class File

A File object is a representation of a file in the underlying platform.

Class File extends module FileTest, supporting such singleton methods as File.exist?.

File Permissions

A File object has permissions, an octal integer representing the permissions of an actual file in the underlying platform.

Note that file permissions are quite different from the mode of a file stream (File object). See Modes at IO.

In a File object, the permissions are available thus, where method mode, despite its name, returns permissions:

f = File.new('t.txt')
f.lstat.mode.to_s(8) # => "100644"

On a Unix-based operating system, the three low-order octal digits represent the permissions for owner (6), group (4), and world (4). The triplet of bits in each octal digit represent, respectively, read, write, and execute permissions.

Permissions 0644 thus represent read-write access for owner and read-only access for group and world. See man pages open(2) and chmod(2).

For a directory, the meaning of the execute bit changes: when set, the directory can be searched.

Higher-order bits in permissions may indicate the type of file (plain, directory, pipe, socket, etc.) and various other special features.

On non-Posix operating systems, permissions may include only read-only or read-write, in which case, the remaining permission will resemble typical values. On Windows, for instance, the default permissions are 0644; The only change that can be made is to make the file read-only, which is reported as 0444.

For a method that actually creates a file in the underlying platform (as opposed to merely creating a File object), permissions may be specified:

File.new('t.tmp', File::CREAT, 0644)
File.new('t.tmp', File::CREAT, 0444)

Permissions may also be changed:

f = File.new('t.tmp', File::CREAT, 0444)
f.chmod(0644)
f.chmod(0444)

File Constants

Various constants for use in File and IO methods may be found in module File::Constants; an array of their names is returned by File::Constants.constants.

Example Files

Many examples here use these filenames and their corresponding files:

What’s Here

First, what’s elsewhere. Class File:

Here, class File provides methods that are useful for:

Creating

Querying

Paths

Times

Types

Contents

Settings

Other

Constants

ALT_SEPARATOR

platform specific alternative separator

PATH_SEPARATOR

path list separator

SEPARATOR

separates directory parts in path

Separator

separates directory parts in path

Public Class Methods

absolute_path(file_name [, dir_string] ) → abs_file_name click to toggle source

Converts a pathname to an absolute pathname. Relative paths are referenced from the current working directory of the process unless dir_string is given, in which case it will be used as the starting point. If the given pathname starts with a “~” it is NOT expanded, it is treated as a normal directory name.

File.absolute_path("~oracle/bin")       #=> "<relative_path>/~oracle/bin"
static VALUE
s_absolute_path(int c, const VALUE * v, VALUE _)
{
    return rb_file_s_absolute_path(c, v);
}
absolute_path?(file_name) → true or false click to toggle source

Returns true if file_name is an absolute path, and false otherwise.

File.absolute_path?("c:/foo")     #=> false (on Linux), true (on Windows)
static VALUE
s_absolute_path_p(VALUE klass, VALUE fname)
{
    VALUE path = rb_get_path(fname);

    if (!rb_is_absolute_path(RSTRING_PTR(path))) return Qfalse;
    return Qtrue;
}
atime(file_name) → time click to toggle source

Returns the last access time for the named file as a Time object.

file_name can be an IO object.

File.atime("testfile")   #=> Wed Apr 09 08:51:48 CDT 2003
static VALUE
rb_file_s_atime(VALUE klass, VALUE fname)
{
    struct stat st;

    if (rb_stat(fname, &st) < 0) {
        int e = errno;
        FilePathValue(fname);
        rb_syserr_fail_path(e, fname);
    }
    return stat_atime(&st);
}
basename(file_name [, suffix] ) → base_name click to toggle source

Returns the last component of the filename given in file_name (after first stripping trailing separators), which can be formed using both File::SEPARATOR and File::ALT_SEPARATOR as the separator when File::ALT_SEPARATOR is not nil. If suffix is given and present at the end of file_name, it is removed. If suffix is “.*”, any extension will be removed.

File.basename("/home/gumby/work/ruby.rb")          #=> "ruby.rb"
File.basename("/home/gumby/work/ruby.rb", ".rb")   #=> "ruby"
File.basename("/home/gumby/work/ruby.rb", ".*")    #=> "ruby"
static VALUE
rb_file_s_basename(int argc, VALUE *argv, VALUE _)
{
    VALUE fname, fext, basename;
    const char *name, *p;
    long f, n;
    rb_encoding *enc;

    fext = Qnil;
    if (rb_check_arity(argc, 1, 2) == 2) {
        fext = argv[1];
        StringValue(fext);
        enc = check_path_encoding(fext);
    }
    fname = argv[0];
    FilePathStringValue(fname);
    if (NIL_P(fext) || !(enc = rb_enc_compatible(fname, fext))) {
        enc = rb_enc_get(fname);
        fext = Qnil;
    }
    if ((n = RSTRING_LEN(fname)) == 0 || !*(name = RSTRING_PTR(fname)))
        return rb_str_new_shared(fname);

    p = ruby_enc_find_basename(name, &f, &n, enc);
    if (n >= 0) {
        if (NIL_P(fext)) {
            f = n;
        }
        else {
            const char *fp;
            fp = StringValueCStr(fext);
            if (!(f = rmext(p, f, n, fp, RSTRING_LEN(fext), enc))) {
                f = n;
            }
            RB_GC_GUARD(fext);
        }
        if (f == RSTRING_LEN(fname)) return rb_str_new_shared(fname);
    }

    basename = rb_str_new(p, f);
    rb_enc_copy(basename, fname);
    return basename;
}
birthtime(p1) click to toggle source
RUBY_FUNC_EXPORTED VALUE
rb_file_s_birthtime(VALUE klass, VALUE fname)
{
    statx_data st;

    if (rb_statx(fname, &st, STATX_BTIME) < 0) {
        int e = errno;
        FilePathValue(fname);
        rb_syserr_fail_path(e, fname);
    }
    return statx_birthtime(&st, fname);
}
blockdev?(filepath) → true or false click to toggle source

Returns true if filepath points to a block device, false otherwise:

File.blockdev?('/dev/sda1')       # => true
File.blockdev?(File.new('t.tmp')) # => false
static VALUE
rb_file_blockdev_p(VALUE obj, VALUE fname)
{
#ifndef S_ISBLK
#   ifdef S_IFBLK
#       define S_ISBLK(m) (((m) & S_IFMT) == S_IFBLK)
#   else
#       define S_ISBLK(m) (0)  /* anytime false */
#   endif
#endif

#ifdef S_ISBLK
    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qfalse;
    if (S_ISBLK(st.st_mode)) return Qtrue;

#endif
    return Qfalse;
}
chardev?(filepath) → true or false click to toggle source

Returns true if filepath points to a character device, false otherwise.

