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;
  22
  23         int depth = MAXDEPTH;
  24         char *last_elem = NULL;
  25         struct stat st;
  26
  27         /* We've already done it */
  28         if (path == buf || path == next_buf)
  29                 return path;
  30
  31         if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
  32                 die ("Too long path: %.*s", 60, path);
  33
  34         while (depth--) {
  35                 if (!is_directory(buf)) {
  36                         char *last_slash = strrchr(buf, '/');
  37                         if (last_slash) {
  38                                 *last_slash = '\0';
  39                                 last_elem = xstrdup(last_slash + 1);
  40                         } else {
  41                                 last_elem = xstrdup(buf);
  42                                 *buf = '\0';
  43                         }
  44                 }
  45
  46                 if (*buf) {
  47                         if (!*cwd && !getcwd(cwd, sizeof(cwd)))
  48                                 die_errno ("Could not get current working directory");
  49
  50                         if (chdir(buf))
  51                                 die_errno ("Could not switch to '%s'", buf);
  52                 }
  53                 if (!getcwd(buf, PATH_MAX))
  54                         die_errno ("Could not get current working directory");
  55
  56                 if (last_elem) {
  57                         size_t len = strlen(buf);
  58                         if (len + strlen(last_elem) + 2 > PATH_MAX)
  59                                 die ("Too long path name: '%s/%s'",
  60                                                 buf, last_elem);
  61                         if (len && buf[len-1] != '/')
  62                                 buf[len++] = '/';
  63                         strcpy(buf + len, last_elem);
  64                         free(last_elem);
  65                         last_elem = NULL;
  66                 }
  67
  68                 if (!lstat(buf, &st) && S_ISLNK(st.st_mode)) {
  69                         ssize_t len = readlink(buf, next_buf, PATH_MAX);
  70                         if (len < 0)
  71                                 die_errno ("Invalid symlink '%s'", buf);
  72                         if (PATH_MAX <= len)
  73                                 die("symbolic link too long: %s", buf);
  74                         next_buf[len] = '\0';
  75                         buf = next_buf;
  76                         buf_index = 1 - buf_index;
  77                         next_buf = bufs[buf_index];
  78                 } else
  79                         break;
  80         }
  81
  82         if (*cwd && chdir(cwd))
  83                 die_errno ("Could not change back to '%s'", cwd);
  84
  85         return buf;
  86 }
  87
  88 static const char *get_pwd_cwd(void)
  89 {
  90         static char cwd[PATH_MAX + 1];
  91         char *pwd;
  92         struct stat cwd_stat, pwd_stat;
  93         if (getcwd(cwd, PATH_MAX) == NULL)
  94                 return NULL;
  95         pwd = getenv("PWD");
  96         if (pwd && strcmp(pwd, cwd)) {
  97                 stat(cwd, &cwd_stat);
  98                 if (!stat(pwd, &pwd_stat) &&
  99                     pwd_stat.st_dev == cwd_stat.st_dev &&
 100                     pwd_stat.st_ino == cwd_stat.st_ino) {
 101                         strlcpy(cwd, pwd, PATH_MAX);
 102                 }
 103         }
 104         return cwd;
 105 }
 106
 107 const char *make_nonrelative_path(const char *path)
 108 {
 109         static char buf[PATH_MAX + 1];
 110
 111         if (is_absolute_path(path)) {
 112                 if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
 113                         die("Too long path: %.*s", 60, path);
 114         } else {
 115                 size_t len;
 116                 const char *fmt;
 117                 const char *cwd = get_pwd_cwd();
 118                 if (!cwd)
 119                         die_errno("Cannot determine the current working directory");
 120                 len = strlen(cwd);
 121                 fmt = (len > 0 && is_dir_sep(cwd[len-1])) ? "%s%s" : "%s/%s";
 122                 if (snprintf(buf, PATH_MAX, fmt, cwd, path) >= PATH_MAX)
 123                         die("Too long path: %.*s", 60, path);
 124         }
 125         return buf;
 126 }