symlinks.c

   1 #include "cache.h"
   2
   3 int has_symlink_leading_path(const char *name, char *last_symlink)
   4 {
   5         char path[PATH_MAX];
   6         const char *sp, *ep;
   7         char *dp;
   8
   9         sp = name;
  10         dp = path;
  11
  12         if (last_symlink && *last_symlink) {
  13                 size_t last_len = strlen(last_symlink);
  14                 size_t len = strlen(name);
  15                 if (last_len < len &&
  16                     !strncmp(name, last_symlink, last_len) &&
  17                     name[last_len] == '/')
  18                         return 1;
  19                 *last_symlink = '\0';
  20         }
  21
  22         while (1) {
  23                 size_t len;
  24                 struct stat st;
  25
  26                 ep = strchr(sp, '/');
  27                 if (!ep)
  28                         break;
  29                 len = ep - sp;
  30                 if (PATH_MAX <= dp + len - path + 2)
  31                         return 0; /* new name is longer than that??? */
  32                 memcpy(dp, sp, len);
  33                 dp[len] = 0;
  34
  35                 if (lstat(path, &st))
  36                         return 0;
  37                 if (S_ISLNK(st.st_mode)) {
  38                         if (last_symlink)
  39                                 strcpy(last_symlink, path);
  40                         return 1;
  41                 }
  42
  43                 dp[len++] = '/';
  44                 dp = dp + len;
  45                 sp = ep + 1;
  46         }
  47         return 0;
  48 }