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d60d9f65 SS |
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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
21 | ||
22 | #if defined (HAVE_CONFIG_H) | |
23 | # include <config.h> | |
24 | #endif | |
25 | ||
26 | #if defined (HAVE_UNISTD_H) | |
27 | # ifdef _MINIX | |
28 | # include <sys/types.h> | |
29 | # endif | |
30 | # include <unistd.h> | |
31 | #endif | |
32 | ||
33 | #if defined (HAVE_STRING_H) | |
34 | # include <string.h> | |
35 | #else /* !HAVE_STRING_H */ | |
36 | # include <strings.h> | |
37 | #endif /* !HAVE_STRING_H */ | |
38 | ||
39 | #if defined (HAVE_STDLIB_H) | |
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 | ||
d60d9f65 SS |
50 | #if !defined (HAVE_GETPW_DECLS) |
51 | extern struct passwd *getpwuid (), *getpwnam (); | |
52 | #endif /* !HAVE_GETPW_DECLS */ | |
53 | ||
54 | #if !defined (savestring) | |
55 | extern char *xmalloc (); | |
56 | # ifndef strcpy | |
57 | extern char *strcpy (); | |
58 | # endif | |
59 | #define savestring(x) strcpy (xmalloc (1 + strlen (x)), (x)) | |
60 | #endif /* !savestring */ | |
61 | ||
62 | #if !defined (NULL) | |
63 | # if defined (__STDC__) | |
64 | # define NULL ((void *) 0) | |
65 | # else | |
66 | # define NULL 0x0 | |
67 | # endif /* !__STDC__ */ | |
68 | #endif /* !NULL */ | |
69 | ||
70 | #if defined (TEST) || defined (STATIC_MALLOC) | |
71 | static char *xmalloc (), *xrealloc (); | |
72 | #else | |
73 | extern char *xmalloc (), *xrealloc (); | |
74 | #endif /* TEST || STATIC_MALLOC */ | |
75 | ||
c862e87b JM |
76 | /* If being compiled as part of bash, these will be satisfied from |
77 | variables.o. If being compiled as part of readline, they will | |
78 | be satisfied from shell.o. */ | |
79 | extern char *get_home_dir (); | |
80 | extern char *get_env_value (); | |
81 | ||
d60d9f65 SS |
82 | /* The default value of tilde_additional_prefixes. This is set to |
83 | whitespace preceding a tilde so that simple programs which do not | |
84 | perform any word separation get desired behaviour. */ | |
85 | static char *default_prefixes[] = | |
86 | { " ~", "\t~", (char *)NULL }; | |
87 | ||
88 | /* The default value of tilde_additional_suffixes. This is set to | |
89 | whitespace or newline so that simple programs which do not | |
90 | perform any word separation get desired behaviour. */ | |
91 | static char *default_suffixes[] = | |
92 | { " ", "\n", (char *)NULL }; | |
93 | ||
94 | /* If non-null, this contains the address of a function that the application | |
95 | wants called before trying the standard tilde expansions. The function | |
96 | is called with the text sans tilde, and returns a malloc()'ed string | |
97 | which is the expansion, or a NULL pointer if the expansion fails. */ | |
98 | CPFunction *tilde_expansion_preexpansion_hook = (CPFunction *)NULL; | |
99 | ||
100 | /* If non-null, this contains the address of a function to call if the | |
101 | standard meaning for expanding a tilde fails. The function is called | |
102 | with the text (sans tilde, as in "foo"), and returns a malloc()'ed string | |
103 | which is the expansion, or a NULL pointer if there is no expansion. */ | |
104 | CPFunction *tilde_expansion_failure_hook = (CPFunction *)NULL; | |
105 | ||
106 | /* When non-null, this is a NULL terminated array of strings which | |
107 | are duplicates for a tilde prefix. Bash uses this to expand | |
108 | `=~' and `:~'. */ | |
