158 lines
6.4 KiB
Plaintext
158 lines
6.4 KiB
Plaintext
--- Reading and Writing Files.
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module 'io'
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---
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-- Equivalent to `file:close()`. Without a `file`, closes the default
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-- output file.
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function io.close(file) end
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---
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-- Equivalent to `file:flush` over the default output file.
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function io.flush() end
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---
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-- When called with a file name, it opens the named file (in text mode),
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-- and sets its handle as the default input file. When called with a file
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-- handle, it simply sets this file handle as the default input file. When
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-- called without parameters, it returns the current default input file.
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-- In case of errors this function raises the error, instead of returning an
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-- error code.
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function io.input(file) end
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---
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-- Opens the given file name in read mode and returns an iterator function
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-- that, each time it is called, returns a new line from the file. Therefore,
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-- the construction
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-- for line in io.lines(filename) do *body* end
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-- will iterate over all lines of the file. When the iterator function detects
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-- the end of file, it returns nil (to finish the loop) and automatically
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-- closes the file.
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-- The call `io.lines()` (with no file name) is equivalent to
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-- `io.input():lines()`; that is, it iterates over the lines of the default
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-- input file. In this case it does not close the file when the loop ends.
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function io.lines(filename) end
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---
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-- This function opens a file, in the mode specified in the string `mode`. It
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-- returns a new file handle, or, in case of errors, nil plus an error message.
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-- The `mode` string can be any of the following:
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-- "r": read mode (the default);
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-- "w": write mode;
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-- "a": append mode;
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-- "r+": update mode, all previous data is preserved;
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-- "w+": update mode, all previous data is erased;
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-- "a+": append update mode, previous data is preserved, writing is only
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-- allowed at the end of file.
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-- The `mode` string can also have a '`b`' at the end, which is needed in
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-- some systems to open the file in binary mode. This string is exactly what
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-- is used in the standard C function `fopen`.
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function io.open(filename , mode) end
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---
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-- Similar to `io.input`, but operates over the default output file.
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function io.output(file) end
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---
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-- Starts program `prog` in a separated process and returns a file handle
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-- that you can use to read data from this program (if `mode` is `"r"`,
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-- the default) or to write data to this program (if `mode` is `"w"`).
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-- This function is system dependent and is not available on all platforms.
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function io.popen(prog , mode) end
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---
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-- Equivalent to `io.input():read`.
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function io.read(...) end
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-- * `io.stderr`: Standard error.
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-- * `io.stdin`: Standard in.
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-- * `io.stdout`: Standard out.
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---
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-- Returns a handle for a temporary file. This file is opened in update
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-- mode and it is automatically removed when the program ends.
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function io.tmpfile() end
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---
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-- Checks whether `obj` is a valid file handle. Returns the string `"file"`
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-- if `obj` is an open file handle, `"closed file"` if `obj` is a closed file
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-- handle, or nil if `obj` is not a file handle.
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function io.type(obj) end
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---
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-- Equivalent to `io.output():write`.
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function io.write(...) end
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---
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-- Closes `file`. Note that files are automatically closed when their
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-- handles are garbage collected, but that takes an unpredictable amount of
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-- time to happen.
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function file:close() end
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---
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-- Saves any written data to `file`.
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function file:flush() end
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---
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-- Returns an iterator function that, each time it is called, returns a
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-- new line from the file. Therefore, the construction
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-- for line in file:lines() do *body* end
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-- will iterate over all lines of the file. (Unlike `io.lines`, this function
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-- does not close the file when the loop ends.)
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function file:lines() end
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---
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-- Reads the file `file`, according to the given formats, which specify
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-- what to read. For each format, the function returns a string (or a number)
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-- with the characters read, or nil if it cannot read data with the specified
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-- format. When called without formats, it uses a default format that reads
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-- the entire next line (see below).
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-- The available formats are
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-- "*n": reads a number; this is the only format that returns a number
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-- instead of a string.
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-- "*a": reads the whole file, starting at the current position. On end of
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-- file, it returns the empty string.
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-- "*l": reads the next line (skipping the end of line), returning nil on
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-- end of file. This is the default format.
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-- *number*: reads a string with up to this number of characters, returning
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-- nil on end of file. If number is zero, it reads nothing and returns an
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-- empty string, or nil on end of file.
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function file:read(...) end
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---
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-- Sets and gets the file position, measured from the beginning of the
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-- file, to the position given by `offset` plus a base specified by the string
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-- `whence`, as follows:
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-- "set": base is position 0 (beginning of the file);
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-- "cur": base is current position;
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-- "end": base is end of file;
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-- In case of success, function `seek` returns the final file position,
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-- measured in bytes from the beginning of the file. If this function fails,
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-- it returns nil, plus a string describing the error.
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-- The default value for `whence` is `"cur"`, and for `offset` is 0. Therefore,
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-- the call `file:seek()` returns the current file position, without changing
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-- it; the call `file:seek("set")` sets the position to the beginning of the
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-- file (and returns 0); and the call `file:seek("end")` sets the position
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-- to the end of the file, and returns its size.
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function file:seek(whence , offset) end
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---
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-- Sets the buffering mode for an output file. There are three available
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-- modes:
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--
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-- * "no": no buffering; the result of any output operation appears immediately.
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-- * "full": full buffering; output operation is performed only when the
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-- buffer is full (or when you explicitly `flush` the file (see `io.flush`)).
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-- * "line": line buffering; output is buffered until a newline is output or
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-- there is any input from some special files (such as a terminal device).
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-- For the last two cases, `size` specifies the size of the buffer, in
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-- bytes. The default is an appropriate size.
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function file:setvbuf(mode , size) end
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---
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-- Writes the value of each of its arguments to the `file`. The arguments
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-- must be strings or numbers. To write other values, use `tostring` or
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-- `string.format` before `write`.
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function file:write(...) end
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