File.chardev?($stdin)     # => true
File.chardev?('t.txt')     # => false
static VALUE
rb_file_chardev_p(VALUE obj, VALUE fname)
{
#ifndef S_ISCHR
#   define S_ISCHR(m) (((m) & S_IFMT) == S_IFCHR)
#endif

    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qfalse;
    if (S_ISCHR(st.st_mode)) return Qtrue;

    return Qfalse;
}
chmod(mode_int, file_name, ... ) → integer click to toggle source

Changes permission bits on the named file(s) to the bit pattern represented by mode_int. Actual effects are operating system dependent (see the beginning of this section). On Unix systems, see chmod(2) for details. Returns the number of files processed.

File.chmod(0644, "testfile", "out")   #=> 2
static VALUE
rb_file_s_chmod(int argc, VALUE *argv, VALUE _)
{
    mode_t mode;

    apply2args(1);
    mode = NUM2MODET(*argv++);

    return apply2files(chmod_internal, argc, argv, &mode);
}
chown(owner_int, group_int, file_name, ...) → integer click to toggle source

Changes the owner and group of the named file(s) to the given numeric owner and group id’s. Only a process with superuser privileges may change the owner of a file. The current owner of a file may change the file’s group to any group to which the owner belongs. A nil or -1 owner or group id is ignored. Returns the number of files processed.

File.chown(nil, 100, "testfile")
static VALUE
rb_file_s_chown(int argc, VALUE *argv, VALUE _)
{
    struct chown_args arg;

    apply2args(2);
    arg.owner = to_uid(*argv++);
    arg.group = to_gid(*argv++);

    return apply2files(chown_internal, argc, argv, &arg);
}
ctime(file_name) → time click to toggle source

Returns the change time for the named file (the time at which directory information about the file was changed, not the file itself).

file_name can be an IO object.

Note that on Windows (NTFS), returns creation time (birth time).

File.ctime("testfile")   #=> Wed Apr 09 08:53:13 CDT 2003
static VALUE
rb_file_s_ctime(VALUE klass, VALUE fname)
{
    struct stat st;

    if (rb_stat(fname, &st) < 0) {
        int e = errno;
        FilePathValue(fname);
        rb_syserr_fail_path(e, fname);
    }
    return stat_ctime(&st);
}
delete(file_name, ...) → integer click to toggle source
unlink(file_name, ...) → integer

Deletes the named files, returning the number of names passed as arguments. Raises an exception on any error. Since the underlying implementation relies on the unlink(2) system call, the type of exception raised depends on its error type (see linux.die.net/man/2/unlink) and has the form of e.g. Errno::ENOENT.

See also Dir::rmdir.

static VALUE
rb_file_s_unlink(int argc, VALUE *argv, VALUE klass)
{
    return apply2files(unlink_internal, argc, argv, 0);
}
directory?(path) → true or false click to toggle source

With string object given, returns true if path is a string path leading to a directory, or to a symbolic link to a directory; false otherwise:

File.directory?('.')              # => true
File.directory?('foo')            # => false
File.symlink('.', 'dirlink')      # => 0
File.directory?('dirlink')        # => true
File.symlink('t,txt', 'filelink') # => 0
File.directory?('filelink')       # => false

Argument path can be an IO object.

VALUE
rb_file_directory_p(VALUE obj, VALUE fname)
{
#ifndef S_ISDIR
#   define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#endif

    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qfalse;
    if (S_ISDIR(st.st_mode)) return Qtrue;
    return Qfalse;
}
dirname(file_name, level = 1) → dir_name click to toggle source

Returns all components of the filename given in file_name except the last one (after first stripping trailing separators). The filename can be formed using both File::SEPARATOR and File::ALT_SEPARATOR as the separator when File::ALT_SEPARATOR is not nil.

File.dirname("/home/gumby/work/ruby.rb")   #=> "/home/gumby/work"

If level is given, removes the last level components, not only one.

File.dirname("/home/gumby/work/ruby.rb", 2) #=> "/home/gumby"
File.dirname("/home/gumby/work/ruby.rb", 4) #=> "/"
static VALUE
rb_file_s_dirname(int argc, VALUE *argv, VALUE klass)
{
    int n = 1;
    if ((argc = rb_check_arity(argc, 1, 2)) > 1) {
        n = NUM2INT(argv[1]);
    }
    return rb_file_dirname_n(argv[0], n);
}
zero?(file_name) → true or false click to toggle source

Returns true if the named file exists and has a zero size.

file_name can be an IO object.

static VALUE
rb_file_zero_p(VALUE obj, VALUE fname)
{
    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qfalse;
    return RBOOL(st.st_size == 0);
}
executable?(file_name) → true or false click to toggle source

Returns true if the named file is executable by the effective user and group id of this process. See eaccess(3).

Windows does not support execute permissions separately from read permissions. On Windows, a file is only considered executable if it ends in .bat, .cmd, .com, or .exe.

Note that some OS-level security features may cause this to return true even though the file is not executable by the effective user/group.

static VALUE
rb_file_executable_p(VALUE obj, VALUE fname)
{
    return RBOOL(rb_eaccess(fname, X_OK) >= 0);
}
executable_real?(file_name) → true or false click to toggle source

Returns true if the named file is executable by the real user and group id of this process. See access(3).

Windows does not support execute permissions separately from read permissions. On Windows, a file is only considered executable if it ends in .bat, .cmd, .com, or .exe.

Note that some OS-level security features may cause this to return true even though the file is not executable by the real user/group.

static VALUE
rb_file_executable_real_p(VALUE obj, VALUE fname)
{
    return RBOOL(rb_access(fname, X_OK) >= 0);
}
exist?(file_name) → true or false click to toggle source

Return true if the named file exists.

file_name can be an IO object.