109 | char **tilde_additional_prefixes = default_prefixes; | |
110 | ||
111 | /* When non-null, this is a NULL terminated array of strings which match | |
112 | the end of a username, instead of just "/". Bash sets this to | |
113 | `:' and `=~'. */ | |
114 | char **tilde_additional_suffixes = default_suffixes; | |
115 | ||
116 | /* Find the start of a tilde expansion in STRING, and return the index of | |
117 | the tilde which starts the expansion. Place the length of the text | |
118 | which identified this tilde starter in LEN, excluding the tilde itself. */ | |
119 | static int | |
120 | tilde_find_prefix (string, len) | |
121 | char *string; | |
122 | int *len; | |
123 | { | |
124 | register int i, j, string_len; | |
125 | register char **prefixes = tilde_additional_prefixes; | |
126 | ||
127 | string_len = strlen (string); | |
128 | *len = 0; | |
129 | ||
130 | if (*string == '\0' || *string == '~') | |
131 | return (0); | |
132 | ||
133 | if (prefixes) | |
134 | { | |
135 | for (i = 0; i < string_len; i++) | |
136 | { | |
137 | for (j = 0; prefixes[j]; j++) | |
138 | { | |
139 | if (strncmp (string + i, prefixes[j], strlen (prefixes[j])) == 0) | |
140 | { | |
141 | *len = strlen (prefixes[j]) - 1; | |
142 | return (i + *len); | |
143 | } | |
144 | } | |
145 | } | |
146 | } | |
147 | return (string_len); | |
148 | } | |
149 | ||
150 | /* Find the end of a tilde expansion in STRING, and return the index of | |
151 | the character which ends the tilde definition. */ | |
152 | static int | |
153 | tilde_find_suffix (string) | |
154 | char *string; | |
155 | { | |
156 | register int i, j, string_len; | |
157 | register char **suffixes; | |
158 | ||
159 | suffixes = tilde_additional_suffixes; | |
160 | string_len = strlen (string); | |
161 | ||
162 | for (i = 0; i < string_len; i++) | |
163 | { | |
164 | if (string[i] == '/' /* || !string[i] */) | |
165 | break; | |
166 | ||
167 | for (j = 0; suffixes && suffixes[j]; j++) | |
168 | { | |
169 | if (strncmp (string + i, suffixes[j], strlen (suffixes[j])) == 0) | |
170 | return (i); | |
171 | } | |
172 | } | |
173 | return (i); | |
174 | } | |
175 | ||
d60d9f65 SS |
176 | /* Return a new string which is the result of tilde expanding STRING. */ |
177 | char * | |
178 | tilde_expand (string) | |
179 | char *string; | |
180 | { | |
181 | char *result; | |
182 | int result_size, result_index; | |
183 | ||
184 | result_index = result_size = 0; | |
185 | if (result = strchr (string, '~')) | |
186 | result = xmalloc (result_size = (strlen (string) + 16)); | |
187 | else | |
188 | result = xmalloc (result_size = (strlen (string) + 1)); | |
189 | ||
190 | /* Scan through STRING expanding tildes as we come to them. */ | |
191 | while (1) | |
192 | { | |
193 | register int start, end; | |
194 | char *tilde_word, *expansion; | |
195 | int len; | |
196 | ||
197 | /* Make START point to the tilde which starts the expansion. */ | |
198 | start = tilde_find_prefix (string, &len); | |
199 | ||
200 | /* Copy the skipped text into the result. */ | |
201 | if ((result_index + start + 1) > result_size) | |
202 | result = xrealloc (result, 1 + (result_size += (start + 20))); | |
203 | ||
204 | strncpy (result + result_index, string, start); | |
205 | result_index += start; | |
206 | ||
207 | /* Advance STRING to the starting tilde. */ | |
208 | string += start; | |
209 | ||
210 | /* Make END be the index of one after the last character of the | |
