File

Class

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?.

About the Examples

Many examples here use these variables:

# English text with newlines.
text = <<~EOT
  First line
  Second line

  Fourth line
  Fifth line
EOT

# Russian text.
russian = "\u{442 435 441 442}" # => "тест"

# Binary data.
data = "\u9990\u9991\u9992\u9993\u9994"

# Text file.
File.write('t.txt', text)

# File with Russian text.
File.write('t.rus', russian)

# File with binary data.
f = File.new('t.dat', 'wb:UTF-16')
f.write(data)
f.close

Access Modes

Methods File.new and File.open each create a File object for a given file path.

String Access Modes

Methods File.new and File.open each may take string argument mode, which:

Begins with a 1- or 2-character read/write mode.
May also contain a 1-character data mode.
May also contain a 1-character file-create mode.

Read/Write Mode

The read/write mode determines:

Whether the file is to be initially truncated.
Whether reading is allowed, and if so:
- The initial read position in the file.
- Where in the file reading can occur.
Whether writing is allowed, and if so:
- The initial write position in the file.
- Where in the file writing can occur.

These tables summarize:

Read/Write Modes for Existing File

|------|-----------|----------|----------|----------|-----------|
| R/W  | Initial   |          | Initial  |          | Initial   |
| Mode | Truncate? |  Read    | Read Pos |  Write   | Write Pos |
|------|-----------|----------|----------|----------|-----------|
| 'r'  |    No     | Anywhere |    0     |   Error  |     -     |
| 'w'  |    Yes    |   Error  |    -     | Anywhere |     0     |
| 'a'  |    No     |   Error  |    -     | End only |    End    |
| 'r+' |    No     | Anywhere |    0     | Anywhere |     0     |
| 'w+' |    Yes    | Anywhere |    0     | Anywhere |     0     |
| 'a+' |    No     | Anywhere |   End    | End only |    End    |
|------|-----------|----------|----------|----------|-----------|

Read/Write Modes for \File To Be Created

|------|----------|----------|----------|-----------|
| R/W  |          | Initial  |          | Initial   |
| Mode |  Read    | Read Pos |  Write   | Write Pos |
|------|----------|----------|----------|-----------|
| 'w'  |   Error  |    -     | Anywhere |     0     |
| 'a'  |   Error  |    -     | End only |     0     |
| 'w+' | Anywhere |    0     | Anywhere |     0     |
| 'a+' | Anywhere |    0     | End only |    End    |
|------|----------|----------|----------|-----------|

Note that modes 'r' and 'r+' are not allowed for a non-existent file (exception raised).

In the tables:

Anywhere means that methods IO#rewind, IO#pos=, and IO#seek may be used to change the file’s position, so that allowed reading or writing may occur anywhere in the file.
End only means that writing can occur only at end-of-file, and that methods IO#rewind, IO#pos=, and IO#seek do not affect writing.
Error means that an exception is raised if disallowed reading or writing is attempted.

Read/Write Modes for Existing File

'r':

File is not initially truncated:

f = File.new('t.txt') # => #<File:t.txt>
f.size == 0           # => false

File’s initial read position is 0:
```
f.pos # => 0
```

File may be read anywhere; see IO#rewind, IO#pos=, IO#seek:

f.readline # => "First line\n"
f.readline # => "Second line\n"

f.rewind
f.readline # => "First line\n"

f.pos = 1
f.readline # => "irst line\n"

f.seek(1, :CUR)
f.readline # => "econd line\n"

Writing is not allowed:
```
f.write('foo') # Raises IOError.
```

'w':

File is initially truncated:

path = 't.tmp'
File.write(path, text)
f = File.new(path, 'w')
f.size == 0 # => true

File’s initial write position is 0:
```
f.pos # => 0
```

File may be written anywhere (even past end-of-file); see IO#rewind, IO#pos=, IO#seek:

f.write('foo')
f.flush
File.read(path) # => "foo"
f.pos # => 3

f.write('bar')
f.flush
File.read(path) # => "foobar"
f.pos # => 6

f.rewind
f.write('baz')
f.flush
File.read(path) # => "bazbar"
f.pos # => 3

f.pos = 3
f.write('foo')
f.flush
File.read(path) # => "bazfoo"
f.pos # => 6

f.seek(-3, :END)
f.write('bam')
f.flush
File.read(path) # => "bazbam"
f.pos # => 6

f.pos = 8
f.write('bah')  # Zero padding as needed.
f.flush
File.read(path) # => "bazbam\u0000\u0000bah"
f.pos # => 11

