# class File

A `File` is an abstraction of any file object accessible by the program and is closely associated with class `IO`. `File` includes the methods of module `FileTest` as class methods, allowing you to write (for example) `File.exist?("foo")`.

In the description of `File` methods, permission bits are a platform-specific set of bits that indicate permissions of a file. On Unix-based systems, permissions are viewed as a set of three octets, for the owner, the group, and the rest of the world. For each of these entities, permissions may be set to read, write, or execute the file:

The permission bits `0644` (in octal) would thus be interpreted as read/write for owner, and read-only for group and other. Higher-order bits may also be used to indicate the type of file (plain, directory, pipe, socket, and so on) and various other special features. If the permissions are for a directory, the meaning of the execute bit changes; when set the directory can be searched.

On non-Posix operating systems, there may be only the ability to make a file read-only or read-write. In this case, the remaining permission bits will be synthesized to resemble typical values. For instance, on Windows NT the default permission bits are `0644`, which means read/write for owner, read-only for all others. The only change that can be made is to make the file read-only, which is reported as `0444`.

Various constants for the methods in `File` can be found in `File::Constants`.

### 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?(file_name) → true or false click to toggle source

Returns `true` if the named file is a block device.

file_name can be an `IO` object.

    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?(file_name) → true or false click to toggle source

Returns `true` if the named file is a character device.

file_name can be an `IO` object.

    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?(file_name) → true or false click to toggle source

Returns `true` if the named file is a directory, or a symlink that points at a directory, and `false` otherwise.

file_name can be an `IO` object.

    File.directory?(".")

    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) → 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"

    static VALUE
    rb_file_s_dirname(VALUE klass, VALUE fname)
    {
        return rb_file_dirname(fname);
    }

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;
        if (st.st_size == 0) return Qtrue;
        return Qfalse;
    }

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)
    {
        if (rb_eaccess(fname, X_OK) < 0) return Qfalse;
        return Qtrue;
    }

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)
    {
        if (rb_access(fname, X_OK) < 0) return Qfalse;
        return Qtrue;
    }

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;
        if (S_ISREG(st.st_mode)) return Qtrue;
        return Qfalse;
    }

fnmatch( pattern, path, [flags] ) → (true or false) click to toggle source
fnmatch?( pattern, path, [flags] ) → (true or false)

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 files 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

    rbfiles = '**' '/' '*.rb' # you don't have to do like this. just write in single string.
    File.fnmatch(rbfiles, 'main.rb')                    #=> false
    File.fnmatch(rbfiles, './main.rb')                  #=> false
    File.fnmatch(rbfiles, '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

    pattern = '*' '/' '*'
    File.fnmatch(pattern, 'dave/.profile', File::FNM_PATHNAME)  #=> false
    File.fnmatch(pattern, 'dave/.profile', File::FNM_PATHNAME | File::FNM_DOTMATCH) #=> true

    pattern = '**' '/' 'foo'
    File.fnmatch(pattern, 'a/b/c/foo', File::FNM_PATHNAME)     #=> true
    File.fnmatch(pattern, '/a/b/c/foo', File::FNM_PATHNAME)    #=> true
    File.fnmatch(pattern, 'c:/a/b/c/foo', File::FNM_PATHNAME)  #=> true
    File.fnmatch(pattern, 'a/.b/c/foo', File::FNM_PATHNAME)    #=> false
    File.fnmatch(pattern, 'a/.b/c/foo', File::FNM_PATHNAME | File::FNM_DOTMATCH) #=> true

    static VALUE
    file_s_fnmatch(int argc, VALUE *argv, VALUE obj)
    {
        VALUE pattern, path;
        VALUE rflags;
        int flags;

        if (rb_scan_args(argc, argv, "21", &pattern, &path, &rflags) == 3)
            flags = NUM2INT(rflags);
        else
            flags = 0;

        StringValueCStr(pattern);
        FilePathStringValue(path);

        if (flags & FNM_EXTGLOB) {
            struct brace_args args;

            args.value = path;
            args.flags = flags;
            if (ruby_brace_expand(RSTRING_PTR(pattern), flags, fnmatch_brace,
                                  (VALUE)&args, rb_enc_get(pattern), pattern) > 0)
                return Qtrue;
        }
        else {
            rb_encoding *enc = rb_enc_compatible(pattern, path);
            if (!enc) return Qfalse;
            if (fnmatch(RSTRING_PTR(pattern), enc, RSTRING_PTR(path), flags) == 0)
                return Qtrue;
        }
        RB_GC_GUARD(pattern);

        return Qfalse;
    }

fnmatch( pattern, path, [flags] ) → (true or false) click to toggle source
fnmatch?( pattern, path, [flags] ) → (true or false)

