<filesystem> enumerations

This article documents the enumerations in the C++17 std::filesystem implementation of the <filesystem> header.

Note

This page documents the C++17 std::filesystem enumerations. For the historical prestandard enumerations that MSVC provided in <experimental/filesystem>, see <experimental/filesystem> enumerations.

Requirements

Header: <filesystem>

Namespace: std::filesystem

copy_options

An enumeration of bitmask values that is used with copy and copy_file functions to specify behavior.

Syntax

enum class copy_options {
   none = 0,
   skip_existing = 1,
   overwrite_existing = 2,
   update_existing = 4,
   recursive = 8,
   copy_symlinks = 16,
   skip_symlinks = 32,
   directories_only = 64,
   create_symlinks = 128,
   create_hard_links = 256
};

Values

Name	Description
none	Perform the default behavior for the operation.
skip_existing	Do not copy if the file already exists, do not report an error.
overwrite_existing	Overwrite the file if it already exists.
update_existing	Overwrite the file if it already exists and is older than the replacement.
recursive	Recursively copy subdirectories and their contents.
copy_symlinks	Copy symbolic links as symbolic links, instead of copying the files they point to.
skip_symlinks	Ignore symbolic links.
directories_only	Only iterate over directories, ignore files.
create_symlinks	Make symbolic links instead of copying files. An absolute path must be used as the source path unless the destination is the current directory.
create_hard_links	Make hard links instead of copying files.

directory_options

A bitmask enumeration that controls how directory iteration handles symbolic links to directories and permission-denied errors.

Syntax

enum class directory_options {
   none = 0,
   follow_directory_symlink = 1,
   skip_permission_denied = 2
};

Values

Name	Description
none	Default behavior: don't follow symbolic links to directories, and treat permission denied as an error.
follow_directory_symlink	Follow symbolic links to directories rather than skipping them.
skip_permission_denied	Silently skip directories that would otherwise result in a permission-denied error.

file_type

An enumeration for file types.

Syntax

enum class file_type {
    none = 0,
    not_found,
    regular,
    directory,
    symlink,
    block,
    character,
    fifo,
    socket,
    unknown
};

The C++ standard doesn't fix the underlying integer values of these enumerators, so don't depend on specific numeric values.

Values

Name	Description
none	The file type hasn't been evaluated yet, or an error occurred when evaluating it.
not_found	The file wasn't found.
regular	A regular file.
directory	A directory.
symlink	A symbolic link.
block	A block-special file. (Not used on Windows.)
character	A character-special file. (Not used on Windows.)
fifo	A FIFO or pipe file. (Not used on Windows.)
socket	A socket. (Not used on Windows.)
unknown	The file exists but its type can't be determined.

perm_options

A bitmask enumeration that controls how the permissions function applies permission bits.

Syntax

enum class perm_options {
   replace = 1,
   add = 2,
   remove = 4,
   nofollow = 8
};

Values

Name	Description
replace	Replace the file's permission bits with the specified permissions.
add	Add the specified permission bits to the file's current permissions.
remove	Remove the specified permission bits from the file's current permissions.
nofollow	Change the permissions of a symbolic link itself rather than the file it resolves to.

perms

A bitmask enumeration of file permission bits. On Windows, the supported values are essentially "read-only" and all. For a read-only file, none of the *_write bits are set. Otherwise, the all bit (0777) is set.

Syntax

enum class perms {// names for permissions
   none = 0,
   owner_read = 0400,  // S_IRUSR
   owner_write = 0200, // S_IWUSR
   owner_exec = 0100,  // S_IXUSR
   owner_all = 0700,   // S_IRWXU
   group_read = 040,   // S_IRGRP
   group_write = 020,  // S_IWGRP
   group_exec = 010,   // S_IXGRP
   group_all = 070,    // S_IRWXG
   others_read = 04,   // S_IROTH
   others_write = 02,  // S_IWOTH
   others_exec = 01,   // S_IXOTH
   others_all = 07,    // S_IRWXO
   all = 0777,
   set_uid = 04000,    // S_ISUID
   set_gid = 02000,    // S_ISGID
   sticky_bit = 01000, // S_ISVTX
   mask = 07777,
   unknown = 0xFFFF
};

See also

Header Files Reference
<filesystem>