Reading is not allowed:
```
f.read # Raises IOError.
```

'a':

File is not initially truncated:

path = 't.tmp'
File.write(path, 'foo')
f = File.new(path, 'a')
f.size == 0 # => false

File’s initial position is 0 (but is ignored):
```
f.pos # => 0
```

File may be written only at end-of-file; IO#rewind, IO#pos=, IO#seek do not affect writing:

f.write('bar')
f.flush
File.read(path) # => "foobar"
f.write('baz')
f.flush
File.read(path) # => "foobarbaz"

f.rewind
f.write('bat')
f.flush
File.read(path) # => "foobarbazbat"

Reading is not allowed:
```
f.read # Raises IOError.
```

'r+':

File is not initially truncated:

path = 't.tmp'
File.write(path, text)
f = File.new(path, 'r+')
f.size == 0 # => false

File’s initial read position is 0:
```
f.pos # => 0
```

File may be read or written anywhere (even past end-of-file); see IO#rewind, IO#pos=, IO#seek:

f.readline # => "First line\n"
f.readline # => "Second line\n"

f.rewind
f.readline # => "First line\n"

f.pos = 1
f.readline # => "irst line\n"

f.seek(1, :CUR)
f.readline # => "econd line\n"

f.rewind
f.write('WWW')
f.flush
File.read(path)
# => "WWWst line\nSecond line\nFourth line\nFifth line\n"

f.pos = 10
f.write('XXX')
f.flush
File.read(path)
# => "WWWst lineXXXecond line\nFourth line\nFifth line\n"

f.seek(-6, :END)
# => 0
f.write('YYY')
# => 3
f.flush
# => #<File:t.tmp>
File.read(path)
# => "WWWst lineXXXecond line\nFourth line\nFifth YYYe\n"

f.seek(2, :END)
f.write('ZZZ') # Zero padding as needed.
f.flush
File.read(path)
# => "WWWst lineXXXecond line\nFourth line\nFifth YYYe\n\u0000\u0000ZZZ"

'a+':

File is not initially truncated:

path = 't.tmp'
File.write(path, 'foo')
f = File.new(path, 'a+')
f.size == 0 # => false

File’s initial read position is 0:
```
f.pos # => 0
```

File may be written only at end-of-file; IO#rewind, IO#pos=, IO#seek do not affect writing:

f.write('bar')
f.flush
File.read(path)      # => "foobar"
f.write('baz')
f.flush
File.read(path)      # => "foobarbaz"

f.rewind
f.write('bat')
f.flush
File.read(path) # => "foobarbazbat"

File may be read anywhere; see IO#rewind, IO#pos=, IO#seek:

f.rewind
f.read # => "foobarbazbat"

f.pos = 3
f.read # => "barbazbat"

f.seek(-3, :END)
f.read # => "bat"

Read/Write Modes for File To Be Created

Note that modes 'r' and 'r+' are not allowed for a non-existent file (exception raised).

'w':

File’s initial write position is 0:

path = 't.tmp'
FileUtils.rm_f(path)
f = File.new(path, 'w')
f.pos # => 0

File may be written anywhere (even past end-of-file); see IO#rewind, IO#pos=, IO#seek:

f.write('foo')
f.flush
File.read(path) # => "foo"
f.pos # => 3

f.write('bar')
f.flush
File.read(path) # => "foobar"
f.pos # => 6

f.rewind
f.write('baz')
f.flush
File.read(path) # => "bazbar"
f.pos # => 3

f.pos = 3
f.write('foo')
f.flush
File.read(path) # => "bazfoo"
f.pos # => 6

f.seek(-3, :END)
f.write('bam')
f.flush
File.read(path) # => "bazbam"
f.pos # => 6

f.pos = 8
f.write('bah')  # Zero padding as needed.
f.flush
File.read(path) # => "bazbam\u0000\u0000bah"
f.pos # => 11

