31 Input/output library [input.output]

31.12 File systems [filesystems]

31.12.8 Enumerations [fs.enum]

31.12.8.1 Enum path::format [fs.enum.path.format]

This enum specifies constants used to identify the format of the character sequence, with the meanings listed in Table 143 .

Table 143 — Enum path::format [tab:fs.enum.path.format]

🔗 Name	Meaning
🔗 native_format	The native pathname format.
🔗 generic_format	The generic pathname format.
🔗 auto_format	The interpretation of the format of the character sequence is implementation-defined. The implementation may inspect the content of the character sequence to determine the format. Recommended practice: For POSIX-based systems, native and generic formats are equivalent and the character sequence should always be interpreted in the same way.

31.12.8.2 Enum class file_type [fs.enum.file.type]

This enum class specifies constants used to identify file types, with the meanings listed in Table 144 .

The values of the constants are distinct.

Table 144 — Enum class file_type [tab:fs.enum.file.type]

🔗 Constant	Meaning
🔗 none	The type of the file has not been determined or an error occurred while trying to determine the type.
🔗 not_found	Pseudo-type indicating the file was not found. [Note 1: The file not being found is not considered an error while determining the type of a file. — end note]
🔗 regular	Regular file
🔗 directory	Directory file
🔗 symlink	Symbolic link file
🔗 block	Block special file
🔗 character	Character special file
🔗 fifo	FIFO or pipe file
🔗 socket	Socket file
🔗 implementation-defined	Implementations that support file systems having file types in addition to the above file_type types shall supply implementation-defined file_type constants to separately identify each of those additional file types
🔗 unknown	The file exists but the type cannot be determined

31.12.8.3 Enum class copy_options [fs.enum.copy.opts]

The enum class type copy_options is a bitmask type ([bitmask.types]) that specifies bitmask constants used to control the semantics of copy operations.

The constants are specified in option groups with the meanings listed in Table 145 .

The constant none represents the empty bitmask, and is shown in each option group for purposes of exposition; implementations shall provide only a single definition.

Every other constant in the table represents a distinct bitmask element.

Table 145 — Enum class copy_options [tab:fs.enum.copy.opts]

🔗 Option group controlling copy_file function effects for existing target files
🔗 Constant	Meaning
🔗 none	(Default) Error; file already exists.
🔗 skip_existing	Do not overwrite existing file, do not report an error.
🔗 overwrite_existing	Overwrite the existing file.
🔗 update_existing	Overwrite the existing file if it is older than the replacement file.
🔗 Option group controlling copy function effects for subdirectories
🔗 Constant	Meaning
🔗 none	(Default) Do not copy subdirectories.
🔗 recursive	Recursively copy subdirectories and their contents.
🔗 Option group controlling copy function effects for symbolic links
🔗 Constant	Meaning
🔗 none	(Default) Follow symbolic links.
🔗 copy_symlinks	Copy symbolic links as symbolic links rather than copying the files that they point to.
🔗 skip_symlinks	Ignore symbolic links.
🔗 Option group controlling copy function effects for choosing the form of copying
🔗 Constant	Meaning
🔗 none	(Default) Copy content.
🔗 directories_only	Copy directory structure only, do not copy non-directory files.
🔗 create_symlinks	Make symbolic links instead of copies of files. The source path shall be an absolute path unless the destination path is in the current directory.
🔗 create_hard_links	Make hard links instead of copies of files.

31.12.8.4 Enum class perms [fs.enum.perms]

The enum class type perms is a bitmask type ([bitmask.types]) that specifies bitmask constants used to identify file permissions, with the meanings listed in Table 146 .

Table 146 — Enum class perms [tab:fs.enum.perms]

🔗 Name	Value	POSIX	Definition or notes
🔗	(octal)	macro
🔗 none	0		There are no permissions set for the file.
🔗 owner_read	0400	S_IRUSR	Read permission, owner
🔗 owner_write	0200	S_IWUSR	Write permission, owner
🔗 owner_exec	0100	S_IXUSR	Execute/search permission, owner
🔗 owner_all	0700	S_IRWXU	Read, write, execute/search by owner; owner_read \| owner_write \| owner_exec
🔗 group_read	040	S_IRGRP	Read permission, group
🔗 group_write	020	S_IWGRP	Write permission, group
🔗 group_exec	010	S_IXGRP	Execute/search permission, group
🔗 group_all	070	S_IRWXG	Read, write, execute/search by group; group_read \| group_write \| group_exec
🔗 others_read	04	S_IROTH	Read permission, others
🔗 others_write	02	S_IWOTH	Write permission, others
🔗 others_exec	01	S_IXOTH	Execute/search permission, others
🔗 others_all	07	S_IRWXO	Read, write, execute/search by others; others_read \| others_write \| others_exec
🔗 all	0777		owner_all \| group_all \| others_all
🔗 set_uid	04000	S_ISUID	Set-user-ID on execution
🔗 set_gid	02000	S_ISGID	Set-group-ID on execution
🔗 sticky_bit	01000	S_ISVTX	Operating system dependent.
🔗 mask	07777		all \| set_uid \| set_gid \| sticky_bit
🔗 unknown	0xFFFF		The permissions are not known, such as when a file_status object is created without specifying the permissions

31.12.8.5 Enum class perm_options [fs.enum.perm.opts]

The enum class type perm_options is a bitmask type ([bitmask.types]) that specifies bitmask constants used to control the semantics of permissions operations, with the meanings listed in Table 147 .

The bitmask constants are bitmask elements.

In Table 147 perm denotes a value of type perms passed to permissions.

Table 147 — Enum class perm_options [tab:fs.enum.perm.opts]

🔗 Name	Meaning
🔗 replace	permissions shall replace the file's permission bits with perm
🔗 add	permissions shall replace the file's permission bits with the bitwise or of perm and the file's current permission bits.
🔗 remove	permissions shall replace the file's permission bits with the bitwise and of the complement of perm and the file's current permission bits.
🔗 nofollow	permissions shall change the permissions of a symbolic link itself rather than the permissions of the file the link resolves to.

31.12.8.6 Enum class directory_options [fs.enum.dir.opts]

The enum class type directory_options is a bitmask type ([bitmask.types]) that specifies bitmask constants used to identify directory traversal options, with the meanings listed in Table 148 .

The constant none represents the empty bitmask; every other constant in the table represents a distinct bitmask element.

Table 148 — Enum class directory_options [tab:fs.enum.dir.opts]

🔗 Name	Meaning
🔗 none	(Default) Skip directory symlinks, permission denied is an error.
🔗 follow_directory_symlink	Follow rather than skip directory symlinks.
🔗 skip_permission_denied	Skip directories that would otherwise result in permission denied.