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 files 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

    rbfiles = '**' '/' '*.rb' # you don't have to do like this. just write in single string.
    File.fnmatch(rbfiles, 'main.rb')                    #=> false
    File.fnmatch(rbfiles, './main.rb')                  #=> false
    File.fnmatch(rbfiles, '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

    pattern = '*' '/' '*'
    File.fnmatch(pattern, 'dave/.profile', File::FNM_PATHNAME)  #=> false
    File.fnmatch(pattern, 'dave/.profile', File::FNM_PATHNAME | File::FNM_DOTMATCH) #=> true

    pattern = '**' '/' 'foo'
    File.fnmatch(pattern, 'a/b/c/foo', File::FNM_PATHNAME)     #=> true
    File.fnmatch(pattern, '/a/b/c/foo', File::FNM_PATHNAME)    #=> true
    File.fnmatch(pattern, 'c:/a/b/c/foo', File::FNM_PATHNAME)  #=> true
    File.fnmatch(pattern, 'a/.b/c/foo', File::FNM_PATHNAME)    #=> false
    File.fnmatch(pattern, 'a/.b/c/foo', File::FNM_PATHNAME | File::FNM_DOTMATCH) #=> true

    static VALUE
    file_s_fnmatch(int argc, VALUE *argv, VALUE obj)
    {
        VALUE pattern, path;
        VALUE rflags;
        int flags;

        if (rb_scan_args(argc, argv, "21", &pattern, &path, &rflags) == 3)
            flags = NUM2INT(rflags);
        else
            flags = 0;

        StringValueCStr(pattern);
        FilePathStringValue(path);

        if (flags & FNM_EXTGLOB) {
            struct brace_args args;

            args.value = path;
            args.flags = flags;
            if (ruby_brace_expand(RSTRING_PTR(pattern), flags, fnmatch_brace,
                                  (VALUE)&args, rb_enc_get(pattern), pattern) > 0)
                return Qtrue;
        }
        else {
            rb_encoding *enc = rb_enc_compatible(pattern, path);
            if (!enc) return Qfalse;
            if (fnmatch(RSTRING_PTR(pattern), enc, RSTRING_PTR(path), flags) == 0)
                return Qtrue;
        }
        RB_GC_GUARD(pattern);

        return Qfalse;
    }

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);
    }

link(old_name, new_name) → 0 click to toggle source

Creates a new name for an existing file using a hard link. Will not overwrite new_name if it already exists (raising a subclass of `SystemCallError`). Not available on all platforms.

    File.link("testfile", ".testfile")   #=> 0
    IO.readlines(".testfile")[0]         #=> "This is line one\n"

    static VALUE
    rb_file_s_link(VALUE klass, VALUE from, VALUE to)
    {
        FilePathValue(from);
        FilePathValue(to);
        from = rb_str_encode_ospath(from);
        to = rb_str_encode_ospath(to);

        if (link(StringValueCStr(from), StringValueCStr(to)) < 0) {
            sys_fail2(from, to);
        }
        return INT2FIX(0);
    }

lstat(file_name) → stat click to toggle source

Same as `File::stat`, but does not follow the last symbolic link. Instead, reports on the link itself.

    File.symlink("testfile", "link2test")   #=> 0
    File.stat("testfile").size              #=> 66
    File.lstat("link2test").size            #=> 8
    File.stat("link2test").size             #=> 66

    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(filename, mode="r" [, opt]) → file click to toggle source
new(filename [, mode [, perm]] [, opt]) → file

Opens the file named by `filename` according to the given `mode` and returns a new `File` object.

See `IO.new` for a description of `mode` and `opt`.

If a file is being created, permission bits may be given in `perm`. These mode and permission bits are platform dependent; on Unix systems, see open(2) and chmod(2) man pages for details.

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=` about sync mode.

### Examples¶ ↑

    f = File.new("testfile", "r")
    f = File.new("newfile",  "w+")
    f = File.new("newfile", File::CREAT|File::TRUNC|File::RDWR, 0644)

    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(filename, mode="r" [, opt]) → file click to toggle source
open(filename [, mode [, perm]] [, opt]) → file
open(filename, mode="r" [, opt]) {|file| block } → obj
open(filename [, mode [, perm]] [, opt]) {|file| block } → obj

With no associated block, `File.open` is a synonym for `File.new`. If the optional code block is given, it will be passed the opened `file` as an argument and the `File` object will automatically be closed when the block terminates. The value of the block will be returned from `File.open`.

If a file is being created, its initial permissions may be set using the `perm` parameter. See `File.new` for further discussion.

See `IO.new` for a description of the `mode` and `opt` parameters.

    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;
        if (st.st_uid == geteuid()) return Qtrue;
        return Qfalse;
    }

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?(file_name) → true or false click to toggle source

Returns `true` if the named file is a pipe.

file_name can be an `IO` object.