“file exists” means that stat() or fstat() system call is successful.

static VALUE
rb_file_exist_p(VALUE obj, VALUE fname)
{
    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qfalse;
    return Qtrue;
}
expand_path(file_name [, dir_string] ) → abs_file_name click to toggle source

Converts a pathname to an absolute pathname. Relative paths are referenced from the current working directory of the process unless dir_string is given, in which case it will be used as the starting point. The given pathname may start with a “~”, which expands to the process owner’s home directory (the environment variable HOME must be set correctly). “~user” expands to the named user’s home directory.

File.expand_path("~oracle/bin")           #=> "/home/oracle/bin"

A simple example of using dir_string is as follows.

File.expand_path("ruby", "/usr/bin")      #=> "/usr/bin/ruby"

A more complex example which also resolves parent directory is as follows. Suppose we are in bin/mygem and want the absolute path of lib/mygem.rb.

File.expand_path("../../lib/mygem.rb", __FILE__)
#=> ".../path/to/project/lib/mygem.rb"

So first it resolves the parent of __FILE__, that is bin/, then go to the parent, the root of the project and appends lib/mygem.rb.

static VALUE
s_expand_path(int c, const VALUE * v, VALUE _)
{
    return rb_file_s_expand_path(c, v);
}
extname(path) → string click to toggle source

Returns the extension (the portion of file name in path starting from the last period).

If path is a dotfile, or starts with a period, then the starting dot is not dealt with the start of the extension.

An empty string will also be returned when the period is the last character in path.

On Windows, trailing dots are truncated.

File.extname("test.rb")         #=> ".rb"
File.extname("a/b/d/test.rb")   #=> ".rb"
File.extname(".a/b/d/test.rb")  #=> ".rb"
File.extname("foo.")            #=> "" on Windows
File.extname("foo.")            #=> "." on non-Windows
File.extname("test")            #=> ""
File.extname(".profile")        #=> ""
File.extname(".profile.sh")     #=> ".sh"
static VALUE
rb_file_s_extname(VALUE klass, VALUE fname)
{
    const char *name, *e;
    long len;
    VALUE extname;

    FilePathStringValue(fname);
    name = StringValueCStr(fname);
    len = RSTRING_LEN(fname);
    e = ruby_enc_find_extname(name, &len, rb_enc_get(fname));
    if (len < 1)
        return rb_str_new(0, 0);
    extname = rb_str_subseq(fname, e - name, len); /* keep the dot, too! */
    return extname;
}
file?(file) → true or false click to toggle source

Returns true if the named file exists and is a regular file.

file can be an IO object.

If the file argument is a symbolic link, it will resolve the symbolic link and use the file referenced by the link.

static VALUE
rb_file_file_p(VALUE obj, VALUE fname)
{
    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qfalse;
    return RBOOL(S_ISREG(st.st_mode));
}
fnmatch( pattern, path, [flags] ) → (true or false) click to toggle source

Returns true if path matches against pattern. The pattern is not a regular expression; instead it follows rules similar to shell filename globbing. It may contain the following metacharacters:

*

Matches any file. Can be restricted by other values in the glob. Equivalent to /.*/x in regexp.

*

Matches all regular files

c*

Matches all files beginning with c

*c

Matches all files ending with c

*c*

Matches all files that have c in them (including at the beginning or end).

To match hidden files (that start with a .) set the File::FNM_DOTMATCH flag.

**

Matches directories recursively or files expansively.

?

Matches any one character. Equivalent to /.{1}/ in regexp.

[set]

Matches any one character in set. Behaves exactly like character sets in Regexp, including set negation ([^a-z]).

\

Escapes the next metacharacter.

{a,b}

Matches pattern a and pattern b if File::FNM_EXTGLOB flag is enabled. Behaves like a Regexp union ((?:a|b)).

flags is a bitwise OR of the FNM_XXX constants. The same glob pattern and flags are used by Dir::glob.

Examples:

File.fnmatch('cat',       'cat')        #=> true  # match entire string
File.fnmatch('cat',       'category')   #=> false # only match partial string

File.fnmatch('c{at,ub}s', 'cats')                    #=> false # { } isn't supported by default
File.fnmatch('c{at,ub}s', 'cats', File::FNM_EXTGLOB) #=> true  # { } is supported on FNM_EXTGLOB

File.fnmatch('c?t',     'cat')          #=> true  # '?' match only 1 character
File.fnmatch('c??t',    'cat')          #=> false # ditto
File.fnmatch('c*',      'cats')         #=> true  # '*' match 0 or more characters
File.fnmatch('c*t',     'c/a/b/t')      #=> true  # ditto
File.fnmatch('ca[a-z]', 'cat')          #=> true  # inclusive bracket expression
File.fnmatch('ca[^t]',  'cat')          #=> false # exclusive bracket expression ('^' or '!')

File.fnmatch('cat', 'CAT')                     #=> false # case sensitive
File.fnmatch('cat', 'CAT', File::FNM_CASEFOLD) #=> true  # case insensitive
File.fnmatch('cat', 'CAT', File::FNM_SYSCASE)  #=> true or false # depends on the system default

File.fnmatch('?',   '/', File::FNM_PATHNAME)  #=> false # wildcard doesn't match '/' on FNM_PATHNAME
File.fnmatch('*',   '/', File::FNM_PATHNAME)  #=> false # ditto
File.fnmatch('[/]', '/', File::FNM_PATHNAME)  #=> false # ditto

File.fnmatch('\?',   '?')                       #=> true  # escaped wildcard becomes ordinary
File.fnmatch('\a',   'a')                       #=> true  # escaped ordinary remains ordinary
File.fnmatch('\a',   '\a', File::FNM_NOESCAPE)  #=> true  # FNM_NOESCAPE makes '\' ordinary
File.fnmatch('[\?]', '?')                       #=> true  # can escape inside bracket expression

File.fnmatch('*',   '.profile')                      #=> false # wildcard doesn't match leading
File.fnmatch('*',   '.profile', File::FNM_DOTMATCH)  #=> true  # period by default.
File.fnmatch('.*',  '.profile')                      #=> true

File.fnmatch('**/*.rb', 'main.rb')                  #=> false
File.fnmatch('**/*.rb', './main.rb')                #=> false
File.fnmatch('**/*.rb', 'lib/song.rb')              #=> true
File.fnmatch('**.rb', 'main.rb')                    #=> true
File.fnmatch('**.rb', './main.rb')                  #=> false
File.fnmatch('**.rb', 'lib/song.rb')                #=> true
File.fnmatch('*',     'dave/.profile')              #=> true

