glob.c raw
1 #define _BSD_SOURCE
2 #include <glob.h>
3 #include <fnmatch.h>
4 #include <sys/stat.h>
5 #include <dirent.h>
6 #include <limits.h>
7 #include <string.h>
8 #include <stdlib.h>
9 #include <errno.h>
10 #include <stddef.h>
11 #include <unistd.h>
12 #include <pwd.h>
13
14 struct match
15 {
16 struct match *next;
17 char name[];
18 };
19
20 static int append(struct match **tail, const char *name, size_t len, int mark)
21 {
22 struct match *new = malloc(sizeof(struct match) + len + 2);
23 if (!new) return -1;
24 (*tail)->next = new;
25 new->next = NULL;
26 memcpy(new->name, name, len+1);
27 if (mark && len && name[len-1]!='/') {
28 new->name[len] = '/';
29 new->name[len+1] = 0;
30 }
31 *tail = new;
32 return 0;
33 }
34
35 static int do_glob(char *buf, size_t pos, int type, char *pat, int flags, int (*errfunc)(const char *path, int err), struct match **tail)
36 {
37 /* If GLOB_MARK is unused, we don't care about type. */
38 if (!type && !(flags & GLOB_MARK)) type = DT_REG;
39
40 /* Special-case the remaining pattern being all slashes, in
41 * which case we can use caller-passed type if it's a dir. */
42 if (*pat && type!=DT_DIR) type = 0;
43 while (pos+1 < PATH_MAX && *pat=='/') buf[pos++] = *pat++;
44
45 /* Consume maximal [escaped-]literal prefix of pattern, copying
46 * and un-escaping it to the running buffer as we go. */
47 ptrdiff_t i=0, j=0;
48 int in_bracket = 0, overflow = 0;
49 for (; pat[i]!='*' && pat[i]!='?' && (!in_bracket || pat[i]!=']'); i++) {
50 if (!pat[i]) {
51 if (overflow) return 0;
52 pat += i;
53 pos += j;
54 i = j = 0;
55 break;
56 } else if (pat[i] == '[') {
57 in_bracket = 1;
58 } else if (pat[i] == '\\' && !(flags & GLOB_NOESCAPE)) {
59 /* Backslashes inside a bracket are (at least by
60 * our interpretation) non-special, so if next
61 * char is ']' we have a complete expression. */
62 if (in_bracket && pat[i+1]==']') break;
63 /* Unpaired final backslash never matches. */
64 if (!pat[i+1]) return 0;
65 i++;
66 }
67 if (pat[i] == '/') {
68 if (overflow) return 0;
69 in_bracket = 0;
70 pat += i+1;
71 i = -1;
72 pos += j+1;
73 j = -1;
74 }
75 /* Only store a character if it fits in the buffer, but if
76 * a potential bracket expression is open, the overflow
77 * must be remembered and handled later only if the bracket
78 * is unterminated (and thereby a literal), so as not to
79 * disallow long bracket expressions with short matches. */
80 if (pos+(j+1) < PATH_MAX) {
81 buf[pos+j++] = pat[i];
82 } else if (in_bracket) {
83 overflow = 1;
84 } else {
85 return 0;
86 }
87 /* If we consume any new components, the caller-passed type
88 * or dummy type from above is no longer valid. */
89 type = 0;
90 }
91 buf[pos] = 0;
92 if (!*pat) {
93 /* If we consumed any components above, or if GLOB_MARK is
94 * requested and we don't yet know if the match is a dir,
95 * we must confirm the file exists and/or determine its type.