Reading is not allowed:
```
f.read # Raises IOError.
```

'a':

File’s initial write position is 0:

path = 't.tmp'
FileUtils.rm_f(path)
f = File.new(path, 'a')
f.pos # => 0

Writing occurs only at end-of-file:

f.write('foo')
f.pos # => 3
f.write('bar')
f.pos # => 6
f.flush
File.read(path) # => "foobar"

f.rewind
f.write('baz')
f.flush
File.read(path) # => "foobarbaz"

Reading is not allowed:
```
f.read # Raises IOError.
```

'w+':

File’s initial position is 0:

path = 't.tmp'
FileUtils.rm_f(path)
f = File.new(path, 'w+')
f.pos # => 0

File may be written anywhere (even past end-of-file); see IO#rewind, IO#pos=, IO#seek:

f.write('foo')
f.flush
File.read(path) # => "foo"
f.pos # => 3

f.write('bar')
f.flush
File.read(path) # => "foobar"
f.pos # => 6

f.rewind
f.write('baz')
f.flush
File.read(path) # => "bazbar"
f.pos # => 3

f.pos = 3
f.write('foo')
f.flush
File.read(path) # => "bazfoo"
f.pos # => 6

f.seek(-3, :END)
f.write('bam')
f.flush
File.read(path) # => "bazbam"
f.pos # => 6

f.pos = 8
f.write('bah')  # Zero padding as needed.
f.flush
File.read(path) # => "bazbam\u0000\u0000bah"
f.pos # => 11

File may be read anywhere (even past end-of-file); see IO#rewind, IO#pos=, IO#seek:

f.rewind
# => 0
f.read
# => "bazbam\u0000\u0000bah"

f.pos = 3
# => 3
f.read
# => "bam\u0000\u0000bah"

f.seek(-3, :END)
# => 0
f.read
# => "bah"

'a+':

File’s initial write position is 0:

path = 't.tmp'
FileUtils.rm_f(path)
f = File.new(path, 'a+')
f.pos # => 0

Writing occurs only at end-of-file:

f.write('foo')
f.pos # => 3
f.write('bar')
f.pos # => 6
f.flush
File.read(path) # => "foobar"

f.rewind
f.write('baz')
f.flush
File.read(path) # => "foobarbaz"

File may be read anywhere (even past end-of-file); see IO#rewind, IO#pos=, IO#seek:

f.rewind
f.read # => "foobarbaz"

f.pos = 3
f.read # => "barbaz"

f.seek(-3, :END)
f.read # => "baz"

f.pos = 800
f.read # => ""

Data Mode

To specify whether data is to be treated as text or as binary data, either of the following may be suffixed to any of the string read/write modes above:

't': Text data; sets the default external encoding to Encoding::UTF_8; on Windows, enables conversion between EOL and CRLF and enables interpreting 0x1A as an end-of-file marker.
'b': Binary data; sets the default external encoding to Encoding::ASCII_8BIT; on Windows, suppresses conversion between EOL and CRLF and disables interpreting 0x1A as an end-of-file marker.

If neither is given, the stream defaults to text data.

Examples:

File.new('t.txt', 'rt')
File.new('t.dat', 'rb')

When the data mode is specified, the read/write mode may not be omitted, and the data mode must precede the file-create mode, if given:

File.new('t.dat', 'b')   # Raises an exception.
File.new('t.dat', 'rxb') # Raises an exception.

File-Create Mode

The following may be suffixed to any writable string mode above:

'x': Creates the file if it does not exist; raises an exception if the file exists.

Example:

File.new('t.tmp', 'wx')

When the file-create mode is specified, the read/write mode may not be omitted, and the file-create mode must follow the data mode:

File.new('t.dat', 'x')   # Raises an exception.
File.new('t.dat', 'rxb') # Raises an exception.

Integer Access Modes

When mode is an integer it must be one or more of the following constants, which may be combined by the bitwise OR operator |:

File::RDONLY: Open for reading only.
File::WRONLY: Open for writing only.
File::RDWR: Open for reading and writing.
File::APPEND: Open for appending only.

