
| 298 | const char *suffix; |
| 299 | int suffind; |
| 300 | { |
| 301 | char *ret; |
| 302 | int plen, slen; |
| 303 | |
| 304 | plen = (prefix && *prefix) ? strlen (prefix) : 0; |
| 305 | slen = strlen (suffix + suffind); |
| 306 | ret = (char *)xmalloc (plen + slen + 1); |
| 307 | if (plen) |
| 308 | strlcpy (ret, prefix, plen + slen + 1); |
| 309 | strlcat (ret, suffix + suffind, plen + slen + 1); |
| 310 | return ret; |
| 311 | } |
| 312 | |
| 313 | /* Do the work of tilde expansion on FILENAME. FILENAME starts with a |
| 314 | tilde. If there is no expansion, call tilde_expansion_failure_hook. |
| 315 | This always returns a newly-allocated string, never static storage. */ |
| 316 | char * |
| 317 | tilde_expand_word (filename) |
| 318 | const char *filename; |
| 319 | { |
| 320 | char *dirname, *expansion, *username; |
| 321 | int user_len; |
| 322 | struct passwd *user_entry; |
| 323 | |
| 324 | if (filename == 0) |
| 325 | return ((char *)NULL((void *)0)); |
| 326 | |
| 327 | if (*filename != '~') |
| 328 | return (savestring (filename)xstrdup(filename)); |
| 329 | |
| 330 | /* A leading `~/' or a bare `~' is *always* translated to the value of |
| 331 | $HOME or the home directory of the current user, regardless of any |
| 332 | preexpansion hook. */ |
| 333 | if (filename[1] == '\0' || filename[1] == '/') |
| 334 | { |
| 335 | /* Prefix $HOME to the rest of the string. */ |
| 336 | expansion = sh_get_env_value ("HOME"); |
| 337 | |
| 338 | /* If there is no HOME variable, look up the directory in |
| 339 | the password database. */ |
| 340 | if (expansion == 0 || *expansion == '\0') |
| 341 | expansion = sh_get_home_dir (); |
| 342 | |
| 343 | return (glue_prefix_and_suffix (expansion, filename, 1)); |
| 344 | } |
| 345 | |
| 346 | username = isolate_tilde_prefix (filename, &user_len); |
| 347 | |
| 348 | if (tilde_expansion_preexpansion_hook) |
| 349 | { |
| 350 | expansion = (*tilde_expansion_preexpansion_hook) (username); |
| 351 | if (expansion) |
| 352 | { |
| 353 | dirname = glue_prefix_and_suffix (expansion, filename, user_len); |
| 354 | free (username); |
| 355 | free (expansion); |
| 356 | return (dirname); |
| 357 | } |
| 358 | } |
| 359 | |
| 360 | /* No preexpansion hook, or the preexpansion hook failed. Look in the |
| 361 | password database. */ |
| 362 | dirname = (char *)NULL((void *)0); |
| 363 | user_entry = getpwnam (username); |
| 364 | if (user_entry == 0) |
| 365 | { |
| 366 | /* If the calling program has a special syntax for expanding tildes, |
| 367 | and we couldn't find a standard expansion, then let them try. */ |
| 368 | if (tilde_expansion_failure_hook) |
| 369 | { |
| 370 | expansion = (*tilde_expansion_failure_hook) (username); |
| 371 | if (expansion) |
| 372 | { |
| 373 | dirname = glue_prefix_and_suffix (expansion, filename, user_len); |
| 374 | free (expansion); |
| 375 | } |
| 376 | } |
| 377 | free (username); |
| 378 | /* If we don't have a failure hook, or if the failure hook did not |
| 379 | expand the tilde, return a copy of what we were passed. */ |
| 380 | if (dirname == 0) |
| 381 | dirname = savestring (filename)xstrdup(filename); |
| 382 | } |
| 383 | else |
| 384 | { |
| 385 | free (username); |
| 386 | dirname = glue_prefix_and_suffix (user_entry->pw_dir, filename, user_len); |
| 387 | } |
| 388 | |
| 389 | endpwent (); |
| 390 | return (dirname); |
| 391 | } |
| 392 | |
| 393 | |
| 394 | #if defined (TEST) |
| 395 | #undef NULL((void *)0) |
| 396 | #include <stdio.h> |
| 397 | |
| 398 | main (argc, argv) |
| 399 | int argc; |
| 400 | char **argv; |
| 401 | { |
| 402 | char *result, line[512]; |
| 403 | int done = 0; |
| 404 | |
| 405 | while (!done) |
| 406 | { |
| 407 | printf ("~expand: "); |
| 408 | fflush (stdout(&__sF[1])); |
| 409 | |
| 410 | if (!fgets (line, sizeof(line), stdin(&__sF[0]))) |
| 411 | strlcpy (line, "done", sizeof(line)); |
| 412 | else if (line[strlen(line) - 1] == '\n') |
| 413 | line[strlen(line) - 1] = '\0'; |
| 414 | if ((strcmp (line, "done") == 0) || |
| 415 | (strcmp (line, "quit") == 0) || |
| 416 | (strcmp (line, "exit") == 0)) |
| 417 | { |
| 418 | done = 1; |
| 419 | break; |
| 420 | } |
| 421 | |
| 422 | result = tilde_expand (line); |
| 423 | printf (" --> %s\n", result); |
| 424 | free (result); |
| 425 | } |
| 426 | exit (0); |
| 427 | } |
| 428 | |
| 429 | static void memory_error_and_abort (); |
| 430 | |
| 431 | static void * |
| 432 | xmalloc (bytes) |
| 433 | size_t bytes; |
| 434 | { |
| 435 | void *temp = (char *)malloc (bytes); |
| 436 | |
| 437 | if (!temp) |
| 438 | memory_error_and_abort (); |
| 439 | return (temp); |
| 440 | } |
| 441 | |
| 442 | static void * |
| 443 | xrealloc (pointer, bytes) |
| 444 | void *pointer; |
| 445 | int bytes; |
| 446 | { |
| 447 | void *temp; |
| 448 | |
| 449 | if (!pointer) |
| 450 | temp = malloc (bytes); |
| 451 | else |
| 452 | temp = realloc (pointer, bytes); |
| 453 | |
| 454 | if (!temp) |
| 455 | memory_error_and_abort (); |
| 456 | |
| 457 | return (temp); |
| 458 | } |
| 459 | |
| 460 | static void |
| 461 | memory_error_and_abort () |
| 462 | { |
| 463 | fprintf (stderr(&__sF[2]), "readline: out of virtual memory\n"); |
| 464 | abort (); |
| 465 | } |
| 466 | |
| 467 | /* |
| 468 | * Local variables: |
| 469 | * compile-command: "gcc -g -DTEST -o tilde tilde.c" |
| 470 | * end: |
| 471 | */ |
| 472 | #endif /* TEST */ |