abspath.c

   1 #include "cache.h"
   2
   3 /*
   4  * Do not use this for inspecting *tracked* content.  When path is a
   5  * symlink to a directory, we do not want to say it is a directory when
   6  * dealing with tracked content in the working tree.
   7  */
   8 int is_directory(const char *path)
   9 {
  10         struct stat st;
  11         return (!stat(path, &st) && S_ISDIR(st.st_mode));
  12 }
  13
  14 /* We allow "recursive" symbolic links. Only within reason, though. */
  15 #define MAXDEPTH 5
  16
  17 const char *make_absolute_path(const char *path)
  18 {
  19         static char bufs[2][PATH_MAX + 1], *buf = bufs[0], *next_buf = bufs[1];
  20         char cwd[1024] = "";
  21         int buf_index = 1, len;
  22
  23         int depth = MAXDEPTH;
  24         char *last_elem = NULL;
  25         struct stat st;
  26
  27         if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
  28                 die ("Too long path: %.*s", 60, path);
  29
  30         while (depth--) {
  31                 if (!is_directory(buf)) {
  32                         char *last_slash = strrchr(buf, '/');
  33                         if (last_slash) {
  34                                 *last_slash = '\0';
  35                                 last_elem = xstrdup(last_slash + 1);
  36                         } else {
  37                                 last_elem = xstrdup(buf);
  38                                 *buf = '\0';
  39                         }
  40                 }
  41
  42                 if (*buf) {
  43                         if (!*cwd && !getcwd(cwd, sizeof(cwd)))
  44                                 die ("Could not get current working directory");
  45
  46                         if (chdir(buf))
  47                                 die ("Could not switch to '%s'", buf);
  48                 }
  49                 if (!getcwd(buf, PATH_MAX))
  50                         die ("Could not get current working directory");
  51
  52                 if (last_elem) {
  53                         int len = strlen(buf);
  54                         if (len + strlen(last_elem) + 2 > PATH_MAX)
  55                                 die ("Too long path name: '%s/%s'",
  56                                                 buf, last_elem);
  57                         buf[len] = '/';
  58                         strcpy(buf + len + 1, last_elem);
  59                         free(last_elem);
  60                         last_elem = NULL;
  61                 }
  62
  63                 if (!lstat(buf, &st) && S_ISLNK(st.st_mode)) {
  64                         len = readlink(buf, next_buf, PATH_MAX);
  65                         if (len < 0)
  66                                 die ("Invalid symlink: %s", buf);
  67                         if (PATH_MAX <= len)
  68                                 die("symbolic link too long: %s", buf);
  69                         next_buf[len] = '\0';
  70                         buf = next_buf;
  71                         buf_index = 1 - buf_index;
  72                         next_buf = bufs[buf_index];
  73                 } else
  74                         break;
  75         }
  76
  77         if (*cwd && chdir(cwd))
  78                 die ("Could not change back to '%s'", cwd);
  79
  80         return buf;
  81 }
  82
  83 static const char *get_pwd_cwd(void)
  84 {
  85         static char cwd[PATH_MAX + 1];
  86         char *pwd;
  87         struct stat cwd_stat, pwd_stat;
  88         if (getcwd(cwd, PATH_MAX) == NULL)
  89                 return NULL;
  90         pwd = getenv("PWD");
  91         if (pwd && strcmp(pwd, cwd)) {
  92                 stat(cwd, &cwd_stat);
  93                 if (!stat(pwd, &pwd_stat) &&
  94                     pwd_stat.st_dev == cwd_stat.st_dev &&
  95                     pwd_stat.st_ino == cwd_stat.st_ino) {
  96                         strlcpy(cwd, pwd, PATH_MAX);
  97                 }
  98         }
  99         return cwd;
 100 }
 101
 102 const char *make_nonrelative_path(const char *path)
 103 {
 104         static char buf[PATH_MAX + 1];
 105
 106         if (is_absolute_path(path)) {
 107                 if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
 108                         die("Too long path: %.*s", 60, path);
 109         } else {
 110                 const char *cwd = get_pwd_cwd();
 111                 if (!cwd)
 112                         die("Cannot determine the current working directory");
 113                 if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
 114                         die("Too long path: %.*s", 60, path);
 115         }
 116         return buf;
 117 }