Examples:

File.new('t.txt', File::RDONLY)
File.new('t.tmp', File::RDWR | File::CREAT | File::EXCL)

Note: Method IO#set_encoding does not allow the mode to be specified as an integer.

File-Create Mode Specified as an Integer

These constants may also be ORed into the integer mode:

File::CREAT: Create file if it does not exist.
File::EXCL: Raise an exception if File::CREAT is given and the file exists.

Data Mode Specified as an Integer

Data mode cannot be specified as an integer. When the stream access mode is given as an integer, the data mode is always text, never binary.

Note that although there is a constant File::BINARY, setting its value in an integer stream mode has no effect; this is because, as documented in File::Constants, the File::BINARY value disables line code conversion, but does not change the external encoding.

Encodings

Any of the string modes above may specify encodings - either external encoding only or both external and internal encodings - by appending one or both encoding names, separated by colons:

f = File.new('t.dat', 'rb')
f.external_encoding # => #<Encoding:ASCII-8BIT>
f.internal_encoding # => nil
f = File.new('t.dat', 'rb:UTF-16')
f.external_encoding # => #<Encoding:UTF-16 (dummy)>
f.internal_encoding # => nil
f = File.new('t.dat', 'rb:UTF-16:UTF-16')
f.external_encoding # => #<Encoding:UTF-16 (dummy)>
f.internal_encoding # => #<Encoding:UTF-16>
f.close

The numerous encoding names are available in array Encoding.name_list:

Encoding.name_list.take(3) # => ["ASCII-8BIT", "UTF-8", "US-ASCII"]

When the external encoding is set, strings read are tagged by that encoding when reading, and strings written are converted to that encoding when writing.

When both external and internal encodings are set, strings read are converted from external to internal encoding, and strings written are converted from internal to external encoding. For further details about transcoding input and output, see Encodings.

If the external encoding is 'BOM|UTF-8', 'BOM|UTF-16LE' or 'BOM|UTF16-BE', Ruby checks for a Unicode BOM in the input document to help determine the encoding. For UTF-16 encodings the file open mode must be binary. If the BOM is found, it is stripped and the external encoding from the BOM is used.

Note that the BOM-style encoding option is case insensitive, so 'bom|utf-8' is also valid.

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).

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.

What’s Here

First, what’s elsewhere. Class File:

Inherits from class IO, in particular, methods for creating, reading, and writing files
Includes module FileTest, which provides dozens of additional methods.

Here, class File provides methods that are useful for:

Creating

::new: Opens the file at the given path; returns the file.
::open: Same as ::new, but when given a block will yield the file to the block, and close the file upon exiting the block.
::link: Creates a new name for an existing file using a hard link.
::mkfifo: Returns the FIFO file created at the given path.
::symlink: Creates a symbolic link for the given file path.

Querying

Paths

::absolute_path: Returns the absolute file path for the given path.
::absolute_path?: Returns whether the given path is the absolute file path.
::basename: Returns the last component of the given file path.
::dirname: Returns all but the last component of the given file path.
::expand_path: Returns the absolute file path for the given path, expanding ~ for a home directory.
::extname: Returns the file extension for the given file path.
::fnmatch? (aliased as ::fnmatch): Returns whether the given file path matches the given pattern.
::join: Joins path components into a single path string.
::path: Returns the string representation of the given path.
::readlink: Returns the path to the file at the given symbolic link.
::realdirpath: Returns the real path for the given file path, where the last component need not exist.
::realpath: Returns the real path for the given file path, where all components must exist.
::split: Returns an array of two strings: the directory name and basename of the file at the given path.
path (aliased as to_path): Returns the string representation of the given path.

Times

::atime: Returns a Time for the most recent access to the given file.
::birthtime: Returns a Time for the creation of the given file.
::ctime: Returns a Time for the metadata change of the given file.
::mtime: Returns a Time for the most recent data modification to the content of the given file.
atime: Returns a Time for the most recent access to self.
birthtime: Returns a Time the creation for self.
ctime: Returns a Time for the metadata change of self.
mtime: Returns a Time for the most recent data modification to the content of self.