    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)
    {
        if (rb_eaccess(fname, R_OK) < 0) return Qfalse;
        return Qtrue;
    }

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)
    {
        if (rb_access(fname, R_OK) < 0) return Qfalse;
        return Qtrue;
    }

readlink(link_name) → file_name click to toggle source

Returns the name of the file referenced by the given link. Not available on all platforms.

    File.symlink("testfile", "link2test")   #=> 0
    File.readlink("link2test")              #=> "testfile"

    static VALUE
    rb_file_s_readlink(VALUE klass, VALUE path)
    {
        return rb_readlink(path, rb_filesystem_encoding());
    }

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?(file_name) → true or false click to toggle source

Returns `true` if the named file is a socket.

file_name can be an `IO` object.

    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(file_name) → stat click to toggle source

Returns a `File::Stat` object for the named file (see `File::Stat`).

    File.stat("testfile").mtime   #=> Tue Apr 08 12:58:04 CDT 2003

    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
    }

symlink(old_name, new_name) → 0 click to toggle source

Creates a symbolic link called new_name for the existing file old_name. Raises a NotImplemented exception on platforms that do not support symbolic links.

    File.symlink("testfile", "link2test")   #=> 0

    static VALUE
    rb_file_s_symlink(VALUE klass, VALUE from, VALUE to)
    {
        FilePathValue(from);
        FilePathValue(to);
        from = rb_str_encode_ospath(from);
        to = rb_str_encode_ospath(to);

        if (symlink(StringValueCStr(from), StringValueCStr(to)) < 0) {
            sys_fail2(from, to);
        }
        return INT2FIX(0);
    }

symlink?(file_name) → true or false click to toggle source

Returns `true` if the named file is a symbolic link.

    static VALUE
    rb_file_symlink_p(VALUE obj, VALUE fname)
    {
    #ifndef S_ISLNK
    #  ifdef _S_ISLNK
    #    define S_ISLNK(m) _S_ISLNK(m)
    #  else
    #    ifdef _S_IFLNK
    #      define S_ISLNK(m) (((m) & S_IFMT) == _S_IFLNK)
    #    else
    #      ifdef S_IFLNK
    #        define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
    #      endif
    #    endif
    #  endif
    #endif

    #ifdef S_ISLNK
        struct stat st;

        FilePathValue(fname);
        fname = rb_str_encode_ospath(fname);
        if (lstat_without_gvl(StringValueCStr(fname), &st) < 0) return Qfalse;
        if (S_ISLNK(st.st_mode)) return Qtrue;
    #endif

        return Qfalse;
    }

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);
    }

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);
    }

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)
    {
        if (rb_eaccess(fname, W_OK) < 0) return Qfalse;
        return Qtrue;
    }

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)
    {
        if (rb_access(fname, W_OK) < 0) return Qfalse;
        return Qtrue;
    }

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;
        if (st.st_size == 0) return Qtrue;
        return Qfalse;
    }

### 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

Same as `IO#stat`, but does not follow the last symbolic link. Instead, reports on the link itself.

    File.symlink("testfile", "link2test")   #=> 0
    File.stat("testfile").size              #=> 66
    f = File.new("link2test")
    f.lstat.size                            #=> 8
    f.stat.size                             #=> 66

    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 → filename click to toggle source

Returns the pathname used to create file as a string. Does not normalize the name.

The pathname may not point to the file corresponding to file. For instance, the pathname becomes void when the file has been moved or deleted.

This method raises `IOError` for a file created using File::Constants::TMPFILE because they don't have a pathname.

    File.new("testfile").path               #=> "testfile"
    File.new("/tmp/../tmp/xxx", "w").path   #=> "/tmp/../tmp/xxx"

    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 → integer click to toggle source

Returns the size of file in bytes.

    File.new("testfile").size   #=> 66

    static VALUE
    rb_file_size(VALUE obj)
    {
        rb_io_t *fptr;
        struct stat st;

        GetOpenFile(obj, fptr);
        if (fptr->mode & FMODE_WRITABLE) {
            rb_io_flush_raw(obj, 0);
        }
        if (fstat(fptr->fd, &st) == -1) {
            rb_sys_fail_path(fptr->pathv);
        }
        return OFFT2NUM(st.st_size);
    }

to_path → filename

Returns the pathname used to create file as a string. Does not normalize the name.

The pathname may not point to the file corresponding to file. For instance, the pathname becomes void when the file has been moved or deleted.

This method raises `IOError` for a file created using File::Constants::TMPFILE because they don't have a pathname.

    File.new("testfile").path               #=> "testfile"
    File.new("/tmp/../tmp/xxx", "w").path   #=> "/tmp/../tmp/xxx"

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
    }