File.fnmatch('**/foo', 'a/b/c/foo', File::FNM_PATHNAME)     #=> true
File.fnmatch('**/foo', '/a/b/c/foo', File::FNM_PATHNAME)    #=> true
File.fnmatch('**/foo', 'c:/a/b/c/foo', File::FNM_PATHNAME)  #=> true
File.fnmatch('**/foo', 'a/.b/c/foo', File::FNM_PATHNAME)    #=> false
File.fnmatch('**/foo', 'a/.b/c/foo', File::FNM_PATHNAME | File::FNM_DOTMATCH) #=> true
# File dir.rb, line 311
def fnmatch(pattern, path, flags = 0)
end
Also aliased as: fnmatch?
fnmatch?(pattern, path, flags = 0)
Alias for: fnmatch
ftype(file_name) → string click to toggle source

Identifies the type of the named file; the return string is one of “file”, “directory”, “characterSpecial”, “blockSpecial”, “fifo”, “link”, “socket”, or “unknown”.

File.ftype("testfile")            #=> "file"
File.ftype("/dev/tty")            #=> "characterSpecial"
File.ftype("/tmp/.X11-unix/X0")   #=> "socket"
static VALUE
rb_file_s_ftype(VALUE klass, VALUE fname)
{
    struct stat st;

    FilePathValue(fname);
    fname = rb_str_encode_ospath(fname);
    if (lstat_without_gvl(StringValueCStr(fname), &st) == -1) {
        rb_sys_fail_path(fname);
    }

    return rb_file_ftype(&st);
}
grpowned?(file_name) → true or false click to toggle source

Returns true if the named file exists and the effective group id of the calling process is the owner of the file. Returns false on Windows.

file_name can be an IO object.

static VALUE
rb_file_grpowned_p(VALUE obj, VALUE fname)
{
#ifndef _WIN32
    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qfalse;
    if (rb_group_member(st.st_gid)) return Qtrue;
#endif
    return Qfalse;
}
identical?(file_1, file_2) → true or false click to toggle source

Returns true if the named files are identical.

file_1 and file_2 can be an IO object.

open("a", "w") {}
p File.identical?("a", "a")      #=> true
p File.identical?("a", "./a")    #=> true
File.link("a", "b")
p File.identical?("a", "b")      #=> true
File.symlink("a", "c")
p File.identical?("a", "c")      #=> true
open("d", "w") {}
p File.identical?("a", "d")      #=> false
static VALUE
rb_file_identical_p(VALUE obj, VALUE fname1, VALUE fname2)
{
#ifndef _WIN32
    struct stat st1, st2;

    if (rb_stat(fname1, &st1) < 0) return Qfalse;
    if (rb_stat(fname2, &st2) < 0) return Qfalse;
    if (st1.st_dev != st2.st_dev) return Qfalse;
    if (st1.st_ino != st2.st_ino) return Qfalse;
    return Qtrue;
#else
    extern VALUE rb_w32_file_identical_p(VALUE, VALUE);
    return rb_w32_file_identical_p(fname1, fname2);
#endif
}
join(string, ...) → string click to toggle source

Returns a new string formed by joining the strings using "/".

File.join("usr", "mail", "gumby")   #=> "usr/mail/gumby"
static VALUE
rb_file_s_join(VALUE klass, VALUE args)
{
    return rb_file_join(args);
}
lchmod(mode_int, file_name, ...) → integer click to toggle source

Equivalent to File::chmod, but does not follow symbolic links (so it will change the permissions associated with the link, not the file referenced by the link). Often not available.

static VALUE
rb_file_s_lchmod(int argc, VALUE *argv, VALUE _)
{
    mode_t mode;

    apply2args(1);
    mode = NUM2MODET(*argv++);

    return apply2files(lchmod_internal, argc, argv, &mode);
}
lchown(owner_int, group_int, file_name,..) → integer click to toggle source

Equivalent to File::chown, but does not follow symbolic links (so it will change the owner associated with the link, not the file referenced by the link). Often not available. Returns number of files in the argument list.

static VALUE
rb_file_s_lchown(int argc, VALUE *argv, VALUE _)
{
    struct chown_args arg;

    apply2args(2);
    arg.owner = to_uid(*argv++);
    arg.group = to_gid(*argv++);

    return apply2files(lchown_internal, argc, argv, &arg);
}
lstat(filepath) → stat click to toggle source

Like File::stat, but does not follow the last symbolic link; instead, returns a File::Stat object for the link itself.

File.symlink('t.txt', 'symlink')
File.stat('symlink').size  # => 47
File.lstat('symlink').size # => 5
static VALUE
rb_file_s_lstat(VALUE klass, VALUE fname)
{
#ifdef HAVE_LSTAT
    struct stat st;

    FilePathValue(fname);
    fname = rb_str_encode_ospath(fname);
    if (lstat_without_gvl(StringValueCStr(fname), &st) == -1) {
        rb_sys_fail_path(fname);
    }
    return rb_stat_new(&st);
#else
    return rb_file_s_stat(klass, fname);
#endif
}
lutime(atime, mtime, file_name, ...) → integer click to toggle source

Sets the access and modification times of each named file to the first two arguments. If a file is a symlink, this method acts upon the link itself as opposed to its referent; for the inverse behavior, see File.utime. Returns the number of file names in the argument list.

static VALUE
rb_file_s_lutime(int argc, VALUE *argv, VALUE _)
{
    return utime_internal_i(argc, argv, TRUE);
}
mkfifo(file_name, mode=0666) → 0 click to toggle source

Creates a FIFO special file with name file_name. mode specifies the FIFO’s permissions. It is modified by the process’s umask in the usual way: the permissions of the created file are (mode & ~umask).

static VALUE
rb_file_s_mkfifo(int argc, VALUE *argv, VALUE _)
{
    VALUE path;
    struct mkfifo_arg ma;

    ma.mode = 0666;
    rb_check_arity(argc, 1, 2);
    if (argc > 1) {
        ma.mode = NUM2MODET(argv[1]);
    }
    path = argv[0];
    FilePathValue(path);
    path = rb_str_encode_ospath(path);
    ma.path = RSTRING_PTR(path);
    if (rb_thread_call_without_gvl(nogvl_mkfifo, &ma, RUBY_UBF_IO, 0)) {
        rb_sys_fail_path(path);
    }
    return INT2FIX(0);
}
mtime(file_name) → time click to toggle source

Returns the modification time for the named file as a Time object.

file_name can be an IO object.

