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Lua io functions

Lua io functions

These are the functions in the "io" table.

Implicit operations (eg. io.read, io.write) use the standard file descriptors io.stdin, io.stdout, and io.stderr.

You can operate on other files by getting a "file descriptor" from io.open, io.input, or io.output, and using that.

Note the syntactical difference, that you follow a file descriptor by a colon, eg. f:close ()

Also see the description for the "os" table for operating system functions that do things like remove and rename files.




The operations whose name start with "f:" (such as f:read) depend on having an open file handle returned from io.open, io.input, or io.output.

Note the colon after the f, as this indicates that the file handle (userdata from the open) is to be supplied as the first argument to the function.

Lua functions

f:close - Closes a file
f:flush - Flushes outstanding data to disk
f:lines - Returns an iterator function for reading the file line-by-line
f:read - Reads the file according to the specified formats
f:seek - Sets and gets the current file position
f:setvbuf - Sets the buffering mode for an output file
f:write - Writes to a file
io.close - Closes a file
io.flush - Flushes outstanding data to disk for the default output file
io.input - Opens filename for input in text mode
io.lines - Returns an iterator function for reading a named file line-by-line
io.open - Opens a file
io.output - Opens a file for output
io.popen - Creates a pipe and executes a command
io.read - Reads from the default input file
io.stderr - File handle for standard error file
io.stdin - File handle for standard input file
io.stdout - File handle for standard output file
io.tmpfile - Returns a handle to a temporary file
io.type - Returns type of file handle
io.write - Writes to the default output file

Topics

Lua base functions
Lua bc (big number) functions
Lua bit manipulation functions
Lua coroutine functions
Lua debug functions
Lua math functions
Lua os functions
Lua package functions
Lua PCRE regular expression functions
Lua script extensions
Lua string functions
Lua syntax
Lua table functions
Lua utilities
Scripting
Scripting callbacks - plugins

(Help topic: general=lua_io)

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