96 *
97 * If marking dirs, symlink type is inconclusive; we need the
98 * type for the symlink target, and therefore must try stat
99 * first unless type is known not to be a symlink. Otherwise,
100 * or if that fails, use lstat for determining existence to
101 * avoid false negatives in the case of broken symlinks. */
102 struct stat st;
103 if ((flags & GLOB_MARK) && (!type||type==DT_LNK) && !stat(buf, &st)) {
104 if (S_ISDIR(st.st_mode)) type = DT_DIR;
105 else type = DT_REG;
106 }
107 if (!type && lstat(buf, &st)) {
108 if (errno!=ENOENT && (errfunc(buf, errno) || (flags & GLOB_ERR)))
109 return GLOB_ABORTED;
110 return 0;
111 }
112 if (append(tail, buf, pos, (flags & GLOB_MARK) && type==DT_DIR))
113 return GLOB_NOSPACE;
114 return 0;
115 }
116 char *p2 = strchr(pat, '/'), saved_sep = '/';
117 /* Check if the '/' was escaped and, if so, remove the escape char
118 * so that it will not be unpaired when passed to fnmatch. */
119 if (p2 && !(flags & GLOB_NOESCAPE)) {
120 char *p;
121 for (p=p2; p>pat && p[-1]=='\\'; p--);
122 if ((p2-p)%2) {
123 p2--;
124 saved_sep = '\\';
125 }
126 }
127 DIR *dir = opendir(pos ? buf : ".");
128 if (!dir) {
129 if (errfunc(buf, errno) || (flags & GLOB_ERR))
130 return GLOB_ABORTED;
131 return 0;
132 }
133 int old_errno = errno;
134 struct dirent *de;
135 while (errno=0, de=readdir(dir)) {
136 /* Quickly skip non-directories when there's pattern left. */
137 if (p2 && de->d_type && de->d_type!=DT_DIR && de->d_type!=DT_LNK)
138 continue;
139
140 size_t l = strlen(de->d_name);
141 if (l >= PATH_MAX-pos) continue;
142
143 if (p2) *p2 = 0;
144
145 int fnm_flags= ((flags & GLOB_NOESCAPE) ? FNM_NOESCAPE : 0)
146 | ((!(flags & GLOB_PERIOD)) ? FNM_PERIOD : 0);
147
148 if (fnmatch(pat, de->d_name, fnm_flags))
149 continue;
150
151 /* With GLOB_PERIOD, don't allow matching . or .. unless
152 * fnmatch would match them with FNM_PERIOD rules in effect. */
153 if (p2 && (flags & GLOB_PERIOD) && de->d_name[0]=='.'
154 && (!de->d_name[1] || de->d_name[1]=='.' && !de->d_name[2])
155 && fnmatch(pat, de->d_name, fnm_flags | FNM_PERIOD))
156 continue;
157
158 memcpy(buf+pos, de->d_name, l+1);
159 if (p2) *p2 = saved_sep;
160 int r = do_glob(buf, pos+l, de->d_type, p2 ? p2 : "", flags, errfunc, tail);
161 if (r) {
162 closedir(dir);
163 return r;
164 }
165 }
166 int readerr = errno;
167 if (p2) *p2 = saved_sep;
168 closedir(dir);
169 if (readerr && (errfunc(buf, errno) || (flags & GLOB_ERR)))
170 return GLOB_ABORTED;
171 errno = old_errno;
172 return 0;
173 }
174
175 static int ignore_err(const char *path, int err)
176 {
177 return 0;
178 }
179
180 static void freelist(struct match *head)
181 {
182 struct match *match, *next;
183 for (match=head->next; match; match=next) {
184 next = match->next;
185 free(match);
186 }
187 }
188
189 static int sort(const void *a, const void *b)
190 {
191 return strcmp(*(const char **)a, *(const char **)b);
192 }
193
