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         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_errno ("Could not get current working directory");
  45
  46                         if (chdir(buf))
  47                                 die_errno ("Could not switch to '%s'", buf);
  48                 }
  49                 if (!getcwd(buf, PATH_MAX))
  50                         die_errno ("Could not get current working directory");
  51
  52                 if (last_elem) {
  53                         size_t 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                         if (len && buf[len-1] != '/')
  58                                 buf[len++] = '/';
  59                         strcpy(buf + len, last_elem);
  60                         free(last_elem);
  61                         last_elem = NULL;
  62                 }
  63
  64                 if (!lstat(buf, &st) && S_ISLNK(st.st_mode)) {
  65                         ssize_t len = readlink(buf, next_buf, PATH_MAX);
  66                         if (len < 0)
  67                                 die_errno ("Invalid symlink '%s'", buf);
  68                         if (PATH_MAX <= len)
  69                                 die("symbolic link too long: %s", buf);
  70                         next_buf[len] = '\0';
  71                         buf = next_buf;
  72                         buf_index = 1 - buf_index;
  73                         next_buf = bufs[buf_index];
  74                 } else
  75                         break;
  76         }
  77
  78         if (*cwd && chdir(cwd))
  79                 die_errno ("Could not change back to '%s'", cwd);
  80
  81         return buf;
  82 }
  83
  84 static const char *get_pwd_cwd(void)
  85 {
  86         static char cwd[PATH_MAX + 1];
  87         char *pwd;
  88         struct stat cwd_stat, pwd_stat;
  89         if (getcwd(cwd, PATH_MAX) == NULL)
  90                 return NULL;
  91         pwd = getenv("PWD");
  92         if (pwd && strcmp(pwd, cwd)) {
  93                 stat(cwd, &cwd_stat);
  94                 if (!stat(pwd, &pwd_stat) &&
  95                     pwd_stat.st_dev == cwd_stat.st_dev &&
  96                     pwd_stat.st_ino == cwd_stat.st_ino) {
  97                         strlcpy(cwd, pwd, PATH_MAX);
  98                 }
  99         }
 100         return cwd;
 101 }
 102
 103 const char *make_nonrelative_path(const char *path)
 104 {
 105         static char buf[PATH_MAX + 1];
 106
 107         if (is_absolute_path(path)) {
 108                 if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
 109                         die("Too long path: %.*s", 60, path);
 110         } else {
 111                 size_t len;
 112                 const char *fmt;
 113                 const char *cwd = get_pwd_cwd();
 114                 if (!cwd)
 115                         die_errno("Cannot determine the current working directory");
 116                 len = strlen(cwd);
 117                 fmt = (len > 0 && is_dir_sep(cwd[len-1])) ? "%s%s" : "%s/%s";
 118                 if (snprintf(buf, PATH_MAX, fmt, cwd, path) >= PATH_MAX)
 119                         die("Too long path: %.*s", 60, path);
 120         }
 121         return buf;
 122 }