File.mtime("testfile")   #=> Tue Apr 08 12:58:04 CDT 2003
static VALUE
rb_file_s_mtime(VALUE klass, VALUE fname)
{
    struct stat st;

    if (rb_stat(fname, &st) < 0) {
        int e = errno;
        FilePathValue(fname);
        rb_syserr_fail_path(e, fname);
    }
    return stat_mtime(&st);
}
new(path, mode = 'r', perm = 0666, **opts) → file click to toggle source

Opens the file at the given path according to the given mode; creates and returns a new File object for that file.

The new File object is buffered mode (or non-sync mode), unless filename is a tty. See IO#flush, IO#fsync, IO#fdatasync, and IO#sync=.

Argument path must be a valid file path:

File.new('/etc/fstab')
File.new('t.txt')

Optional argument mode (defaults to ‘r’) must specify a valid mode see Modes at IO:

File.new('t.tmp', 'w')
File.new('t.tmp', File::RDONLY)

Optional argument perm (defaults to 0666) must specify valid permissions see File Permissions:

File.new('t.tmp', File::CREAT, 0644)
File.new('t.tmp', File::CREAT, 0444)

Optional keyword arguments opts specify:

Examples:

File.new('t.tmp', autoclose: true)
File.new('t.tmp', internal_encoding: nil)
static VALUE
rb_file_initialize(int argc, VALUE *argv, VALUE io)
{
    if (RFILE(io)->fptr) {
        rb_raise(rb_eRuntimeError, "reinitializing File");
    }
    if (0 < argc && argc < 3) {
        VALUE fd = rb_check_to_int(argv[0]);

        if (!NIL_P(fd)) {
            argv[0] = fd;
            return rb_io_initialize(argc, argv, io);
        }
    }
    rb_open_file(argc, argv, io);

    return io;
}
open(path, mode = 'r', perm = 0666, **opts) → file click to toggle source
open(path, mode = 'r', perm = 0666, **opts) {|f| ... } → object

Creates a new File object, via File.new with the given arguments.

With no block given, returns the File object.

With a block given, calls the block with the File object and returns the block’s value.

static VALUE
rb_io_s_open(int argc, VALUE *argv, VALUE klass)
{
    VALUE io = rb_class_new_instance_kw(argc, argv, klass, RB_PASS_CALLED_KEYWORDS);

    if (rb_block_given_p()) {
        return rb_ensure(rb_yield, io, io_close, io);
    }

    return io;
}
owned?(file_name) → true or false click to toggle source

Returns true if the named file exists and the effective used id of the calling process is the owner of the file.

file_name can be an IO object.

static VALUE
rb_file_owned_p(VALUE obj, VALUE fname)
{
    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qfalse;
    return RBOOL(st.st_uid == geteuid());
}
path(path) → string click to toggle source

Returns the string representation of the path

File.path("/dev/null")          #=> "/dev/null"
File.path(Pathname.new("/tmp")) #=> "/tmp"
static VALUE
rb_file_s_path(VALUE klass, VALUE fname)
{
    return rb_get_path(fname);
}
pipe?(filepath) → true or false click to toggle source

Returns true if filepath points to a pipe, false otherwise:

File.mkfifo('tmp/fifo')
File.pipe?('tmp/fifo') # => true
File.pipe?('t.txt')    # => false
static VALUE
rb_file_pipe_p(VALUE obj, VALUE fname)
{
#ifdef S_IFIFO
#  ifndef S_ISFIFO
#    define S_ISFIFO(m) (((m) & S_IFMT) == S_IFIFO)
#  endif

    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qfalse;
    if (S_ISFIFO(st.st_mode)) return Qtrue;

#endif
    return Qfalse;
}
readable?(file_name) → true or false click to toggle source

Returns true if the named file is readable by the effective user and group id of this process. See eaccess(3).

Note that some OS-level security features may cause this to return true even though the file is not readable by the effective user/group.

static VALUE
rb_file_readable_p(VALUE obj, VALUE fname)
{
    return RBOOL(rb_eaccess(fname, R_OK) >= 0);
}
readable_real?(file_name) → true or false click to toggle source

Returns true if the named file is readable by the real user and group id of this process. See access(3).

Note that some OS-level security features may cause this to return true even though the file is not readable by the real user/group.

static VALUE
rb_file_readable_real_p(VALUE obj, VALUE fname)
{
    return RBOOL(rb_access(fname, R_OK) >= 0);
}
realdirpath(pathname [, dir_string]) → real_pathname click to toggle source

Returns the real (absolute) pathname of pathname in the actual filesystem. The real pathname doesn’t contain symlinks or useless dots.

If dir_string is given, it is used as a base directory for interpreting relative pathname instead of the current directory.

The last component of the real pathname can be nonexistent.

static VALUE
rb_file_s_realdirpath(int argc, VALUE *argv, VALUE klass)
{
    VALUE basedir = (rb_check_arity(argc, 1, 2) > 1) ? argv[1] : Qnil;
    VALUE path = argv[0];
    FilePathValue(path);
    return rb_realpath_internal(basedir, path, 0);
}
realpath(pathname [, dir_string]) → real_pathname click to toggle source

Returns the real (absolute) pathname of pathname in the actual filesystem not containing symlinks or useless dots.

If dir_string is given, it is used as a base directory for interpreting relative pathname instead of the current directory.

All components of the pathname must exist when this method is called.

static VALUE
rb_file_s_realpath(int argc, VALUE *argv, VALUE klass)
{
    VALUE basedir = (rb_check_arity(argc, 1, 2) > 1) ? argv[1] : Qnil;
    VALUE path = argv[0];
    FilePathValue(path);
    return rb_realpath_internal(basedir, path, 1);
}
rename(old_name, new_name) → 0 click to toggle source

Renames the given file to the new name. Raises a SystemCallError if the file cannot be renamed.