Types

::blockdev?: Returns whether the file at the given path is a block device.
::chardev?: Returns whether the file at the given path is a character device.
::directory?: Returns whether the file at the given path is a directory.
::executable?: Returns whether the file at the given path is executable by the effective user and group of the current process.
::executable_real?: Returns whether the file at the given path is executable by the real user and group of the current process.
::exist?: Returns whether the file at the given path exists.
::file?: Returns whether the file at the given path is a regular file.
::ftype: Returns a string giving the type of the file at the given path.
::grpowned?: Returns whether the effective group of the current process owns the file at the given path.
::identical?: Returns whether the files at two given paths are identical.
::lstat: Returns the File::Stat object for the last symbolic link in the given path.
::owned?: Returns whether the effective user of the current process owns the file at the given path.
::pipe?: Returns whether the file at the given path is a pipe.
::readable?: Returns whether the file at the given path is readable by the effective user and group of the current process.
::readable_real?: Returns whether the file at the given path is readable by the real user and group of the current process.
::setgid?: Returns whether the setgid bit is set for the file at the given path.
::setuid?: Returns whether the setuid bit is set for the file at the given path.
::socket?: Returns whether the file at the given path is a socket.
::stat: Returns the File::Stat object for the file at the given path.
::sticky?: Returns whether the file at the given path has its sticky bit set.
::symlink?: Returns whether the file at the given path is a symbolic link.
::umask: Returns the umask value for the current process.
::world_readable?: Returns whether the file at the given path is readable by others.
::world_writable?: Returns whether the file at the given path is writable by others.
::writable?: Returns whether the file at the given path is writable by the effective user and group of the current process.
::writable_real?: Returns whether the file at the given path is writable by the real user and group of the current process.
lstat: Returns the File::Stat object for the last symbolic link in the path for self.

Contents

::empty? (aliased as ::zero?): Returns whether the file at the given path exists and is empty.
::size: Returns the size (bytes) of the file at the given path.
::size?: Returns nil if there is no file at the given path, or if that file is empty; otherwise returns the file size (bytes).
size: Returns the size (bytes) of self.

Settings

::chmod: Changes permissions of the file at the given path.
::chown: Change ownership of the file at the given path.
::lchmod: Changes permissions of the last symbolic link in the given path.
::lchown: Change ownership of the last symbolic in the given path.
::lutime: For each given file path, sets the access time and modification time of the last symbolic link in the path.
::rename: Moves the file at one given path to another given path.
::utime: Sets the access time and modification time of each file at the given paths.
flock: Locks or unlocks self.

Other

::truncate: Truncates the file at the given file path to the given size.
::unlink (aliased as ::delete): Deletes the file for each given file path.
truncate: Truncates self to the given size.

Constants

Separator

separates directory parts in path

SEPARATOR

separates directory parts in path

ALT_SEPARATOR

platform specific alternative separator

PATH_SEPARATOR

path list separator

Class Methods

File.absolute_path(file_name [, dir_string] ) → abs_file_name

file.c View on GitHub

          
            static VALUE
s_absolute_path(int c, const VALUE * v, VALUE _)
{
    return rb_file_s_absolute_path(c, v);
}

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"

File.absolute_path?(file_name) → true or false

file.c View on GitHub

          
            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;
}

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

File.absolute_path?("c:/foo")     #=> false (on Linux), true (on Windows)

File.atime(file_name) → time

file.c View on GitHub

          
            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);
}

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

File.basename(file_name [, suffix] ) → base_name

file.c View on GitHub

          
            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;
}

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"

File.birthtime(file_name) → time

file.c View on GitHub

          
            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);
}

Returns the birth time for the named file.

file_name can be an IO object.

File.birthtime("testfile")   #=> Wed Apr 09 08:53:13 CDT 2003

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

File.blockdev?(filepath) → true or false

file.c View on GitHub

          
            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;
}

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

File.blockdev?('/dev/sda1')       # => true
File.blockdev?(File.new('t.tmp')) # => false

File.chardev?(filepath) → true or false

file.c View on GitHub

          
            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;
}

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

File.chardev?($stdin)     # => true
File.chardev?('t.txt')     # => false

File.chmod(mode_int, file_name, ... ) → integer

file.c View on GitHub

          
            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);
}

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

File.chown(owner_int, group_int, file_name, ...) → integer

file.c View on GitHub

          
            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);
}

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")

File.ctime(file_name) → time

file.c View on GitHub

          
            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);
}

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

File.delete(file_name, ...) → integer

File.unlink(file_name, ...) → integer

file.c View on GitHub

          
            static VALUE
rb_file_s_unlink(int argc, VALUE *argv, VALUE klass)
{
    return apply2files(unlink_internal, argc, argv, 0);
}

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.

