Command line interface

luacheck program accepts files, directories and rockspecs as arguments.

• Given a file, luacheck will check it.
• Given -, luacheck will check stdin.
• Given a directory, luacheck will check all files with .lua extension within it.
• Given a rockspec (a file with .rockspec extension), luacheck will check all files with .lua extension mentioned in the rockspec in build.install.lua, build.install.bin and build.modules tables.

The output of luacheck consists of separate reports for each checked file and ends with a summary:

$ luacheck src
Checking src/bad_code.lua                         Failure

    src/bad_code.lua:3:16: unused variable helper
    src/bad_code.lua:3:23: unused variable length argument
    src/bad_code.lua:7:10: setting non-standard global variable embrace
    src/bad_code.lua:8:10: variable opt was previously defined as an argument on line 7
    src/bad_code.lua:9:11: accessing undefined variable hepler

Checking src/good_code.lua                        OK
Checking src/python_code.lua                      Syntax error
Checking src/unused_code.lua                      Failure

    src/unused_code.lua:3:18: unused argument baz
    src/unused_code.lua:4:8: unused loop variable i
    src/unused_code.lua:5:13: unused variable q
    src/unused_code.lua:7:11: unused loop variable a
    src/unused_code.lua:7:14: unused loop variable b
    src/unused_code.lua:7:17: unused loop variable c
    src/unused_code.lua:13:7: value assigned to variable x is unused
    src/unused_code.lua:14:1: value assigned to variable x is unused
    src/unused_code.lua:22:1: value assigned to variable z is unused

Total: 14 warnings / 1 error in 4 files

luacheck exits with 0 if no warnings or errors occured and with a positive number otherwise.

Command line options

Short options that do not take an argument can be combined into one, so that -qqu is equivalent to -q -q -u. For long options, both --option value or --option=value can be used.

Options taking several arguments can be used several time; --ignore foo --ignore bar is equivalent to --ignore foo bar.

Note that options that may take several arguments, such as --globals, should not be used immidiately before positional arguments; given --globals foo bar file.lua, luacheck will consider all foo, bar and file.lua global and then panic as there are no file names left.

Option	Meaning
-g | no-global	Filter out warnings related to global variables.
-r | no-redefined	Filter out warnings related to redefined variables.
-u | no-unused	Filter out warnings related to unused variables.
-a | no-unused-args	Filter out warnings related to unused arguments and loop variables.
-v | no-unused-values	Filter out warnings related to unused values.
--std <std>	Set standard globals. <std> must be one of: _G - globals of the Lua interpreter luacheck runs on (default); lua51 - globals of Lua 5.1; lua52 - globals of Lua 5.2; lua52c - globals of Lua 5.2 compiled with LUA_COMPAT_ALL; luajit - globals of LuaJIT 2.0; min - intersection of globals of Lua 5.1, Lua 5.2 and LuaJIT 2.0; max - union of globals of Lua 5.1, Lua 5.2 and LuaJIT 2.0; none - no standard globals.
--globals [<global>] ...	Add custom globals on top of standard ones.
--new-globals [<global>] ...	Set custom globals. Removes custom globals added previously.
-c | --compat	Equivalent to --std=max.
-d | --allow-defined	Allow defining globals by setting them. See Implicit definition.
--no-unused-globals	Filter out warnings related to set but unused global variables.
--ignore <var> [<var>] ...	Filter out warnings related to variables named <var>.
--only <var> [<var>] ...	Filter out warnings not related to variables named <var>.
-l <limit> | --limit <limit>	Exit with 0 if there are <limit> or less warnings (default: 0).
--config <config>	Path to custom configuration file (default: .luacheckrc).
--no-config	Do not look up custom configuration file.
-q | --quiet	Suppress report output for files without warnings. -qq - Suppress output of warnings. -qqq - Only output summary.
--no-color	Do not colorize output.
-h | --help	Show help and exit.