File.rename("afile", "afile.bak")   #=> 0
static VALUE
rb_file_s_rename(VALUE klass, VALUE from, VALUE to)
{
    struct rename_args ra;
    VALUE f, t;

    FilePathValue(from);
    FilePathValue(to);
    f = rb_str_encode_ospath(from);
    t = rb_str_encode_ospath(to);
    ra.src = StringValueCStr(f);
    ra.dst = StringValueCStr(t);
#if defined __CYGWIN__
    errno = 0;
#endif
    if ((int)(VALUE)rb_thread_call_without_gvl(no_gvl_rename, &ra,
                                         RUBY_UBF_IO, 0) < 0) {
        int e = errno;
#if defined DOSISH
        switch (e) {
          case EEXIST:
            if (chmod(ra.dst, 0666) == 0 &&
                unlink(ra.dst) == 0 &&
                rename(ra.src, ra.dst) == 0)
                return INT2FIX(0);
        }
#endif
        syserr_fail2(e, from, to);
    }

    return INT2FIX(0);
}
setgid?(file_name) → true or false click to toggle source

Returns true if the named file has the setgid bit set.

file_name can be an IO object.

static VALUE
rb_file_sgid_p(VALUE obj, VALUE fname)
{
#ifdef S_ISGID
    return check3rdbyte(fname, S_ISGID);
#else
    return Qfalse;
#endif
}
setuid?(file_name) → true or false click to toggle source

Returns true if the named file has the setuid bit set.

file_name can be an IO object.

static VALUE
rb_file_suid_p(VALUE obj, VALUE fname)
{
#ifdef S_ISUID
    return check3rdbyte(fname, S_ISUID);
#else
    return Qfalse;
#endif
}
size(file_name) → integer click to toggle source

Returns the size of file_name.

file_name can be an IO object.

static VALUE
rb_file_s_size(VALUE klass, VALUE fname)
{
    struct stat st;

    if (rb_stat(fname, &st) < 0) {
        int e = errno;
        FilePathValue(fname);
        rb_syserr_fail_path(e, fname);
    }
    return OFFT2NUM(st.st_size);
}
size?(file_name) → Integer or nil click to toggle source

Returns nil if file_name doesn’t exist or has zero size, the size of the file otherwise.

file_name can be an IO object.

static VALUE
rb_file_size_p(VALUE obj, VALUE fname)
{
    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qnil;
    if (st.st_size == 0) return Qnil;
    return OFFT2NUM(st.st_size);
}
socket?(filepath) → true or false click to toggle source

Returns true if filepath points to a socket, false otherwise:

require 'socket'
File.socket?(Socket.new(:INET, :STREAM)) # => true
File.socket?(File.new('t.txt'))          # => false
static VALUE
rb_file_socket_p(VALUE obj, VALUE fname)
{
#ifndef S_ISSOCK
#  ifdef _S_ISSOCK
#    define S_ISSOCK(m) _S_ISSOCK(m)
#  else
#    ifdef _S_IFSOCK
#      define S_ISSOCK(m) (((m) & S_IFMT) == _S_IFSOCK)
#    else
#      ifdef S_IFSOCK
#        define S_ISSOCK(m) (((m) & S_IFMT) == S_IFSOCK)
#      endif
#    endif
#  endif
#endif

#ifdef S_ISSOCK
    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qfalse;
    if (S_ISSOCK(st.st_mode)) return Qtrue;

#endif
    return Qfalse;
}
split(file_name) → array click to toggle source

Splits the given string into a directory and a file component and returns them in a two-element array. See also File::dirname and File::basename.

File.split("/home/gumby/.profile")   #=> ["/home/gumby", ".profile"]
static VALUE
rb_file_s_split(VALUE klass, VALUE path)
{
    FilePathStringValue(path);          /* get rid of converting twice */
    return rb_assoc_new(rb_file_dirname(path), rb_file_s_basename(1,&path,Qundef));
}
stat(filepath) → stat click to toggle source

Returns a File::Stat object for the file at filepath (see File::Stat):

File.stat('t.txt').class # => File::Stat
static VALUE
rb_file_s_stat(VALUE klass, VALUE fname)
{
    struct stat st;

    FilePathValue(fname);
    fname = rb_str_encode_ospath(fname);
    if (stat_without_gvl(RSTRING_PTR(fname), &st) < 0) {
        rb_sys_fail_path(fname);
    }
    return rb_stat_new(&st);
}
sticky?(file_name) → true or false click to toggle source

Returns true if the named file has the sticky bit set.

file_name can be an IO object.

static VALUE
rb_file_sticky_p(VALUE obj, VALUE fname)
{
#ifdef S_ISVTX
    return check3rdbyte(fname, S_ISVTX);
#else
    return Qfalse;
#endif
}
truncate(file_name, integer) → 0 click to toggle source

Truncates the file file_name to be at most integer bytes long. Not available on all platforms.

f = File.new("out", "w")
f.write("1234567890")     #=> 10
f.close                   #=> nil
File.truncate("out", 5)   #=> 0
File.size("out")          #=> 5
static VALUE
rb_file_s_truncate(VALUE klass, VALUE path, VALUE len)
{
    struct truncate_arg ta;
    int r;

    ta.pos = NUM2POS(len);
    FilePathValue(path);
    path = rb_str_encode_ospath(path);
    ta.path = StringValueCStr(path);

    r = (int)(VALUE)rb_thread_call_without_gvl(nogvl_truncate, &ta,
                                                RUBY_UBF_IO, NULL);
    if (r < 0)
        rb_sys_fail_path(path);
    return INT2FIX(0);
#undef NUM2POS
}
umask() → integer click to toggle source
umask(integer) → integer

Returns the current umask value for this process. If the optional argument is given, set the umask to that value and return the previous value. Umask values are subtracted from the default permissions, so a umask of 0222 would make a file read-only for everyone.

File.umask(0006)   #=> 18
File.umask         #=> 6
static VALUE
rb_file_s_umask(int argc, VALUE *argv, VALUE _)
{
    mode_t omask = 0;

    switch (argc) {
      case 0:
        omask = umask(0);
        umask(omask);
        break;
      case 1:
        omask = umask(NUM2MODET(argv[0]));
        break;
      default:
        rb_error_arity(argc, 0, 1);
    }
    return MODET2NUM(omask);
}
utime(atime, mtime, file_name, ...) → integer click to toggle source

Sets the access and modification times of each named file to the first two arguments. If a file is a symlink, this method acts upon its referent rather than the link itself; for the inverse behavior see File.lutime. Returns the number of file names in the argument list.

static VALUE
rb_file_s_utime(int argc, VALUE *argv, VALUE _)
{
    return utime_internal_i(argc, argv, FALSE);
}
world_readable?(file_name) → integer or nil click to toggle source

If file_name is readable by others, returns an integer representing the file permission bits of file_name. Returns nil otherwise. The meaning of the bits is platform dependent; on Unix systems, see stat(2).

file_name can be an IO object.