File.directory?(path) → true or false

file.c View on GitHub

          
            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;
}

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.

File.dirname(file_name, level = 1) → dir_name

file.c View on GitHub

          
            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);
}

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) #=> "/"

File.zero?(file_name) → true or false

file.c View on GitHub

          
            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);
}

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

file_name can be an IO object.

File.executable?(file_name) → true or false

file.c View on GitHub

          
            static VALUE
rb_file_executable_p(VALUE obj, VALUE fname)
{
    return RBOOL(rb_eaccess(fname, X_OK) >= 0);
}

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.

File.executable_real?(file_name) → true or false

file.c View on GitHub

          
            static VALUE
rb_file_executable_real_p(VALUE obj, VALUE fname)
{
    return RBOOL(rb_access(fname, X_OK) >= 0);
}

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.

File.exist?(file_name) → true or false

file.c View on GitHub

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

    if (rb_stat(fname, &st) < 0) return Qfalse;
    return Qtrue;
}

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.

File.expand_path(file_name [, dir_string] ) → abs_file_name

file.c View on GitHub

          
            static VALUE
s_expand_path(int c, const VALUE * v, VALUE _)
{
    return rb_file_s_expand_path(c, v);
}

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.

File.extname(path) → string

file.c View on GitHub

          
            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;
}

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"

File.file?(file) → true or false

file.c View on GitHub

          
            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));
}

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.

File.fnmatch( pattern, path, [flags] ) → (true or false)

dir.rb View on GitHub

          
            # File tmp/rubies/ruby-3.4.0-preview1/dir.rb, line 503
def fnmatch(pattern, path, flags = 0)
end

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.fnmatch?( pattern, path, [flags] ) → (true or false)

dir.rb View on GitHub

An alias for fnmatch

File.ftype(file_name) → string

file.c View on GitHub

          
            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);
}

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"

File.grpowned?(file_name) → true or false

file.c View on GitHub

          
            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;
}

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.

File.identical?(file_1, file_2) → true or false

file.c View on GitHub

          
            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
}

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

File.join(string, ...) → string

file.c View on GitHub

          
            static VALUE
rb_file_s_join(VALUE klass, VALUE args)
{
    return rb_file_join(args);
}

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

File.join("usr", "mail", "gumby")   #=> "usr/mail/gumby"

File.lchmod(mode_int, file_name, ...) → integer

file.c View on GitHub

          
            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);
}

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.

File.lchown(owner_int, group_int, file_name,..) → integer

file.c View on GitHub

          
            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);
}

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.

File.link(old_name, new_name) → 0

file.c View on GitHub

          
            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);
}

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"

File.lstat(filepath) → stat

file.c View on GitHub

          
            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
}

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

File.lutime(atime, mtime, file_name, ...) → integer

file.c View on GitHub

          
            static VALUE
rb_file_s_lutime(int argc, VALUE *argv, VALUE _)
{
    return utime_internal_i(argc, argv, TRUE);
}

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.

File.mkfifo(file_name, mode=0666) => 0

file.c View on GitHub

          
            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 (IO_WITHOUT_GVL(nogvl_mkfifo, &ma)) {
        rb_sys_fail_path(path);
    }
    return INT2FIX(0);
}

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).

File.mtime(file_name) → time

file.c View on GitHub

          
            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);
}

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

File.new(path, mode = 'r', perm = 0666, **opts) → file

io.c View on GitHub

          
            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;
}

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:

f = File.new('/etc/fstab')
f.close
f = File.new('t.txt')
f.close

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

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

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

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

Optional keyword arguments opts specify:

Open Options.
Encoding options.

File.open(path, mode = 'r', perm = 0666, **opts) → file

File.open(path, mode = 'r', perm = 0666, **opts) {|f| ... } → object

io.c View on GitHub

          
            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;
}

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.

