LDoc/ldoc/builtin/io.lua at 1.3.1 · hishamhm/LDoc

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--- Reading and Writing Files.

module 'io'

---

-- Equivalent to `file:close()`. Without a `file`, closes the default

-- output file.

function io.close(file) end

---

-- Equivalent to `file:flush` over the default output file.

function io.flush() end

---

-- When called with a file name, it opens the named file (in text mode),

-- and sets its handle as the default input file. When called with a file

-- handle, it simply sets this file handle as the default input file. When

-- called without parameters, it returns the current default input file.

-- In case of errors this function raises the error, instead of returning an

-- error code.

function io.input(file) end

---

-- Opens the given file name in read mode and returns an iterator function

-- that, each time it is called, returns a new line from the file. Therefore,

-- the construction

-- for line in io.lines(filename) do *body* end

-- will iterate over all lines of the file. When the iterator function detects

-- the end of file, it returns nil (to finish the loop) and automatically

-- closes the file.

-- The call `io.lines()` (with no file name) is equivalent to

-- `io.input():lines()`; that is, it iterates over the lines of the default

-- input file. In this case it does not close the file when the loop ends.

function io.lines(filename) end

---

-- This function opens a file, in the mode specified in the string `mode`. It

-- returns a new file handle, or, in case of errors, nil plus an error message.

-- The `mode` string can be any of the following:

-- "r": read mode (the default);

-- "w": write mode;

-- "a": append mode;

-- "r+": update mode, all previous data is preserved;

-- "w+": update mode, all previous data is erased;

-- "a+": append update mode, previous data is preserved, writing is only

-- allowed at the end of file.

-- The `mode` string can also have a '`b`' at the end, which is needed in

-- some systems to open the file in binary mode. This string is exactly what

-- is used in the standard C function `fopen`.

function io.open(filename , mode) end

---

-- Similar to `io.input`, but operates over the default output file.

function io.output(file) end

---

-- Starts program `prog` in a separated process and returns a file handle

-- that you can use to read data from this program (if `mode` is `"r"`,

-- the default) or to write data to this program (if `mode` is `"w"`).

-- This function is system dependent and is not available on all platforms.

function io.popen(prog , mode) end

---

-- Equivalent to `io.input():read`.

function io.read(...) end

-- * `io.stderr`: Standard error.

-- * `io.stdin`: Standard in.

-- * `io.stdout`: Standard out.

---

-- Returns a handle for a temporary file. This file is opened in update

-- mode and it is automatically removed when the program ends.

function io.tmpfile() end

---

-- Checks whether `obj` is a valid file handle. Returns the string `"file"`

-- if `obj` is an open file handle, `"closed file"` if `obj` is a closed file

-- handle, or nil if `obj` is not a file handle.

function io.type(obj) end

---

-- Equivalent to `io.output():write`.

function io.write(...) end

---

-- Closes `file`. Note that files are automatically closed when their

-- handles are garbage collected, but that takes an unpredictable amount of

-- time to happen.

function file:close() end

---

-- Saves any written data to `file`.

function file:flush() end

---

-- Returns an iterator function that, each time it is called, returns a

-- new line from the file. Therefore, the construction

-- for line in file:lines() do *body* end

-- will iterate over all lines of the file. (Unlike `io.lines`, this function

-- does not close the file when the loop ends.)

function file:lines() end

---

-- Reads the file `file`, according to the given formats, which specify

-- what to read. For each format, the function returns a string (or a number)

-- with the characters read, or nil if it cannot read data with the specified

-- format. When called without formats, it uses a default format that reads

-- the entire next line (see below).

-- The available formats are

-- "*n": reads a number; this is the only format that returns a number

-- instead of a string.

-- "*a": reads the whole file, starting at the current position. On end of

-- file, it returns the empty string.

-- "*l": reads the next line (skipping the end of line), returning nil on

-- end of file. This is the default format.

-- *number*: reads a string with up to this number of characters, returning

-- nil on end of file. If number is zero, it reads nothing and returns an

-- empty string, or nil on end of file.

function file:read(...) end

---

-- Sets and gets the file position, measured from the beginning of the

-- file, to the position given by `offset` plus a base specified by the string

-- `whence`, as follows:

-- "set": base is position 0 (beginning of the file);

-- "cur": base is current position;

-- "end": base is end of file;

-- In case of success, function `seek` returns the final file position,

-- measured in bytes from the beginning of the file. If this function fails,

-- it returns nil, plus a string describing the error.

-- The default value for `whence` is `"cur"`, and for `offset` is 0. Therefore,

-- the call `file:seek()` returns the current file position, without changing

-- it; the call `file:seek("set")` sets the position to the beginning of the

-- file (and returns 0); and the call `file:seek("end")` sets the position

-- to the end of the file, and returns its size.

function file:seek(whence , offset) end

---

-- Sets the buffering mode for an output file. There are three available

-- modes:

-- * "no": no buffering; the result of any output operation appears immediately.

-- * "full": full buffering; output operation is performed only when the

-- buffer is full (or when you explicitly `flush` the file (see `io.flush`)).

-- * "line": line buffering; output is buffered until a newline is output or

-- there is any input from some special files (such as a terminal device).

-- For the last two cases, `size` specifies the size of the buffer, in

-- bytes. The default is an appropriate size.

function file:setvbuf(mode , size) end

---

-- Writes the value of each of its arguments to the `file`. The arguments

-- must be strings or numbers. To write other values, use `tostring` or

-- `string.format` before `write`.

function file:write(...) end

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