bsnes/nall/file-system-object.hpp

#ifndef NALL_STORAGE_HPP
#define NALL_STORAGE_HPP

//generic abstraction layer for common storage operations against both files and directories
//these functions are not recursive; use directory::create() and directory::remove() for recursion

#include <nall/platform.hpp>
#include <nall/string.hpp>

namespace nall {

struct file_system_object {
  enum class time : unsigned { access, modify };

  static auto exists(const string& name) -> bool {
    return access(name, F_OK) == 0;
  }

  static auto readable(const string& name) -> bool {
    return access(name, R_OK) == 0;
  }

  static auto writable(const string& name) -> bool {
    return access(name, W_OK) == 0;
  }

  static auto executable(const string& name) -> bool {
    return access(name, X_OK) == 0;
  }

  static auto uid(const string& name) -> unsigned {
    struct stat data{0};
    stat(name, &data);
    return data.st_uid;
  }

  static auto gid(const string& name) -> unsigned {
    struct stat data{0};
    stat(name, &data);
    return data.st_gid;
  }

  static auto mode(const string& name) -> unsigned {
    struct stat data{0};
    stat(name, &data);
    return data.st_mode;
  }

  static auto timestamp(const string& name, time mode = time::modify) -> time_t {
    struct stat data = {0};
    stat(name, &data);
    switch(mode) { default:
    case time::access: return data.st_atime;
    case time::modify: return data.st_mtime;
    }
  }

  //returns true if 'name' already exists
  static auto create(const string& name, unsigned permissions = 0755) -> bool {
    if(exists(name)) return true;
    if(name.endsWith("/")) return mkdir(name, permissions) == 0;
    int fd = open(name, O_CREAT | O_EXCL, permissions);
    if(fd < 0) return false;
    return close(fd), true;
  }

  //returns false if 'name' and 'targetname' are on different file systems (requires copy)
  static auto rename(const string& name, const string& targetname) -> bool {
    return ::rename(name, targetname) == 0;
  }

  //returns false if 'name' is a directory that is not empty
  static auto remove(const string& name) -> bool {
    if(name.endsWith("/")) return rmdir(name) == 0;
    return unlink(name) == 0;
  }
};

}

#endif