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.


See Also ...

Topics

DOC_lua_base Lua base functions
DOC_lua_bc Lua bc (big number) functions
DOC_lua_bit Lua bit manipulation functions
DOC_lua_coroutines Lua coroutine functions
DOC_lua_debug Lua debug functions
DOC_lua_math Lua math functions
DOC_lua_os Lua os functions
DOC_lua_package Lua package functions
DOC_lua_rex Lua PCRE regular expression functions
DOC_lua Lua script extensions
DOC_lua_string Lua string functions
DOC_lua_tables Lua table functions
DOC_lua_utils Lua utilities
DOC_scripting Scripting

Lua functions

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

(Help topic: general=lua_io)

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