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 */ |