File.world_readable?("/etc/passwd")           #=> 420
m = File.world_readable?("/etc/passwd")
sprintf("%o", m)                              #=> "644"
static VALUE
rb_file_world_readable_p(VALUE obj, VALUE fname)
{
#ifdef S_IROTH
    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qnil;
    if ((st.st_mode & (S_IROTH)) == S_IROTH) {
        return UINT2NUM(st.st_mode & (S_IRUGO|S_IWUGO|S_IXUGO));
    }
#endif
    return Qnil;
}
world_writable?(file_name) → integer or nil click to toggle source

If file_name is writable by others, returns an integer representing the file permission bits of file_name. Returns nil otherwise. The meaning of the bits is platform dependent; on Unix systems, see stat(2).

file_name can be an IO object.

File.world_writable?("/tmp")                  #=> 511
m = File.world_writable?("/tmp")
sprintf("%o", m)                              #=> "777"
static VALUE
rb_file_world_writable_p(VALUE obj, VALUE fname)
{
#ifdef S_IWOTH
    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qnil;
    if ((st.st_mode & (S_IWOTH)) == S_IWOTH) {
        return UINT2NUM(st.st_mode & (S_IRUGO|S_IWUGO|S_IXUGO));
    }
#endif
    return Qnil;
}
writable?(file_name) → true or false click to toggle source

Returns true if the named file is writable by the effective user and group id of this process. See eaccess(3).

Note that some OS-level security features may cause this to return true even though the file is not writable by the effective user/group.

static VALUE
rb_file_writable_p(VALUE obj, VALUE fname)
{
    return RBOOL(rb_eaccess(fname, W_OK) >= 0);
}
writable_real?(file_name) → true or false click to toggle source

Returns true if the named file is writable by the real user and group id of this process. See access(3).

Note that some OS-level security features may cause this to return true even though the file is not writable by the real user/group.

static VALUE
rb_file_writable_real_p(VALUE obj, VALUE fname)
{
    return RBOOL(rb_access(fname, W_OK) >= 0);
}
zero?(file_name) → true or false click to toggle source

Returns true if the named file exists and has a zero size.

file_name can be an IO object.

static VALUE
rb_file_zero_p(VALUE obj, VALUE fname)
{
    struct stat st;

    if (rb_stat(fname, &st) < 0) return Qfalse;
    return RBOOL(st.st_size == 0);
}

Public Instance Methods

atime → time click to toggle source

Returns the last access time (a Time object) for file, or epoch if file has not been accessed.

File.new("testfile").atime   #=> Wed Dec 31 18:00:00 CST 1969
static VALUE
rb_file_atime(VALUE obj)
{
    rb_io_t *fptr;
    struct stat st;

    GetOpenFile(obj, fptr);
    if (fstat(fptr->fd, &st) == -1) {
        rb_sys_fail_path(fptr->pathv);
    }
    return stat_atime(&st);
}
birthtime → time click to toggle source

Returns the birth time for file.

File.new("testfile").birthtime   #=> Wed Apr 09 08:53:14 CDT 2003

If the platform doesn’t have birthtime, raises NotImplementedError.

static VALUE
rb_file_birthtime(VALUE obj)
{
    rb_io_t *fptr;
    statx_data st;

    GetOpenFile(obj, fptr);
    if (fstatx_without_gvl(fptr->fd, &st, STATX_BTIME) == -1) {
        rb_sys_fail_path(fptr->pathv);
    }
    return statx_birthtime(&st, fptr->pathv);
}
chmod(mode_int) → 0 click to toggle source

Changes permission bits on file to the bit pattern represented by mode_int. Actual effects are platform dependent; on Unix systems, see chmod(2) for details. Follows symbolic links. Also see File#lchmod.

f = File.new("out", "w");
f.chmod(0644)   #=> 0
static VALUE
rb_file_chmod(VALUE obj, VALUE vmode)
{
    rb_io_t *fptr;
    mode_t mode;
#if !defined HAVE_FCHMOD || !HAVE_FCHMOD
    VALUE path;
#endif

    mode = NUM2MODET(vmode);

    GetOpenFile(obj, fptr);
#ifdef HAVE_FCHMOD
    if (fchmod(fptr->fd, mode) == -1) {
        if (HAVE_FCHMOD || errno != ENOSYS)
            rb_sys_fail_path(fptr->pathv);
    }
    else {
        if (!HAVE_FCHMOD) return INT2FIX(0);
    }
#endif
#if !defined HAVE_FCHMOD || !HAVE_FCHMOD
    if (NIL_P(fptr->pathv)) return Qnil;
    path = rb_str_encode_ospath(fptr->pathv);
    if (chmod(RSTRING_PTR(path), mode) == -1)
        rb_sys_fail_path(fptr->pathv);
#endif

    return INT2FIX(0);
}
chown(owner_int, group_int ) → 0 click to toggle source

Changes the owner and group of file to the given numeric owner and group id’s. Only a process with superuser privileges may change the owner of a file. The current owner of a file may change the file’s group to any group to which the owner belongs. A nil or -1 owner or group id is ignored. Follows symbolic links. See also File#lchown.

File.new("testfile").chown(502, 1000)
static VALUE
rb_file_chown(VALUE obj, VALUE owner, VALUE group)
{
    rb_io_t *fptr;
    rb_uid_t o;
    rb_gid_t g;
#ifndef HAVE_FCHOWN
    VALUE path;
#endif

    o = to_uid(owner);
    g = to_gid(group);
    GetOpenFile(obj, fptr);
#ifndef HAVE_FCHOWN
    if (NIL_P(fptr->pathv)) return Qnil;
    path = rb_str_encode_ospath(fptr->pathv);
    if (chown(RSTRING_PTR(path), o, g) == -1)
        rb_sys_fail_path(fptr->pathv);
#else
    if (fchown(fptr->fd, o, g) == -1)
        rb_sys_fail_path(fptr->pathv);
#endif

    return INT2FIX(0);
}
ctime → time click to toggle source

Returns the change time for file (that is, the time directory information about the file was changed, not the file itself).

Note that on Windows (NTFS), returns creation time (birth time).

