2.1 KiB
^title File Class
Lets you work with files on the file system. An instance of this class represents an open file with a file descriptor.
When you are done with a file object, it's a good idea to explicitly close it. If you don't, the GC will close it when the file is no longer used and gets finalized, but that may take a while. In the meantime, leaving it open wastes a file descriptor.
Static Methods
File.open(path, fn)
Opens the file at path and passes it to fn. After the function returns, the
file is automatically closed.
:::wren
File.open("words.txt") {|file|
file.readBytes(5)
}
File.read(path)
Reads the entire contents of the file at path and returns it as a string.
:::wren
File.read("words.txt")
The encoding or decoding is done. If the file is UTF-8, then the resulting string will be a UTF-8 string. Otherwise, it will be a string of bytes in whatever encoding the file uses.
File.size(path)
Returns the size in bytes of the contents of the file at path.
File.stat(path)
"Stats" the file or directory at path. Returns a Stat object describing
the low-level details of the file system entry.
Constructors
File.open(path)
Opens the file at path for reading.
Methods
descriptor
The numeric file descriptor used to access the file.
isOpen
Whether the file is still open or has been closed.
size
The size of the contents of the file in bytes.
close()
Closes the file. After calling this, you can read or write from it.
readBytes(count)
Reads up to count bytes starting from the beginning of the file.
:::wren
// Assume this file contains "I am a file!".
File.open("example.txt") {|file|
System.print(file.readBytes(6)) //> I am a
}
readBytes(count, offset)
Reads up to count bytes starting at offset bytes from the beginning of
the file.
:::wren
// Assume this file contains "I am a file!".
File.open("example.txt") {|file|
System.print(file.readBytes(6, 2)) //> am a f
}