Posix_stat (posix-stat.Posix

Example

  (* Get file information *)
  let info = stat "/etc/passwd" in
  Printf.printf "Size: %Ld bytes\n" (Posix_types.Off.to_int64 info.st_size);

  (* Check if it's a regular file *)
  if s_isreg info.st_mode then print_endline "Regular file"

File Type Constants

Constants for the file type portion of st_mode. Use s_ifmt to mask out the file type bits.

val s_ifmt : Posix_types.mode_t

File type mask. Use as Posix_types.Mode.logand mode s_ifmt.

val s_ifreg : Posix_types.mode_t

Regular file (S_IFREG).

val s_ifdir : Posix_types.mode_t

Directory (S_IFDIR).

val s_iflnk : Posix_types.mode_t

Symbolic link (S_IFLNK).

val s_ifchr : Posix_types.mode_t

Character device (S_IFCHR).

val s_ifblk : Posix_types.mode_t

Block device (S_IFBLK).

val s_ififo : Posix_types.mode_t

FIFO/named pipe (S_IFIFO).

val s_ifsock : Posix_types.mode_t

Socket (S_IFSOCK).

Permission Bit Constants

Constants for file permission bits in st_mode.

Special Mode Bits

val s_isuid : Posix_types.mode_t

Set-user-ID on execution (S_ISUID).

val s_isgid : Posix_types.mode_t

Set-group-ID on execution (S_ISGID).

val s_isvtx : Posix_types.mode_t

Sticky bit (S_ISVTX). On directories, restricts file deletion.

Owner Permissions

val s_irwxu : Posix_types.mode_t

Owner: read, write, execute (S_IRWXU = 0o700).

val s_irusr : Posix_types.mode_t

Owner: read permission (S_IRUSR = 0o400).

val s_iwusr : Posix_types.mode_t

Owner: write permission (S_IWUSR = 0o200).

val s_ixusr : Posix_types.mode_t

Owner: execute permission (S_IXUSR = 0o100).

Group Permissions

val s_irwxg : Posix_types.mode_t

Group: read, write, execute (S_IRWXG = 0o070).

val s_irgrp : Posix_types.mode_t

Group: read permission (S_IRGRP = 0o040).

val s_iwgrp : Posix_types.mode_t

Group: write permission (S_IWGRP = 0o020).

val s_ixgrp : Posix_types.mode_t

Group: execute permission (S_IXGRP = 0o010).

Others Permissions

val s_irwxo : Posix_types.mode_t

Others: read, write, execute (S_IRWXO = 0o007).

val s_iroth : Posix_types.mode_t

Others: read permission (S_IROTH = 0o004).

val s_iwoth : Posix_types.mode_t

Others: write permission (S_IWOTH = 0o002).

val s_ixoth : Posix_types.mode_t

Others: execute permission (S_IXOTH = 0o001).

File Type Test Functions

These functions test the st_mode field to determine file type. They are equivalent to the POSIX S_IS* macros.

val s_isreg : Posix_types.mode_t -> bool

s_isreg mode returns true if mode indicates a regular file.

val s_isdir : Posix_types.mode_t -> bool

s_isdir mode returns true if mode indicates a directory.

val s_islnk : Posix_types.mode_t -> bool

s_islnk mode returns true if mode indicates a symbolic link.

val s_ischr : Posix_types.mode_t -> bool

s_ischr mode returns true if mode indicates a character device.

val s_isblk : Posix_types.mode_t -> bool

s_isblk mode returns true if mode indicates a block device.

val s_isfifo : Posix_types.mode_t -> bool

s_isfifo mode returns true if mode indicates a FIFO/named pipe.

val s_issock : Posix_types.mode_t -> bool

s_issock mode returns true if mode indicates a socket.

File Status Structure

type stat = {

st_dev : Posix_types.dev_t;
st_ino : Posix_types.ino_t;
st_mode : Posix_types.mode_t;
st_nlink : Posix_types.nlink_t;
st_uid : Posix_types.uid_t;
st_gid : Posix_types.gid_t;
st_rdev : Posix_types.dev_t;
st_size : Posix_types.off_t;
st_atim : Posix_time2.Timespec.t;
st_mtim : Posix_time2.Timespec.t;
st_ctim : Posix_time2.Timespec.t;
st_blksize : Posix_types.blksize_t;
st_blocks : Posix_types.blkcnt_t;

}

File status information returned by stat, fstat, and lstat. Corresponds to POSIX struct stat.

File Status Functions

val stat : string -> stat

Get file status, following symbolic links.

See stat(2).

raises Unix.Unix_error
on failure.

val fstat : Unix.file_descr -> stat

Get file status for an open file descriptor.

See fstat(2).

raises Unix.Unix_error
on failure.

val lstat : string -> stat

Get file status without following symbolic links.

Returns information about the symbolic link itself, not its target.

See lstat(2).

raises Unix.Unix_error
on failure.

Permission Functions

val chmod : string -> Posix_types.mode_t -> unit

Change file permissions.

See chmod(2).

raises Unix.Unix_error
on failure.

val fchmod : Unix.file_descr -> Posix_types.mode_t -> unit

Change file permissions using a file descriptor.

See fchmod(2).

raises Unix.Unix_error
on failure.

File Creation

val mkdir : string -> Posix_types.mode_t -> unit

Create a directory.

See mkdir(2).

raises Unix.Unix_error
on failure.

val mkfifo : string -> Posix_types.mode_t -> unit

Create a FIFO (named pipe).

See mkfifo(3).

raises Unix.Unix_error
on failure.

File Creation Mask

val umask : Posix_types.mode_t -> Posix_types.mode_t

Set the file mode creation mask.

See umask(2).

The umask is used to turn off permission bits when creating files. For example, umask (Mode.of_int 0o022) prevents group and others write permissions on newly created files.

returns
The previous umask value.

Directory-Relative Operations

These functions operate relative to a directory file descriptor, providing protection against certain race conditions (TOCTOU).

See *at(2) functions.

val at_fdcwd : int

Use current working directory as the base for relative paths. Pass this as dirfd to use CWD like the non-*at functions.

val at_symlink_nofollow : int

Flag: do not follow symbolic links.

val at_removedir : int

Flag: remove directory instead of file (for unlinkat).

val at_eaccess : int

Flag: use effective IDs for access checks (for faccessat).

val fstatat : ?dirfd:Unix.file_descr -> ?flags:int list -> string -> stat

Like stat/lstat but relative to a directory file descriptor.

See fstatat(2).

parameter dirfd
Base directory (default: current working directory).

parameter flags
May include at_symlink_nofollow to not follow symlinks.

raises Unix.Unix_error
on failure.

val fchmodat : 
  ?dirfd:Unix.file_descr ->
  ?flags:int list ->
  string ->
  Posix_types.mode_t ->
  unit

Like chmod but relative to a directory file descriptor.

See fchmodat(2).

parameter dirfd
Base directory (default: current working directory).

parameter flags
Optional flags.

raises Unix.Unix_error
on failure.

val mkdirat : ?dirfd:Unix.file_descr -> string -> Posix_types.mode_t -> unit

Like mkdir but relative to a directory file descriptor.

See mkdirat(2).

parameter dirfd
Base directory (default: current working directory).

raises Unix.Unix_error
on failure.

val mkfifoat : ?dirfd:Unix.file_descr -> string -> Posix_types.mode_t -> unit

Like mkfifo but relative to a directory file descriptor.

See mkfifoat(3).

parameter dirfd
Base directory (default: current working directory).

raises Unix.Unix_error
on failure.