File.owned?(file_name) → true or false

file.c View on GitHub

          
            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());
}

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.

File.path(path) → string

file.c View on GitHub

          
            static VALUE
rb_file_s_path(VALUE klass, VALUE fname)
{
    return rb_get_path(fname);
}

Returns the string representation of the path

File.path(File::NULL)           #=> "/dev/null"
File.path(Pathname.new("/tmp")) #=> "/tmp"

File.pipe?(filepath) → true or false

file.c View on GitHub

          
            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;
}

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

File.mkfifo('tmp/fifo')
File.pipe?('tmp/fifo') # => true
File.pipe?('t.txt')    # => false

File.readable?(file_name) → true or false

file.c View on GitHub

          
            static VALUE
rb_file_readable_p(VALUE obj, VALUE fname)
{
    return RBOOL(rb_eaccess(fname, R_OK) >= 0);
}

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.

File.readable_real?(file_name) → true or false

file.c View on GitHub

          
            static VALUE
rb_file_readable_real_p(VALUE obj, VALUE fname)
{
    return RBOOL(rb_access(fname, R_OK) >= 0);
}

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.

File.readlink(link_name) → file_name

file.c View on GitHub

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

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"

File.realdirpath(pathname [, dir_string]) → real_pathname

file.c View on GitHub

          
            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);
}

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.

File.realpath(pathname [, dir_string]) → real_pathname

file.c View on GitHub

          
            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);
}

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.

File.rename(old_name, new_name) → 0

file.c View on GitHub

          
            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 (IO_WITHOUT_GVL_INT(no_gvl_rename, &ra) < 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);
}

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

File.rename("afile", "afile.bak")   #=> 0

File.setgid?(file_name) → true or false

file.c View on GitHub

          
            static VALUE
rb_file_sgid_p(VALUE obj, VALUE fname)
{
#ifdef S_ISGID
    return check3rdbyte(fname, S_ISGID);
#else
    return Qfalse;
#endif
}

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

file_name can be an IO object.

File.setuid?(file_name) → true or false

file.c View on GitHub

          
            static VALUE
rb_file_suid_p(VALUE obj, VALUE fname)
{
#ifdef S_ISUID
    return check3rdbyte(fname, S_ISUID);
#else
    return Qfalse;
#endif
}

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

file_name can be an IO object.

File.size(file_name) → integer

file.c View on GitHub

          
            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);
}

Returns the size of file_name.

file_name can be an IO object.

File.size?(file_name) → Integer or nil

file.c View on GitHub

          
            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);
}

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.

File.socket?(filepath) → true or false

file.c View on GitHub

          
            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;
}

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

File.split(file_name) → array

file.c View on GitHub

          
            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));
}

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"]

File.stat(filepath) → stat

file.c View on GitHub

          
            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);
}

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

File.stat('t.txt').class # => File::Stat

File.sticky?(file_name) → true or false

file.c View on GitHub

          
            static VALUE
rb_file_sticky_p(VALUE obj, VALUE fname)
{
#ifdef S_ISVTX
    return check3rdbyte(fname, S_ISVTX);
#else
    return Qfalse;
#endif
}

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

file_name can be an IO object.

File.symlink(old_name, new_name) → 0

file.c View on GitHub

          
            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);
}

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

File.symlink?(filepath) → true or false

file.c View on GitHub

          
            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;
}

Returns true if filepath points to a symbolic link, false otherwise:

symlink = File.symlink('t.txt', 'symlink')
File.symlink?('symlink') # => true
File.symlink?('t.txt')   # => false

File.truncate(file_name, integer) → 0

file.c View on GitHub

          
            static VALUE
rb_file_s_truncate(VALUE klass, VALUE path, VALUE len)
{
    struct truncate_arg ta;
    int r;

    ta.pos = NUM2OFFT(len);
    FilePathValue(path);
    path = rb_str_encode_ospath(path);
    ta.path = StringValueCStr(path);

    r = IO_WITHOUT_GVL_INT(nogvl_truncate, &ta);
    if (r < 0)
        rb_sys_fail_path(path);
    return INT2FIX(0);
}

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

File.umask() → integer

File.umask(integer) → integer

file.c View on GitHub

          
            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);
}

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

File.delete(file_name, ...) → integer

File.unlink(file_name, ...) → integer

file.c View on GitHub

          
            static VALUE
rb_file_s_unlink(int argc, VALUE *argv, VALUE klass)
{
    return apply2files(unlink_internal, argc, argv, 0);
}

File.utime(atime, mtime, file_name, ...) → integer

file.c View on GitHub

          
            static VALUE
rb_file_s_utime(int argc, VALUE *argv, VALUE _)
{
    return utime_internal_i(argc, argv, FALSE);
}

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.

