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
.
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.
::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.
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 diretory.
::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 forself
.
Contents
::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.
truncate
-
Truncates
self
to the given size.
separates directory parts in path
separates directory parts in path
platform specific alternative separator
path list separator
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"
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)
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);
}
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"
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);
}
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 the named file is a block 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;
}
Returns true
if the named file is a character device.
file_name can be an IO
object.
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
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")
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
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.
See also Dir::rmdir
.
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;
}
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?(".")
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) #=> "/"
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.
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.
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.
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.
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
.
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"
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 tmp/rubies/ruby-3.1.3/dir.rb, line 311
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 inRegexp
, 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
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"
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.
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
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"
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.
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.
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"
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
}
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_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.
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);
}
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_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);
}
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 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_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;
}
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_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.
static VALUE
rb_file_s_path(VALUE klass, VALUE fname)
{
return rb_get_path(fname);
}
Returns the string representation of the path
File.path("/dev/null") #=> "/dev/null" File.path(Pathname.new("/tmp")) #=> "/tmp"
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 the named file is a pipe.
file_name can be an IO
object.
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.
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.
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"
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.
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.
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);
}
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_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.
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.
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.
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.
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 the named file is a socket.
file_name can be an IO
object.
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"]
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 named file (see File::Stat
).
File.stat("testfile").mtime #=> Tue Apr 08 12:58:04 CDT 2003
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.
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
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 the named file is a symbolic link.
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
}
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_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
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.
See also Dir::rmdir
.
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.
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"
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"
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.
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.
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.
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
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
.
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);
}
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_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);
}
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_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
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 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_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
}
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_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
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);
}
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
file_size(VALUE self)
{
return OFFT2NUM(rb_file_size(self));
}
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
}
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