1 #define _FILE_OFFSET_BITS 64
2 #ifndef _LARGEFILE_SOURCE
3 #define _LARGEFILE_SOURCE
4 #endif
5 #ifndef _LARGEFILE64_SOURCE
6 #define _LARGEFILE64_SOURCE
7 #endif
8
9 #include <unistd.h>
10 #ifndef _POSIX_SOURCE
11 #define _POSIX_SOURCE
12 #endif
13 #include <stdio.h>
14 #include <stdlib.h>
15 #ifdef HAVE_MALLOC_H
16 #include <malloc.h>
17 #endif
18 #include <string.h>
19 #include <fcntl.h>
20 #include <sys/param.h>
21 #include <sys/types.h>
22 #include <sys/stat.h>
23 #include <dirent.h>
24 #include <time.h>
25 #include <stddef.h>
26 #include <errno.h>
27
28 #ifndef S_ISLNK
29 #define S_ISLNK(mode) (((mode) & (_S_IFMT)) == (_S_IFLNK))
30 #endif
31
32 #ifndef PATH_MAX
33 #define PATH_MAX 1024
34 #endif
35
36 #define progver "%s: scan/change symbolic links - v1.3 - by Mark Lord\n\n"
37 static char *progname;
38 static int verbose = 0, fix_links = 0, recurse = 0, delete = 0, shorten = 0,
39 testing = 0, single_fs = 1;
40
41 /*
42 * tidypath removes excess slashes and "." references from a path string
43 */
44
substr(char * s,char * old,char * new)45 static int substr (char *s, char *old, char *new)
46 {
47 char *tmp = NULL;
48 int oldlen = strlen(old), newlen = 0;
49
50 if (NULL == strstr(s, old))
51 return 0;
52
53 if (new)
54 newlen = strlen(new);
55
56 if (newlen > oldlen) {
57 if ((tmp = malloc(strlen(s))) == NULL) {
58 fprintf(stderr, "no memory\n");
59 exit (1);
60 }
61 }
62
63 while (NULL != (s = strstr(s, old))) {
64 char *p, *old_s = s;
65
66 if (new) {
67 if (newlen > oldlen)
68 old_s = strcpy(tmp, s);
69 p = new;
70 while (*p)
71 *s++ = *p++;
72 }
73 p = old_s + oldlen;
74 while ((*s++ = *p++));
75 }
76 if (tmp)
77 free(tmp);
78 return 1;
79 }
80
81
tidy_path(char * path)82 static int tidy_path (char *path)
83 {
84 int tidied = 0;
85 char *s, *p;
86
87 s = path + strlen(path) - 1;
88 if (s[0] != '/') { /* tmp trailing slash simplifies things */
89 s[1] = '/';
90 s[2] = '\0';
91 }
92 while (substr(path, "/./", "/"))
93 tidied = 1;
94 while (substr(path, "//", "/"))
95 tidied = 1;
96
97 while ((p = strstr(path,"/../")) != NULL) {
98 s = p+3;
99 for (p--; p != path; p--) if (*p == '/') break;
100 if (*p != '/')
101 break;
102 while ((*p++ = *s++));
103 tidied = 1;
104 }
105 if (*path == '\0')
106 strcpy(path,"/");
107 p = path + strlen(path) - 1;
108 if (p != path && *p == '/')
109 *p-- = '\0'; /* remove tmp trailing slash */
110 while (p != path && *p == '/') { /* remove any others */
111 *p-- = '\0';
112 tidied = 1;
113 }
114 while (!strncmp(path,"./",2)) {
115 for (p = path, s = path+2; (*p++ = *s++););
116 tidied = 1;
117 }
118 return tidied;
119 }
120
shorten_path(char * path,char * abspath)121 static int shorten_path (char *path, char *abspath)
122 {
123 static char dir[PATH_MAX];
124 int shortened = 0;
125 char *p;
126
127 /* get rid of unnecessary "../dir" sequences */
128 while (abspath && strlen(abspath) > 1 && (p = strstr(path,"../"))) {
129 /* find innermost occurance of "../dir", and save "dir" */
130 int slashes = 2;
131 char *a, *s, *d = dir;
132 while ((s = strstr(p+3, "../"))) {
133 ++slashes;
134 p = s;
135 }
136 s = p+3;
137 *d++ = '/';
138 while (*s && *s != '/')
139 *d++ = *s++;
140 *d++ = '/';