194 static int expand_tilde(char **pat, char *buf, size_t *pos)
195 {
196 char *p = *pat + 1;
197 size_t i = 0;
198
199 char delim, *name_end = __strchrnul(p, '/');
200 if ((delim = *name_end)) *name_end++ = 0;
201 *pat = name_end;
202
203 char *home = *p ? NULL : getenv("HOME");
204 if (!home) {
205 struct passwd pw, *res;
206 switch (*p ? getpwnam_r(p, &pw, buf, PATH_MAX, &res)
207 : getpwuid_r(getuid(), &pw, buf, PATH_MAX, &res)) {
208 case ENOMEM:
209 return GLOB_NOSPACE;
210 case 0:
211 if (!res)
212 default:
213 return GLOB_NOMATCH;
214 }
215 home = pw.pw_dir;
216 }
217 while (i < PATH_MAX - 2 && *home)
218 buf[i++] = *home++;
219 if (*home)
220 return GLOB_NOMATCH;
221 if ((buf[i] = delim))
222 buf[++i] = 0;
223 *pos = i;
224 return 0;
225 }
226
227 int glob(const char *restrict pat, int flags, int (*errfunc)(const char *path, int err), glob_t *restrict g)
228 {
229 struct match head = { .next = NULL }, *tail = &head;
230 size_t cnt, i;
231 size_t offs = (flags & GLOB_DOOFFS) ? g->gl_offs : 0;
232 int error = 0;
233 char buf[PATH_MAX];
234
235 if (!errfunc) errfunc = ignore_err;
236
237 if (!(flags & GLOB_APPEND)) {
238 g->gl_offs = offs;
239 g->gl_pathc = 0;
240 g->gl_pathv = NULL;
241 }
242
243 if (*pat) {
244 char *p = strdup(pat);
245 if (!p) return GLOB_NOSPACE;
246 buf[0] = 0;
247 size_t pos = 0;
248 char *s = p;
249 if ((flags & (GLOB_TILDE | GLOB_TILDE_CHECK)) && *p == '~')
250 error = expand_tilde(&s, buf, &pos);
251 if (!error)
252 error = do_glob(buf, pos, 0, s, flags, errfunc, &tail);
253 free(p);
254 }
255
256 if (error == GLOB_NOSPACE) {
257 freelist(&head);
258 return error;
259 }
260
261 for (cnt=0, tail=head.next; tail; tail=tail->next, cnt++);
262 if (!cnt) {
263 if (flags & GLOB_NOCHECK) {
264 tail = &head;
265 if (append(&tail, pat, strlen(pat), 0))
266 return GLOB_NOSPACE;
267 cnt++;
268 } else
269 return GLOB_NOMATCH;
270 }
271
272 if (flags & GLOB_APPEND) {
273 char **pathv = realloc(g->gl_pathv, (offs + g->gl_pathc + cnt + 1) * sizeof(char *));
274 if (!pathv) {
275 freelist(&head);
276 return GLOB_NOSPACE;
277 }
278 g->gl_pathv = pathv;
279 offs += g->gl_pathc;
280 } else {
281 g->gl_pathv = malloc((offs + cnt + 1) * sizeof(char *));
282 if (!g->gl_pathv) {
283 freelist(&head);
284 return GLOB_NOSPACE;
285 }
286 for (i=0; i<offs; i++)
287 g->gl_pathv[i] = NULL;
288 }
289 for (i=0, tail=head.next; i<cnt; tail=tail->next, i++)
290 g->gl_pathv[offs + i] = tail->name;
291 g->gl_pathv[offs + i] = NULL;
292 g->gl_pathc += cnt;
293
294 if (!(flags & GLOB_NOSORT))
295 qsort(g->gl_pathv+offs, cnt, sizeof(char *), sort);
296
297 return error;
298 }
299
300 void globfree(glob_t *g)
301 {
302 size_t i;
303 for (i=0; i<g->gl_pathc; i++)
304 free(g->gl_pathv[g->gl_offs + i] - offsetof(struct match, name));
305 free(g->gl_pathv);
306 g->gl_pathc = 0;
307 g->gl_pathv = NULL;
308 }
309
310 weak_alias(glob, glob64);
311 weak_alias(globfree, globfree64);
312