luac [ options ] [ filenames ]
luac is the Lua compiler. It translates programs written in the Lua
programming language into binary files containing precompiled chunks that can
be later loaded and executed.
The main advantages of precompiling chunks are: faster loading,
protecting source code from accidental user changes, and off-line syntax
checking. Precompiling does not imply faster execution because in Lua chunks
are always compiled into bytecodes before being executed. luac simply
allows those bytecodes to be saved in a file for later execution.
Precompiled chunks are not necessarily smaller than the corresponding
source. The main goal in precompiling is faster loading.
In the command line, you can mix text files containing Lua source
and binary files containing precompiled chunks. luac produces a
single output file containing the combined bytecodes for all files given.
Executing the combined file is equivalent to executing the given files. By
default, the output file is named luac.out, but you can change this
with the -o option.
Precompiled chunks are not portable across different
architectures. Moreover, the internal format of precompiled chunks is likely
to change when a new version of Lua is released. Make sure you save the
source files of all Lua programs that you precompile.
- -l
- produce a listing of the compiled bytecode for Lua's virtual machine.
Listing bytecodes is useful to learn about Lua's virtual machine. If no
files are given, then luac loads luac.out and lists its
contents. Use -l -l for a full listing.
- -o file
- output to file, instead of the default luac.out. (You can
use '-' for standard output, but not on platforms that open
standard output in text mode.) The output file may be one of the given
files because all files are loaded before the output file is written. Be
careful not to overwrite precious files.
- -p
- load files but do not generate any output file. Used mainly for syntax
checking and for testing precompiled chunks: corrupted files will probably
generate errors when loaded. If no files are given, then luac loads
luac.out and tests its contents. No messages are displayed if the
file loads without errors.
- -s
- strip debug information before writing the output file. This saves some
space in very large chunks, but if errors occur when running a stripped
chunk, then the error messages may not contain the full information they
usually do. In particular, line numbers and names of local variables are
lost.
- -v
- show version information.
- --
- stop handling options.
- -
- stop handling options and process standard input.
lua(1)
The documentation at lua.org.
Error messages should be self explanatory.
R. Ierusalimschy, L. H. de Figueiredo, W. Celes