141 *d = '\0';
142 if (!strcmp(dir,"//"))
143 break;
144 /* note: p still points at ../dir */
145 if (*s != '/' || !*++s)
146 break;
147 a = abspath + strlen(abspath) - 1;
148 while (slashes-- > 0) {
149 if (a <= abspath)
150 goto ughh;
151 while (*--a != '/') {
152 if (a <= abspath)
153 goto ughh;
154 }
155 }
156 if (strncmp(dir, a, strlen(dir)))
157 break;
158 while ((*p++ = *s++)); /* delete the ../dir */
159 shortened = 1;
160 }
161 ughh:
162 return shortened;
163 }
164
165
fix_symlink(char * path,dev_t my_dev)166 static void fix_symlink (char *path, dev_t my_dev)
167 {
168 static char lpath[PATH_MAX], new[PATH_MAX], abspath[PATH_MAX];
169 char *p, *np, *lp, *tail, *msg;
170 struct stat stbuf, lstbuf;
171 int c, fix_abs = 0, fix_messy = 0, fix_long = 0;
172
173 if ((c = readlink(path, lpath, sizeof(lpath) - 1)) == -1) {
174 perror(path);
175 return;
176 }
177 lpath[c] = '\0'; /* readlink does not null terminate it */
178
179 /* construct the absolute address of the link */
180 abspath[0] = '\0';
181 if (lpath[0] != '/') {
182 strcat(abspath,path);
183 c = strlen(abspath);
184 if ((c > 0) && (abspath[c-1] == '/'))
185 abspath[c-1] = '\0'; /* cut trailing / */
186 if ((p = strrchr(abspath,'/')) != NULL)
187 *p = '\0'; /* cut last component */
188 strcat(abspath,"/");
189 }
190 strcat(abspath,lpath);
191 (void) tidy_path(abspath);
192
193 /* check for various things */
194 if (stat(abspath, &stbuf) == -1) {
195 printf("dangling: %s -> %s\n", path, lpath);
196 if (delete) {
197 if (unlink (path)) {
198 perror(path);
199 } else
200 printf("deleted: %s -> %s\n", path, lpath);
201 }
202 return;
203 }
204
205 if (single_fs)
206 lstat(abspath, &lstbuf); /* if the above didn't fail, then this shouldn't */
207
208 if (single_fs && lstbuf.st_dev != my_dev) {
209 msg = "other_fs:";
210 } else if (lpath[0] == '/') {
211 msg = "absolute:";
212 fix_abs = 1;
213 } else if (verbose) {
214 msg = "relative:";
215 } else
216 msg = NULL;
217 fix_messy = tidy_path(strcpy(new,lpath));
218 if (shorten)
219 fix_long = shorten_path(new, path);
220 if (!fix_abs) {
221 if (fix_messy)
222 msg = "messy: ";
223 else if (fix_long)
224 msg = "lengthy: ";
225 }
226 if (msg != NULL)
227 printf("%s %s -> %s\n", msg, path, lpath);
228 if (!(fix_links || testing) || !(fix_messy || fix_abs || fix_long))
229 return;
230
231 if (fix_abs) {
232 /* convert an absolute link to relative: */
233 /* point tail at first part of lpath that differs from path */
234 /* point p at first part of path that differs from lpath */
235 (void) tidy_path(lpath);
236 tail = lp = lpath;
237 p = path;
238 while (*p && (*p == *lp)) {
239 if (*lp++ == '/') {
240 tail = lp;
241 while (*++p == '/');
242 }
243 }
244
245 /* now create new, with "../"s followed by tail */
246 np = new;
247 while (*p) {
248 if (*p++ == '/') {
249 *np++ = '.';
250 *np++ = '.';
251 *np++ = '/';
252 while (*p == '/') ++p;
253 }
254 }
255 strcpy (np, tail);
256 (void) tidy_path(new);
257 if (shorten) (void) shorten_path(new, path);
258 }
259 shorten_path(new,path);
260 if (!testing) {
261 if (unlink (path)) {
262 perror(path);
263 return;
264 }
265 if (symlink(new, path)) {
266 perror(path);
267 return;