File.world_readable?(file_name) → integer or nil

file.c View on GitHub

          
            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;
}

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"

File.world_writable?(file_name) → integer or nil

file.c View on GitHub

          
            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;
}

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"

File.writable?(file_name) → true or false

file.c View on GitHub

          
            static VALUE
rb_file_writable_p(VALUE obj, VALUE fname)
{
    return RBOOL(rb_eaccess(fname, W_OK) >= 0);
}

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.

File.writable_real?(file_name) → true or false

file.c View on GitHub

          
            static VALUE
rb_file_writable_real_p(VALUE obj, VALUE fname)
{
    return RBOOL(rb_access(fname, W_OK) >= 0);
}

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.

File.zero?(file_name) → true or false

file.c View on GitHub

          
            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);
}

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

file_name can be an IO object.

Instance Methods

file.atime → time

file.c View on GitHub

          
            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);
}

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

file.birthtime → time

file.c View on GitHub

          
            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);
}

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.

file.chmod(mode_int) → 0

file.c View on GitHub

          
            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 (rb_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 (rb_chmod(RSTRING_PTR(path), mode) == -1)
        rb_sys_fail_path(fptr->pathv);
#endif

    return INT2FIX(0);
}

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

file.chown(owner_int, group_int ) → 0

file.c View on GitHub

          
            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 (rb_chown(RSTRING_PTR(path), o, g) == -1)
        rb_sys_fail_path(fptr->pathv);
#else
    if (rb_fchown(fptr->fd, o, g) == -1)
        rb_sys_fail_path(fptr->pathv);
#endif

    return INT2FIX(0);
}

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)

file.ctime → time

file.c View on GitHub

          
            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);
}

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

flock(locking_constant) → 0 or false

file.c View on GitHub

          
            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);
}

Locks or unlocks file self according to the given locking_constant, a bitwise OR of the values in the table below.

Not available on all platforms.

Returns false if File::LOCK_NB is specified and the operation would have blocked; otherwise returns 0.

Constant	Lock	Effect
`File::LOCK_EX`	Exclusive	Only one process may hold an exclusive lock for `self` at a time.
`File::LOCK_NB`	Non-blocking	No blocking; may be combined with `File::LOCK_SH` or `File::LOCK_EX` using the bitwise OR operator `\|`.
`File::LOCK_SH`	Shared	Multiple processes may each hold a shared lock for `self` at the same time.
`File::LOCK_UN`	Unlock	Remove an existing lock held by this process.

Example:

# Update a counter using an exclusive lock.
# Don't use File::WRONLY because it truncates the file.
File.open('counter', File::RDWR | File::CREAT, 0644) do |f|
  f.flock(File::LOCK_EX)
  value = f.read.to_i + 1
  f.rewind
  f.write("#{value}\n")
  f.flush
  f.truncate(f.pos)
end

# Read the counter using a shared lock.
File.open('counter', 'r') do |f|
  f.flock(File::LOCK_SH)
  f.read
end

lstat → stat

file.c View on GitHub

          
            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
}

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

file.mtime → time

file.c View on GitHub

          
            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);
}

Returns the modification time for file.

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

file.size → integer

file.c View on GitHub

          
            static VALUE
file_size(VALUE self)
{
    return OFFT2NUM(rb_file_size(self));
}

Returns the size of file in bytes.

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

file.truncate(integer) → 0

file.c View on GitHub

          
            static VALUE
rb_file_truncate(VALUE obj, VALUE len)
{
    rb_io_t *fptr;
    struct ftruncate_arg fa;

    fa.pos = NUM2OFFT(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);
}

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