File.new("testfile").ctime   #=> Wed Apr 09 08:53:14 CDT 2003
static VALUE
rb_file_ctime(VALUE obj)
{
    rb_io_t *fptr;
    struct stat st;

    GetOpenFile(obj, fptr);
    if (fstat(fptr->fd, &st) == -1) {
        rb_sys_fail_path(fptr->pathv);
    }
    return stat_ctime(&st);
}
flock(locking_constant) → 0 or false click to toggle source

Locks or unlocks a file according to locking_constant (a logical or of the values in the table below). Returns false if File::LOCK_NB is specified and the operation would otherwise have blocked. Not available on all platforms.

Locking constants (in class File):

LOCK_EX   | Exclusive lock. Only one process may hold an
          | exclusive lock for a given file at a time.
----------+------------------------------------------------
LOCK_NB   | Don't block when locking. May be combined
          | with other lock options using logical or.
----------+------------------------------------------------
LOCK_SH   | Shared lock. Multiple processes may each hold a
          | shared lock for a given file at the same time.
----------+------------------------------------------------
LOCK_UN   | Unlock.

Example:

# update a counter using write lock
# don't use "w" because it truncates the file before lock.
File.open("counter", File::RDWR|File::CREAT, 0644) {|f|
  f.flock(File::LOCK_EX)
  value = f.read.to_i + 1
  f.rewind
  f.write("#{value}\n")
  f.flush
  f.truncate(f.pos)
}

# read the counter using read lock
File.open("counter", "r") {|f|
  f.flock(File::LOCK_SH)
  p f.read
}
static VALUE
rb_file_flock(VALUE obj, VALUE operation)
{
    rb_io_t *fptr;
    int op[2], op1;
    struct timeval time;

    op[1] = op1 = NUM2INT(operation);
    GetOpenFile(obj, fptr);
    op[0] = fptr->fd;

    if (fptr->mode & FMODE_WRITABLE) {
        rb_io_flush_raw(obj, 0);
    }
    while ((int)rb_thread_io_blocking_region(rb_thread_flock, op, fptr->fd) < 0) {
        int e = errno;
        switch (e) {
          case EAGAIN:
          case EACCES:
#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
          case EWOULDBLOCK:
#endif
            if (op1 & LOCK_NB) return Qfalse;

            time.tv_sec = 0;
            time.tv_usec = 100 * 1000; /* 0.1 sec */
            rb_thread_wait_for(time);
            rb_io_check_closed(fptr);
            continue;

          case EINTR:
#if defined(ERESTART)
          case ERESTART:
#endif
            break;

          default:
            rb_syserr_fail_path(e, fptr->pathv);
        }
    }
    return INT2FIX(0);
}
lstat → stat click to toggle source

Like File#stat, but does not follow the last symbolic link; instead, returns a File::Stat object for the link itself:

File.symlink('t.txt', 'symlink')
f = File.new('symlink')
f.stat.size  # => 47
f.lstat.size # => 11
static VALUE
rb_file_lstat(VALUE obj)
{
#ifdef HAVE_LSTAT
    rb_io_t *fptr;
    struct stat st;
    VALUE path;

    GetOpenFile(obj, fptr);
    if (NIL_P(fptr->pathv)) return Qnil;
    path = rb_str_encode_ospath(fptr->pathv);
    if (lstat_without_gvl(RSTRING_PTR(path), &st) == -1) {
        rb_sys_fail_path(fptr->pathv);
    }
    return rb_stat_new(&st);
#else
    return rb_io_stat(obj);
#endif
}
mtime → time click to toggle source

Returns the modification time for file.

File.new("testfile").mtime   #=> Wed Apr 09 08:53:14 CDT 2003
static VALUE
rb_file_mtime(VALUE obj)
{
    rb_io_t *fptr;
    struct stat st;

    GetOpenFile(obj, fptr);
    if (fstat(fptr->fd, &st) == -1) {
        rb_sys_fail_path(fptr->pathv);
    }
    return stat_mtime(&st);
}
path → filepath click to toggle source

Returns the string filepath used to create self:

f = File.new('t.txt') # => #<File:t.txt>
f.path                # => "t.txt"

Does not normalize the returned filepath:

f = File.new('../files/t.txt') # => #<File:../files/t.txt>
f.path                         # => "../files/t.txt"

Raises IOError for a file created using File::Constants::TMPFILE, because it has no filename.

File#to_path is an alias for File#path.

static VALUE
rb_file_path(VALUE obj)
{
    rb_io_t *fptr;

    fptr = RFILE(rb_io_taint_check(obj))->fptr;
    rb_io_check_initialized(fptr);

    if (NIL_P(fptr->pathv)) {
        rb_raise(rb_eIOError, "File is unnamed (TMPFILE?)");
    }

    return rb_str_dup(fptr->pathv);
}
Also aliased as: to_path
size() click to toggle source
static VALUE
file_size(VALUE self)
{
    return OFFT2NUM(rb_file_size(self));
}
to_path()

Returns the string filepath used to create self:

f = File.new('t.txt') # => #<File:t.txt>
f.path                # => "t.txt"

Does not normalize the returned filepath:

f = File.new('../files/t.txt') # => #<File:../files/t.txt>
f.path                         # => "../files/t.txt"

Raises IOError for a file created using File::Constants::TMPFILE, because it has no filename.

File#to_path is an alias for File#path.

Alias for: path
truncate(integer) → 0 click to toggle source

Truncates file to at most integer bytes. The file must be opened for writing. Not available on all platforms.

f = File.new("out", "w")
f.syswrite("1234567890")   #=> 10
f.truncate(5)              #=> 0
f.close()                  #=> nil
File.size("out")           #=> 5
static VALUE
rb_file_truncate(VALUE obj, VALUE len)
{
    rb_io_t *fptr;
    struct ftruncate_arg fa;

    fa.pos = NUM2POS(len);
    GetOpenFile(obj, fptr);
    if (!(fptr->mode & FMODE_WRITABLE)) {
        rb_raise(rb_eIOError, "not opened for writing");
    }
    rb_io_flush_raw(obj, 0);
    fa.fd = fptr->fd;
    if ((int)rb_thread_io_blocking_region(nogvl_ftruncate, &fa, fa.fd) < 0) {
        rb_sys_fail_path(fptr->pathv);
    }
    return INT2FIX(0);
#undef NUM2POS
}