268 }
269 }
270 printf("changed: %s -> %s\n", path, new);
271 }
272
dirwalk(char * path,int pathlen,dev_t dev)273 static void dirwalk (char *path, int pathlen, dev_t dev)
274 {
275 char *name;
276 DIR *dfd;
277 static struct stat st;
278 static struct dirent *dp;
279
280 if ((dfd = opendir(path)) == NULL) {
281 perror(path);
282 return;
283 }
284
285 name = path + pathlen;
286 if (*(name-1) != '/')
287 *name++ = '/';
288
289 while ((dp = readdir(dfd)) != NULL ) {
290 strcpy(name, dp->d_name);
291 if (strcmp(name, ".") && strcmp(name,"..")) {
292 if (lstat(path, &st) == -1) {
293 perror(path);
294 } else if (st.st_dev == dev) {
295 if (S_ISLNK(st.st_mode)) {
296 fix_symlink (path, dev);
297 } else if (recurse && S_ISDIR(st.st_mode)) {
298 dirwalk(path, strlen(path), dev);
299 }
300 }
301 }
302 }
303 closedir(dfd);
304 path[pathlen] = '\0';
305 }
306
usage_error(void)307 static void usage_error (void)
308 {
309 fprintf(stderr, progver, progname);
310 fprintf(stderr, "Usage:\t%s [-cdorstv] LINK|DIR ...\n\n", progname);
311 fprintf(stderr, "Flags:"
312 "\t-c == change absolute/messy links to relative\n"
313 "\t-d == delete dangling links\n"
314 "\t-o == warn about links across file systems\n"
315 "\t-r == recurse into subdirs\n"
316 "\t-s == shorten lengthy links (displayed in output only when -c not specified)\n"
317 "\t-t == show what would be done by -c\n"
318 "\t-v == verbose (show all symlinks)\n\n");
319 exit(1);
320 }
321
main(int argc,char ** argv)322 int main(int argc, char **argv)
323 {
324 #if defined (_GNU_SOURCE) && defined (__GLIBC__)
325 static char path[PATH_MAX+2];
326 char* cwd = get_current_dir_name();
327 #else
328 static char path[PATH_MAX+2], cwd[PATH_MAX+2];
329 #endif
330 int dircount = 0;
331 char c, *p;
332
333 if ((progname = (char *) strrchr(*argv, '/')) == NULL)
334 progname = *argv;
335 else
336 progname++;
337
338 #if defined (_GNU_SOURCE) && defined (__GLIBC__)
339 if (NULL == cwd) {
340 fprintf(stderr,"get_current_dir_name() failed\n");
341 #else
342 if (NULL == getcwd(cwd,PATH_MAX)) {
343 fprintf(stderr,"getcwd() failed\n");
344 #endif
345 exit (1);
346 }
347 #if defined (_GNU_SOURCE) && defined (__GLIBC__)
348 cwd = realloc(cwd, strlen(cwd)+2);
349 if (cwd == NULL) {
350 fprintf(stderr, "realloc() failed\n");
351 exit (1);
352 }
353 #endif
354 if (!*cwd || cwd[strlen(cwd)-1] != '/')
355 strcat(cwd,"/");
356
357 while (--argc) {
358 p = *++argv;
359 if (*p == '-') {
360 if (*++p == '\0')
361 usage_error();
362 while ((c = *p++)) {
363 if (c == 'c') fix_links = 1;
364 else if (c == 'd') delete = 1;
365 else if (c == 'o') single_fs = 0;
366 else if (c == 'r') recurse = 1;
367 else if (c == 's') shorten = 1;
368 else if (c == 't') testing = 1;
369 else if (c == 'v') verbose = 1;
370 else usage_error();
371 }
372 } else {
373 struct stat st;
374 if (*p == '/')
375 *path = '\0';
376 else
377 strcpy(path,cwd);
378 tidy_path(strcat(path, p));
379 if (lstat(path, &st) == -1)
380 perror(path);
381 else if (S_ISLNK(st.st_mode))
382 fix_symlink(path, st.st_dev);
383 else
384 dirwalk(path, strlen(path), st.st_dev);
385 ++dircount;
386 }
387 }
388 if (dircount == 0)
389 usage_error();
390 exit (0);
391 }
392