211 | username. */ | |
212 | end = tilde_find_suffix (string); | |
213 | ||
214 | /* If both START and END are zero, we are all done. */ | |
215 | if (!start && !end) | |
216 | break; | |
217 | ||
218 | /* Expand the entire tilde word, and copy it into RESULT. */ | |
219 | tilde_word = xmalloc (1 + end); | |
220 | strncpy (tilde_word, string, end); | |
221 | tilde_word[end] = '\0'; | |
222 | string += end; | |
223 | ||
224 | expansion = tilde_expand_word (tilde_word); | |
225 | free (tilde_word); | |
226 | ||
227 | len = strlen (expansion); | |
228 | if ((result_index + len + 1) > result_size) | |
229 | result = xrealloc (result, 1 + (result_size += (len + 20))); | |
230 | ||
231 | strcpy (result + result_index, expansion); | |
232 | result_index += len; | |
233 | free (expansion); | |
234 | } | |
235 | ||
236 | result[result_index] = '\0'; | |
237 | ||
238 | return (result); | |
239 | } | |
240 | ||
241 | /* Take FNAME and return the tilde prefix we want expanded. If LENP is | |
242 | non-null, the index of the end of the prefix into FNAME is returned in | |
243 | the location it points to. */ | |
244 | static char * | |
245 | isolate_tilde_prefix (fname, lenp) | |
246 | char *fname; | |
247 | int *lenp; | |
248 | { | |
249 | char *ret; | |
250 | int i; | |
251 | ||
252 | ret = xmalloc (strlen (fname)); | |
253 | for (i = 1; fname[i] && fname[i] != '/'; i++) | |
254 | ret[i - 1] = fname[i]; | |
255 | ret[i - 1] = '\0'; | |
256 | if (lenp) | |
257 | *lenp = i; | |
258 | return ret; | |
259 | } | |
260 | ||
261 | /* Return a string that is PREFIX concatenated with SUFFIX starting at | |
262 | SUFFIND. */ | |
263 | static char * | |
264 | glue_prefix_and_suffix (prefix, suffix, suffind) | |
265 | char *prefix, *suffix; | |
266 | int suffind; | |
267 | { | |
268 | char *ret; | |
269 | int plen, slen; | |
270 | ||
271 | plen = (prefix && *prefix) ? strlen (prefix) : 0; | |
272 | slen = strlen (suffix + suffind); | |
273 | ret = xmalloc (plen + slen + 1); | |
274 | if (prefix && *prefix) | |
275 | strcpy (ret, prefix); | |
276 | strcpy (ret + plen, suffix + suffind); | |
277 | return ret; | |
278 | } | |
279 | ||
d60d9f65 SS |
280 | /* Do the work of tilde expansion on FILENAME. FILENAME starts with a |
281 | tilde. If there is no expansion, call tilde_expansion_failure_hook. | |
282 | This always returns a newly-allocated string, never static storage. */ | |
283 | char * | |
284 | tilde_expand_word (filename) | |
285 | char *filename; | |
286 | { | |
287 | char *dirname, *expansion, *username; | |
288 | int user_len; | |
289 | struct passwd *user_entry; | |
290 | ||
291 | if (filename == 0) | |
292 | return ((char *)NULL); | |
293 | ||
294 | if (*filename != '~') | |
295 | return (savestring (filename)); | |
296 | ||
297 | /* A leading `~/' or a bare `~' is *always* translated to the value of | |
298 | $HOME or the home directory of the current user, regardless of any | |
299 | preexpansion hook. */ | |
300 | if (filename[1] == '\0' || filename[1] == '/') | |
301 | { | |
302 | /* Prefix $HOME to the rest of the string. */ | |
c862e87b | 303 | expansion = get_env_value ("HOME"); |
d60d9f65 SS |
304 | |
305 | /* If there is no HOME variable, look up the directory in | |
306 | the password database. */ | |
307 | if (expansion == 0) | |
308 | expansion = get_home_dir (); | |
309 | ||
310 | return (glue_prefix_and_suffix (expansion, filename, 1)); | |
311 | } | |
