File

The class for accessing files. Normally, created by open. This class has singleton-methods that the FileTest class has.

SuperClass:

IO

Class Methods:

atime(filename)

Returns the last accessed time of the file.

basename(filename[, suffix])

Returns the last slash-delimited component of the filename. If suffix is supplied and is identical to the end of name, it is removed from filename.

Example:

basename("ruby/ruby.c")
	=> "ruby.c"
basename("ruby/ruby.c", ".c")
        => "ruby"

ctime(filename)

Returns the last status change time of the file.

chmod(mode, path, file...)

Change the mode of the files to the mode. Returns the number of the file it processed. See chmod(2).

chown(owner, group, file...)

Change the owner and the groups of the files to the owner. Only super-user can change the owner of the file. Returns the number of the file it processed.

The owner and the group can leave unchanged with supplying nil or -1 to as the argument.

dirname(filename)

Returns all but the final slash-delimited component of filename. Returns "." (meaning the current directory), if filename is a single component.

expand_path(path[,default_dir])

Converts path to absolute, and canonicalized path. Second arg default_dir is directory to start with if path is relative (does not start with slash); if default_dir is nil or missing, the current directory of the process is used. An initial `~' expands to your home directory. An initial `~USER' expands to USER's home directory.

expand_path("..")
       => "/home/matz/work"
expand_path("~")
       => "/home/matz"
expand_path("~matz")
       => "/home/matz"

ftype(filename)

Returns a string which describes the type of the file. The string is either:

"file"
"directory"
"characterSpecial"
"blockSpecial"
"fifo"
"link"
"socket"

join(item...)

Combines file names using File::Separator.

It works just like:

[items,..].join(File::Separator)

link(old, new)

Creates a new hard link to old (existing) file. See link(2).

lstat(filename)

Does the same thing as the stat, but stats a symbolic link instead of the file the symbolic link points to.

mtime(filename)

Returns the last modified time of the file.

open(path[, mode])

new(path[, mode])

Opens the file specified by path, and returns a File object associated with that file.

The mode argument specifies the mode for the opened file, which is either "r", "r+", "w", "w+", "a", "a+". See fopen(3). If mode omitted, the default is "r".

if mode is a integer, it is considered like the second argument to open(2). One of the flags must be either RDONLY, WRONLY or RDWR. Flags may also be bitwise-or'd with one or more of APPEND, CREAT, EXCL, NONBLOCK, TRUNC, NOCTTY, BINARY.

If a new file is created as part of opening it, permissions (an integer) is used to set the permissions for the new file in conjunction with the process's file mode creation mask. Permissions defaults to 0666.

If open is called with block, the block will be executed with a newly opened file object. The file object will be closed automatically after executing the block.

readlink(path)

Returns the symbolic link path as a string.

rename(from, to)

Renames file, moving it across the directories if required. See rename(2). If to-file already exists, it will be overwritten.

size(pathname)

Returns the size of the file specified by the pathname in bytes.

split(pathname)

Splits the pathname in a pair [head, tail], where tail is the last pathname component and head is everything leading up to that.

stat(filename)

Returns the status info of the filename in the Stat structure, which has attributes as follows:

dev	 	# device number of file-system
ino		# i-node number
mode		# file mode
nlink		# number of hard links
uid		# user ID of owner
gid		# group ID of owner
rdev		# device type (special files only)
size		# total size, in bytes
blksize		# preferred blocksize for file-system I/O
blocks		# number of blocks allocated
atime		# time of last access
mtime		# time of last modification
ctime		# time of last i-node change

For more detail, see stat(2). Some fields are filled with 0, if that field is not supported on your system.

symlink(old, new)

Created a new symbolic link to the old-file.

truncate(path, length)

truncate the file specified by path to at most length byte.

unlink(file...)

delete(file...)

Deletes files. Returns the number of files successfully deleted. Use Dir.rmdir instead to delete directories.

umask([umask])

Changes umask of the user. Returns the current mask. If umask is not specified, just current returns the current mask value.

utime(atime, mtime, file...)

Change the access and modification times on each files. Returns the number of files successfully changed. The first two arguments must be either the number or the instance of the Time class.

In addition, the File class has class methods defined in FileTest.

Methods:

atime

Returns the last accessed time of the file.

ctime

Returns the last status change time of the file.

chmod(mode)

Change the mode of the files to the mode. See chmod(2).

chown(owner, group)

Change the owner and the groups of the files to the owner. Only super-user can change the owner of the file. The owner and the group can be unchanched with supplying nil or -1 to as the argument.

eof

eof?

Returns true, if the file pointer reached at the end of file.

flock(operation)

Applys or removes an advisory lock on the file. flock() returns false if LOCK_NB supplied as the operation and the call would block. Valid operations are given below:

LOCK_SH

Shared lock. More than one process may hold a shared lock for a given file at a given time.

LOCK_EX

Exclusive lock. Only one process may hold an exclusive lock for a given file at a given time.

LOCK_UN

Unlock.

LOCK_NB

Don't block when locking. May be specified (by or'ing) along with one of the other operations.

These constants are defined under the class File.

lstat

Does the same thing as the stat, but stats a symbolic link instead of the file the symbolic link points to.

mtime

Returns the last modified time of the file.

reopen(io)

Reconnect self to io. It also changes the class of the stream.

reopen(path, mode)

Opens and reconnects the file specified by path, with mode.

path

Returns pathname of the opened file.

stat

Returns the status info of the file in the Stat structure.

truncate(length)

truncate the file to at most length byte. The file must be opened in the write mode.

Constants:

Separator

The separating character of the file path, which is normally "/".

matz@netlab.co.jp