Ruby why close file

Matches any one character in set. Behaves like a Regexp union? The same glob pattern and flags are used by Dir. 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. 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. 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. Returns number of files in the argument list. Creates a new name for an existing file using a hard link. Not available on all platforms. Same as File::stat , but does not follow the last symbolic link. Instead, reports on the link itself. 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 ::utime. Returns the number of file names in the argument list.

Opens the file named by filename according to the given mode and returns a new File object. See IO. 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. With no associated block, File. 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. If a file is being created, its initial permissions may be set using the perm parameter.

See ::new for further discussion. Returns true if the named file exists and the effective used id of the calling process is the owner of the file. Returns true if the named file is readable by the effective user and group id of this process. Returns true if the named file is readable by the real user and group id of this process. Returns the real absolute pathname of pathname in the actual filesystem. The real pathname doesn't contain symlinks or useless dots. Returns the real absolute pathname of pathname in the actual filesystem not containing symlinks or useless dots.

Renames the given file to the new name. Raises a SystemCallError if the file cannot be renamed. 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. Raises a NotImplemented exception on platforms that do not support symbolic links.

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 would make a file read-only for everyone.

If a file is a symlink, this method acts upon its referent rather than the link itself; for the inverse behavior see ::lutime.

Returns nil otherwise. The meaning of the bits is platform dependent; on Unix systems, see stat 2. Returns true if the named file is writable by the effective user and group id of this process. Returns true if the named file is writable by the real user and group id of this process. Returns the last access time a Time object for file , or epoch if file has not been accessed. 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. Do we need to explicitly close If yes then why does the GC autoclose? If not then why the option? Asked By: clyfe. Answered By: Tonttu.

Answered By: skozz. Answered By: Satya. Answered By: Kumar KS. What is the difference between Reader and InputStream? The existence of these temp files can make it harder to determine a new Tempfile filename. Therefore, one should always call unlink or close in an ensure block, like this:. Please refer to unlink for more information and a code example.

Tempfile itself however may not be entirely thread-safe. If you access the same Tempfile object from multiple threads then you should protect it with a mutex. Creates a temporary file as usual File object not Tempfile. If no block is given, this is similar to ::new except creating File instead of Tempfile. The created file is not removed automatically. You should use File.

If a block is given, then a File object will be constructed, and the block is invoked with the object as the argument.

The File object will be automatically closed and the temporary file is removed after the block terminates. The call returns the value of the block. The basename parameter is used to determine the name of the temporary file. You can either pass a String or an Array with 2 String elements. For example:. The temporary file will be placed in the directory as specified by the tmpdir parameter.

By default, this is Dir. You can also pass an options hash. Under the hood, Tempfile creates the temporary file using File.