312 | ||
313 | username = isolate_tilde_prefix (filename, &user_len); | |
314 | ||
315 | if (tilde_expansion_preexpansion_hook) | |
316 | { | |
317 | expansion = (*tilde_expansion_preexpansion_hook) (username); | |
318 | if (expansion) | |
319 | { | |
320 | dirname = glue_prefix_and_suffix (expansion, filename, user_len); | |
321 | free (username); | |
322 | free (expansion); | |
323 | return (dirname); | |
324 | } | |
325 | } | |
326 | ||
327 | /* No preexpansion hook, or the preexpansion hook failed. Look in the | |
328 | password database. */ | |
329 | dirname = (char *)NULL; | |
330 | user_entry = getpwnam (username); | |
331 | if (user_entry == 0) | |
332 | { | |
333 | /* If the calling program has a special syntax for expanding tildes, | |
334 | and we couldn't find a standard expansion, then let them try. */ | |
335 | if (tilde_expansion_failure_hook) | |
336 | { | |
337 | expansion = (*tilde_expansion_failure_hook) (username); | |
338 | if (expansion) | |
339 | { | |
340 | dirname = glue_prefix_and_suffix (expansion, filename, user_len); | |
341 | free (expansion); | |
342 | } | |
343 | } | |
344 | free (username); | |
345 | /* If we don't have a failure hook, or if the failure hook did not | |
346 | expand the tilde, return a copy of what we were passed. */ | |
347 | if (dirname == 0) | |
348 | dirname = savestring (filename); | |
349 | } | |
350 | else | |
351 | { | |
352 | free (username); | |
353 | dirname = glue_prefix_and_suffix (user_entry->pw_dir, filename, user_len); | |
354 | } | |
355 | ||
356 | endpwent (); | |
357 | return (dirname); | |
358 | } | |
359 | ||
360 | \f | |
361 | #if defined (TEST) | |
362 | #undef NULL | |
363 | #include <stdio.h> | |
364 | ||
365 | main (argc, argv) | |
366 | int argc; | |
367 | char **argv; | |
368 | { | |
369 | char *result, line[512]; | |
370 | int done = 0; | |
371 | ||
372 | while (!done) | |
373 | { | |
374 | printf ("~expand: "); | |
375 | fflush (stdout); | |
376 | ||
377 | if (!gets (line)) | |
378 | strcpy (line, "done"); | |
379 | ||
380 | if ((strcmp (line, "done") == 0) || | |
381 | (strcmp (line, "quit") == 0) || | |
382 | (strcmp (line, "exit") == 0)) | |
383 | { | |
384 | done = 1; | |
385 | break; | |
386 | } | |
387 | ||
388 | result = tilde_expand (line); | |
389 | printf (" --> %s\n", result); | |
390 | free (result); | |
391 | } | |
392 | exit (0); | |
393 | } | |
394 | ||
395 | static void memory_error_and_abort (); | |
396 | ||
397 | static char * | |
398 | xmalloc (bytes) | |
399 | int bytes; | |
400 | { | |
401 | char *temp = (char *)malloc (bytes); | |
402 | ||
403 | if (!temp) | |
404 | memory_error_and_abort (); | |
405 | return (temp); | |
406 | } | |
407 | ||
408 | static char * | |
409 | xrealloc (pointer, bytes) | |
410 | char *pointer; | |
411 | int bytes; | |
412 | { | |
413 | char *temp; | |
414 | ||
415 | if (!pointer) | |
416 | temp = (char *)malloc (bytes); | |
417 | else | |
418 | temp = (char *)realloc (pointer, bytes); | |
419 | ||
420 | if (!temp) | |
421 | memory_error_and_abort (); | |
422 | ||
423 | return (temp); | |
424 | } | |
425 | ||
426 | static void | |
427 | memory_error_and_abort () | |
428 | { | |
429 | fprintf (stderr, "readline: out of virtual memory\n"); | |
430 | abort (); | |
431 | } | |
432 | ||
433 | /* | |
434 | * Local variables: | |
435 | * compile-command: "gcc -g -DTEST -o tilde tilde.c" | |
436 | * end: | |
437 | */ | |
438 | #endif /* TEST */ |