LUAC(1) General Commands Manual LUAC(1)
NAME
luac - Lua compiler
SYNOPSIS
luac [ options ] [ filenames ]
DESCRIPTION
luac is the Lua compiler. It translates programs written in the Lua programming language into binary files
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.
Pre-compiling 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.
Pre-compiled chunks are not necessarily smaller than the corresponding source. The main goal in pre-compiling
is faster loading.
The binary files created by luac are portable only among architectures with the same word size and byte order.
luac produces a single output file containing the bytecodes for all source files given. By default, the out‐
put file is named luac.out, but you can change this with the -o option.
In the command line, you can mix text files containing Lua source and binary files containing precompiled
chunks. This is useful to combine several precompiled chunks, even from different (but compatible) platforms,
into a single precompiled chunk.
You can use '-' to indicate the standard input as a source file and '--' to signal the end of options (that
is, all remaining arguments will be treated as files even if they start with '-').
The internal format of the binary files produced by luac is likely to change when a new version of Lua is
released. So, save the source files of all Lua programs that you precompile.
OPTIONS
Options must be separate.
-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 con‐
tents.
-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 a source file 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 pre‐
compiled chunks: corrupted files will probably generate errors when loaded. Lua always performs a
thorough integrity test on precompiled chunks. Bytecode that passes this test is completely safe, in
the sense that it will not break the interpreter. However, there is no guarantee that such code does
anything sensible. (None can be given, because the halting problem is unsolvable.) If no files are
given, then luac loads luac.out and tests its contents. No messages are displayed if the file passes
the integrity test.
-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
Error messages should be self explanatory.
AUTHORS
L. H. de Figueiredo, R. Ierusalimschy and W. Celes
$Date: 2006/01/06 16:03:34 $ LUAC(1)
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